Optimizing Nitrogen, Phosphorus, and Potassium Fertilization Levels for Container Plants of Lagerstroemia Indica ‘Whit III’ Based on the Comprehensive Quality Evaluation

Authors:
Yijing Wu Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education and College of Landscape Architecture, College of Landscape Architecture, Beijing Forestry University, Beijing 100083, China

Search for other papers by Yijing Wu in
This Site
Google Scholar
Close
,
Qingyu Lu Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education and College of Landscape Architecture, College of Landscape Architecture, Beijing Forestry University, Beijing 100083, China

Search for other papers by Qingyu Lu in
This Site
Google Scholar
Close
,
Yao Gong Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education and College of Landscape Architecture, College of Landscape Architecture, Beijing Forestry University, Beijing 100083, China

Search for other papers by Yao Gong in
This Site
Google Scholar
Close
,
Yiming Zhang Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education and College of Landscape Architecture, College of Landscape Architecture, Beijing Forestry University, Beijing 100083, China

Search for other papers by Yiming Zhang in
This Site
Google Scholar
Close
,
Yan Xu Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education and College of Landscape Architecture, College of Landscape Architecture, Beijing Forestry University, Beijing 100083, China

Search for other papers by Yan Xu in
This Site
Google Scholar
Close
,
Ming Cai Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education and College of Landscape Architecture, College of Landscape Architecture, Beijing Forestry University, Beijing 100083, China

Search for other papers by Ming Cai in
This Site
Google Scholar
Close
,
Huitang Pan Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education and College of Landscape Architecture, College of Landscape Architecture, Beijing Forestry University, Beijing 100083, China

Search for other papers by Huitang Pan in
This Site
Google Scholar
Close
, and
Qixiang Zhang Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education and College of Landscape Architecture, College of Landscape Architecture, Beijing Forestry University, Beijing 100083, China

Search for other papers by Qixiang Zhang in
This Site
Google Scholar
Close

Click on author name to view affiliation information

Abstract

To improve plant quality and fertilizing efficiency, we conducted a study to elucidate the effects of nitrogen (N), phosphorous (P), and potassium (K) fertilizers on the growth, nutrient accumulation, and quality of Lagerstroemia indica plants grown in containers and determine the optimal fertilization levels. Both single-factor and multifactor experiments involving N, P, K fertilizers were designed. Integrated with the plant growth, physiological traits, nutrient levels, and other indices, we used a membership function analysis to comprehensively evaluate plant quality. During the single-factor experiments, the best levels of the single fertilizers applied were 8 g/plant N, 2 g/plant P, and 4 g/plant K. We also found that, within a certain range, N, P, and K fertilizers promoted vegetative growth, increased the chlorophyll, soluble sugar, and soluble protein concentrations, and enhanced nutrient accumulation of L. indica. To avoid the wasting of fertilizers and promote plant quality, the optimal application levels were calculated using a regression analysis. The suggested N, P, and K applications were 6.89 g/plant, 1.97 g/plant, and 3.33 g/plant, respectively. Our results revealed that N, P, and K effect the performance of L. indica container plants, which paves the way for developing reliable and precise fertilizing techniques for growing L. indica.

Lagerstroemia indica (crape myrtle) is a deciduous shrub or small tree with a long cultivation history. The plant is a summer landscape flowering plant that popular in many countries because of its long-lasting bloom and colorful flowers (Cabrera 2004). In the United States, the sale value of crape myrtle plants was nearly $70 million in 2019, thus ranking first among deciduous flowering trees (US Department of Agriculture 2019). Lagerstroemia indica ‘Whit III’, which is also known as ‘Pink Velour’, is widely grown in China because of its outstanding pink–red flowers and new red sprouts. ‘Whit III’ was mainly grown in the field using traditional cultivation methods. Recently, the interest of nursery owners in growing crape myrtle in containers has been increasing because container production enables the large-scale production of plants with an intact root system and uniform dimensions in all seasons. However, the lack of information about precision fertilization during the growing season has become a key factor limiting the production of high-quality container plants.

Nitrogen (N), phosphorus (P), and potassium (K) are key factors that regulate plant growth. These three nutrients have crucial effects on plant growth and development: N has a fundamental role in growth and development because it is an essential component of chlorophyll, amino acids, proteins, nucleic acids, and cell walls (Djidonou et al. 2019); P is an important constituent element of phospholipids, nucleic acids, and ATP, and it also influences important physiological processes, including various enzyme-catalyzed reactions and energy transfer (Jia et al. 2021); and K, usually in an ionic state, is necessary for many biochemical pathways, including osmoregulation, photosynthesis, cell elongation, oxidative phosphorylation, and protein activation (Johnson et al. 2022; Marschner 2012). The lack of sufficient nutrients typically leads to stunted plants that are susceptible to both biotic and abiotic stresses.

The nutrient status of plants may be improved by applying fertilizers, which are used to supply plants with necessary nutrients for growth as well as for increasing yield and quality (Akakpo et al. 2021). The market value of woody ornamental plants is usually associated with their height and spread; therefore, nursery growers often provide large and continuous applications of fertilizers to maximize plant growth. However, most plants exhibit saturation responses or asymptotic growth behaviors after the application of increasing amounts of fertilizer. Subsequently, unnecessary or excessive fertilization may have toxic effects on plants, leading to decreased growth, yield, and metabolite synthesis (Luciano et al. 2017). Moreover, this abuse reduces fertilizer use efficiency and produces high losses from leaching, thus leading to severe environmental pollution (de Aquino et al. 2021; Pitton et al. 2022; Yeager, et al. 1993). A desirable fertilization method should provide plants with adequate amounts of available nutrients without excess nutrient leaching to the environment. Therefore, an evaluation of the appropriate amount of fertilizer is critical for optimizing fertilization programs. Precision fertilization for plants relies on the nutrient requirements of a species or cultivar, plant growth stage, climate conditions, and substrate composition (Casamali et al. 2021; Davis and Strik, 2022; Shreckhise et al. 2020). Few studies have investigated the effects of different fertilizer amounts on different crape myrtle cultivars, and the available studies mainly focused on N fertilizer. Rawson and Harkess (1998) found that L. indica ‘Victor’ and ‘Zuni’ had the highest growth indices and floral ratings using a 200 mg⋅L−1 N liquid feed, whereas 60 mg⋅L−1 N contributed to the optimal growth performance of L. indica × fauriei ‘Tonto’ (Cabrera and Devereaux 1998). It was noticeable that excessive N resulted in the limited plant growth of L. indica and increased leaching (Cabrera 2003). Regarding P, the vegetative and flowering vigor peaks of mature crape myrtle plants grown in urban areas appeared when the P application level was 200% of the initial soil content (Júnior et al. 2020). The optimal level of K fertilizer supply has not been reported. Additionally, Witche (2003) evaluated several methods of applying a slow-release fertilizer to crape myrtle and determined that it did not significantly affect its vegetative growth.

In the nursery industry, the commercial value relies on plant quality, which is based on the grading standard (such as plant height and ground diameter) and physiological traits (indicating the growth potential). Therefore, the comprehensive evaluation of plant quality should combine morphological characteristics, physiological vigor, and nutritional status, which have been reported for Medicago sativa, Malus halliana, and other plants, but not for L. indica (Liu et al. 2020; Wang et al. 2019). The objectives of this study were to compare the effects of different N, P, and K fertilizer quantities on the growth, nutrient accumulation, and quality of crape myrtle, and to determine the optimal fertilizer formula based on the comprehensive evaluation of plant quality.

Materials and Methods

Experimental sites and plant materials.

From Apr to Oct 2021, all cultivation experiments were performed on the field of the National Engineering Research Center for Floriculture, Changping district, Beijing, China (lat. 40°9′22.74N, long. 116°27′12.13E). The 2-year-old bare-root L. indica ‘Whit III’ plants, which were provided by Woye Agriculture Technology Development Co., Ltd. (Zhenjiang, Jiangsu, China), were transplanted to containers (diameter: 24 cm; height: 21.8 cm; volume: 7 L) with culture medium [peat: vermiculite: perlite = 1:1:1 (volume:volume:volume)]. The culture medium properties were as follows: pH, 5.87; electrical conductivity, 853 μs⋅cm−1; organic matter, 0.467 g⋅kg−1; and available N, P, and K concentrations, 816.05 mg⋅kg−1, 65.05 mg⋅kg−1, and 147.31 mg⋅kg−1, respectively. All the plants were pruned to a height of ≈40 cm to create a uniform shape before vegetative growth and placed under a transparent rain canopy to avoid unexpected fertilizer leaching by rainfall. We watered the plants by drip irrigation at a rate of 2 L⋅h−1; the daily irrigation volume was 70 to 170 mL, depending on different temperatures. The water supplied through fertilizer application was not included. From planting to sample collection, the daily maximum temperatures were 26  to 40 °C, and the daily minimum temperatures were 13  to 23 °C.

Experimental design.

Four experiments, including three single-factor experiments and one multifactor experiment, were designed for this study. For all experiments, N, P, and K were supplied as urea (46% N), superphosphate (12% P), and potassium sulfate (52% K), which were produced by Zhonghai Petroleum Tianye Chemical Co., Ltd. (Inner Mongolia, China), Sinochem Fertilizer Co., Ltd. (Beijing, China), and Sdic Xinjiang Luobupo Potash Co., Ltd. (Xinjiang, China), respectively. All experimental plants were fertilized on the same day.

N fertilizer single-factor experiment.

Plants were treated with the following five N levels: N0, 0 g/plant; N1, 4 g/plant; N2, 8 g/plant; N3: 12 g/plant; and N4, 16 g/plant. The total P and K amounts were 1 g/plant and 2 g/plant, respectively. The N fertilizer (dissolved in 200 mL water) was applied as five equally divided five parts at 3-week intervals. The P and K fertilizers were top-dressed after planting once as base fertilizer on 10 May. This experiment had a randomized block design with three replicates of 10 plants for each treatment. The same experiment design and replicates were used for P and K fertilizer single-factor experiments.

P fertilizer single-factor experiment.

The five P levels were as follows: P0, 0 g/plant; P1, 1 g/plant; P2, 2 g/plant; P3: 3 g/plant; and P4, 4 g/plant. The total N and K amounts were 2 g/plant and 2 g/plant, respectively. The N fertilizer (dissolved in 200 mL water) was applied as five equally divided parts at 3-week intervals. The P and K fertilizers were top-dressed after planting once as base fertilizer.

K fertilizer single-factor experiment.

The five K levels were as follows: K0, 0 g/plant; K1, 2 g/plant; K2, 4 g/plant; K3: 6 g/plant; and K4, 8 g/plant. The total N and P amounts were 2 g/plant and 1 g/plant, respectively. The P fertilizer was top-dressed after planting once as a base fertilizer. The N and K fertilizers (dissolved in 200 mL water) were applied as five equally divided parts at 3-week intervals, except for the K1 treatment in which K fertilizer was supplied as the base fertilizer.

N, P, and K combined fertilizer application experiment.

The quadratic-regression-orthogonal-rotation combination design is an optimized test method that combines the advantages of an orthogonal design and regression analysis (Gao et al. 2016). After referring to the aforementioned single-factor experiments to determine the upper, zero, and lower levels, we considered 23 different combinations of N, P, and K fertilizer treatments using a three-factor, five-level quadratic-regression-orthogonal-rotation combination design (Wang et al. 2021). The ranges of the factorial levels were designed as 0 to 16 g/plant N (xN), 0 to 4 g/plant P (xP), and 0 to 8 g/plant K (xK). Codes and levels of factors are shown in Table 1. They were assigned following the quadratic-orthogonal-rotation combination design. Table 2 shows the design scheme and observations of the experimental indices of each combination. In terms of precision, nine replicate runs at central points of the design were performed to estimate pure errors.

Table 1.

Quadratic-regression-orthogonal-rotation combination design with the corresponding coded factors for the variable level.

Table 1.
Table 2.

Quadratic orthogonal rotary combination design and corresponding experiment results.

Table 2.

The P fertilizer was top-dressed after planting once as a base fertilizer. For K fertilizer treatments with less than 2 g/plant (treatments 2, 4, 6, and 8), K fertilizer was also applied as base fertilizer. For the other treatments, the K fertilizer was applied along with the N fertilizer (dissolved in 200 mL water) in five equally divided parts at 3-week intervals. Each treatment was completed using 10 plants.

Measurement of growth and physiological indices.

At the beginning and the end of each experiment, plant height and ground stem diameter were measured using a previously described method (Chen et al. 2021). The difference between two measurements was used for subsequent analyses. Plants were harvested and divided into three parts (roots, stems, and leaves) that were dried in an oven before biomass measurements were performed (Zou et al. 2020).

Root morphology, including the total root length (RL), root surface area (RSA), and root volume (RV), was analyzed using WinRhizo Pro STD4800 root analysis software (Regent Instruments, Quebec, Canada). After scanning, the leaf area was calculated using the second to fifth fully expanded leaves from the top and AutoCAD 2016 software (Autodesk Inc., San Rafael, CA).

Chlorophyll was extracted from 0.1 g leaf tissues using pure acetone (Chen et al. 2021). After the leaves turned white, the absorbances (at 645 nm and 663 nm wavelengths) of the extracts were determined using an ultraviolet spectrophotometer. The leaf soluble sugar concentration was determined based on the anthrone colorimetry method (Wang et al. 2022), with the modification that we incubated the sample solution for 10 min in a water bath at 95 °C. The soluble protein concentration was determined according to the bicinchoninic acid method (Song et al. 2015), with the modification that the sample solution was incubated for 30 min in water at 60 °C.

Plant nutrient analysis.

The plant samples used for the biomass analysis were ground to powder in a grinder and then filtered using a sieve with a 100-mesh screen. The ground materials (0.2 g) were digested with H2SO4–H2O2 (Negi et al. 2021). The total N concentration was determined using the Kjeldahl method and the KDY-9820 type automatic azotometer (Beijing Tongrunyuan Electromechanical Technology Co., Ltd., Beijing, China). The total P concentration was determined using the vandomolybdophosphoric yellow color method and ultraviolet-2550 ultraviolet-visible spectrophotometer (Shimadzu Co., Kyoto, Japan). The total K concentration was determined using SpectraAA220 atomic absorption spectroscopy (Varian Medical Systems, Inc., Palo Alto, CA). Nutrient contents in the plant roots, stems, and leaves were calculated using a previous described formula (Shi et al. 2022).

Data analysis.

The analysis of variance and Duncan’s multiple range test were performed to investigate significant differences (P < 0.05) in N and K in single-factor experiments using SPSS 22.0 software (IBM Corp., Armonk, NY). The data were expressed as the mean ± SE. To comprehensively represent the plant quality, we performed a membership function analysis (Liu et al. 2020).

For the combined fertilizer application experiment, data were analyzed using SPSS software (IBM Corp.). Based on similar studies, the relationship between the plant height, ground diameter, or other data and the fertilizer amounts was determined using the quadratic regression rotation model (Yu et al. 2021).

The regression coefficients in the quadratic polynomial equations were estimated by least squares and statistical tests. After partitioning residual variance into variances for lack of fit and random error, the lack-of-fit test showed whether the quadratic polynomial equation was suitable for the data (Jiang et al. 2011). We used DPS 7.05 statistical software (DPS Software, Hangzhou Ruifeng Information Technology Co., Ltd., Zhejiang, China; http://www.statforum.com) to complete the regression analysis and frequency analysis of the optimal fertilizer amounts.

Results

Effects of N, P, and K fertilizer applications on crape myrtle growth indices.

The applied amount of N fertilizer had different influences on growth indices (Table 3). Plant height significantly increased with the N applied, but there was no significant difference among N1, N2, N3, and N4. The ground diameter increment (N1–N3) was significantly greater than those of N0 and N4. The total biomass peaked at N2 and N1, and was significantly higher than those of other treatments. The RL, RSA, and RV for N2 were significantly higher than those for the other treatments. The N supply significantly increased RL compared with N0. The maximum leaf number and leaf area with N2 were recorded, but there was no significant difference between N1 and N2.

Table 3.

Effects of nitrogen (N), phosphorous (P), and potassium (K) fertilizers on growth.

Table 3.

Similarly, plant height, ground diameter, and total biomass were improved by increasing P fertilizer, with the highest values appearing with P2 (Table 3). The RL, RSA, and RV for P2 and P1 were significantly higher than those for the other treatments, with no significant difference between P2 and P1. The P supply significantly increased the leaf number and leaf area, without significantly influencing the leaf number among P1, P2, P3, and P4.

Most changes in the growth indices followed an arch shape that initially increased with the K supply and then decreased after K3, which probably implied the negative effects of extra K fertilizer (Table 3). The height and ground diameter reached the largest values with K1 and K2, respectively, and were significantly higher than those with K4. The stem, leaf, and total biomasses with K1, K2, and K3 were significantly higher than those with K0 and K4. K2 and K3 treatments significantly enhanced the root biomass, RL, RSA, and RV. Specifically, the improvement of RV with K1 was not significantly different than that with K2 and K3. The K2 treatment harvested the greatest leaf area, which was significantly higher than that obtained with the other treatments, but the K application had no significant effect on the leaf number.

Effects of N, P, K fertilizer applications on crape myrtle physiological indices.

Physiological indices increased initially; then, they decreased with the increasing N level (Table 4). The chlorophyll a (Chl A) concentration (N1–N3) was significantly greater than those of N0 and N4. The N application improved chlorophyll b (Chl B), peaking at N1 and N2. The total chlorophyll (Chl T) concentration was increased by 63.79% to 100.02%, which was significantly higher at N1 and N2. The soluble sugar concentration with the N1 treatment was higher than that with the other treatments; however, there was no significant difference among N1, N2, and N3. Noticeably, after peaking at N2 and N1, the soluble protein concentration decreased sharply with N3 and N4, and was even lower than that with N0.

Table 4.

Effects of nitrogen (N), phosphorous (P), and potassium (K) fertilizers on physiological indices.

Table 4.

Similar to the effects of N fertilizer, the top levels of physiological indices were recorded with P1 or P2, except the Chl B concentration was slightly, but not significantly, influenced by the P application. The concentrations of Chl A, Chl B, and Chl T showed similar arch shape patterns that peaked at K2. With regard to the soluble sugar concentration, there was no significant difference between K1 and K0, and it decreased thereafter (K2–K4). The maximum soluble protein concentration appeared with K3 and was significantly higher than that with the other treatments.

Effects of N, P, K fertilizer applications on the nutrient concentration and nutrient content.

The nutrient concentration of different tissues was influenced by the N fertilizer application. The root N concentration increased with significant differences among N0, N1, N2, N3, and N4 treatments. The stem and leaf N concentrations consistently increased until N3; then, they declined slightly at N4, with a significant difference. Furthermore, the leaf N concentration was higher than that of the stem or the root (Fig. 1A). The N supply had no significant effect on the root and stem P concentrations, but it significantly decreased the leaf P concentration (Fig. 1B). The root K concentration decreased with the N supply. However, the stem and leaf K concentration showed a U-shape trend, decreasing to the lowest levels with N2 (Fig. 1C). The effects of the P fertilizer on the nutrient concentration in each tissue are presented (Fig. 1D–F). The P application decreased the N concentration of three tissues; however, the leaf N concentration with P1 was slightly higher than that with P0 and P2, with significant differences. Moreover, the leaf N concentration was higher than both the root and stem N concentrations (Fig. 1D). The root P concentrations of P1, P2, and P3 were significantly higher than those of P0 and P4. The maximum stem and leaf P concentrations were observed with P1 and P3, respectively (Fig. 1E). The stem and leaf K concentrations presented an arch shape trend, peaking at P2; however, there was a continuous decrease in the root K concentration (Fig. 1F). With the K supply, the leaf N and P concentrations generally decreased; however, the leaf K concentration significantly increased. The stem nutrient concentration demonstrated an arch shape pattern. Compared with the stem N and P concentrations, the stem K concentration reached its peak level with K3, not with K1 or K2. The highest root N concentration was observed with K1, and the root P concentration gradually increased and the root K concentration decreased (Fig. 1G–I).

Fig. 1.
Fig. 1.

Effects of nitrogen (N), phosphorous (P), and potassium (K) fertilizers on the nutrient concentration of crape myrtle. (AC) Tissue N, P, and K concentrations affected by N fertilizer levels in the root, stem, and leaf. (DF) Tissue N, P, and K concentrations affected by P fertilizer levels in the root, stem, and leaf. (GI) Tissue N, P, and K concentrations affected by K fertilizer levels in the root, stem, and leaf. Different letters on bars indicate a significant difference between treatments at P < 0.05. Error bars represent ± SD.

Citation: HortScience 58, 2; 10.21273/HORTSCI16980-22

Consistent with those of biomass, most trends of the nutrient contents increased and decreased with the increasing fertilizer supply, except for the nutrient content of the root affected by N and K, as well as the nutrient content of the leaf affected by P (Fig. 2). The N application could enhance the root N content, without significant difference, among N0, N1, N2, N3, and N4. The root P content was greatest with N1 and N2 and significantly higher than those with N0, N3, and N4. The N supply resulted in a significant decrease in the root K content (Fig. 2A–C). During the P fertilizer experiment, the leaf N content significantly increased as P was applied, but there was no significant difference among P1, P2, P3, and P4 (Fig. 2D). The stem and leaf K contents peaked with P3 and P2, respectively, and were significantly higher than those with P0 and P1, with no significant difference recorded among P2, P3, and P4 (Fig. 2E and F). The significantly higher root N content appeared with K1 and K2 (Fig. 2G). The root P content decreased with the increasing K level, without significant difference between K0 and K1 (Fig. 2H); however, the root K content showed a consistent increase (Fig. 2I).

Fig. 2.
Fig. 2.

Effects of nitrogen (N), phosphorous (P), and potassium (K) fertilizers on the nutrient content of crape myrtle. (AC) Tissue N, P, and K contents affected by N fertilizer levels in the root, stem, and leaf. (DF) Tissue N, P, and K contents affected by P fertilizer levels in the root, stem, and leaf. (GI) Tissue N, P, and K contents affected by K fertilizer levels in the root, stem, and leaf. Different letters on bars indicate a significant difference between treatments at P < 0.05. Error bars represent ± SD.

Citation: HortScience 58, 2; 10.21273/HORTSCI16980-22

Comprehensive evaluation of plant quality.

Because it was difficult to assess plant quality by using a single index, we established a comprehensive statistical system including growth, physiological, and nutrient data based on the membership function analysis. According to the D value (Table 5), the rank order for N treatments was as follows: N2 (0.90), N1 (0.83), N3 (0.46), N4 (0.27), and N0 (0.13). The rank order for the P treatments was as follows: P2 (0.92), P1 (0.79), P3 (0.42), P4 (0.23), and P0 (0.12). The rank order for the K treatments was as follows: K2 (0.81), K1 (0.64), K3 (0.53), K0 (0.25), and K4 (0.18). To verify whether selected indices were appropriate, a cluster analysis was performed using all indices (Supplemental Fig. S1). The results showed that treatments with similar values were classified in the same group, which indicated that the comprehensive evaluation method was reliable.

Table 5.

Index function values and synthetic valuation of plant quality in different treatments.

Table 5.

N, P, and K fertilizer combination application experiment.

Based on the height increment, ground diameter increment, biomass, and Chl T data shown in Table 2, regression equations (Eqs. [S1][S4]) were established by statistically testing each regression coefficient. The frequency analysis was performed to determine the optimal fertilizer combination. Each independent variable was scanned over the interval −1.682 to 1.682; thereafter, 53 = 125 level combinations were substituted into Eqs. [S1] to [S4] to predict the four experimental indices. Optimal combinations were estimated from the predicted values of indices that were greater than the average (Supplemental Table S1). According to the actual fertilizer amount (N, P, and K) demonstrated in Table 6, we comprehensively optimized the main indices to reveal the optimal fertilizer combination, which was 6.89 g of N, 1.97 g of P, and 3.33 g of K per plant.

Table 6.

Optimized results and the actual fertilizer amounts.

Table 6.

Discussion

Vegetative growth indices of crape myrtle, such as plant height, ground diameter, biomass, root development, and leaf status, responded significantly to the changes in fertilizer levels, with different responses among tissues. The fertilizer application significantly affected the biomass allocation. For example, the root-to-stem biomass ratio decreased as the N fertilizer amount increased. Cabrera and Devereaux (1998) also observed that increasing the N supply reduced the root biomass-to-branch biomass ratio of crape myrtle because of the inhibitory effects on root growth. Similar results were reported for Vitis vinifera, Schima superba, and Cryptocarya concinna (Mo et al. 2008; Walker et al. 2022). These findings implied that when nutrient levels were limited, plants allocated more resources to the root system to boost the uptake of underground resources, including nutrients and water, thereby decreasing the growth and reproduction of the aboveground plant parts (Cuesta et al. 2010; Salifu and Timmer 2003). During this study, P fertilizer also differentially affected the root-to-stem ratio, possibly because of the substantial effects of P on root growth (Hobbie et al. 2013). Root morphology changed the plant nutrient uptake capacity by activating root tip cell activity when the soil nutrient levels were altered by fertilization (Robinson 1994). Furthermore, we found that the changes in the ground diameter of crape myrtle were not completely in accordance with changes in the root or stem biomass, suggesting that the stem biomass was more susceptible than the stem diameter in response to certain fertilizer applications. The increases in the stem biomass showed enhanced vascular cambium activities and/or increased xylem cell size, whereas stem growth was influenced by lateral meristem activities (Seija et al. 2004).

In plants, N, P, and K are usually considered profound elements for normal physiological activities. The abundance of N, which is a constituent element of chlorophyll and macromolecules related to chloroplast synthesis, such as enzymes, proteins, and nucleic acids, may significantly modulate the chlorophyll content (Wen et al. 2019). Under N-deficient conditions, N was transported to more active tissues where chlorophyll had degraded, resulting in leaf senescence (Qiu et al. 2015). Our study revealed that N2 was superior to N3 and N4 (Table 4), indicating that excess N exceeds the tolerance of plants because of the high salinity of soil solution and plant water loss (Xiao et al. 2018). Furthermore, P deficiency also decreased the chlorophyll content because an insufficient P supply induced the redistribution of P from chloroplasts and cytosols to the growing or reserve organs (de Aquino et al. 2021; Pan et al. 2022). According to our study, P fertilizer did not significantly affect the Chl B content of crape myrtle leaves, which was in accordance with the results of Júnior et al. (2020). A possible reason was that chlorophyll a contributed more to photosynthesis than chlorophyll b; therefore, plants required more chlorophyll a than chlorophyll b. During this study, the soluble sugar and soluble protein concentrations generally decreased when the fertilizer was excessive. Wang et al. (2004) suggested that plants might increase their respiration intensity to protect against high N stress, thus leading to membrane damage and a significant decrease in osmotic regulators such as soluble sugar. Interestingly, whether the K fertilizer supply contributed to an overall downward trend in the soluble sugar concentration of crape myrtle leaves was investigated (Table 4), and the results were in agreement with those of Tectona grandis (Ai 2018). de Azeredo et al. (2004), who studied the effects of N and K fertilizers on the soluble sugar contents of specific tissues in two potato cultivars, determined that the leaf soluble sugar concentration decreased if K was applied along with N, but this decrease might vary among different cultivars. In contrast, the leaf soluble sugar concentration first increased and then decreased when potato plants were treated with K fertilizer without N. We speculated that this was attributable to the plant species and the interaction between different amounts of N and K fertilizers.

The nutrient status is a key contributor to plant growth, nutrient storage, and stress tolerance. According to the nutrition theory, it could be divided into the following stages: nutrient deficiency, sufficiency, luxury consumption, and toxicity. The nutrient concentration increased as nutrients were applied during the first three stages. If the plant biomass did not change significantly, then increasing the nutrient concentration promoted the nutrient content and plant growth, which occurred during the “luxury consumption” stage and was considered to present the ideal nutrient status (Birge et al. 2007). The nutrient concentration in the plant might increase by continuing to supply nutrients, but the biomass and nutrient content would decrease significantly when the plant had been poisoned (Salifu and Timmer 2003). Similar to most other plants, the effects of N, P, and K fertilizers on the nutrient concentration and nutrient content of crape myrtle tissues were consistent with the aforementioned theory (Fig. 1). During our single-factor experiments, the single fertilizer supply obviously affected the concentration of the other nutrient elements. Overall, N fertilizer decreased the leaf P concentration, whereas the K supply decreased the leaf N and P concentrations. Apart from the interactions between elements, adding just one deficient nutrient element would stimulate plant growth, but it might induce the deficiency of other nutrients by dilution (Marschner 2012). This has been reported for crape myrtle, Quercus rubra, Q. alba, Rhododendron species, and other plants (Cabrera and Devereaux 1998; Li et al. 2019; Salifu et al. 2009). We found that P fertilizer was beneficial to N and K accumulations in crape myrtle leaves. As mentioned, P significantly promoted root development, leading to a vigorous root system that could efficiently take-up P and other nutrients in the soil (Razaq et al. 2017). The application of P fertilizer increased N availability and enhanced N accumulation in the young leaves and branches of Cunninghamia lanceolata (Chen et al. 2015). The nutrient distribution pattern of plants, which was influenced by the fertilizer formula and amount, consistently affected plant growth and development. Many studies have indicated that leaves tended to have the highest N concentration among plant tissues. The rank order of the N concentration in tissues of crape myrtle was as follows: leaf > root > stem (Fig. 1). The uptake and transport of N, which is a highly mobile nutrient element in plant tissues, were affected by external conditions and internal physiological factors (Noroozlo et al. 2019). Furthermore, N was often distributed in the most metabolically active plant parts and transferred to the plant growth point, which was usually regarded as the leaves, during growth seasons (Saghaiesh et al. 2019; Zhang et al. 2022). Cabrera (2003) revealed that the root N concentration of crape myrtle was higher than the stem N concentration under N-deficient conditions, whereas the opposite trend occurred under N-sufficient condition. We found that the root N concentration was higher than the stem N concentration with N2 and N3. The difference might be explained by the fact that our samples were collected at the end of the growth season, when nutrients in the leaves were transported to the roots (Cheng and Fuchigami 2002; Salifu et al. 2009).

The nutrient content reflected the nutrient load of plants better than the nutrient concentration (Salifu and Timmer 2003; Seija et al. 2004). Accordingly, the nutrient content, rather than the nutrient concentration, was included in our indicator evaluation system. During this study, we focused on the effects of N, P, and K fertilizers on plants. It might be reasonable to optimize the amount of fertilizer based on the plant performance without the medium nutrient content after sample collection (Bayer 2021; Clark and Zheng 2020; Li et al. 2019; Zahreddine et al. 2007).

The membership function method was often used to perform the plant quality evaluation, adaptation or resistance evaluation, and breeding. Some similar studies combined it with the principal component analysis. However, during this study, the principal component analysis was too limited to reduce the dimensionality and select the indices because the number of treatments was smaller than the number of observed indices. A cluster analysis comprises numerical techniques that separate data into constituent groups of individuals; it aims to generate a set of groups in such a way that individuals within a cluster are more similar to each other than they are to those in other clusters (Jalali 2007). A multivariate analysis was performed to conclude the overall effect of a particular treatment combining all the indices during some studies including genetic diversity analyses and germplasm and treatment evaluations (Bayat et al. 2015; Ganopoulos et al. 2015; Sharangi and Sahu 2009). Therefore, we used a cluster analysis combined with the membership function method to verify the accuracy of the selected indices and the results of a comprehensive evaluation.

Conclusion

During the present study, the appropriate application of N, P, and K fertilizers promoted the vegetative growth of L. indica ‘Whit III’, increased the chlorophyll, soluble sugar, and soluble protein concentrations, and enhanced nutrient accumulation. Based on the results of single-factor and multifactor experiments, we suggest that the optimal fertilizer formula is 6.89 g of N, 1.97 g of P, and 3.33 g of K per plant.

References Cited

  • Ai, J, Hou, L, Shao, G, Li, Z, Lu, L, Li, C & Sun, Q. 2018 Matrix formula with forest waste and their effects on Tectona grandis growth J. Zh. A&F Univ. 35 6 1027 1037 https://doi.org/10.11833/j.issn.2095-0756.2018.06.005

    • Search Google Scholar
    • Export Citation
  • Akakpo, PS, Sedibe, MM, Zaid, B, Khetsha, ZP, Theka-Kutumela, MP & Mudau, FN. 2021 Potassium fertigation to enhance the performance of Hypoxis hemerocallidea HortScience. 56 12 1585 1593 https://doi.org/10.21273/HORTSCI16216-21

    • Search Google Scholar
    • Export Citation
  • Bayat, H, Nemati, H, Tehranifar, A & Gazanchian, A. 2015 Screening different crested wheatgrass [Agropyron cristatum (L.) Gaertner.] accessions for drought stress tolerance. Archi Agrono Soil Sci. 62 6 769 780 https://doi.org/10.1080/03650340.2015.1094182

    • Search Google Scholar
    • Export Citation
  • Bayer, A. 2021 Astilbe and coneflower growth as affected by fertilizer rate and substrate volumetric water content Horticulturae. 7 52 https://doi.org/10.3390/horticulturae7030052

    • Search Google Scholar
    • Export Citation
  • Birge, ZKD, Salifu, FK & Jacobs, DF. 2007 Modified exponential nitrogen loading to promote morphological quality and nutrient storage of bareroot-cultured Quercus rubra and Quercus alba seedlings Scand J For Res. 21 4 306 316 https://doi.org/10.1080/02827580600761611

    • Search Google Scholar
    • Export Citation
  • Cabrera, RI. 2003 Nitrogen balance for two container-grown woody ornamental plants Scientia Hortic. 97 3 297 308 https://doi.org/10.1016/S0304-4238(02)00151-6

    • Search Google Scholar
    • Export Citation
  • Cabrera, RI. 2004 Evaluating and promoting the cosmopolitan and multipurpose Lagerstroemia Acta Hortic. 630 177 184 https://doi.org/10.17660/ActaHortic.2004.630.21

    • Search Google Scholar
    • Export Citation
  • Cabrera, RI & Devereaux, DR. 1998 Effects of nitrogen supply on growth and nutrient status of containerized crape myrtle J Environ Hortic. 16 2 98 104 https://doi.org/10.24266/0738-2898-16.2.98

    • Search Google Scholar
    • Export Citation
  • Casamali, B, van Iersel, MW & Chavez, DJ. 2021 Plant growth and physiological responses to improved irrigation and fertilization management for young peach trees in the southeastern United States HortScience. 56 3 336 346 https://doi.org/10.21273/hortsci15505-20

    • Search Google Scholar
    • Export Citation
  • Chen, FS, Niklas, KJ, Liu, Y, Fang, XM, Wan, SZ & Wang, H. 2015 Nitrogen and phosphorus additions alter nutrient dynamics but not resorption efficiencies of Chinese fir leaves and twigs differing in age Tree Physiol. 35 10 1106 1117 https://doi.org/10.1093/treephys/tpv076

    • Search Google Scholar
    • Export Citation
  • Chen, M, Zhu, K, Tan, P, Liu, J, Xie, J, Yao, X, Chu, G & Peng, F. 2021 Ammonia–nitrate mixture dominated by NH4 +–N promoted growth, photosynthesis and nutrient accumulation in pecan (Carya illinoinensis) Forests. 12 1808 https://doi.org/10.3390/f12121808

    • Search Google Scholar
    • Export Citation
  • Cheng, L & Fuchigami, LH. 2002 Growth of young apple trees in relation to reserve nitrogen and carbohydrates Tree Physiol. 22 18 1297 1303 https://doi.org/10.1093/treephys/22.18.1297

    • Search Google Scholar
    • Export Citation
  • Clark, MJ & Zheng, Y. 2020 Fertilization methods for organic and conventional potted blueberry plants HortScience. 55 3 304 309 https://doi.org/10.21273/hortsci14416-19

    • Search Google Scholar
    • Export Citation
  • Cuesta, B, Vega, J, Villar-Salvador, P & Rey-Benayas, JM. 2010 Root growth dynamics of Aleppo pine (Pinus halepensis Mill.) seedlings in relation to shoot elongation, plant size and tissue nitrogen concentration Trees (Berl). 24 5 899 908 https://doi.org/10.1007/s00468-010-0459-0

    • Search Google Scholar
    • Export Citation
  • Davis, AJ & Strik, BC. 2022 Long-term effects of pre-plant incorporation with sawdust, sawdust mulch, and nitrogen fertilizer rate on ‘Elliott’ highbush blueberry HortScience. 57 3 414 421 https://doi.org/10.21273/hortsci16359-21

    • Search Google Scholar
    • Export Citation
  • de Aquino, RFBA, Cavalcante, AG, Clemente, JM, Macedo, WR, Novais, RF & de Aquino, LA. 2021 Split fertilization of phosphate in onion as strategy to improve the phosphorus use efficiency Scientia Hortic. 290 110494 https://doi.org/10.1016/j.scienta.2021.110494

    • Search Google Scholar
    • Export Citation
  • de Azeredo, EHd, Lima, E & Cassino, PCR. 2004 Impacto dos nutrientes N e K e de açúcares solúveis sobre populações de Diabrotica speciosa (Germar) (Coleoptera, Chrysomelidae) e Agrotis ipsilon (Hüfnagel) (Lepidoptera, Noctuidae) na cultura da batata, Solanum tuberosum L. (Solanaceae) Revista Brasileira de Entomologia. 48 1 105 113 https://doi.org/10.1590/S0085-56262004000100018

    • Search Google Scholar
    • Export Citation
  • Djidonou, D, Zhao, X, Koch, KE & Zotarelli, L. 2019 Nitrogen accumulation and root distribution of grafted tomato plants as affected by nitrogen fertilization HortScience. 54 11 1907 1914 https://doi.org/10.21273/hortsci14066-19

    • Search Google Scholar
    • Export Citation
  • Ganopoulos, I, Moysiadis, T, Xanthopoulou, A, Ganopoulou, M, Avramidou, E, Aravanopoulos, FA, Tani, E, Panagiotis, M, Athanasios, T & Kazantzis, K. 2015 Diversity of morpho-physiological traits in worldwide sweet cherry cultivars of GeneBank collection using multivariate analysis Scientia Hortic. 197 381 391 https://doi.org/10.1016/j.scienta.2015.09.061

    • Search Google Scholar
    • Export Citation
  • Gao, G, Feng, T, Yang, H & Li, F. 2016 Development and optimization of end-effector for extraction of potted anthurium seedlings during transplanting Appl Eng Agric. 32 1 37 46 https://doi.org/10.13031/aea.32.11086

    • Search Google Scholar
    • Export Citation
  • Hobbie, SE, Baker, LA, Buyarski, C, Nidzgorski, D & Finlay, JC. 2013 Decomposition of tree leaf litter on pavement: Implications for urban water quality Urban Ecosyst. 17 2 369 385 https://doi.org/10.1007/s11252-013-0329-9

    • Search Google Scholar
    • Export Citation
  • Jia, X, Wang, L, Zeng, H & Yi, K. 2021 Insights of intracellular/intercellular phosphate transport and signaling in unicellular green algae and multicellular land plants New Phytol. 232 4 1566 1571 https://doi.org/10.1111/nph.17716

    • Search Google Scholar
    • Export Citation
  • Jalali, M. 2007 Site-specific potassium application based on the fertilizer potassium availability index of soil Precis Agric. 8 4 199 211 https://doi.org/10.1007/s11119-007-9039-8

    • Search Google Scholar
    • Export Citation
  • Jiang, N, Zhang, AZ, Yang, RQ & Zhang, YC. 2011 An experimental approach to optimize several processing conditions when extruding soybeans Anim Feed Sci Technol. 170 3-4 277 283 https://doi.org/10.1016/j.anifeedsci.2011.09.005

    • Search Google Scholar
    • Export Citation
  • Johnson, R, Vishwakarma, K, Hossen, MS, Kumar, V, Shackira, AM, Puthur, JT, Abdi, G, Sarraf, M & Hasanuzzaman, M. 2022 Potassium in plants: Growth regulation, signaling, and environmental stress tolerance Plant Physiol Biochem. 172 56 69 https://doi.org/10.1016/j.plaphy.2022.01.001

    • Search Google Scholar
    • Export Citation
  • Júnior, S, Bobrowski, R & Lombardi, KCJF. 2020 Which vigor variables can be influenced by phosphate fertilization in mature Lagerstroemia indica L. trees? Floresta. 50 1 1021 1030 https://doi.org/10.5380/rf.v50i1.60617

    • Search Google Scholar
    • Export Citation
  • Li, T, Bi, G, Harkess, RL & Blythe, EK. 2019 Mineral nutrient uptake of Encore azalea ‘Chiffon’ affected by nitrogen, container, and irrigation frequency HortScience. 54 12 2240 2248 https://doi.org/10.21273/hortsci14386-19

    • Search Google Scholar
    • Export Citation
  • Liu, J, Liu, X, Zhang, Q, Li, S, Sun, Y, Lu, W & Ma, C. 2020 Response of alfalfa growth to arbuscular mycorrhizal fungi and phosphate-solubilizing bacteria under different phosphorus application levels AMB Express. 10 1 200 https://doi.org/10.1186/s13568-020-01137-w

    • Search Google Scholar
    • Export Citation
  • Luciano, A-J, Irineo, T-P, Rosalia Virginia, O-V, Feregrino-Perez, AA, Hernandez, AC & Ramon Gerardo, G-G. 2017 Integrating plant nutrients and elicitors for production of secondary metabolites, sustainable crop production and human health: A review Int J Agric Biol. 19 03 391 402 https://doi.org/10.17957/ijab/15.0297

    • Search Google Scholar
    • Export Citation
  • Marschner, P. 2012 Mineral nutrition of higher plants Academic Press Salt Lake City, UT, USA

  • Mo, J, Li, D & Gundersen, P. 2008 Seedling growth response of two tropical tree species to nitrogen deposition in southern China Eur J For Res. 127 4 275 283 https://doi.org/10.1007/s10342-008-0203-0

    • Search Google Scholar
    • Export Citation
  • Negi, YK, Sajwan, P, Uniyal, S & Mishra, AC. 2021 Enhancement in yield and nutritive qualities of strawberry fruits by the application of organic manures and biofertilizers Scientia Hortic. 283 110038 https://doi.org/10.1016/j.scienta.2021.110038

    • Search Google Scholar
    • Export Citation
  • Noroozlo, YA, Souri, MK & Delshad, M. 2019 Stimulation effects of foliar applied glycine and glutamine amino acids on lettuce growth Open Agric. 4 1 164 172 https://doi.org/10.1515/opag-2019-0016

    • Search Google Scholar
    • Export Citation
  • Pan, Y, Song, Y, Zhao, L, Chen, P, Bu, C, Liu, P & Zhang, D. 2022 The genetic basis of phosphorus utilization efficiency in plants provide new insight into woody perennial plants improvement Int J Mol Sci. 23 2253 https://doi.org/10.3390/ijms23042353

    • Search Google Scholar
    • Export Citation
  • Pitton, BJL, Oki, LR, Sisneroz, J & Evans, RY. 2022 A nursery system nitrogen balance for production of a containerized woody ornamental plant Scientia Hortic. 291 110569 https://doi.org/10.1016/j.scienta.2021.110569

    • Search Google Scholar
    • Export Citation
  • Saghaiesh, PS, Souri, MK & Moghaddam, M. 2019 Characterization of nutrients uptake and enzymes activity in Khatouni melon (Cucumis melo var. inodorus) seedlings under different concentrations of nitrogen, potassium and phosphorus of nutrient solution J Plant Nutr. 42 2 178 185 https://doi.org/10.1080/01904167.2018.1551491

    • Search Google Scholar
    • Export Citation
  • Qiu, K, Li, Z, Yang, Z, Chen, J, Wu, S, Zhu, X, Gao, S, Gao, J, Ren, G, Kuai, B & Zhou, X. 2015 EIN3 and ORE1 accelerate degreening during ethylene-mediated leaf senescence by directly activating chlorophyll catabolic genes in Arabidopsis PLoS Genet. 11 7 e1005399 https://doi.org/10.1371/journal.pgen.1005399

    • Search Google Scholar
    • Export Citation
  • Rawson, JM & Harkess, RL. 1998 Growth and flowering of Lagerstroemia in response to pinching, photoperiod, and fertilization HortScience. 33 4 590 590 https://doi.org/10.21273/HORTSCI.33.4.590b

    • Search Google Scholar
    • Export Citation
  • Razaq Zhang, M, Shen, P & Salahuddin, HL 2017 Influence of nitrogen and phosphorous on the growth and root morphology of Acer mono PLoS One. 12 2 e0171321 https://doi.org/10.1371/journal.pone.0171321

    • Search Google Scholar
    • Export Citation
  • Robinson, D. 1994 The responses of plants to non-uniform supplies of nutrients New Phytol. 127 4 635 674 https://doi.org/10.1111/j.1469-8137.1994.tb02969.x

    • Search Google Scholar
    • Export Citation
  • Salifu, KF, Jacobs, DF & Birge, ZKD. 2009 Nursery nitrogen loading improves field performance of bareroot oak seedlings planted on abandoned mine lands Restor Ecol. 17 3 339 349 https://doi.org/10.1111/j.1526-100X.2008.00373.x

    • Search Google Scholar
    • Export Citation
  • Salifu, KF & Timmer, VR. 2003 Optimizing nitrogen loading of Picea mariana seedlings during nursery culture Can J Res. 33 7 1287 1294 https://doi.org/10.1139/x03-057

    • Search Google Scholar
    • Export Citation
  • Seija, K, Annika, J, Sari, I & Elina, VJTP. 2004 Growth, allocation and tissue chemistry of Picea abies seedlings affected by nutrient supply during the second growing season Tree Physiol. 24 6 707 719 https://doi.org/10.1093/treephys/24.6.707

    • Search Google Scholar
    • Export Citation
  • Sharangi, AB & Sahu, PK. 2009 Effect of placement and dose of phosphatic fertilizers on onion J Plant Nutr. 32 11 1901 1913 https://doi.org/10.1080/01904160903242383

    • Search Google Scholar
    • Export Citation
  • Shi, Z, Wei, F, Wan, R, Li, Y, Wang, Y, An, W, Qin, K, Dai, G, Gao, Y, Chen, X, Wang, X & Yang, L. 2022 Comprehensive evaluation of nitrogen use efficiency of different Lycium barbarum L. cultivars under nitrogen stress Scientia Hortic. 295 110807 https://doi.org/10.1016/j.scienta.2021.110807

    • Search Google Scholar
    • Export Citation
  • Shreckhise, JH, Owen, JS, Eick, MJ, Niemiera, AX, Altland, JE & Jackson, BE. 2020 Dolomite and micronutrient fertilizer affect phosphorus fate when growing crape myrtle in pine bark HortScience. 55 6 832 840 https://doi.org/10.21273/hortsci14558-20

    • Search Google Scholar
    • Export Citation
  • Song, I, Kim, DS, Kim, MK, Jamal, A, Hwang, K-A & Ko, K. 2015 Comparison of total soluble protein in various horticultural crops and evaluation of its quantification methods Hortic Environ Biotechnol. 56 1 123 129 https://doi.org/10.1007/s13580-015-0097-y

    • Search Google Scholar
    • Export Citation
  • US Department of Agriculture 2019 2012 Census of Agriculture Census of Horticultural Specialties (2019). US Department of Agriculture, Washington, DC. https://www.nass.usda.gov/Publications/AgCensus/2017/Online_Resources/Census_of_Horticulture_Specialties/HORTIC.pdf [accessed 19 Oct 2022]

    • Search Google Scholar
    • Export Citation
  • Walker, HV, Swarts, ND, Jones, JE & Kerslake, F. 2022 Nitrogen use efficiency, partitioning, and storage in cool climate potted Pinot Noir vines Scientia Hortic. 291 110603 https://doi.org/10.1016/j.scienta.2021.110603

    • Search Google Scholar
    • Export Citation
  • Wang, L, Ding, L, Wang, P, Zhao, L & Yu, Q. 2021 Production of dallisgrass in response to NPK fertilizer in southwest China and its implications for cultivation Grassl Sci. 67 4 285 298 https://doi.org/10.1111/grs.12315

    • Search Google Scholar
    • Export Citation
  • Wang, M, Ye, Y, Chu, X, Zhao, Y, Zhang, S, Chen, H, Qin, W & Wang, Y. 2022 Responses of garlic quality and yields to various types and rates of potassium fertilizer applications HortScience. 57 1 72 80 https://doi.org/10.21273/hortsci15984-21

    • Search Google Scholar
    • Export Citation
  • Wang, Q, Ding, Y, Yan, D, Zhao, C, Jie, S & Huang, P. 2004 Effect of nitrogen application rate on morphological and physiological characters of rice dry seedbed seedlings J. Nanj. Agric. Univ. 27 3 11 14

    • Search Google Scholar
    • Export Citation
  • Wang, Y, Zhu, Y, Chen, B, Hu, Y & Dawuda, MM. 2019 Effects of paclobutrazol on the physiological characteristics of Malus halliana Koehne seedlings under drought stress via principal component analysis and membership function analysis Arid Land Res Manage. 33 1 97 113 https://doi.org/10.1080/15324982.2018.1488300

    • Search Google Scholar
    • Export Citation
  • Wen, B, Li, C, Fu, X, Li, D, Li, L, Chen, X, Wu, H, Gui, X, Zhang, X, Shen, H, Zhang, W, Xiao, W & Gao, D. 2019 Effects of nitrate deficiency on nitrate assimilation and chlorophyll synthesis of detached apple leaves Plant Physiol Biochem. 142 363 371 https://doi.org/10.1016/j.plaphy.2019.07.007

    • Search Google Scholar
    • Export Citation
  • Witche, AL. 2003 Evaluation of fertilizer and irrigation production systems for large nursery containers (PhD Diss) Louisiana State University, Baton Rouge, LA, USA. https://digitalcommons.lsu.edu/gradschool_theses/1974. [accessed 26 Mar 2021]

    • Search Google Scholar
    • Export Citation
  • Xiao, F, Yang, Z, Huang, H, Yang, F, Zhu, L & Han, D. 2018 Nitrogen fertilization in soil affects physiological characteristics and quality of green tea leaves HortScience. 53 5 715 722 https://doi.org/10.21273/hortsci12897-18

    • Search Google Scholar
    • Export Citation
  • Yeager, TH, Wright, R, Fare, D, Gilliam, CH & Zondag, R. 1993 Six state survey of container nursery nitrate nitrogen runoff J Environ Hortic. 11 206 208 https://doi.org/10.24266/0738-2898-11.4.206

    • Search Google Scholar
    • Export Citation
  • Yu, J, Zhang, H, Pan, T, Qiu, Z, Gao, X & Zhang, S. 2021 Study on the container seedling substrate ratio and fertilization of Pinus armandii on the north slope of the Qinling mountains based on regression rotation analysis J. Central South. Univ. of Forestry and Technol. 41 1 109 116 https://doi.org/10.14067/j.cnki.1673-923x. 2021.01.011

    • Search Google Scholar
    • Export Citation
  • Zahreddine, HG, Struve, DK & Talhouk, SN. 2007 Growth and nutrient partitioning of containerized Cercis siliquastrum L. under two fertilizer regimes Scientia Hortic. 112 1 80 88 https://doi.org/10.1016/j.scienta.2006.11.013

    • Search Google Scholar
    • Export Citation
  • Zhang, W, Zhang, S-B & Fan, Z-X. 2022 Quantifying the nitrogen allocation and resorption for an orchid pseudobulb in relation to nitrogen supply Scientia Hortic. 291 110580 https://doi.org/10.1016/j.scienta.2021.110580

    • Search Google Scholar
    • Export Citation
  • Zou, N, Huang, L, Chen, H, Huang, X, Song, Q, Yang, Q & Wang, T. 2020 Nitrogen form plays an important role in the growth of moso bamboo (Phyllostachys edulis) seedlings PeerJ. 8 e9938 https://doi.org/10.7717/peerj.9938.55

    • Search Google Scholar
    • Export Citation

Supplementary Materials

Regression equations (Supplemental Eqs. [S1][S4])

The analysis of the data in Table 2 showed that the statistical test for the lack of fit for each experimental index (the statistic used was F1) was not significant, but that the whole regression relationship (the statistic used was F2) was highly significant. Regression equations for the indices were established by statistically testing each regression coefficient (xN, the coded value of N; xP, the coded value of P; xK, the coded value of K).

For the height increment:
y^1=31.681.36xN+1.10xP0.13xK3.66xN23.33xP21.42xK21.03xNxp0.48xNxK+0.36xPxK,

F1 = 1.70, P > 0.05; F2 = 17.71, P < 0.01.

For the ground diameter increment:
y^2 =3.780.20xN+0.02xP0.13xK0.31xN20.29xP20.17xK2+0.24xNxp+0.04xNxK+0.03xPxK,

F1 = 1.67, P > 0.05; F2 = 7.44, P < 0.01.

For the biomass:
y^3=44.511.02xN0.87xP0.32xK3.70xN22.84xP22.40xK2+1.59xNxp+1.54xNxK+0.48xPxK,

F1 = 2.81, P > 0.05; F2 = 12.49, P < 0.01.

For the total chlorophyll concentration:
y^4 =1.21+0.05xN0.001xP+0.04xK0.14xN20.08xP20.07xK2+0.05xNxP+0.04xNxK+0.002xPxK,

F1 = 2.09, P > 0.05; F2 = 4.81, P < 0.01.

Supplemental Fig. S1.
Supplemental Fig. S1.

Cluster analysis results of the observation indices. (A) Nitrogen single-factor experiment. (B) Phosphorous single-factor experiment. (C) Potassium single-factor experiment. As an example, N0-1 represents the first replicate of the N0 treatment. All treatments were different from each other, and three replicates of one treatment were classified in the same group, which means experimental errors were controlled within an acceptable limit.

Citation: HortScience 58, 2; 10.21273/HORTSCI16980-22

Supplemental Table S1.

Value frequency distribution of the amounts of nitrogen (N), phosphorous (P), and potassium (K) fertilizers.

Supplemental Table S1.
  • Fig. 1.

    Effects of nitrogen (N), phosphorous (P), and potassium (K) fertilizers on the nutrient concentration of crape myrtle. (AC) Tissue N, P, and K concentrations affected by N fertilizer levels in the root, stem, and leaf. (DF) Tissue N, P, and K concentrations affected by P fertilizer levels in the root, stem, and leaf. (GI) Tissue N, P, and K concentrations affected by K fertilizer levels in the root, stem, and leaf. Different letters on bars indicate a significant difference between treatments at P < 0.05. Error bars represent ± SD.

  • Fig. 2.

    Effects of nitrogen (N), phosphorous (P), and potassium (K) fertilizers on the nutrient content of crape myrtle. (AC) Tissue N, P, and K contents affected by N fertilizer levels in the root, stem, and leaf. (DF) Tissue N, P, and K contents affected by P fertilizer levels in the root, stem, and leaf. (GI) Tissue N, P, and K contents affected by K fertilizer levels in the root, stem, and leaf. Different letters on bars indicate a significant difference between treatments at P < 0.05. Error bars represent ± SD.

  • Supplemental Fig. S1.

    Cluster analysis results of the observation indices. (A) Nitrogen single-factor experiment. (B) Phosphorous single-factor experiment. (C) Potassium single-factor experiment. As an example, N0-1 represents the first replicate of the N0 treatment. All treatments were different from each other, and three replicates of one treatment were classified in the same group, which means experimental errors were controlled within an acceptable limit.

  • Ai, J, Hou, L, Shao, G, Li, Z, Lu, L, Li, C & Sun, Q. 2018 Matrix formula with forest waste and their effects on Tectona grandis growth J. Zh. A&F Univ. 35 6 1027 1037 https://doi.org/10.11833/j.issn.2095-0756.2018.06.005

    • Search Google Scholar
    • Export Citation
  • Akakpo, PS, Sedibe, MM, Zaid, B, Khetsha, ZP, Theka-Kutumela, MP & Mudau, FN. 2021 Potassium fertigation to enhance the performance of Hypoxis hemerocallidea HortScience. 56 12 1585 1593 https://doi.org/10.21273/HORTSCI16216-21

    • Search Google Scholar
    • Export Citation
  • Bayat, H, Nemati, H, Tehranifar, A & Gazanchian, A. 2015 Screening different crested wheatgrass [Agropyron cristatum (L.) Gaertner.] accessions for drought stress tolerance. Archi Agrono Soil Sci. 62 6 769 780 https://doi.org/10.1080/03650340.2015.1094182

    • Search Google Scholar
    • Export Citation
  • Bayer, A. 2021 Astilbe and coneflower growth as affected by fertilizer rate and substrate volumetric water content Horticulturae. 7 52 https://doi.org/10.3390/horticulturae7030052

    • Search Google Scholar
    • Export Citation
  • Birge, ZKD, Salifu, FK & Jacobs, DF. 2007 Modified exponential nitrogen loading to promote morphological quality and nutrient storage of bareroot-cultured Quercus rubra and Quercus alba seedlings Scand J For Res. 21 4 306 316 https://doi.org/10.1080/02827580600761611

    • Search Google Scholar
    • Export Citation
  • Cabrera, RI. 2003 Nitrogen balance for two container-grown woody ornamental plants Scientia Hortic. 97 3 297 308 https://doi.org/10.1016/S0304-4238(02)00151-6

    • Search Google Scholar
    • Export Citation
  • Cabrera, RI. 2004 Evaluating and promoting the cosmopolitan and multipurpose Lagerstroemia Acta Hortic. 630 177 184 https://doi.org/10.17660/ActaHortic.2004.630.21

    • Search Google Scholar
    • Export Citation
  • Cabrera, RI & Devereaux, DR. 1998 Effects of nitrogen supply on growth and nutrient status of containerized crape myrtle J Environ Hortic. 16 2 98 104 https://doi.org/10.24266/0738-2898-16.2.98

    • Search Google Scholar
    • Export Citation
  • Casamali, B, van Iersel, MW & Chavez, DJ. 2021 Plant growth and physiological responses to improved irrigation and fertilization management for young peach trees in the southeastern United States HortScience. 56 3 336 346 https://doi.org/10.21273/hortsci15505-20

    • Search Google Scholar
    • Export Citation
  • Chen, FS, Niklas, KJ, Liu, Y, Fang, XM, Wan, SZ & Wang, H. 2015 Nitrogen and phosphorus additions alter nutrient dynamics but not resorption efficiencies of Chinese fir leaves and twigs differing in age Tree Physiol. 35 10 1106 1117 https://doi.org/10.1093/treephys/tpv076

    • Search Google Scholar
    • Export Citation
  • Chen, M, Zhu, K, Tan, P, Liu, J, Xie, J, Yao, X, Chu, G & Peng, F. 2021 Ammonia–nitrate mixture dominated by NH4 +–N promoted growth, photosynthesis and nutrient accumulation in pecan (Carya illinoinensis) Forests. 12 1808 https://doi.org/10.3390/f12121808

    • Search Google Scholar
    • Export Citation
  • Cheng, L & Fuchigami, LH. 2002 Growth of young apple trees in relation to reserve nitrogen and carbohydrates Tree Physiol. 22 18 1297 1303 https://doi.org/10.1093/treephys/22.18.1297

    • Search Google Scholar
    • Export Citation
  • Clark, MJ & Zheng, Y. 2020 Fertilization methods for organic and conventional potted blueberry plants HortScience. 55 3 304 309 https://doi.org/10.21273/hortsci14416-19

    • Search Google Scholar
    • Export Citation
  • Cuesta, B, Vega, J, Villar-Salvador, P & Rey-Benayas, JM. 2010 Root growth dynamics of Aleppo pine (Pinus halepensis Mill.) seedlings in relation to shoot elongation, plant size and tissue nitrogen concentration Trees (Berl). 24 5 899 908 https://doi.org/10.1007/s00468-010-0459-0

    • Search Google Scholar
    • Export Citation
  • Davis, AJ & Strik, BC. 2022 Long-term effects of pre-plant incorporation with sawdust, sawdust mulch, and nitrogen fertilizer rate on ‘Elliott’ highbush blueberry HortScience. 57 3 414 421 https://doi.org/10.21273/hortsci16359-21

    • Search Google Scholar
    • Export Citation
  • de Aquino, RFBA, Cavalcante, AG, Clemente, JM, Macedo, WR, Novais, RF & de Aquino, LA. 2021 Split fertilization of phosphate in onion as strategy to improve the phosphorus use efficiency Scientia Hortic. 290 110494 https://doi.org/10.1016/j.scienta.2021.110494

    • Search Google Scholar
    • Export Citation
  • de Azeredo, EHd, Lima, E & Cassino, PCR. 2004 Impacto dos nutrientes N e K e de açúcares solúveis sobre populações de Diabrotica speciosa (Germar) (Coleoptera, Chrysomelidae) e Agrotis ipsilon (Hüfnagel) (Lepidoptera, Noctuidae) na cultura da batata, Solanum tuberosum L. (Solanaceae) Revista Brasileira de Entomologia. 48 1 105 113 https://doi.org/10.1590/S0085-56262004000100018

    • Search Google Scholar
    • Export Citation
  • Djidonou, D, Zhao, X, Koch, KE & Zotarelli, L. 2019 Nitrogen accumulation and root distribution of grafted tomato plants as affected by nitrogen fertilization HortScience. 54 11 1907 1914 https://doi.org/10.21273/hortsci14066-19

    • Search Google Scholar
    • Export Citation
  • Ganopoulos, I, Moysiadis, T, Xanthopoulou, A, Ganopoulou, M, Avramidou, E, Aravanopoulos, FA, Tani, E, Panagiotis, M, Athanasios, T & Kazantzis, K. 2015 Diversity of morpho-physiological traits in worldwide sweet cherry cultivars of GeneBank collection using multivariate analysis Scientia Hortic. 197 381 391 https://doi.org/10.1016/j.scienta.2015.09.061

    • Search Google Scholar
    • Export Citation
  • Gao, G, Feng, T, Yang, H & Li, F. 2016 Development and optimization of end-effector for extraction of potted anthurium seedlings during transplanting Appl Eng Agric. 32 1 37 46 https://doi.org/10.13031/aea.32.11086

    • Search Google Scholar
    • Export Citation
  • Hobbie, SE, Baker, LA, Buyarski, C, Nidzgorski, D & Finlay, JC. 2013 Decomposition of tree leaf litter on pavement: Implications for urban water quality Urban Ecosyst. 17 2 369 385 https://doi.org/10.1007/s11252-013-0329-9

    • Search Google Scholar
    • Export Citation
  • Jia, X, Wang, L, Zeng, H & Yi, K. 2021 Insights of intracellular/intercellular phosphate transport and signaling in unicellular green algae and multicellular land plants New Phytol. 232 4 1566 1571 https://doi.org/10.1111/nph.17716

    • Search Google Scholar
    • Export Citation
  • Jalali, M. 2007 Site-specific potassium application based on the fertilizer potassium availability index of soil Precis Agric. 8 4 199 211 https://doi.org/10.1007/s11119-007-9039-8

    • Search Google Scholar
    • Export Citation
  • Jiang, N, Zhang, AZ, Yang, RQ & Zhang, YC. 2011 An experimental approach to optimize several processing conditions when extruding soybeans Anim Feed Sci Technol. 170 3-4 277 283 https://doi.org/10.1016/j.anifeedsci.2011.09.005

    • Search Google Scholar
    • Export Citation
  • Johnson, R, Vishwakarma, K, Hossen, MS, Kumar, V, Shackira, AM, Puthur, JT, Abdi, G, Sarraf, M & Hasanuzzaman, M. 2022 Potassium in plants: Growth regulation, signaling, and environmental stress tolerance Plant Physiol Biochem. 172 56 69 https://doi.org/10.1016/j.plaphy.2022.01.001

    • Search Google Scholar
    • Export Citation
  • Júnior, S, Bobrowski, R & Lombardi, KCJF. 2020 Which vigor variables can be influenced by phosphate fertilization in mature Lagerstroemia indica L. trees? Floresta. 50 1 1021 1030 https://doi.org/10.5380/rf.v50i1.60617

    • Search Google Scholar
    • Export Citation
  • Li, T, Bi, G, Harkess, RL & Blythe, EK. 2019 Mineral nutrient uptake of Encore azalea ‘Chiffon’ affected by nitrogen, container, and irrigation frequency HortScience. 54 12 2240 2248 https://doi.org/10.21273/hortsci14386-19

    • Search Google Scholar
    • Export Citation
  • Liu, J, Liu, X, Zhang, Q, Li, S, Sun, Y, Lu, W & Ma, C. 2020 Response of alfalfa growth to arbuscular mycorrhizal fungi and phosphate-solubilizing bacteria under different phosphorus application levels AMB Express. 10 1 200 https://doi.org/10.1186/s13568-020-01137-w

    • Search Google Scholar
    • Export Citation
  • Luciano, A-J, Irineo, T-P, Rosalia Virginia, O-V, Feregrino-Perez, AA, Hernandez, AC & Ramon Gerardo, G-G. 2017 Integrating plant nutrients and elicitors for production of secondary metabolites, sustainable crop production and human health: A review Int J Agric Biol. 19 03 391 402 https://doi.org/10.17957/ijab/15.0297

    • Search Google Scholar
    • Export Citation
  • Marschner, P. 2012 Mineral nutrition of higher plants Academic Press Salt Lake City, UT, USA

  • Mo, J, Li, D & Gundersen, P. 2008 Seedling growth response of two tropical tree species to nitrogen deposition in southern China Eur J For Res. 127 4 275 283 https://doi.org/10.1007/s10342-008-0203-0

    • Search Google Scholar
    • Export Citation
  • Negi, YK, Sajwan, P, Uniyal, S & Mishra, AC. 2021 Enhancement in yield and nutritive qualities of strawberry fruits by the application of organic manures and biofertilizers Scientia Hortic. 283 110038 https://doi.org/10.1016/j.scienta.2021.110038

    • Search Google Scholar
    • Export Citation
  • Noroozlo, YA, Souri, MK & Delshad, M. 2019 Stimulation effects of foliar applied glycine and glutamine amino acids on lettuce growth Open Agric. 4 1 164 172 https://doi.org/10.1515/opag-2019-0016

    • Search Google Scholar
    • Export Citation
  • Pan, Y, Song, Y, Zhao, L, Chen, P, Bu, C, Liu, P & Zhang, D. 2022 The genetic basis of phosphorus utilization efficiency in plants provide new insight into woody perennial plants improvement Int J Mol Sci. 23 2253 https://doi.org/10.3390/ijms23042353

    • Search Google Scholar
    • Export Citation
  • Pitton, BJL, Oki, LR, Sisneroz, J & Evans, RY. 2022 A nursery system nitrogen balance for production of a containerized woody ornamental plant Scientia Hortic. 291 110569 https://doi.org/10.1016/j.scienta.2021.110569

    • Search Google Scholar
    • Export Citation
  • Saghaiesh, PS, Souri, MK & Moghaddam, M. 2019 Characterization of nutrients uptake and enzymes activity in Khatouni melon (Cucumis melo var. inodorus) seedlings under different concentrations of nitrogen, potassium and phosphorus of nutrient solution J Plant Nutr. 42 2 178 185 https://doi.org/10.1080/01904167.2018.1551491

    • Search Google Scholar
    • Export Citation
  • Qiu, K, Li, Z, Yang, Z, Chen, J, Wu, S, Zhu, X, Gao, S, Gao, J, Ren, G, Kuai, B & Zhou, X. 2015 EIN3 and ORE1 accelerate degreening during ethylene-mediated leaf senescence by directly activating chlorophyll catabolic genes in Arabidopsis PLoS Genet. 11 7 e1005399 https://doi.org/10.1371/journal.pgen.1005399

    • Search Google Scholar
    • Export Citation
  • Rawson, JM & Harkess, RL. 1998 Growth and flowering of Lagerstroemia in response to pinching, photoperiod, and fertilization HortScience. 33 4 590 590 https://doi.org/10.21273/HORTSCI.33.4.590b

    • Search Google Scholar
    • Export Citation
  • Razaq Zhang, M, Shen, P & Salahuddin, HL 2017 Influence of nitrogen and phosphorous on the growth and root morphology of Acer mono PLoS One. 12 2 e0171321 https://doi.org/10.1371/journal.pone.0171321

    • Search Google Scholar
    • Export Citation
  • Robinson, D. 1994 The responses of plants to non-uniform supplies of nutrients New Phytol. 127 4 635 674 https://doi.org/10.1111/j.1469-8137.1994.tb02969.x

    • Search Google Scholar
    • Export Citation
  • Salifu, KF, Jacobs, DF & Birge, ZKD. 2009 Nursery nitrogen loading improves field performance of bareroot oak seedlings planted on abandoned mine lands Restor Ecol. 17 3 339 349 https://doi.org/10.1111/j.1526-100X.2008.00373.x

    • Search Google Scholar
    • Export Citation
  • Salifu, KF & Timmer, VR. 2003 Optimizing nitrogen loading of Picea mariana seedlings during nursery culture Can J Res. 33 7 1287 1294 https://doi.org/10.1139/x03-057

    • Search Google Scholar
    • Export Citation
  • Seija, K, Annika, J, Sari, I & Elina, VJTP. 2004 Growth, allocation and tissue chemistry of Picea abies seedlings affected by nutrient supply during the second growing season Tree Physiol. 24 6 707 719 https://doi.org/10.1093/treephys/24.6.707

    • Search Google Scholar
    • Export Citation
  • Sharangi, AB & Sahu, PK. 2009 Effect of placement and dose of phosphatic fertilizers on onion J Plant Nutr. 32 11 1901 1913 https://doi.org/10.1080/01904160903242383

    • Search Google Scholar
    • Export Citation
  • Shi, Z, Wei, F, Wan, R, Li, Y, Wang, Y, An, W, Qin, K, Dai, G, Gao, Y, Chen, X, Wang, X & Yang, L. 2022 Comprehensive evaluation of nitrogen use efficiency of different Lycium barbarum L. cultivars under nitrogen stress Scientia Hortic. 295 110807 https://doi.org/10.1016/j.scienta.2021.110807

    • Search Google Scholar
    • Export Citation
  • Shreckhise, JH, Owen, JS, Eick, MJ, Niemiera, AX, Altland, JE & Jackson, BE. 2020 Dolomite and micronutrient fertilizer affect phosphorus fate when growing crape myrtle in pine bark HortScience. 55 6 832 840 https://doi.org/10.21273/hortsci14558-20

    • Search Google Scholar
    • Export Citation
  • Song, I, Kim, DS, Kim, MK, Jamal, A, Hwang, K-A & Ko, K. 2015 Comparison of total soluble protein in various horticultural crops and evaluation of its quantification methods Hortic Environ Biotechnol. 56 1 123 129 https://doi.org/10.1007/s13580-015-0097-y

    • Search Google Scholar
    • Export Citation
  • US Department of Agriculture 2019 2012 Census of Agriculture Census of Horticultural Specialties (2019). US Department of Agriculture, Washington, DC. https://www.nass.usda.gov/Publications/AgCensus/2017/Online_Resources/Census_of_Horticulture_Specialties/HORTIC.pdf [accessed 19 Oct 2022]

    • Search Google Scholar
    • Export Citation
  • Walker, HV, Swarts, ND, Jones, JE & Kerslake, F. 2022 Nitrogen use efficiency, partitioning, and storage in cool climate potted Pinot Noir vines Scientia Hortic. 291 110603 https://doi.org/10.1016/j.scienta.2021.110603

    • Search Google Scholar
    • Export Citation
  • Wang, L, Ding, L, Wang, P, Zhao, L & Yu, Q. 2021 Production of dallisgrass in response to NPK fertilizer in southwest China and its implications for cultivation Grassl Sci. 67 4 285 298 https://doi.org/10.1111/grs.12315

    • Search Google Scholar
    • Export Citation
  • Wang, M, Ye, Y, Chu, X, Zhao, Y, Zhang, S, Chen, H, Qin, W & Wang, Y. 2022 Responses of garlic quality and yields to various types and rates of potassium fertilizer applications HortScience. 57 1 72 80 https://doi.org/10.21273/hortsci15984-21

    • Search Google Scholar
    • Export Citation
  • Wang, Q, Ding, Y, Yan, D, Zhao, C, Jie, S & Huang, P. 2004 Effect of nitrogen application rate on morphological and physiological characters of rice dry seedbed seedlings J. Nanj. Agric. Univ. 27 3 11 14

    • Search Google Scholar
    • Export Citation
  • Wang, Y, Zhu, Y, Chen, B, Hu, Y & Dawuda, MM. 2019 Effects of paclobutrazol on the physiological characteristics of Malus halliana Koehne seedlings under drought stress via principal component analysis and membership function analysis Arid Land Res Manage. 33 1 97 113 https://doi.org/10.1080/15324982.2018.1488300

    • Search Google Scholar
    • Export Citation
  • Wen, B, Li, C, Fu, X, Li, D, Li, L, Chen, X, Wu, H, Gui, X, Zhang, X, Shen, H, Zhang, W, Xiao, W & Gao, D. 2019 Effects of nitrate deficiency on nitrate assimilation and chlorophyll synthesis of detached apple leaves Plant Physiol Biochem. 142 363 371 https://doi.org/10.1016/j.plaphy.2019.07.007

    • Search Google Scholar
    • Export Citation
  • Witche, AL. 2003 Evaluation of fertilizer and irrigation production systems for large nursery containers (PhD Diss) Louisiana State University, Baton Rouge, LA, USA. https://digitalcommons.lsu.edu/gradschool_theses/1974. [accessed 26 Mar 2021]

    • Search Google Scholar
    • Export Citation
  • Xiao, F, Yang, Z, Huang, H, Yang, F, Zhu, L & Han, D. 2018 Nitrogen fertilization in soil affects physiological characteristics and quality of green tea leaves HortScience. 53 5 715 722 https://doi.org/10.21273/hortsci12897-18

    • Search Google Scholar
    • Export Citation
  • Yeager, TH, Wright, R, Fare, D, Gilliam, CH & Zondag, R. 1993 Six state survey of container nursery nitrate nitrogen runoff J Environ Hortic. 11 206 208 https://doi.org/10.24266/0738-2898-11.4.206

    • Search Google Scholar
    • Export Citation
  • Yu, J, Zhang, H, Pan, T, Qiu, Z, Gao, X & Zhang, S. 2021 Study on the container seedling substrate ratio and fertilization of Pinus armandii on the north slope of the Qinling mountains based on regression rotation analysis J. Central South. Univ. of Forestry and Technol. 41 1 109 116 https://doi.org/10.14067/j.cnki.1673-923x. 2021.01.011

    • Search Google Scholar
    • Export Citation
  • Zahreddine, HG, Struve, DK & Talhouk, SN. 2007 Growth and nutrient partitioning of containerized Cercis siliquastrum L. under two fertilizer regimes Scientia Hortic. 112 1 80 88 https://doi.org/10.1016/j.scienta.2006.11.013

    • Search Google Scholar
    • Export Citation
  • Zhang, W, Zhang, S-B & Fan, Z-X. 2022 Quantifying the nitrogen allocation and resorption for an orchid pseudobulb in relation to nitrogen supply Scientia Hortic. 291 110580 https://doi.org/10.1016/j.scienta.2021.110580

    • Search Google Scholar
    • Export Citation
  • Zou, N, Huang, L, Chen, H, Huang, X, Song, Q, Yang, Q & Wang, T. 2020 Nitrogen form plays an important role in the growth of moso bamboo (Phyllostachys edulis) seedlings PeerJ. 8 e9938 https://doi.org/10.7717/peerj.9938.55

    • Search Google Scholar
    • Export Citation
Yijing Wu Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education and College of Landscape Architecture, College of Landscape Architecture, Beijing Forestry University, Beijing 100083, China

Search for other papers by Yijing Wu in
Google Scholar
Close
,
Qingyu Lu Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education and College of Landscape Architecture, College of Landscape Architecture, Beijing Forestry University, Beijing 100083, China

Search for other papers by Qingyu Lu in
Google Scholar
Close
,
Yao Gong Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education and College of Landscape Architecture, College of Landscape Architecture, Beijing Forestry University, Beijing 100083, China

Search for other papers by Yao Gong in
Google Scholar
Close
,
Yiming Zhang Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education and College of Landscape Architecture, College of Landscape Architecture, Beijing Forestry University, Beijing 100083, China

Search for other papers by Yiming Zhang in
Google Scholar
Close
,
Yan Xu Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education and College of Landscape Architecture, College of Landscape Architecture, Beijing Forestry University, Beijing 100083, China

Search for other papers by Yan Xu in
Google Scholar
Close
,
Ming Cai Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education and College of Landscape Architecture, College of Landscape Architecture, Beijing Forestry University, Beijing 100083, China

Search for other papers by Ming Cai in
Google Scholar
Close
,
Huitang Pan Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education and College of Landscape Architecture, College of Landscape Architecture, Beijing Forestry University, Beijing 100083, China

Search for other papers by Huitang Pan in
Google Scholar
Close
, and
Qixiang Zhang Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education and College of Landscape Architecture, College of Landscape Architecture, Beijing Forestry University, Beijing 100083, China

Search for other papers by Qixiang Zhang in
Google Scholar
Close

Contributor Notes

This work was supported by the National Key Research and Development Program of China (2020YFD1000502, 2019YFD1001004) and College Students’ innovation and entrepreneurship training program of Beijing Forestry University (X202110022083).

We thank Dr. Youping Sun of Utah State University and Dr. He Li of Central South University of Forestry and Technology for manuscript revision suggestions.

M.C. is the corresponding author. E-mail: mingcai82@bjfu.edu.cn.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 917 599 37
PDF Downloads 613 366 34
  • Fig. 1.

    Effects of nitrogen (N), phosphorous (P), and potassium (K) fertilizers on the nutrient concentration of crape myrtle. (AC) Tissue N, P, and K concentrations affected by N fertilizer levels in the root, stem, and leaf. (DF) Tissue N, P, and K concentrations affected by P fertilizer levels in the root, stem, and leaf. (GI) Tissue N, P, and K concentrations affected by K fertilizer levels in the root, stem, and leaf. Different letters on bars indicate a significant difference between treatments at P < 0.05. Error bars represent ± SD.

  • Fig. 2.

    Effects of nitrogen (N), phosphorous (P), and potassium (K) fertilizers on the nutrient content of crape myrtle. (AC) Tissue N, P, and K contents affected by N fertilizer levels in the root, stem, and leaf. (DF) Tissue N, P, and K contents affected by P fertilizer levels in the root, stem, and leaf. (GI) Tissue N, P, and K contents affected by K fertilizer levels in the root, stem, and leaf. Different letters on bars indicate a significant difference between treatments at P < 0.05. Error bars represent ± SD.

  • Supplemental Fig. S1.

    Cluster analysis results of the observation indices. (A) Nitrogen single-factor experiment. (B) Phosphorous single-factor experiment. (C) Potassium single-factor experiment. As an example, N0-1 represents the first replicate of the N0 treatment. All treatments were different from each other, and three replicates of one treatment were classified in the same group, which means experimental errors were controlled within an acceptable limit.

 

Advertisement
Longwood Gardens Fellows Program 2024

 

Advertisement
Save