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Open access

Job Teixeira de Oliveira, Fernando França da Cunha, Rubens Alves de Oliveira, and Catariny Cabral Aleman Pina

Path coefficient analysis has been widely used to understand production better and determine the relationships between fruit and their constituents. This study evaluated the correlations between mass and other physical characteristics, and contributes to selecting cape gooseberry fruit. The attributes assessed were the total mass of the cape gooseberry fruit (TM) (fruit mass with husk), fruit mass (FM) (fruit mass without husk), husk mass (HM), husk length (HL), the largest transverse husk diameter (LD), fruit diameter (FD), and color of the husk (CH). Using path analysis, it was possible to verify directly that, among the physical components of the study, TM and FD have a direct and positive influence on FM. Fruit mass had a direct and negative correlation with HM, indicating that fruit with the heaviest husk (and green color) have not yet reached full maturation, nor reached their greatest mass. This result suggests that TM is strongly indirectly influenced by the HL, husk diameter, HM, and FD.

Open access

Zanzan Li, Jinyu Hu, Hang Tang, Liping Cao, Yuhang Chen, Qiaosheng Guo, and Changlin Wang

The spicas of Prunella vulgaris are widely used in the medical, beverage, and ornamental fields. Temperature and photoperiod are the two main ecological factors that determine the transformation of many plants from vegetative growth to reproductive growth. To explore the response of P. vulgaris flowering to temperature and photoperiod induction, we adopted vernalization long-day, vernalization short-day, nonvernalization long-day, and nonvernalization short-day treatments. The results showed that the morphology (total number of leaves, number of branches, number of leaves per branch, and branch length) of the vernalization treatment groups was significantly different from that of other nonvernalization groups, and the photosynthetic pigments, net photosynthetic rate, water use efficiency, stomatal conductance, intercellular CO2 concentration, and transpiration rate increased in the vernalization treatment group. However, the gibberellin 3 (GA3), indole-3-acetic acid and zeatin riboside (ZR) contents were significantly increased under the short-day treatments groups, and the results were the same for the expression of endogenous hormone synthesis genes, except for abscisic acid (ABA). The flowering-related genes soc1, elf3, svp, ga20ox, and cry1 were highly expressed under the vernalization short-day. Therefore, the induction of vernalization is more conducive to the increase in the photosynthetic rate. Temperature and photoperiod synergistically induced the synthesis and accumulation of starch, sugar, amino acids, and protein and affected the content of endogenous hormones and the expression of genes involved in their synthesis. GA3 and ZR had thresholds for their regulation of the flowering process in P. vulgaris, and high concentrations of ABA promoted flowering. Temperature and photoperiod coordinate the expression of the flowering-related genes soc1, elf3, svp, ga20ox, and cry1, thereby affecting the flowering process in P. vulgaris.

Open access

Richard P. Marini, Emily K. Lavely, Tara Auxt Baugher, Robert Crassweller, and James R. Schupp

‘Honeycrisp’ is a popular apple cultivar, but it is prone to several disorders, especially bitter pit. Previously reported models for predicting bitter pit are biased, indicating that the models are missing one or more important predictor variables. To identify additional variables that may improve bitter pit prediction, a study was undertaken to investigate the influence of canopy position, spur characteristics, and individual fruit characteristics on bitter pit development. ‘Honeycrisp’ trees from two orchards over 2 years provided four combinations of orchards and years. Fruits were sampled from spurs at different canopy positions and with varying bourse shoot lengths and numbers of fruits and leaves. Following cold storage, bitter pit was assessed in three ways: 1) bitter pit severity was recorded as the number of pits per fruit, 2) bitter pit was recorded as a binomial response (yes, no) for each fruit, and 3) the incidence of bitter pit was recorded as the proportion of fruit developing bitter pit. As a result of the high fruit-to-fruit variation, bitter pit severity was associated with canopy position or spur characteristics to a lesser extent than bitter pit incidence. Bitter pit incidence was generally greater for fruits developing on spurs with only one fruit and spurs from the lower canopy. Binomial data were analyzed with a generalized linear mixed model. Fruit harvested from trees with heavy crop loads, and those developing on spurs with multiple fruit and spurs with long bourse shoots had the lowest probability of developing bitter pit. Regardless of how bitter pit was assessed, bitter pit related positively to fruit weight (FW), but the relationship usually depended on other variables such as canopy position, fruit per spur, and leaves per spur. The advantages of fitting binomial data with logistic regression models are discussed.

Open access

Juan Guillermo Cruz-Castillo

‘Utopia’ [Zantedeschia aethiopica (L.) K. Spreng] is a perennial calla developed by Chapingo Autonomous University, Mexico. The calla belongs to the Araceae family and is an ornamental native of Africa (Kuehny, 2000). In Mexico it is popular and is used for weddings and other celebrations. Most of the calla produced in Mexico are a perennial type with white spathes. In Latin America, this calla also grows in Argentina, Bolivia, Brazil, Colombia, Ecuador, and Guatemala. In some markets of Mexico, the perennial cultivar Green Goddess is found. It is characterized by green spots mixed with white in

Open access

Samuel Kwakye, Davie M. Kadyampakeni, Edzard van Santen, Tripti Vashisth, and Alan Wright

Improving nutrient uptake and tree health play an important role in managing Huanglongbing (HLB)-affected citrus trees in Florida. A greenhouse experiment was conducted to evaluate the effect of increasing rates of manganese (Mn) on growth and development of sweet orange [Citrus sinensis (L.) Osbeck] trees at the University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center in Lake Alfred, FL. Half the trees were graft-inoculated with the HLB pathogen and the remainder were used as the HLB-free (non HLB) control trees. Four rates of Mn (0.0 kg·ha−1 Mn (Control), 5.6 kg·ha−1 Mn (1x—standard rate), 11.2 kg·ha−1 Mn (2x—standard rate), and 22.4 kg·ha−1 Mn (4x—standard rate) were split applied quarterly to both sets of the trees in a completely randomized design. There were seven single tree replicates for each treatment. Response variables measured were trunk diameter, tree height, leaf Mn concentration, plus above- and belowground biomass. The accumulated Mn in leaf tissues significantly increased trunk diameter but did not affect tree height for both HLB-affected and non-HLB trees, the 2x rate had the maximum value for trunk diameter relative to the 4x rate. This study established a positive correlation between soil available Mn with Fe and Cu, but negative correlation with B and Zn. A strong correlation of −0.76, −0.69, and 0.65 was observed between soil Mn and B, Zn, and Cu, respectively, as compared with 0.49 with Mn and Fe. Among HLB-affected trees, the 2x rate gave the most belowground dry matter, which was 3% greater than the control and 5% greater than 4x. Aboveground dry matter had at least 30% more biomass than belowground matter among all treatments within HLB-affected trees. For small and medium roots, Mn accumulation increased with Mn application until 2x rate and decreased thereafter for HLB-affected trees. The results from our study showed an Mn rate of 8.9–11.5 kg·ha−1 Mn, as the optimum Mn level for young ‘Valencia’ HLB-affected trees in Florida.

Open access

Jingran Lian, Yuyan Li, Haiying Li, Yuxin Chen, Sijie Wang, Juan Zhou, Chen Lian, and Yan Ao

Yellow-horn (Xanthoceras sorbifolium Bunge) is a rare woody oil plant mainly distributed in China, with nutritious seeds that contain a high oil content in the seed kernels (Xie and Zhang, 2018). It is suitable for both biodiesel production and high-grade edible oil (Liu et al., 2017). Because it is mainly distributed in northern China, it has been referred to as “northern oil tea” (Chang et al., 2019). The State Forestry Administration has listed yellow-horn as the main tree species for the construction of biomass diesel raw material base. At the same time,

Open access

Jie Zeng, Ting Zhou, Donglin Zhang, and Wangxiang Zhang

Crabapple is one of the most important ornamental small trees and shrubs, and includes all wild species of the genus Malus and its horticultural cultivars (fruit diameter ≤ 5 cm). Most are highly valued due to their range of flower colors (purple, red, pink, white, etc.) as well as colorful fruits (primarily purple, red, pink, orange, yellow, and green), and wide range of growth habits (columnar, fastigiate, upright, spreading, drooping, and weeping) (UPOV, 2003; Wyman, 1955). In addition, crabapples show strong environmental adaptability including drought resistance, cold resistance, saline alkali tolerance, and barren resistance.

Open access

Marcia R. Ostrom, David S. Conner, Heleene Tambet, Katherine Selting Smith, J. Robert Sirrine, Philip H. Howard, and Michelle Miller

Hard cider is an important and growing part of the U.S. beverage market. Previous research suggests there is an opportunity for growers interested in selling locally grown cider-specific apple (Malus domestica) varieties. However, cider apple growers face production, distribution, and marketing challenges. This article fills a gap in the literature using survey data from four states. We find that growers are interested in expanding cider apple production to supply local craft cider makers, but may be constrained by gaps in current production information, such as how to grow cider varieties. Uncertainty about the regional suitability of different varieties, disease management, and the willingness of cider makers to pay a premium for cider apple production constitute significant concerns. Survey respondents most commonly requested information on horticultural qualities of varieties and disease management. Top marketing needs include the ability to garner premium prices. A regional “terroir” approach to cider marketing holds promise.

Open access

Isha Poudel and Anthony L. Witcher

Weeds are a major problem in cutting propagation and compete with the main crop for water, sunlight, and nutrients, thus reducing growth and marketable quality of rooted cuttings. Due to the high labor cost of hand weeding, mulches can be an alternative method for weed control in the propagation environment. The objective of this research was to determine the effect of mulches (coarse vermiculite, rice hulls, paper pellets, and pine pellets) on rooting of stem cuttings and weed control when applied at 0.5- and 1-inch depths. Cuttings of three plant species [‘Nanho Blue’ butterfly bush (Buddleja davidii), ‘Catawba’ crape myrtle (Lagerstroemia indica), ‘Phantom’ hydrangea (Hydrangea paniculata)] were stuck in 2.5-inch-diameter containers filled with pine bark substrate and treated with mulch. In a separate study, seeds of four weed species [creeping woodsorrel (Oxalis corniculata), hairy bittercress (Cardamine hirsuta), large crabgrass (Digitaria sanguinalis), mulberry weed (Fatoua villosa)] were sown onto the mulch surface. Rooting percentage was unaffected by mulch type or depth for any of the three crop species (‘Nanho Blue’ butterfly bush, ‘Catawba’ crape myrtle, ‘Phantom’ hydrangea). Pine pellets did not affect root dry weight of any crop species, but root length and volume of ‘Catawba’ crape myrtle was reduced by pine pellets at 1-inch depth. Rice hulls slightly reduced the root length and volume of ‘Catawba’ crape myrtle, but the reduction was less than 50%. Pine pellets and paper pellets (both depths) reduced growth of all four weed species. Even though weed seeds germinated in pine and paper pellets, seedlings did not grow large enough to potentially affect crop rooting. In conclusion, pine pellets and paper pellets at 0.5-inch depth can be effective in suppressing weed populations with minimal effect on rooting.

Open access

Stephen C. Smith, Katherine M. Jennings, David W. Monks, David L. Jordan, S. Chris Reberg-Horton, and Michael R. Schwarz

Field studies were conducted in North Carolina in 2019 and 2020 to determine the effect of a reduced-tillage, high-residue rye (Secale cereal) cover crop system on soil health, and growth and storage root yield of sweetpotato (Ipomoea batatas) cultivars having upright (NC04-0531 or NC15-650) or prostrate (Covington or Bayou Belle) vining characteristics. Sweetpotato canopy width expanded quicker in the conventional tillage system than the reduced-tillage rye system. Prostrate sweetpotato cultivars had greater late-season canopy widths than upright cultivars. Soil bulk density of raised beds was greatest in the reduced-tillage rye system, but both systems remained within the U.S. Department of Agriculture recommended range for soil bulk density. The conventional-tillage system resulted in 17% more marketable roots; however, no differences were observed in total marketable root weight between systems. ‘Covington’ and ‘NC15-650’ had greater marketable yield than ‘NC04-0531’ but less marketable yield than ‘Bayou Belle’.