Cu treatments on Cu concentrations, vegetative growth, C Lasiaticus genome copy number, and nutrient acquisition were evaluated. Materials and Methods Plant culture and HLB treatments. The experiment was conducted in a psyllid-free greenhouse at the
Robert C. Ebel, Said Hamido and Kelly T. Morgan
Azadeh Behrooz, Kourosh Vahdati, Farhad Rejali, Mahmoud Lotfi, Saadat Sarikhani and Charles Leslie
application of AM fungi, especially G. etunicatum , and PGPB can improve growth and nutrient acquisition of walnut plants under drought stress. AM and PGPB increased some osmotic compounds significantly, including proline, total carbohydrates, and soluble
James L. Walworth, Scott A. White, Mary J. Comeau and Richard J. Heerema
A field study was conducted to evaluate efficacy of soil-applied zinc (Zn) fertilizer on young pecan [Carya illinoinensis (Wangenh.) K. Koch] trees growing in alkaline, calcareous soils. Chelated Zn ethylenediaminetetraacetic acid (ZnEDTA) was applied at rates of 0, 2.2, or 4.4 kg·ha−1 of Zn via injection into irrigation water (fertigation) in microsprinkler irrigated ‘Western’ and ‘Wichita’ trees. Over the 5-year duration of the study, leaf Zn levels were increased from 22 to 35 µg·g−1 in the highest rate of ZnEDTA treatment compared with 7 to 14 µg·g−1 in unfertilized trees. Zn concentrations in shoot and root tissues were also elevated in Zn-treated trees. Zn treatments largely eliminated visible Zn deficiency symptoms, and increased trunk diameter growth compared with untreated trees. Nut yield (in the third through fifth seasons) were also increased as a result of Zn fertilization. No additional benefit in terms of trunk diameter growth or nut yield was observed by adding a higher rate of Zn (4.4 kg·ha−1) vs. the lower rate (2.2 kg·ha−1). ‘Western’ and ‘Wichita’ trees responded similarly to Zn fertigation.
Eva Bacaicoa and Jose María García-Mina
nutrient extraction from the shoot. To facilitate the analysis of the data related to plant nutrient acquisition, the results were presented as a function of the nutrient extraction from the shoot. This type of data presentation was chosen because, in
Ellen T. Paparozzi
Fertilizer particularly nitrogen is part of the concern about groundwater contamination. Many floricultural and ornamental plants do not need the high rates of nitrogen that are typically recommended. However, whenever one alters the quantity of a given nutrient the overall nutrient balance, as well as other physiological processes, changes. A brief overview of our research on poinsettias, roses, and chrysanthemums will be presented. Suggested ratios, critical S levels and nutrient problems associated with incorrect balances will be shared. Limitations due to statistical methods and the impact nutrient balance has on certain plant processes such as flowering and coloring and thus, consumer acceptance will be summarized. Future plans in this area may focus on the need for new statistical techniques, nutrient acquisition by roots and consumer perceptions of plant quality.
Yongfeng Yang, Zhixiao Yang, Shizhou Yu and Hongli Chen
Organic acid secretion from higher plant roots into the rhizosphere soil plays an important role in nutrient acquisition and metal detoxification; however, their precise functions and the related mechanisms in abiotic stress tolerance remain poorly understood. Tobacco is an important crop plant, so thoroughly elucidating these factors in tobacco is of high priority. In the present study, the activation effect on soil potassium (K), contents of exuded organic acids, and physiological changes in the roots of various tobacco varieties under both normal K supply and K-deficiency stress were investigated. Our results showed that one high-K variety (ND202) exhibited a significantly higher total content of organic acids in the root exudates and the highest available K content in the rhizosphere soil, compared with two common ones (K326 and NC89). Moreover, the high-K tobacco variety was less affected in terms of root vigor under K-deficiency stress, and displayed greater increases in the activities of the stress-resistant enzymes consisting of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). Taken together, these results provide evidence that tobacco roots exude large amounts of organic acids to increase the available K content in the rhizosphere soil and improve the utilization rate of soil K.
G.A. Picchioni, M. Valenzuela-Vazquez and S. Armenta-Sanchez
Lupinus havardii Wats. (Big Bend bluebonnet) has received considerable attention as a new specialty cut flower crop. We studied the consequences of Ca fertigation on growth, water use, and mineral nutrient uptake of L. havardii (`Texas Sapphire') for 88 days in a greenhouse. Four Ca concentrations were included (as CaCl2) in the fertigation solution at concentrations of 0, 2.5, 5.0, or 10.0 mm. Calcium supply did not affect the number of racemes produced per plant or total dry matter accumulation per plant. However, root dry matter accumulation, root: shoot ratio, net root mineral nutrient accumulation (milligrams P, K, Ca, Mg, and Fe per plant; micrograms Mn, B, and Cu per plant), and the preferential allocation of mineral nutrients to roots were influenced quadratically by CaCl2 supply, increasing up to 5.0 mm CaCl2 and then decreasing at 10.0 mm CaCl2. Lack of root sink response by plants exposed to 10.0 mm CaCl2 was associated with lowest daily rate of pot evapotranspiration, probably resulting from osmotic or Cl toxicity stress. Increased root sink strength for dry matter and mineral nutrients in response to CaCl2 supply up to 5.0 mm Ca is consistent with calcicole-like behavior and the native distribution of L. havardii on xeric, calcareous soils, where root growth and expansion favoring water and mineral nutrient acquisition may be of significant adaptive value for survival. The Carelated increase in root growth was reflected in up to a 5% to 20% increase in fertilizer P and K recovery per plant. Results indicate that Ca fertilization may be an effective horticultural strategy in greenhouse production of L. havardii, particularly for matching the natural edaphic habitat of the species and thus increasing efficiency of water and mineral nutrient management.
Allen V. Barker
mitochondrial respiration, thereby distinguishing the process from photorespiration. The importance of mitochondrial respiration in providing energy for plant growth and for maintenance activities such as nutrient acquisition and other functional process in
Luisa Dalla Costa, Nicola Tomasi, Stefano Gottardi, Francesco Iacuzzo, Giovanni Cortella, Lara Manzocco, Roberto Pinton, Tanja Mimmo and Stefano Cesco
harvested stage and maintaining the temperature values of uptake media corresponding to those of the nutrient solutions. As shown in Table 3 , the rise in temperature from 15 to 20 °C induced a clear increase in nutrient acquisition capability of NO 3
Jonathan P. Lynch
greater root growth and nutrient acquisition for a given metabolic investment. Fig. 1. Cross-sections of seminal roots of maize showing genotypic difference in cortical aerenchyma formation, which replaces living cortical cells (left) with air