breeding effort ( Sraffa, 2005 ; Willcox, 1954 ). Foliar nutrient analysis is a well-established method ( Munson and Nelson, 1990 ) to assist in the diagnosis of nutrient-related problems (deficiencies, toxicities, imbalances, etc.) of both annual and
Noa K. Lincoln, Theodore Radovich, Kahealani Acosta, Eli Isele, and Alyssa Cho
J. R. Davenport
Foliar feeding of crop plants is an increasingly popular practice. The use of foliar nutrients relies on the ability of the plant to sorb nutrients through the leaves. Cranberries (Vaccinium macrocarpon Ait.) are known to have a waxy cuticle on the leaf surface which may impede nutrient uptake, leaving only the lower leaf surface for effective uptake. This study was undertaken to determine the extent of foliar nutrient uptake by cranberries using rubidium as a tracer. Rubidium was chosen for its similarity to potassium in plant uptake. In replicated plots, cranberries were sprayed with rubidium at the rate recommended for foliar potassium at three different growth stages and three different times of day. Washed and unwashed leaves were analyzed one day, one week, and one month after rubidium applications. Stem, soil, and root material was analyzed for rubidium at the one week and one month sample times. Results will be discussed with reference to uptake and movement of foliar applied nutrients in cranberries.
Han Xu, Cuihua Bai, Wei Wang, Changmin Zhou, Luwei Zhu, and Lixian Yao
). Foliar nutrient diagnosis has been developed and used in crops for decades, targeting to assess plant nutritional status and adjust nutrient management to promote crop productivity ( Amundson and Koehler, 1987 ; Rubio-Covarrubias et al., 2009 ). Foliar
Esmaeil Fallahi and Thomas Eichert
nutrients, which would reduce the number of sprays required per season ( Peryea et al., 2003 ). It is important to understand the basic physiology of foliar nutrient uptake through the cuticle to develop a more efficient and successful foliar nutrition
Dinesh Phuyal, Thiago Assis Rodrigues Nogueira, Arun D. Jani, Davie M. Kadyampakeni, Kelly T. Morgan, and Rhuanito Soranz Ferrarezi
; Singerman et al., 2018 ). The past studies were limited to tree density only, and scarce literature is available about the effect of high-density plantings with conjunction of soil and foliar nutrient application on grapefruit tree health, fruit yield, and
Stephanie E. Burnett, Donglin Zhang, Lois B. Stack, and Zhongqi He
plants (subsamples) were harvested 42 DAT. There were three blocks (experimental units) for each treatment. For all data, excluding the foliar nutrient data, plants were treated as subsamples and the containers were replicates. As a result of small plant
Susan K. Brown and James N. Cummins
Foliar nutrient concentrations of ‘Redhaven’ peach [Prunus persica (L.) Batsch.] on its own roots and budded on eight rootstocks [vegetatively propagated GF 655-2, ‘Damas’ (GF 1869), ‘Amandier’ (GF 677), and ‘Citation’, and seedlings of ‘Hal-ford’, ‘Lovell’, ‘Bailey’, and ‘Siberian C’] were analyzed for two seasons. Rootstocks selected for calcareous soils (‘Amandier’, ‘Damas’, and GF 655-2) were the most efficient in accumulation of nutrients other than Mg and B, for which they were the least efficient. For N and P, the levels of foliar nutrients were within proposed sufficiency ranges, regardless of the rootstock. Foliar levels of K and Zn were below the sufficiency range for all rootstocks tested. Differences among rootstocks were most evident in the foliar levels of Ca, Mg, Fe, Mn, B, and Cu. Rootstock had a small but significant effect on the foliar nutrient concentration.
G.E. Boyhan, J.D. Norton, and J.A. Pitts
The dwarfing characteristics of St. Julien and Pixy rootstocks, measured by shoot growth, were evident with `AU-Amber' and `AU-Producer' plum (Prunus salicina Lindl.) scions. Dwarfing did not occur with `AU-Rubrum'. Trunk cross-sectional area (TCA) was reduced with `AU-Amber', `AU-Producer', and `AU-Rubrum' scions on St. Julien and Pixy rootstocks. After 3 years, tree survival was 94% for Lovell; 89%, Halford; 57%, Nemaguard; 75%, Nemared; 83%, St. Julien; and 47%, Pixy. Tree survivability was significantly lower on Nemaguard and Pixy rootstocks than on Lovell and Halford. Multiple regression of total shoot growth, TCA, and survivability against foliar nutrient content resulted in the following significant equations: 0.460Mg - 0.210Mn, 0.236B - 0.487Mn, and 0.359N + 0.398Ca - 0.267P - 0.360Fe for each, respectively. Growth, survivability, and foliar nutrient content are significantly affected by rootstock in plum production.
Terence L. Robinson and Zhongbo Ren
Eleven year-old Empire/M.7 apple trees were shaded continously for 4 years with half-tree shading cages. Shading reduced primary spur leaf duration, bourse shoot leaf area, specific leaf weight, spur diameter and bud diameter. Over the four years, shaded spurs continued to increase in length but spur diameter increased very little resulting in long and brittle spurs. However, shaded spurs continued to flower and set fruit. Leaf area development was similar inside and outside the cages at one week after bloom but by 2 weeks after bloom, spurs inside the cages had significantly lower leaf area. Shading reduced fruit set, fruit size, fruit color, fruit soluble solids and fruit dry matter. Fruit growth rate was reduced by shading early in the season but was no different than the unshaded controls by 4 weeks after full bloom.
In an attempt to reverse the negative effects of shading on spur vigor, foliar urea, zinc-EDTA and solubor were sprayed 3 times during the early growing season each year. Rather than increasing spur leaf area, foliar nutrient sprays significantly reduced bourse shoot leaf area and did not increase the duration of primary spur leaves. Although foliar nutrients reduced total spur leaf area, they improved fruit size, color and soluble solids slightly.
Allen D. Owings, Warren A. Meadows, Donald L. Fuller, and Melinda R. Stewart
Recent studies at Louisiana State University evaluated incorporated rates (0.72, 1.08, and 1.44 kg N/m3) of controlled-release fertilizers (Chrysanthemum Mix 12N-4.4P-14.1K, Osmocote 14N-6.1P-11.6K, and Nutricote Type 70 14N-6.1P-11.6K) on the foliar nutrient composition of `Spears' potted chrysanthemums. Recently mature leaf tissue was sampled at flowering and analyzed for N, P, K, Ca, Mg, Fe, Zn, Cu, and Mn.
Increasing application rates reduced Ca and M g content in leaf tissue, while N, P, and K increased with an increase in application rates. Chrysanthemum Mix 12N-4.4P-14.1K provided more K to leaf tissue than did Osmocote or Nutricote Type 70 14N-6.1P-11.6K.