Effects of foliar urea‐ and triazone‐nitrogen, with and without boron, on cotton

Abstract

Optimal lint yield in recently released high-yielding upland cotton (Gossypium hirsutum L.) cultivars requires careful nutrient management. It is not known whether these cultivars are capable of responding to foliar nitrogen (N) and boron (B) fertilizer when conventional soil fertility practices are used. The objectives of this study were (i) to determine the responses of a high-yielding cotton cultivar to foliar N and B fertilizer and (ii) to compare two N sources when applied to foliage of cotton. A two-year field study was conducted with a factorial arrangement of three N treatments and two B treatments. Plants received foliar applications of the surfactant Tween 20 in H 2 O (check), or one of the following treatments plus surfactant: B (as H 3 BO 3 ), triazone-N (24% of N as S-tetrahydrotriazone), triazone-N plus B, urea-N, or urea-N plus B. Leaf blade mineral element composition, lint yield, and fiber properties were determined. Averaged across years, lint yields were significantly higher in the check, both urea treatments, and the triazone plus B treatment than in the B only treatment. Foliar applications of either triazone-N or urea-N increased leaf blade N concentration but did not affect leaf blade B concentration. Foliar applications of B increased leaf 1. Mention of a trade mark, vendor, or proprietary product does not constitute a guarantee or a warranty of this product by the United States Department of Agriculture and does not imply its approval to the exclusion of other products or vendors that may also be suitable. 57 58 HEUHOLT blade B concentration but did not affect leaf blade N concentration. There were no N x B interactions on leaf blade N, leaf blade B, or on most fiber properties. For almost all variables, the effect of triazone-N was similar to that of urea-N. The results of this study suggested that augmenting standard cotton N and B fertility with foliar sprays was likely to increase leaf blade N and B concentrations but was unlikely to significantly effect yield or fiber properties.

Supplemental Boron, Boll Retention Percentage, Ovary Carbohydrates, and Lint Yield in Modern Cotton Genotypes

“…The Solubor preparation contained some Na, but the increase in leaf blade Na from the foliar B application was small, and there were apparently no adverse effects from the Na. In a previous study, leaf blade Na concentrations were higher than those reported here and were negatively correlated to lint yield (Heitholt, 1994).…”

Comparison of Commercial Boron Spray Products Applied at the Pink Flowering Stage on 'Fuji' Apple

“…Failure of the urea additives to enhance B uptake is consistent with Heitholt (1994), who reported that addition of urea to boric acid sprays on cotton failed to increase leaf B. Nitrogen applied in urea sprays is absorbed by apple leaves (Fallahi et al, 2002b;Toselli et al, 2002); hence, some of the spray-applied N likely was absorbed by the fl ower clusters and some retained as spray residue on the unwashed fl ower cluster surfaces. The total Kjeldahl analytical procedure measures N present in urea as well as in most other N compounds, so it should have detected N contributed by the N-Boron and Coron.…”

Foliar Application of Urea and Triazone Nitrogen to Cotton

“…In many studies, normal N fertilization practices were used, then foliar N treatments were imposed on plants which had received adequate N nutrition. In the presence of adequate soil applied N, no significant response to foliar N was reported by Bednarz et al (1992), Heitholt (1994), Hodgson and Macleod (1988), Jenkins et al (1982), Solares-Pareja andMalm (1988), or Smith et al (1987). In other cases, the response to foliar applied N was very small when compared to the variability between plots, therefore it was difficult to confirm a statistically significant response.…”

“…Boquet et al (1993;1994) showed that excessive N application decreased boll production at lower fruiting sites while increasing production of smaller, later maturing bolls on the upper fruiting sites of the plant. Other problems associated with excess N availability are excessive vegetative growth, increased boll rot due to shading of lower bolls, increased insect pressure and more difficult defoliation.…”