Foliar Feeding of Cotton: Evaluating Potassium Sources, Potassium Solution Buffering, and Boron

Abstract

on soils having Mehlich-1 extractable K of 177 kg ha Ϫ1 or less. Yield response to foliar K continued through Foliar applications of K may be used to supplement soil applications two years of soil-applied 112 kg K ha Ϫ1 plus two years to maximize yields of cotton (Gossypium hirsutum L.). Response to foliar K applications may be improved by choice of K source, buffering of foliar-applied K (four applications per year at 4.1 kg the spray solution, or applying K with B. Research was conducted ha Ϫ1 each). Oosterhuis (1993) indicated that responses on a Collins silt loam (coarse-silty, mixed, acid, thermic Aquic Udifluto foliar K can probably be expected when Mehlich-3 vents) and on a Memphis silt loam (fine-silty, mixed, active, thermic soil K level is 308 kg K ha Ϫ1 or lower. This extractable Typic Hapludalfs) to evaluate KNO 3 , K 2 SO 4 , K 2 S 2 O 3 , and KCl as K K level is similar to the 177 level reported above, using sources. A second study evaluated foliar KNO 3 and K 2 SO 4 solutions Mehlich-1 extractant, since Mehlich 3 extracts approxiapplied unbuffered and buffered to pH 6 and 4 on cotton K nutrition mately 1.5 times more K than Mehlich 1 (H.G. Savoy, and yield. Foliar K in both studies was applied at 4.1 kg K ha Ϫ1 per personal communication, 1998). Tillage system may also application. A third study evaluated combinations of soil-applied and contribute to the response to K fertilization. Howard foliar-applied B and K. Foliar treatments were applied in 93.5 L ha Ϫ1 et al. (1997) reported that no-tillage cotton yields were water at early flower or 2 wk after and repeated on a 9-to 14-d interval between the four applications. Yields from the four K sources increased by applying K to a soil having 225 kg Mehaveraged 10% higher than the untreated check and yields with KNO 3 lich-1 extractable K ha Ϫ1 , but conventional-till yields were 4% higher than the other K sources. Buffering two K source were not increased by applying K to a soil having 193 solutions to pH 4 resulted in 10% higher yields than the check or kg extractable K ha Ϫ1. unbuffered K solutions. Adding a surfactant (ethoxylated alkyl aryl The foliar-applied K source may also affect yield rephosphate esters) to KNO 3 resulted in 5% higher yields then the sponse to foliar fertilization. Miley and Oosterhuis check. Compared with untreated check yields, soil-applied B at 0.56 (1994) summarized three years of evaluating KNO 3 , kg B ha Ϫ1 increased yields by 6%, four foliar applications of 0.11 kg K 2 SO 4 , K 2 S 2 O 3 , KCl, and K 2 CO 3 as foliar K sources and B ha Ϫ1 increased yields by 8%, and four foliar applications of 0.11 reported that KNO 3 increased lint yields, relative to the kg B plus 4.1 kg K ha Ϫ1 increased yields by 13%. Foliar K solution other sources, in two of the three years. Mullins and buffering and/or the inclusion of foliar B are relatively inexpensive ways of improving yield response. Based on yield increases in this Burmester (1995) reported that lint yields were instudy, these treatments should return 8 to 10 times the pr...

Foliar boron application affects lint and seed yield and improves seed quality of cotton grown on calcareous soils

“…Also, it is possible that the critical levels of B in cotton were determined by visual symptoms and not by comparative field studies were the yield was determined. Moreover, the data from this study agrees with previous reports where they found an increase in cotton yields due to B applications (Howard et al 1998(Howard et al , 2000. However, there are several other reports where there was no effect of B application on cotton yield (Anderson and Ohki 1972;Heitholt 1994).…”

Effectiveness of potassium sulfate in mitigating salt-induced adverse effects on different physio-biochemical attributes in sunflower (Helianthus annuus L.)

“…Furthermore, foliar application with 5% KNO 3 caused enhanced lint yield in cotton grown under non-stress conditions, while 4% higher total lint yield was observed with KNO 3 application compared with other three K sources, i.e. KCl, K 2 SO 4 , and K 2 S 2 O 3 (Howard et al, 1998). In the same way, while working with grass pea (Lathyrus sativus), Sarker and Malik (2001) reported an improvement in yield attributes with the application of 0.25%, 0.5% or 1.0% KNO 3 solution as a foliar spray.…”

Evaluation of Application Methods and Rates of Zinc and Boron on Nitrogen, Phosphorus and Potassium Contents of Maize Leaf

“…Foliar application of B accelerates the translocation of N compounds, increases protein synthesis and stimulates fruiting. Because small amounts of B are required, foliar application of B may be more efficient than soil application, especially when deficient conditions are suspected (Howard et al, 1998;Seilsepour and Rashidi, 2011). The result of this study is against of Ziaeyan and Rajaie (2009) who conclude that increments in B addition by both methods of fertilizer application significantly decreased the concentration of N in corn leaf and also reported that N concentration in leaf increased with applied Zn.…”