ABSTRACT
Evidence has shown that soil fertilization cannot always meet cotton's high demand for nitrogen and supplementation with foliar fertilizer has become a widespread practice. However, yield responses to foliar-applied nitrogen have not always been consistent. CoRoN™ a slow release nitrogen fertilizer has been proposed as a potentially superior alternative method of foliar feeding with nitrogen. The value of CoRoN™ for enhancing growth and yield of cotton was evaluated in a six-year field study in Arkansas. Foliar application of CoRoN™ to field-grown cotton resulted in significant (P=0.05) yield increases in 2 out of 6 years, with an overall average increase of 51 kg lint ha-1 compared to the control. Compared to foliar-applied urea, CoRoN™ increased yields an average of 28 kg lint/ha but this was not statistically significant. Furthermore, CoRoN™ caused a significant increase in boll weight in 1 out of the 4 years with no significant effect on boll number. The effect of CoRoN™ on petiole nitrate concentrations was inconsistent. Foliar application of CoRoN™ caused no significant phytotoxicity up to 22.4 kg N ha-1 (20 lb. N acre-1), in contrast to foliar-applied urea which caused significant leaf burn at 11.2 kg N ha-1 (10 lb. N acre-1). From this work it can be concluded that the effect of foliar-applied CoRoN™ on yield was not significantly different from urea. CoRoN™ had an advantage of not causing any significant foliar burn. These studies indicate that as a foliar nitrogen fertilizer CoRoN™ does not consistently improve cotton production.
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