Effect of Foliar Spraying with Compounds Rich in Potassium and Phosphorus as an Alternative to Soil Addition on the Growth, Productivity and Quality of Cotton

This study was conducted during two successive seasons (2019 and 2020) on cotton cultivar Giza 86 at El-Gemmeiza Agricultural Research Station, El-Gharbia Governorate, Egypt, to study the effect of foliar feeding with two compounds enriched with phosphorus and potassium [Agrophytex at two levels (2 and 4 cm 3 /L) and potassium phosphate at two levels (2 and 4 g /L)] either alone or in combination at the low and high level compared to the control treatment (sprayed with tap water and fertilized with phosphorus and potassium at the recommended rates as soil application) on cotton productivity and quality.A randomized complete blocks design with 4 replicates was used.The obtained results revealed that foliar feeding with Agrophytex and potassium phosphate combination at the two levels examined significantly increased percentages of N, P, K and contents of chloroplast pigments in cotton leaves in 2019 season.Growth parameters, earliness measurements, seed cotton yield/feddan and its components in both seasons as well as micronaire reading and fiber strength in the second season were also increased.Whereas, boll shedding percentage decreased.Fiber length and uniformity index did not affected.It could be concluded that using combination of Agrophytex and potassium phosphate at the low level (2 cm 3 Agrophytex + 2 g potassium phosphate)/L four times (at seedling stage, squaring initiation, flowering start and peak of flowering stage) as alternative to soil P and K fertilization was recommended to reduce cost, overcome P and K fixation and obtain high productivity under conditions similar to El-Gemmeiza region.