The aim of the study was to evaluate the effect of combined soil and foliar spray potassium doses on seed cotton yield and quality of cotton fiber, in southeastern Goiás State, Brazil. Seed cotton yield gains were observed for potassium applied both through soil (as KCl) and foliar spraying (as KNO3), without interactions between modes of application. With four foliar potassium nitrate sprays at 10 days interval, a maximum of 5% (200 kg yield per ha) seed cotton yield increase was reached with 8 kg KNO3 per spray (Figure 1). There were no effects of doses and mode of application on cotton fiber quality, in the cultivar Delta Opal tested.
Figure 1. The effect of increasing potassium nitrate dose rates on seed cotton yield.
De Freitas, R.J., W. M. Leandro and M.C.S. Carvalho. 2007. Efeito da adubação potássica via solo e foliar sobre a produção e a qualidade da fibra em algodoeiro (Gossypium hirsutum L.). (Effect of soil and foliar potassium application on yield and fiber quality in cotton (Gossypium hirsutum L.). Pesq Agropec Trop 37 (2): 106-112.