Potassium fertiliser on productivity in the lima bean

Resumo

In Brazil, the lima bean bean is cultivated throughout almost the entire country, and has relative economic importance in the Northeast, which is the main producer. Increasing the availability of K via fertilisation, would increase the productivity of the lima bean. Therefore, the aim of this study was to evaluate different doses of potassium on productivity in the lima bean. The study was carried out in the field between January and July 2019, in the town of Raposa, Baturité, Ceará. The experimental design was of randomised blocks, with five treatments and four replications. The treatments consisted of the following doses of potassium: 60, 90, 120, 150 and 180 kg ha^-1 K₂O, using potassium chloride as a source, corresponding to 50%, 75%, 100%, 125% and 150% of the recommended dose. As the pods dried and the grain was collected, the following variables were evaluated: number of pods per plant, pod length, pod diameter, pod weight and productivity. The potassium doses of 130, 109 and 180 kg ha^-1 K₂O afforded the greatest number of pods (124), pod weight (108.64g) and pod diameter (18 mm), respectively. The dose of 106.20 kg ha^-1 K₂O, lower than the recommended dose for the lima bean, determined the maximum grain yield, 1,567 kg ha^-1.