Agronomic components of colored cotton cultivars as a function of potassium doses in the semiarid region¹

Componentes agronômicos de cultivares de algodão colorido em função de doses de potássio no semiárido

ABSTRACT

Potassium is one of the most important nutrients for the cotton plant, being an element that participates in many physiological functions. In addition, its adequate availability favors better production performance of the crop. Therefore, the objective of this study was to evaluate the agronomic components in naturally colored cotton cultivars fertilized with potassium doses in the Brazilian semiarid region. For this, two experiments were conducted at Rafael Fernandes Experimental Farm, located in the municipality of Mossoró, RN, from July to November 2019 and July to November 2021. The experimental design was randomized blocks, arranged in split plots, with four repetitions. Potassium doses (0, 60, 120, 180, and 240 kg ha^-1 of K₂O) were allocated in the plants; and four naturally colored cotton cultivars (BRS Rubi, BRS Safira, BRS Verde, and BRS Topázio) were allocated in the subplots. Colored cotton cultivars respond to potassium fertilization depending on the edaphoclimatic conditions to which they are exposed. BRS Topázio cultivar had higher lint cotton yield and fiber percentage in both growing seasons, highlighting its potential for the region. The dose of 240 kg ha^-1 of K₂O increased the yield of colored cotton, in second crop cultivation. The cultivars BRS Safira, BRS Rubi, and BRS Verde were not very productive.

Key words:
Gossypium hirsutum L.; fertilization; lint yield; fiber

HIGHLIGHTS:

Application of K favors the cultivation of colored cotton under semiarid conditions.

Cultivar BRS Topázio has high lint yield performance even under low K availability in the semiarid region.

Meteorological and soil conditions in semiarid regions alter the response pattern of agronomic components in colored cotton.