Estratégias de irrigação deficitária nas fases fenológicas de genótipos de algodoeiro de fibra colorida.

Abstract

Abiotic stresses affect the production of many agricultural crops, such as water stress, which has been a worldwide problem. Cotton, despite being a water stress tolerant crop, can have deleterious effects on its physiology, morphology and production when subjected to water restriction. Thus, the objective of this work was to evaluate the morphophysiology and production of colored fiber cotton genotypes under water deficit, varying the phenological phases of the plants in the second production cycle. The research was carried out between July and November 2021, at the Agro-Food Science and Technology Center of the Federal University of Campina Grande, Pombal, Paraíba. The experimental design was randomized blocks, in a 3 × 10 factorial scheme, with three cotton genotypes (‘BRS Rubi’, ‘BRS Jade’ and ‘BRS Safira’) and ten irrigation management strategies, with three replications and two plants per plot, totaling 180 plants. The water deficit in the vegetative phase reduced the growth of the colored fiber cotton genotypes in the second production cycle. The BRS Safira genotype showed better development with a higher relative growth rate in plant height and stem diameter stem dry phytomass and total seed mass regardless of the irrigation strategy. In the flowering phase of the cotton plant, irrigation with water deficit can be used in cotton cultivation with the lowest losses in root dry mass, which is negatively affected by the water deficit in the vegetative and fruiting phases.