Doses de boro no desenvolvimento morfológico do algodoeiro colorido

Abstract

The cotton plant is a plant from the malvaceae family whose species Gossypium hirsutum L. is the most cultivated for the production of down used by the textile industries, representing 75% of natural fibers and having enormous economic and social significance for Brazilian agriculture. Colored cotton has become increasingly prominent over time, mainly due to its numerous advantages, including: no need to dye fabrics, higher sales price than white fiber cotton and represents a great alternative for family farmers. The variety of shades of this type of fiber varies from cream to brown, which is one of the biggest challenges for breeders, as it consists of finding fiber attributes with quality so that they are reliable by the industry, in addition to increasing productivity in the field. Among the micronutrients in cotton crops, it has been observed that boron (B) is the most limiting and the one whose deficiency symptoms appear most frequently, with its losses depending on the intensity and time of the deficiency period. Therefore, the present work aimed to evaluate the morphological development between different colored cotton cultivars subjected to doses of boron. The experiment was conducted at the Glória Experimental Farm belonging to the Federal University of Uberlândia (UFU), with coordinates: latitude 18.945074"S, longitude 48.215302"W and altitude of 936 meters, in a region with a temperate Aw climate. In this area there is a predominance of Dystrophic Dark Red Oxisol soil. The design used was a randomized block design (DBC), with four replications. A total of 4 genotypes were used, including commercial cultivars from Embrapa: BRS Rubi, BRS Verde, BRS Safira and BRS Jade. These were compared to 4 doses of boron: 0kg ha-1, 0,5kg ha-1, 1.5kg ha-1 and 2.0kg ha-1. Thus, the phenotypic correlation coefficients were estimated between the characteristics: height (H), insertion height of the first reproductive branch (H1R), vegetative branches (RV), reproductive branches (RR) and leaf area (AF). Only the BRS Rubi genotype was the one that best expressed results regarding the dose of 0.5kg ha-1 in response to the phenotypic characteristic leaf area (AF).