Mepiquat chloride through seed imbibition and foliar application on cotton in ultra narrow row spacing

Abstract

In areas with continuous cultivation and rapid soil depletion, the adoption of ultra narrow row spacing and high plant density are important management practices to rational crop cultivation, especially for cotton. The objective of this work was to evaluate cotton development, production of cottonseeds and fiber quality, under field conditions, using ultra narrow row spacing (0.30 m), when the seeds were soaked on growth regulator. The following doses of Mepiquat Chloride (MC) were tested: 0.0; 3.75; 7.5 and 15.0 g a. i. kg^-1 of seeds of the cultivar IPR 120 for 12h. The interaction of seed treatment with aerial spraying was also evaluated through sequential application (four times) of the MC at a seventeen-day interval, beginning 32 days after emergence. Treatments were displayed in a factorial randomized block design, with four replicates (32 experimental units). The parameters evaluated were cotton plant height, insertion of the first productive branch and number of productive branches, percentage of first position bolls, total number of bolls per plant, cottonseed production, open boll mass, mass of one hundred seeds and plume percentage. The effect of the MC was dose dependent. Size reduction, caused by seed treatment, was apparent until 80 days after planting. The product also negatively affected the height of the branch insertion as well as the number of fruit per plant. There was no interaction among the factors analyzed. Aerial application sole effect was reduction on plant height. There was also no effect of the soaking of cotton seeds and foliar application in the production and weight of the, 100-seed mass, percentage of fiber, number of nodes per plant and percentage of retention of first position bolls.