“SPEED BREEDING” NA CULTURA DO ALGODÃO COM MICRODOSES DE FINISH® EM FASE VEGETATIVA

Abstract

Cotton is an agricultural commodity of major global importance, as it is the largest source of natural fibers. This is partly due to the crop’s genetic improvement programs. However, the development of new cultivars requires long periods and is a slow process, especially in the generational advancement phase, where homozygosity progresses. At this stage, the goal is not a high-yielding plant but rather one that produces seeds faster. Thus, establishing protocols to accelerate this development is highly valuable. This study aimed to evaluate the effect of applying the chemical product Finish® (ethephon + cyclanilide) to test whether it speeds up the cotton plant’s cycle. The experiment was conducted at the BASF research station in Trindade, GO, Brazil. A completely randomized design (CRD) was used in a 5x3 factorial scheme, with five microdoses of the product and three different cycles (early, medium, and late) of cultivars, with four replications. The treatments consisted of four microdoses of Finish® (D1: 50 mL ha⁻¹, D2: 100 mL ha⁻¹, D3: 200 mL ha⁻¹, and D4: 400 mL ha⁻¹) and a control (D0: no Finish® application), applied at V6 stage. The full Finish® dose for cotton is 1.5 L ha⁻¹. The evaluated variables were number of days until the first floral bud appearance, number of days until the first flower appearance, number of days until the first boll appearance, number of seeds harvested, weight of seeds harvested, and number of final bolls harvested. The product application did not accelerate the appearance of the first floral bud, the first flower, or the first boll and negatively affected seed quantity, seed weight, and boll production.