Interferência de populações de Brachiaria brizantha na produtividade de cultivares de cana-de-açúcar

Abstract

RESUMOO manejo das plantas daninhas deve ser realizado de forma racional levando-se em consideração a habilidade competitiva das cultivares, as quais podem ser mais ou menos afetadas pelas espécies daninhas, podendo ser reduzidos o custo de controle e o uso de herbicidas. Neste trabalho avaliou-se a interferência de populações de Brachiaria brizantha em cultivares de canade-açúcar (RB72454, RB867515 e SP801816), com o objetivo de comparar variáveis e estimar a perda de produtividade de colmos da cultura, em decorrência da competição. Para isto foi conduzido um experimento em condições de campo, em que as cultivares conviveram com diferentes densidades populacionais da espécie daninha. Foram avaliadas as variáveis: população de plantas, massa da matéria seca da parte aérea, cobertura do solo e área foliar da B. brizantha. As perdas de produtividade de colmos em virtude da interferência da B. brizantha, podem ser estimadas satisfatoriamente pelo modelo da hipérbole retangular com melhor ajuste para a variável população de plantas da B. brizantha. A cultivar SP80-1816 apresentou maior e a RB867515 menor habilidade competitiva. Palavras-chave: SP801816, RB867515, RB72454, competição Interference of Brachiaria brizantha populations in yield of sugarcane cultivars ABSTRACTThe management of weeds should be conducted in a rational manner, taking into consideration the competitive ability of cultivars, which may be more or less affected by weeds. In this study the interference of Brachiaria brizantha populations was evaluated in sugarcane cultivars (RB72454, RB867515 e SP801816) to compare variables and estimate the stalks yield loss as a result of weed competition. For this, an experiment was conducted under field conditions, where the cultivars coexisted with different weed densities. The variables evaluated were: plant population, dry weight of shoots, ground cover and leaf area of B. brizantha. The stalks yield losses due to the interference of B. brizantha, can be satisfactorily estimated by the hyperbolic model which adjusted better for the variable plant population of B. brizantha. The cultivar SP801816 showed higher and the RB867515 lowest competitive ability.

Interference and level of economic damage of turnip in canola

“…The turnip exerted greater competition on sugarcane (TIRONI et al, 2013) and also caused a decrease in rice leaf area and shoot dry mass (GALON et al, 2007); as in the weed population, there was a significant increase in yield losses of the crops studied.…”

“…In order to perform the simulation of the values of economic damage level -EDL, the explanatory variable loss of productivity (PP) of canola was used, because this is the most used in experiments with this objective (AGOSTINETTO et al, 2010;KALSING, VIDAL, 2013;GALON et al, 2019). It should be noted that this variable has some advantages over others, such as ease, speed and low cost for determination (TIRONI et al, 2013).…”

Emergence and Control of Rottboelia spp. in Different Months in Sugarcane Cultivation1

“…However, herbicides must have a long residual effect on the soil in order to control the flow of weed emergence in the area (Tironi et al, 2013), and wide spectrum of control to suit the demands of the crop; in this respect, herbicide mixtures that meet these criteria are extremely important (Santos et al, 2011). In this sense, the formulated mixture diuron + hexazinone + sulfometuron-methyl is an option for weed management in sugarcane crops.…”