Comparação entre métodos para determinar o período anterior à interferência de plantas daninhas em feijoeiros com distintos tipos de hábitos de crescimento

Abstract

RESUMO -A interferência causada pelas plantas daninhas pode reduzir em até 80% a produtividade de grãos do feijão quando não manejadas de forma correta. Portanto, a decisão sobre o momento de controlá-las é um dos principais aspectos do manejo integrado. Nesse sentido, objetivou-se com este trabalho determinar o período anterior à interferência das plantas daninhas (PAI) em cultivares de feijão com diferentes tipos de hábitos de crescimento. Adotou-se o delineamento experimental de blocos casualizados com quatro repetições. Os tratamentos experimentais foram constituídos de dez períodos de convivência da cultura com as plantas daninhas: 0-7, 0-14, 0-21, 0-28, 0-35, 0-42, 0-49, 0-56, 0-97 (colheita) dias após a emergência (DAE) e mais uma testemunha sem convívio com as plantas daninhas. O PAI foi determinado por meio de distintas abordagens: o nível arbitrário de 5% de perda na produtividade, o nível de tolerância (NT) e o de dano no rendimento econômico (PADRE). O PAI obtido foi diferente em todas as abordagens, e os feijoeiros de crescimento indeterminado tipo II apresentaram os menores tempos de convivência. : 0-7; 0-14; 0-21; 0-28; 0-35; 0-42; 0-49;0-56; 0-97 (harvesting) Palavras-chave: Phaseolus vulgaris, cultivares, competição. ABSTRACT -Beans grain productivity may be reduced by up to 80% and, therefore, knowing the proper time to control weeds becomes fundamental, his research was conducted in order to determine the period prior to interference (PPI) on bean cultivars of different types' plant growth through distinct approaches: arbitrary level of 5% productivity loss; tolerance level (TL), and the Weed Period Prior to Economic Loss (WEEPPEL). Experimental treatments were constituted of ten periods of coexistence, periods of the crop with the weeds

Interference and Economic Threshold Level for Control of Beggartick on Bean Cultivars

“…Although, when the bean plant was analyzed in relation to the biggest LA (100 x 10³ cm 2 m -2 ), it was determined that the cultivars with the biggest and smallest losses was, respectively, IPR Uirapuru -34.13% and BRS Campeiro -14.28% (Figure 2). It can be inferred that the cultivars competition degree, in relation to the beggartick, is influenced by the leaf area of the weed, according to what was determined by Parreira et al (2014), when evaluating the competition between bean cultivars (type carioca) and weeds.…”

“…It was determined, on the whole, for most of the evaluated variables, that the estimated values for the i parameter tend to be smaller in the BRS Esplendor, IPR Tuiuiú and Fepagro 26 cultivars, while the smaller competitiveness was verified to the IPR Uirapuru cultivars, for the variable PP, and BRS Supremo cultivars, for GC and DM, which presented the biggest losses in grain productivity when compared to the others (Figures 1, 2, 3 and 4). Many researches have reported the existence of differentiation among cultivars in their competitive ability in crops when in presence of weeds, fact that is attributed to the group of morphophysiological characteristics inherent to them (Barroso et al, 2010;Vidal et al, 2010;Kalsing and Vidal, 2013;Parreira et al, 2014). …”

“…The losses are aggravated by the broad and the high seed production, when infesting bean crops, and also for the elevated competitive ability presented to the crops by this weed (Santos and Cury, 2011). doi: 10.1590/S0100-83582016340300002 Researches involving the competitive capacity of crops versus weeds allow the development of management strategies, since they can define characteristics that confer a higher competitive ability to crops rather than infesting plants (Vidal et al, 2010;Bressanin et al, 2013;Tavares et al, 2013;Parreira et al, 2014). From the many tools available to study competition between plants in a community, the nonlinear equation of the rectangular hyperbola.…”

“…From the many elements that influence in the competition between weeds and crops, those related to management practice are mentioned, such as, the use of cultivars with higher competitive ability, which can diminish the degree of competition of weed, increasing the ETL and minimizing the need for control measures (Vidal et al, 2010;Kalsing and Vidal, 2013;Parreira et al, 2014). When that information is available, they can hold an important role in the choosing of management methods that depend especially on herbicides, for a system aimed in the ecophysiological knowledge (Bauer and Mortensen, 1992), and, in this way, a more sustainable model of bean infesting weeds control is obtained.…”

Periods of Weed Interference on Transgenic Cotton 'Imacd 6001ll'

“…The turnip was the predominant species, with 1.700 g m -2 of dry matter, followed by extinguishes fire with 900 g m Parreira et al (2013Parreira et al ( , 2014 and found that, in R. raphanistrum reached extremely high density and dry weight values drastically reducing crop yields that were present. When analyzing productivity when the weed community was present throughout the crop cycle, there were drastic losses in production reducing 84.89%.…”