Interferência entre espécies de planta daninha e duas cultivares de feijoeiro em duas épocas de semeadura

Abstract

RESUMOO Brasil é o maior produtor mundial de feijão, mas a interferência das plantas daninhas pode causar reduções de produtividade entre 15% e 80%, devido a fatores como cultivar de feijoeiro e espécies de plantas daninhas presentes na área. Objetivou-se com este trabalho avaliar os efeitos de seis espécies de plantas daninhas sobre o crescimento e a produtividade de duas cultivares de feijoeiro, em duas safras. Observou-se que as plantas eudicotiledôneas causam maior interferência na cultura, principalmente Amaranthus viridis e Raphanus raphanistrum. Todas causam perdas na produção do feijoeiro, exceto Eleusine indica, a menos competitiva. A cultivar ´Rubi´ é mais produtiva e mais competitiva que a ´Carioca´, e a maior produtividade é atingida na safra da seca. A escolha da cultivar e da data correta para a semeadura podem ser estratégias de manejo no controle de invasoras. Palavras-chave: competição, Phaseolus vulgaris, plantas infestantes, Amaranthus viridis, Raphanus raphanistrum. ABSTRACT INTERFERENCE BETWEEN WEED SPECIES AND TWO BEAN CULTIVARS IN TWO TIMES OF SOWINGBrazil is the world's largest producer of bean, but weed interference can cause yield losses between 15 to 80% due several factors such as bean cultivar and weed species in the area. The objective of this study was to evaluate the effects of six weed species on growth and productivity of two bean cultivars, in two sowing seasons. It was observed that the dicot plants cause more interference in the crop, especially Amaranthus viridis and Raphanus raphanistrum. All cause losses in bean yield except Eleusine indica that was less competitive. The ´Rubi´ bean cultivar is more productive and competitive than ´Carioca´, and the higher production is achieved during the drought sowing season. The choice of cultivar and correct season for sowing may be management strategy as in weeds control.

Phytosociological Survey of Weeds in Cultivars of Common Beans With Different Types of Growth in the North of Minas Gerais

“…The species from the Amaranthus genus can cause great losses because they have a high initial growth vigor, efficient root system and seed dormancy, and they can also host plant pathogens (Carvalho and Christoffoleti, 2008). Barroso et al (2010), in a study that assessed competitiveness of several species of weeds on beans, in two sowing periods, saw that A. viridis showed to be the most aggressive among all, causing harm in the growth and development of beans, with reductions that reached 80% in the final productivity of the crop. According to Lorenzi (2008), the species from the Amaranthus sp.…”

Atrazine Reduces the Critical Period of Weed Interference on Narrow Row Corn

“…As a function of the duration of the coexistence period, the interference periods can be estimated: PBI (period before interference), TPIP (total period of interference prevention) and CPIP (critical period of interference prevention), according to Pitelli and Durigan (1984). The duration of these periods is dependent on management conditions, such as fertilization (Bressanin et al, 2013), irrigation (Adigun, 2005), seeding date (Barroso et al, 2010), crop system (Horta et al, 2004), etc. Application of residual herbicides (such as atrazine) can also affect the CPIP, mainly by altering the local weed community.…”

Comunidade infestante e sua interferência no feijoeiro implantado sob plantio direto, na safra de primavera

“…Esse fato é decorrente, entre outros fatores, da interferência de plantas daninhas (Teixeira et al, 2009), que pode representar reduções de até 80% na produtividade de grãos (Barroso et al, 2010), sendo 20 a 30% do custo total de produção da cultura referente ao controle dessas plantas (Silva et al, 2000).…”