Interferência de Brachiaria Ruziziensis sobre plantas daninhas em sistema de consórcio com milho

Abstract

ResumoCom relação às forrageiras tropicais, a espécie Brachiaria ruziziensis destaca-se pela grande aceitabilidade pelos bovinos quando comparada às demais espécies do gênero Brachiaria, além de excelente habilidade para competir com plantas daninhas. Com isso, o estudo objetivou avaliar os efeitos de densidades de Brachiaria ruziziensis no consórcio com a cultura do milho, em relação ao controle e desenvolvimento de plantas daninhas no sistema de integração lavoura-pecuária. O Regarding tropical forage plants, the specie Brachiaria ruziziensis are prominence for to be most acceptable for cattle when compared with others Brachiaria species, besides the excellent competitive ability with weeds. Then, this study aimed to evaluate the effects of Brachiaria ruziziensis density in intercropping with corn crop, about weeds control and weeds development in the crop-cattle integration system. The experiment was realized during the period between December/2007 to May/2008, in the experimental area of Escola Superior de Agricultura "Luiz de Queiroz", Piracicaba -SP. The treatment was composed in a factorial arrangement, by combination of four Brachiaria ruziziensis density (0, 10, 15 and 20 kg ha -1 ) and three weed species ((Ipomoea grandifolia, Digitaria horizontalis e Cenchrus echinatus), in intercropping with corn crop. The evaluations realized were: weed infestation (density m -2 ), the dry biomass (g plant -1 ) and leaf area (cm 2 plant -1 ). It was noted that Brachiaria ruziziensis reduced the all of weeds infestation evaluated. Also, it was checked that Digitaria horizontalis and Ipomoea grandifolia were the weeds with most difficult control. Key words: Brachiaria, competition, forage plants, crop-cattle integration, Zea mays L. AbstractRecebido para publicação 21/02

Weed suppression in the formation of brachiarias under three sowing methods

“…At 30 DAS, Brachiaria ruziziensis provided the highest yield of dry mass, indicating greater occupation of the area in a shorter period, which will be reflected in the greater vegetation cover on the soil and weed suppression. According to Gimenes Jr. et al (2011), the largest occupation of the area by the forage species promotes greater competition for environmental resources, being more efficient in suppressing weeds. Averages in the same row, followed by the same capital letters, and in the same column followed by the same lowercase letters do not differ by Tukey test at p < 0.05.…”

“…In the Cerrado region (vast tropical savanna ecoregion of Brazil), the genus Urochloa has distinguished itself in the formation of ground cover for direct sowing because it keeps growing during the dry season (Machado & Assis, 2010), plus the ability to excel competition with weeds (Gimenes Jr. et al, 2011). Thus, it becomes important to select species of Urochloa in terms of the productive capacity and which are adapted to the adopted management.…”

Phytosociology in agricultural areas submitted to distinct wintercropping management

“…On the other hand, some other species like I. grandifolia, despite its abundance, frequency or dominance, may be a more troublesome weed. Morphophysiological characteristics of weed species cause shifts in the competitive ability of weeds against crop species (Karam et al, 2006;Gimenes et al, 2009). Gimenes et al (2009) also highlight that the high competitive ability of I. grandifolia comes from its growth habit, usually rolling itself around corn plants and causing trouble for the mechanical harvest of the crop.…”

Volunteer RR® corn management in roundup ready® soybean-corn succession system

“…Additionally, this aspect gains importance as, in this region, the soil organic matter (SOM) mineralization rate reaches high levels in residues decomposition due to the high temperature and microbial activity, reducing the amount of these compounds in the soil (Pacheco et al, 2011). It is important to highlight that this dry matter loss coincides with the onset of the total period to prevent weed interference (Nepomuceno et al, 2007), at which the maximum dry matter accumulation on the soil would be desirable, thereby targeting a possible supressing effect on weeds and volunteer corn.…”

“…If we consider that for grain producers chemical control is the main form of weed management, it becomes clear that it is necessary to obtain information on the potential of sustainable and economic techniques that can be applied in the integrated weed management, like the benefits of no-till farming with the presence of dry matter of cover crops on the soil surface (Gimenes et al, 2011). Thus, one alternative is to combine the use of herbicides with cover crops management.…”