Interferência de plantas daninhas na cultura da palma forrageira

Abstract

The Brazilian semi-arid region presents limiting conditions for forage production during the dry season and, therefore, species such as forage cactus (Opuntia spp.) should be established, which have morphophysiological mechanisms that allow them a greater tolerance to drought. In this sense, the research must support solutions to local problems in the management of forage palm and, thus, the crop can express its maximum productive potential. However, some information is still incipient, such as the issue of weed management. In this context, the objective was to determine the interference of weeds in the 'Gigante' forage cactus crop in semi-arid conditions of Guanambi-BA. The study consisted of weed control and coexistence periods in the palm crop, both at 0, 30, 60, 90, 120, 150 and 600 days after planting (DAP), totaling 14 experimental treatments. For the control treatments, forage cactus remained free from weed interference until the determined periods, and for the treatments in collusion, the crop remained under coexistence from planting until the periods described. Green and dry mass yields were determined and the period before interference (PAI), total period of interference prevention (PTPI) and critical period of interference prevention (PCPI) of weeds in cactus forage were calculated. It was found that for green mass productivity the PAI was 16 DAP and the PTPI was 116 DAP according to the adjusted model. Therefore, the PCPI is between 16 and 119 DAP, that is, the period in which the crop must remain free from competition with the weed community. Regarding the dry mass productivity, the PAI values were 16 DAP and the PTPI was 66 DAP, that is, PCPI is between 16 and 66 DAP. The productivity of green mass related to the coexistence treatment of weeds throughout the cycle reduced 83% compared to the treatment kept completely clean. Thus, it is essential to manage weeds within the establishment PCPI, as competition with weeds is extremely harmful during this period.