Márcio Gledson Oliveira da Silva

Manejo de plantas daninhas na cultura da melancia nos sistemas de plantio direto e convencional

We evaluated strategies for weed management on the production of watermelon in no-tillage and conventional systems, in successive cultivation to the melon crop. The research was carried out in split plots, distributed in the experimental design of randomized blocks. Two cropping systems were evaluated in the plots (no-tillage and conventional tillage) and in the sub-plots were evaluated nine strategies of weed management [covered with polyethylene film, with weeding at 14 days after transplanting (DAT); 14 and 28 DAT, 14 and 42 DAT; 14, 28 and 42 DAT; 28 DAT, 28 and 42 DAT; 42 DAT and control without weeding]. Before the implantation of the experiment, the area was cultivated with melon in the respective cropping systems, the straw mulch being used again in the treatments with no-tillage system, as well as polyethylene film in the treatments with use of this material in two cropping systems. At 14, 28 and 42 DAT and at harvest of watermelon (80 DAT), were assessed the density and dry mass of weeds. The weeds were cut at ground level, separated by species, counted and put into oven with forced air at 65°C until constant weight to determine dry mass. From the watermelon crop were evaluated the number of marketable fruits, total number of fruits, average mass of marketable fruits per plant and average fruit mass (total) per plant and marketable and total yield. The no-tillage system reduced the density and dry mass of weeds, requiring only one weeding between 14 and 42 DAT, whereas in the conventional tillage system two weedings were needed, at 14 and 28 DAT. When the crop was maintained without weeding throughout the cycle, there was a reduction of 100 and 35.7% in marketable fruit yields in conventional and no-tillage systems, respectively. The no-tillage and polyethylene film in conventional tillage system enabled the cultivation of watermelon in succession to the melon crop, reducing weed interference and providing satisfactory productivity.

Production and efficiency of water usage in capsicum crops under notillage and conventional planting systems.

This study aimed to evaluate the effect of no-tillage and conventional planting systems, and of weed- management strategies on water-usage efficiency in capsicum crops. The experiment was carried out at the Universidade Federal Rural do Semi-Arido in Mossoro, Rio Grande do Norte, using a split-plot layout in a randomized block design with four replications. The tillage systems were evaluated in the plots, and three weed-management strategies evaluated in the subplots (soil cover with polyethylene film, and with and without weeds). The density and dry mass of the weeds, the commercial and total productivity, and the daily water consumption were all evaluated. It was found that the no-tillage system reduced the density and dry mass of the weeds in comparison to conventional systems, and the interference of these plants reduced commercial productivity under both planting systems. The strategy of weeds under a no-tillage system, despite a higher water consumption, showed a productivity and efficiency of water usage superior to those of the strategies of polyethylene film both under no-tillage and conventional systems, and of weeds under a conventional tillage system.