ABSTRACT
Aiming to evaluate the survival of Macrophomina phaseolina subjected to different soil covers, two experiments were conducted in a greenhouse, in a completely randomized design, 5 x 2 factorial arrangement, with five covers (Brachiaria brizantha, Pennisetum glaucum, Crotalaria spectabilis, polyethylene film and bare soil) and sterilized and unsterilized soil. In the first experiment, the plants were grown in pots and desiccated for subsequent planting of the cowpea, while in the second experiment the culture was sown after the first cultivation. In both experiments, each pot received, at 10cm depth, on the day of planting, four fabric bags containing 10 grams of M. phaseolina inoculum each, of which two were removed at 30 days after planting and the other two were removed at the end of the culture cycle for subsequent plating and determination of the survival. Daily maximum and minimum soil temperatures were also monitored. The treatments of soil covered with straw mulch had lower temperature rise in relation to soil covered with polyethylene film and without cover, which raised the temperature up to 5.9 and 3.9 °C, respectively, relative to the soil covered with P. glaucum straw. The soil covered with polyethylene film and the soil without cover had higher M. phaseolina survival rates, while the soil covered with P. glaucum straw had the lowest rate. Increased survival was observed in the unsterilized soil.
Keywords
Vigna unguiculata (L.); Soil cover; Root pathogen
