Estudo epidemiológico, fatores abióticos e químicos sobre Fusarium guttiforme

Abstract

In the city of Montes Claros, Minas Gerais State, the productivity of pineapple is reduced mainly due to the health of plants. Fusarium wilt is the most important diseases of the culture of pineapple. It has caused great harm to farmers in the countryside in the city of Montes Claros, Minas Gerais State. Thus, the aim in this research was to quantify the incidence of fusarium wilt in four properties in the city of Montes Claros, Minas Gerais State, and the influence of temperature, photoperiod, cow urine lactation and barbatiman extract on the development of isolated of the Fusarium guttiforme, obtained from areas of cultivation, and preventive and curative effect of the cow urine and barbatiman extract on fusarium wilt on seedlings of the pineapple. To evaluate the incidence in the region, they were selected four properties that develop the activity. In each property, they were sampled 10 points, analyzing 500 plants per property. These growing areas were collected and identified four isolates of F. guttiforme to study in controlled conditions. With each isolate (FRU 1, FRU 2, PLA 1 e PLA 2), it set up to twelve experiments, seven in laboratory and five in greenhouse, where it was evaluated the growth rate, number of conidia produced and disease severity. All properties studied showed levels of incidence above of 10% to 64.4%, the highest incidence in the property 2. The isolated fungi showed higher growth rate and conidial production when grown at 25°C and a photoperiod of 12 hours. The data analysis showed that cow urine filtered in Millipore at concentrations of 2 and 4% reduced the mycelial growth of the isolates F. guttiforme PLA 2, FRU 1 and FRU 2. Already the barbatiman extract provided increase in dry weight of the fungus. In general, the severity of the fusarium wilt was not reduced by the use of urine or barbatiman extract.