Epidemiology of Meloidogyne exigua in an upland coffee plantation in Brazil

Abstract

A 24-month study was conducted in a commercial non-irrigated arabica coffee plantation to assess the influence of air temperature, rainfall and soil moisture content on the epidemiology of Meloidogyne exigua. The second stage juvenile (J2) populations in soil and roots showed clear seasonal fluctuations, with an increase in their levels during the dry months (April through September) and a decrease in the rainy months (October through March). The number of galls/5 g of roots induced by the nematode did not show consistent fluctuations through the seasons, although a path analysis indicated that this variable was negatively correlated to mean air temperature and rainfall, but not correlated to soil moisture content. The results of this study suggest that, in the environmental conditions of south-east Brazil, sampling coffee plantations during the dry months may provide a more accurate assessment of J2 populations of M. exigua than sampling during the rainy season.