Efeito do óleo de nim no controle alternativo da cercosporiose em mudas de cafeeiro

Abstract

The object of the present study was to examine the efficacy of neem oil on the fungus Cercospora coffeicola in coffee seedlings. Four doses were tested using a randomized block design: 0 (control), 50, 100 and 150 mL/L of neem oil, with six replications. The efficacy of the product was evaluated by measuring Cercospora leaf spot intensity and characteristics of plant height, stem diameter, dry mass of shoot and root dry mass. Data was subjected to variance analysis with polynomial regression. The dose of 100 mL/L neem oil resulted in a lower incidence of Cercospora leaf spot, giving greater protection to the development of seedlings and plants for up to 45 days of growth. From this point on there was an increase in disease incidence, in a similar manner, for all treatments. It is suggested that the number of applications is increased, and the range of applications of neem oil is reduced, so that the product may be used as an alternative control of fungus in coffee seedlings. Maximum values ​of plant height (23.43) stem diameter (2.72 mm), shoot dry weight (1.73 g) and root biomass (0.62 g) were obtained using doses of 80 to 92 mL/Lof neem oil.