SEASONAL CHANGES AS IT AFFECTS THE INCIDENCE OF VIRAL AND FUNGAL DISEASES OF TOMATO

The experiment was carried out at the National Horticultural Research Institute, Ibadan, Nigeria during the 2009 and 2010 cropping season to examine the incidence of common fungal and viral diseases affecting tomato crop during the rainy and dry season. The experimental design was a Randomised Complete Block Design with four replications. During the rainy season, tomato seeds were sown in the nursery in May and the seedlings transplanted to the field 4weeks after sowing and during the dry season, tomato seeds were sown in December 2009 and transplanted 4 weeks after sowing. The incidence of fungi, virus or mixed fungi and virus diseases was recorded fortnightly starting from 2 to 10 weeks after transplanting in each season. In both the rainy and dry seasons, the incidence of mixed virus and fungi diseases was low during the early growth stage and increased as the plant developed. The most prevalent type of disease during the rainy and dry seasons was the viral disease. The diseased plants showed significant reduction in all the growth and yield attributes examined but there was no significant difference between the early infected and the late infected plant in the growth and yield attributes except for the plant height and the fruit weight. However, the healthy plant had a significantly higher (p < 0.05) growth and yield attributes compared with those with early and late disease infection.