Studies of tomato yellow leaf curl viral disease in some districts in the Central region of Ghana

Abstract

Tomato yellow leaf curl viral disease (TYLCV) is a destructive disease of tomato in Ghana. The study was conducted during the 2013 minor and 2014 major cropping seasons to determine the knowledge of farmers and their agronomic practices they carry out to manage TYLCV disease in three districts in the Central region, screening of thirty six tomato genotypes against TYLCV disease for a possible tolerant variety and phenotypic and molecular evaluation of selected tolerant genotypes at coastal and forest agro ecological zones. Three tomato producing centres (Effutu municipality, Komenda-Edina-Eguafo-Abirem (KEEA), and Mfantseman district) were selected. Ten farmers were interviewed for awareness. Their farms were assessed for their disease incidence and severity in each of the districts. The highest incidence and severity mean scores of TYLCV disease were recorded at KEEA (52.9±2.7, 26.89±1.2), followed by Effutu (49.5±1.19, 25.29±0.9), and Mfantseman (42.1±2.7, 21.41±0.8) respectively. The awareness of farmers of the presence of the disease was very high (92.6%). About 55.6% of the farmers managed the disease by using synthetic insecticide. Out of the 36 genotypes tested only three (K213, K005 and K100) showed mild symptoms whereas the others showed moderate to severe symptoms. Yield correlated negatively but significantly with incidence and severity of the disease (-0.07 ≥ r ≤ -0.47; P < 0.05). Though PCR revealed the presence of TYLCV DNA in K005 and K100, they consistently showed mild symptoms and gave high yields (>8 t ha-1) at both agro ecological zones. There was no complete resistance following molecular screening.Tomato yellow leaf curl viral disease was prevalent at the study area though less severe, and genotypes K213, K005 and K100 were highly tolerant to TYLCV infection.