INFLUENCE OF TWO NIGERIAN STRAINS OF MOROCCAN WATERMELON MOSAIC VIRUS ON THE GROWTH AND YIELD PARAMETERS OF CUCUMBER (CUCUMIS SATIVUS L.)

Abstract

The effects of two Nigerian strains of MWMV namely MWMV-corand MWMV-lag on growth and yield parameters of cucumber werestudied in two separate experiments. Plants were inoculated singlyand with a combination of both strains at 9 days after planting (DAP)and 21 DAP in a randomized complete block design. Plants inoculatedwith the buffer only served as controls. The results of the studyshowed that infection of cucumber by the virus strains singly and inmixed inoculation led to significant reduction in all the yieldparameters at 9 DAP, with reduction ranging between 41.1% - 66.7%for MWMV-cor, 43.3% – 61.9% for MWMV-lag and 42.7% – 71.8%for mixed inoculation. The results obtained for 21 DAP also revealedthat there were losses of between 17.7% – 36.2 % caused by MWMVcor,between 22.9% – 40.0% for MWMV-lag while losses in the yieldparameters due to mixed infection were between 21.5% – 38.1%. Noapparent synergistic effect was observed with mixed inoculation of thevirus strains on both growth and yield parameters as the valuesobtained for the growth and yield parameters at both inoculation ageswere comparable to those singly inoculated by the two strains. Theresults presented here provide evidence that MWMV strainsconstitute a threat to cucumber production and particularly so by themore virulent MWMV-cor, which caused comparatively greater yieldloses than MWMV-lag. Sourcing for and planting of resistantvarieties of cucumber and preventing early aphid introduction can behelpful.