GROWTH AND YIELD RESPONSES OF FIFTEEN CUCUMBER CULTIVARS TO ROOT-KNOT NEMATODE (Meloidogyne incognita)

Abstract

Root-knot nematodes have become a grave menace to the lucrative production of cucumber throughout the world. These nematodes are mainly controlled by applying nematicides, but their use is often associated with hazards. Alternatively, the use of nematode resistant cultivars is considered to be innocuous and economically feasible. For their fitness as nematode-suppressive crops, the reduction in growth and yield parameters of these cultivars must be assessed. As there is little documented data about the effects of Meloidogyne incognita on the damage of cucumber, therefore, in the present study, the effects of M. incognita were evaluated on growth and yield parameters of fifteen cucumber cultivars. M. incognita significantly negatively affected the growth and yield parameters of all the cucumber cultivars. Shoot and root lengths and shoot weights of all the cultivars were significantly reduced as a result of nematode infection. Maximum reductions in these parameters were recorded in highly susceptible cultivars followed by susceptible ones, while the reductions were minimal in resistant followed by moderately resistant cultivars. On the contrary, the infection by M. incognita resulted in an increase in root weights of all the cultivars. The increase was found to be the maximum in highly susceptible cultivars followed by susceptible and moderately susceptible cultivars. Likewise, the minimum increase was observed in the resistant cultivars followed by moderately resistant cultivars. Similarly, significant variations in yield parameters among fifteen cucumber cultivars were also recorded as a result of M. incognita infection. In the case of highly susceptible cultivars, the reductions in yield parameters were maximum, whereas the reductions in resistant and moderately resistant cultivars were found to be minimum. As cultivars Long Green, Marketmore, Pioneer-II, Dynasty and Summer Green experienced no significant damage compared to susceptible cucumber cultivars and therefore, they are approved for cultivation in nematode infested soils.