Effects of root-knot nematode (Meloidogyne incognita) population densities on the growth of cucumber

Cucumber (Cucumis sativus) is an economically significant crop produced in both open and protected farming. Cucumber cultivation has been associated with root-knot nematodes in different parts of the world. Incidentally, the tropical conditions prevalent in Punjab are highly conducive for root-knot nematode leading to severe losses in yield. In view of this, the effect of seven different inoculum levels of root-knot nematode along with control (no inoculum was added) was studied in two susceptible cultivars of cucumber viz Punjab Naveen and Pant Sanker on plant growth parameters and nematode factors. The studies revealed that there was a significant increase in soil and root population of root-knot nematode in cucumber as the inoculum levels increased. The soil population was observed to multiply by more than two times at inoculum levels of 1000 (RF = 2.93) and 2000 J2/kg soil (RF = 2.06). It showed a decrease in the multiplication of nematodes at higher inoculum levels (5000 J2/kg soil) in both varieties. Growth parameters of cucumber were observed to be significantly affected at different inoculum densities studied. Significant reductions in shoot length, root length as well as shoot weight were observed with an increase in inoculum levels. M. incognita has the capacity to severely impede cucumber development, and delaying or preventing its exposure can greatly reduce yield losses in both open and protected cucumber cultivation. © 2022, Indian Phytopathological Society.