Evaluation of 11 potential trap crops for root-knot nematode (RKN) control under glasshouse conditions

Abstract A preliminary study of the development and growth of lettuce crops trap cropped with 11 trap crops for root-knot nematode (RKN) control was studied under glasshouse conditions in Kadoorie Agriculture Research Centre in Palestine Technical University. Main crop growth parameters were evaluated by measuring the shoot height, lateral root length, wet and dry weight, ash percentage, and chlorophyll content. The total RKNs recovered from both main and trap crops from root systems were counted 6 weeks post RKN artificial inoculation. The first screening of the potential trap crops against RKNs showed a significant reduction in nematode numbers in lettuce and the average number of galls per gram fresh root when trap cropped with canola, B.G. pumpkin, mustard, and vetch cv. 976. No eggs were found by the end of the experiment. These trap crops attracted more nematodes and kept them from infecting the main crop. The effect of these trap crops on the growth and development of the main crop was variable. Trap cropping lettuce with canola, mustard, Armenian cucumber, and bottle gourd pumpkin caused a significant reduction of the total wet weight and dry weight compared with the control. Still, trap cropping did not significantly affect the lateral root length and wet weight. Removing the trap crops from the field after 6–8 weeks could be applied to reduce the competition between the main crop and the trap crops.