The use of short cycle crops as trap crops for the control of root-knot nematodes.

The effect of short cycle crops such as lettuce (Lactuca saliva) and radish (Raphanus sativus) to suppress the soil population densities of Meloidogyn e incognita Race 2 was investigated in concrete microplots containing an or ganic soil mix (60% red ferralitic soil and 40% cow dung) in Havana, Cuba. Lettuce and radish crops were grown for 32 and 30 days respectively at high and low initial nematode densities. Thirty to 32 days after planting, plan t root systems were completely removed from the microplots to prevent nemat ode reproduction in those roots and consequent nematode increase in soil. T en percent and 6% of the lettuce. and radish roots, respectively, contained I-nature females with egg masses. Averages of 2 160 and 21 150 J2/m2 were found in the roots of lettuce plants (45/m2) at the lowest and highest infe station level of the roots. Similar results were obtained with the radish t rap crop. The data indicate the importance of completely); removing all sus ceptible roots in order to I educe nematode numbers available to attack a s ubsequent crop. When short cycle crops like lettuce, radish, chinese cabbag e (Brassica raga subsp pekinensis), or Chinese Salt-word (Brassica rata sub sp chinensis) were used to remove nematodes prior to planting a susceptible crop such as tomato (Lycopersicum esculentum), cucumber (Cucumis sativus), or cow pea (Vigna unguiculata), the nematode numbers in soil were decreased by 50% and crop fields Mere increased by 10-20% within 3 to 5 months.