Crotalaria-African leafy vegetable integrated cropping technology to control root knot Nematodes: A crop protection approach

Pest infestation can cause up to 30% leafy vegetable damages worldwide. Different pests are involved in such damages. One such common pest are the root knot nematodes. They damage the plant by colonizing its roots and causing root galls that affect nutrient and water uptake. They feed on the plant roots, thereby causing ports of entry to other secondary pests like bacteria and fungus. Vegetable producers control such pest using chemical nematicides that leave residues in the soil, cause pollution to the environment, at times are ineffective and are expensive to the smallholder farmers.

Crotalaria, an indigenous vegetable, when grown as an intercrop, aliquot solution, a pre-plant before bringing in the main crop, or as a soil amendment, has a capacity to suppress the population of nematodes by inhibiting their growth and development. This is by exuding some chemicals such as monocrotalline that are antagonistic to the root knot nematodes. The introduction of this technology could lead to a sustainable, effective, environmentally friendly, easy to apply and cheap strategy of nematode control in a vegetable cropping system.

I have at this point screened ten different Crotalaria species using the four application methods (preplant, soil amendment, aliquot solution, intercrop) and was able to identify the species Crotalaria Intermedia as the best one in inhibiting and suppressing the populations of root knot nematodes in a cropping system. It caused 75% reduction in the level of damage by nematodes when compared with untreated fields (at 0.5% level of significance). I was able to roll the technology out to over 100 farmers in western Kenya. However, this represented only 5% of the ALV farmers in Kenya. Therefore, I require funds to multiply the Crotalaria spp., then undertake demonstrations and workshops to train farmers of these important technologies. My target aims at covering the western, Eastern, Rift Valley and Central Kenya regions where cropping is done.

Expected outcome

The outcome of this technology adoption will lead to increased incomes especially for women and youth in the society which then reduces poverty, enhances human health through direct consumption of nutritious vegetables and indirectly through supplies to the hospitals, and improved livelihoods through economic empowerment.

Hillary Cheruiyot, Kenya