A resistant pepper used as a trap cover crop in vegetable production strongly decreases root-knot nematode infestation in soil

Root-knot nematodes are causing serious economic losses of vegetable production. Actual agroecological control solutions are not effective enough to control this pest or are difficult to implement in farms. There is little knowledge on the use of crops to trap nematodes in protected cultivation systems. Therefore, we tested a resistant pepper as a trap crop for root-knot nematodes over 4 years in a commercial farm and an experimental station in Southern France. The effects of pepper trap crop on plant damages and soil infestation were compared with a sorghum cover crop. We also surveyed 28 local vegetable farmers for their interest concerning the possible use of the pepper trap crop. Our results show that nematode infestation of the soil decreased by 99 and 80%after the first and second implementation of the trap crop. The gall index measured on Swiss chard decreased from 2.5 to less than 1 after 4 years. Respectively, 21 and 36 % of farmers found the cropping system completely and partially acceptable. The most interested farmers were those having sufficient labor and available land in summer. Farmer criticisms were higher nursery costs and planting duration, versus sorghum. Overall, this is the first design of a cropping system using a resistant cultivar as a dead-end trap crop for root-knot nematodes. The process used, moving from a genetic construct to agronomic innovation through an interdisciplinary and participatory approach, holds promise for scientists seeking new integrated pest management approaches to increase the sustainability of agriculture.