Evaluation of chemical alternatives to methyl bromide in tomato crops in China

- Use of 1,3-D plus CP was beneficial to the increase of the yield of tomatoes.
- The combination of 1,3-D plus CP is an effective MB alternative in tomato crops.
- Combination of 1,3-D plus CP can be used in integrated pest management programs.

Tomato is a high-value cash crop in China that requires vigorous transplants free of pathogens. However, local tomato growers commonly face heavy root-knot nematode and weed infestations, especially while phasing out methyl bromide (MB). The soil fumigants chloropicrin (CP), 1,3-dichloropropene (1,3-D) and dazomet (DZ) were evaluated at several rates alone and in combination as alternatives to MB soil fumigation in tomato production. Field trials revealed that used alone, CP, 1,3-D and DZ were not comparable to MB in the reduction of Meloidogyne incognita, weeds or increase of tomato marketable yield. Only the combination of reduced rates of 1,3-D and CP which had excellent nematicide efficacy and good to moderate weed control, matched the efficacy of MB. The present data indicate that the combination of 1,3-D plus CP is an efficient MB alternative for managing nematodes and weeds in tomato crops and can be used in integrated pest management programs. To get a better weeds control efficacy, it is recommended to add herbicides to the two fumigants combination.