Examples

Use of onion-country cv. white spring onion ( Allium fistulosum ) to control bacterial wilt of tomato in the West Indies „

• Types of use of onion-country : introduction into the rotation, incorporation of aqueous extracts, crop association tomato-onion, biofumigation via the burial of onion crop residues. „
• Two modes of action on the incidence of bacterial wilt :
  - direct process: country onion roots emit toxic substances for the pathogenic bacteria.
  - indirect process: by stimulating the microflora of the soil, these microorganisms, by competition or antagonism, exert an unfavorable effect on the pathogenic bacterium.

• Technical itinerary for the tomato-onion crop association : when planting tomatoes, insert an onion-country plant between two tomato plants. The roots of the onion-country should be close to those of the tomato. During this association, the onion-country must remain in place; however, the aerial parts can be cut for consumption or placed on the soil surface (as mulch) to optimize soil biodisinfection.

Other examples 

Fallow after uprooting the orchard and before replanting with citrus fruits to eliminate the nematodes specific to citrus Tylenchulus semipenetrans , appropriate crop sequence such as solanaceae/radish or turnip or peanut (break in the solanaceae nematode cycle) or carrot/ tomato (break in the cycle of carrot whitefly) in Guadeloupe, peas in association with a marigold with nematifuge properties ( Tagetes lucida ) or nematicides ( Tagetes minuta ) in Guadeloupe, rotation with crotalaria to control symphyla in pineapple cultivation in the West Indies, rotation with rattlesnakes and cives to fight against bacterial wilt in solanaceae cultivation in French Guiana.