Effect of soil amendment with chitin on pea wilt caused by Fusarium oxysporum f. pisi

SUMMARY Chitin applied to soil naturally infested with F. oxysporum f. pisi greatly lessened the severity of wilt in Onward peas, sown at the time the chitin was applied to the field. In the glasshouse, different pea varieties sown in the field soil 8 months after the chitin was applied were protected equally against infection by any of the three races of the fungus. The severity of wilt decreased with increasing amounts of chitin added to the soil. Applying chitin to artificially inoculated soil a month before pea seedlings were planted in pots also greatly diminished the severity of wilt. Adding chitin to soil decreased the population of Fusarium and increased the number of actinomycetes. Many of the actinomycetes were antagonistic towards Fusarium.