Application of bio-pesticide with plant growth promoter made from oligo-chitosan

Aino, Masataka*; Matsuura, Katsunari*; Nagasawa, Naotsugu; Yoshii, Fumio; Taguchi, Mitsumasa; Sato, Katsuya; Narumi, Issei

Chitosan is a linear polysaccharide composed of randomly distributed -(1-4)-linked D-glucosamine and N-acetyl-D-glucosamine. By -irradiation of chitosan in diluted solutions, low molecular weight chitosan (oligo-chitosan) can be obtained. Oligo-chitosan has potential use in agriculture. In this study, the possibility of oligo-chitosan as a plant growth promoter in tomato was investigated. The combination of oligo-chitosan and bio-pesticide was totally ineffective when tomato was treated at same time. On the other hand, the suppression effect against the pathogen significantly increased when tomato was treated with oligo-chitosan one day before transplant to soil contaminated by the pathogen. This result strongly suggests that oligo-chitosan enhances pathogen resistance in tomato seedling treated with bio-pesticide.