Irradiated Chitosan to Decrease Immature Fruit Drop and Increase Bigger Longan Fruit

Longan is a fruit crop in northern Thailand and the most cultivated areas are in the northern part. There is usually an excessive amount of longan production during harvest season. However, longan farmers have experienced a below averaged small fruit problem or immature fruit drop after pollination. These problems usually cause a decrease in production and value of the longan. Longan farmers have been suffering from the loss which leads to a lack of circulating fund and an increase in debts.

          Mr. Jamreon Katkaew, a lecturer and Head of Technology Clinic Unit, Rajamangala University of Technology, Chiang Rai, was aware of the problems occurring to the longan farmers. This led to a concept of using irradiated chitosan which is a substance developed in the outer hard shells of shrimps or crabs. This substance is biodegradable and safe for humans, animals and the environment. This work originally belongs to Dr. Prattana Kilsuwan from Thailand Institute of Nuclear Technology: TINT. Chitosan has not been used only in agriculture, but also in fisheries and livestock, including the food industry, beauty, medical, and the environment. The difference with this type of chitosan, in general, is that it is produced using gamma irradiation. This method helps to shorten the molecules in chitosan which results in better absorption by plants. Gamma irradiation also sterilizes contaminates in chitosan which helps to prevent transmitting disease to plants. In addition, it is non residual which is safe for users, animals, and the environment. Most importantly, it stimulates the growth of trees and seeds.

          To transfer this knowledge to the public, Technology Clinic Unit invited Dr. Prattana Kilsuwan from Thailand Institute of Nuclear Technology to be a guest speaker on the topic of irradiated chitosan. The talk was held in three locations including: Ban Wiang How, Wiang How Sub-district, Pan District; Ban Nong Tum, Rung Than Sub-district, Pan District; and Huay San Don Jun, Pa Kor Dam Sub-district, Mae Lao District, Chiang Rai Province. The aim of the knowledge transfer was to enable famers, communities, and the public to develop agriculture in their households, increase agricultural production and profits.