The efficacy of chitosan to control nematode Aphelenchoides besseyi Christie through seed treatment

Abstract

One of the pathogen that infect rice is white tip nematode (Aphelenchoides besseyi). A. besseyi is a seed-borne pathogen that can cause yield losses 30% to 50%. To overcome this problem, it is necessary to have an effective, efficient, and environmentally friendly control method. The purpose of the research was to study effectiveness of chitosan in controlling white tip nematodes. The experimental design used in this research was completely randomized design. The chitosan concentrations used in this experiment were 0% (control), 0.25%, 0.5%, 0.75%, and 1%. Seeds of each treatment were soaked for 15 min. Each treatment was replicated 5 times, with 25 seeds being used for each replication. Observations including the most effective soaking period, seeds germination, nematodes population, and symptom of morphological damage caused by nematodes. Observations of seed viability were carried out using paper rolls test and directly counting population of nematodes using stereo microscope. The best treatment concentration was determined by % seeds germination and lowest nematodes population. The result showed that chitosan with concentration 0.25% was effective to control A. besseyi and not significantly different with hot water treatment which is an effective control method to control A. besseyi to date. The treatment was also did not adversely affect to seed germination.