Chitin Amendments for Control of Meloidogyne arenaria in Infested Soil. II. Effects on Microbial Population

The effect of chitin on soil microflora and on nematodes was studied in microplots containing a sandy loan [pH = 6.0 and organic matter content 1% (w/w)] infested with Meloidogyne arenaria (Neal) Chitwood. Ground chitin was added to soil at rates of 0-4.0% (w/w). The chitin was allowed to decompose for 10 weeks, during which time soil samples were collected every 15 days. After 10 weeks, soil from each plot was transferred to the greenhouse and planted with 'Summer Crookneck' squash (Cucurbita pepo L.) to assess degree of root galling caused by the nematode. Chitin treatments at rates of 0.4% and above reduced root galling; however, at rates 0.8%, chitin amendments were phytotoxic to the plants. Chitin amendments at rates of 1% and above resulted in an increase in pH, conductivity, nitratenitrogen, ammoniacal-nitrogen and chitinase activity. Fungal populations were stimulated by chitin amendments at rates of 1% and above. Elements of a mycoflora previously associated with parasiti