Root-knot nematode management using chitin rich fish industry by-product in organic brinjal cultivation

Root-knot nematode, Meloidogyne incognita is a major silent enemy in organic brinjal cultivation. Root-knot nematodes are sedentary vascular endoparasites that feed on plant roots and form galls that interfere with the uptake of water and nutrients in brinjal. This led to stunted plant growth and economical damages up to 80% on it. Effective management of root-knot nematode by using synthetic nematicide is detrimental to non-target organisms and the environment. Therefore, this research was conducted to explore the nematicidal effect of chitin amendments viz. shrimp and crab exoskeleton powder against M. incognita. Aqueous industry waste of shrimp and crab exoskeleton were selected and cleaned. Sun-dried exoskeletons were ground into fine powder by mortar and pestle separately. Five grams of each exoskeleton powder were mixed with potting media and allowed to decompose for one week. Two weeks old brinjal plants were planted and inoculated with 5 mature females per pot. Experiments were carried out under Complete Randomized Design. Root-knot index scale as 0-5, plant shoot and root fresh, as well as dry weight, were taken. Data were analyzed using SAS 9.1 software and DMRT was performed to find out the best treatment combination among the treatment at P >0.05. The findings revealed that all the chitin amendments treated plants exhibited a significant reduction in the extent of galls (p <0.05) which indicates chitin amendments have the ability to suppress the infestation of M. incognita. The knot-index was 2 and significant in comparison to untreated control (root-knot index 5) in crab exoskeleton powder treated plant. The growth rate of brinjal was significant in crab and shrimp exoskeleton powder treated plants (P <0.05). Maximum dry shoot weight was achieved in crab exoskeleton powder amended brinjal (4.46±0.35g) followed by shrimp exoskeleton powder (2.66±0.31g) over untreated control (1.39±0.48g). Crab exoskeleton powder treated plant dry root weight (0.02±0.01g) suppressed than shrimp exoskeleton powder (0.05±0.01g) and control (0.14±0.05g) treatment. Based on the findings, it could be confirmed that crab and shrimp exoskeleton powder amendment effectively controlled M.incognita. This finding suggests that the application of chitin is a compatible tactic of organic brinjal production.