Abstract

An experiment was carried out to find out the effect of Paecilomyces lilacinus on leaf nutrient status, chlorophyll content and photosynthetic efficiency of banana cv. Robusta inoculated with the root-knot nematode, Meloidogyne incognita. Reducfion in nitrogen, phosphorus, potassium and magnesium and increase in calcium content of leaves in banana was noticed in the plants inoculated with M incognita which was directly proportionate to the population of nematodes and the leaf nutrient content was improved by the treatments with the biological agent namely Paecilomyces lilacinus. Highest P. K and Mg contents of 0.24, 4.29 and 0.79 per cent was recorded by the treatment P. lilacinus @30 g/kg of soil applied 60 days after planting which also registered the lowest Ca content of 1.05 per cent. The highest N content of 2.19. per cent was recorded in the treatment with Carbofuran 3G @ 40 g/plant applied at the time of planting. It was found that total chlorophyll and photosynthetic efficiency of leaves of banana decreased due to inoculation of M.incognita. The application of P. lilacinus improved the total chlorophyll and photosynthetic efficiency of infected banana plants which was directly proportionate to the dosage. Among the treatments. P. lilacinus@ 30 g kg-1 of soil applied 60 days after planting registered the highest chlorophyll content (7.697 mg/100 g tissue) and photosynthetic efficiency (0.2237 mg CO2 /sec./m²).

Keywords: Paecilomyces lilacinus, Meloidogyne incognita, Leaf nutrient, Photosynthetic efficiency, Total chlorophyll content