Effect of Pesticides on the Nematode Pathogenic Bacteria, Bacillus macerans In vitro

Abstract

Sensitivity of Bacillus macerans Schardinger, 1905, a potent biocontrolagent of root-knot nematode, to different pesticides was tested in vitro by filter paper disc method. The pesticides were metham sodium, phorate, aldicarb, carbofuran and formalin representing nematicides and HCH (BHC), endosulfan, malathion, quinalphos and carbaryl representing insecticides and agallol, . carbendazim, copper oxychloride, maneb, zineband ziram the fungicides. B. macerans was highly sensitive to metham sodium and formaldehyde with an inhibition zone diameter ranging from 20 to 44 m.m. While aldicarb was slightly inhibitory, phorate and carbofuran were non-inhibitory. All insecticides except quinalphos (1000 ppm only) and carbaryl were non-inhibitory. Among the fungicides tested, the systemic fungicide carbendazim was the safest. Methoxy ethyl mercury chloride, mancozeb, zineb and ziram were toxic to B. macerans. These fungicides showed statistically significant increase in inhibition among the different fungicides.