P. C. Trivedi

Nematicidal, Fungicidal and Bactericidal Activities of Manganese (II) Complexes with Heterocyclic Sulphonamide Imines.

Some manganese(II) complexes derived from different sulphadrugs and heterocyclic ketones have been prepared. These complexes have been characterized on the basis of elemental analyses, molecular weight determinations, conductivity measurements, infrared, ESR and magnetic measurements. The spectral data suggest that the ligands act in a monobasic, bidentate manner coordinating through nitrogen atom. A high spin tetrahedral geometry around this metal has been proposed on the basis of magnetic and spectral studies. The isolated products are coloured solids, soluble in DMSO, DMF and MeOH. All the complexes are monomeric in nature as indicated by their molecular weight determinations and conductivity measurements in dry DMF show them to be non-electrolytes. All the ligands and their corresponding complexes have been screened for their fungicidal, bactericidal and nematicidal activities.

BIOLOGICALLY POTENT HETEROCYCLIC SULPHONAMIDE IMINES AND THEIR MANGANESE (II) COMPLEXES

Imines derived from different sulphadrugs and heterocyclic ketones and their Μη (II) complexes have been synthesized and characterized by their elemental analysis, molecular weight determinations, conductance and magnetic measurements. A high spin tetrahedral geometry around this metal ion has been proposed on the basis of magnetic and spectral studies. The unimolar and bimolar reactions of hydrated manganese acetate and chloride with monobasic, bidentate heterocyclic ligands resulted in the formation of the coloured solids which are soluble in DMF and DMSO. The molecular weight determinations indicate them to be monomers and their conductivity measurements in dry DMF show them to be non-electrolytes. All the ligands and their corresponding complexes have been screened for their fungicidal, bactericidal and nematicidal activities.

Screening and Characterisation of Pseudomonas fluorescence: A Biological Control Agent against Wilt Fungus in Cajanus cajan (L.) Millsp.

About 310 Pigeon pea (Cajanus cajan (L.) Millsp.) rhizobacteria were isolated from cultivated soils of North-East India (Alwar district, Rajasthan). Among the total isolates, 25 isolates were confirmed as Pseudomonas fluorescence based on the biochemical tests, such as arginine hydrolysis, catalase activity, production of fluorescing compounds, gelatin liquefaction and growth at 4°C and 42°C. Their antifungal activity against wilt fungus Fusarium udum (strain of pigeon pea) was examined in vitro and in vivo. Survivality of the isolates under stress conditions of temperature and pH was examined. Five strains (BISR-E, BISR-T, BISR-V, BISR-X and BISR-Y) gave maximum temperature tolerance and four strains (BISR-B, BISR-C, BISR-D and BISR-H) could survive under variable pH range 4–10. Twelve isolates of P. fluorescence were exhibited strong antifungal activity against F. udum. Zone of inhibition was measured. Twelve isolates were observed with more than 30% RI value with maximum RI value recorded in strain BISR-W and BISR-N (42.0%). Net house pot studies screening results revealed that 17 isolates (BISR-A, BISR-B, BISR-C, BISR-D, BISR-E, BISR-G, BISR-H, BISR-I, BISR-K, BISR-L, BISR-N, BISR-O, BISR-P, BISR-R, BISR-U, BISR-W and BISR-X) were observed as good plant growthpromoting rhizobacteria and biological control agents. Among these strains, isolate numbers BISR—B, BISR-F, BISR-K, BISR-N, BISR-O, BISR-P, BISR-W and BISR-X were proved themselves superior isolates having good biocontrol potential to manage F. udum in Pigeon pea plant and to enhance plant growth parameters to a significant level. Out of 25 isolates, 20 isolates (BISR-A, BISR-B, BISR-C, BISR-D, BISR-F, BISR-G, BISR-H, BISR-I, BISR-J, BISR-K, BISR-L, BISR-M, BISR-N, BISR-O, BISR-P, BISR-Q, BISR-R, BISR-S, BISR-T and BISR-V) could produce siderophore.