Selected isolates of Pseudomonas fluorescens (Pf1-94, Pf4-92, Pf12-94, Pf151-94 and Pf179-94) and chemical resistance inducers (salicylic acid, acetylsalicylic acid, DL-norvaline, indole-3-carbinol and lichenan) were examined for growth promotion and induced systemic resistance against Fusarium wilt of chickpea. A marked increase in shoot and root length was observed in P. fluorescens treated plants. The isolates of P. fluorescens systemically induced resistance against Fusarium wilt of chickpea caused by Fusarium. oxysporum f.sp. ciceri (FocRs1), and significantly (P = 0.05) reduced the wilt disease by 26-50% as compared to control. Varied degree of protection against Fusarium wilt was recorded with chemical inducers. The reduction in disease was more pronounced when chemical inducers were applied with P. fluorescens. Among chemical inducers, SA showed the highest protection of chickpea seedlings against wilting. Fifty two- to 64% reduction of wilting was observed in soil treated with isolate Pf4-92 along with chemical inducers. A significant (P = 0.05; r = -0.946) negative correlation was observed in concentration of salicylic acid and mycelial growth of FocRs1 and at a concentration of 2000 microg ml(-1) mycelial growth was completely arrested. Exogenously supplied SA also stimulated systemic resistance against wilt and reduced the disease severity by 23% and 43% in the plants treated with 40 and 80 microg ml(-1) of SA through root application. All the isolates of P. fluorescens produced SA in synthetic medium and in root tissues. HPLC analysis indicated that Pf4-92 produced comparatively more SA than the other isolates. 1700 to 2000 nanog SA g(-1) fresh root was detected from the application site of root after one day of bacterization whereas, the amount of SA at distant site ranged between 400-500 nanog. After three days of bacterization the SA level decreased and was found more or less equal at both the detection sites.

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Mangoes (Mangifera indica) are rich in phenolic acids as detected by high-performance liquid chromatography. The phenolics have prominent medicinal properties. Among six important commercial mango cultivars (Deshi, Langra, Chausa, Mallika, Dashahari and Amrapali) tannic acid was maximal in Mallika, while gallic acid was maximal in Chausa and all other varieties. Caffeic acid was maximal in Langra followed by Chausa and Amrapali. Many of the pharmacological properties attributed to mango might be due to the presence of phenolic acids in fairly significant amounts.

The antifungal activity of bergenin against some plant pathogenic fungi, namely, Alternaria alternata, A. brassicae, A. carthami, Fusarium udum, F. oxysporum f.sp. ciceri, Curvularia lunata and Erysiphe pisi, was studied. Bergenin as its monosodium salt was effective against all the fungi and the effective dose for complete inhibition of spore germination varied from 15 mg mL ¹1 for F. udum to 125 mg mL ¹1 for E. pisi. Experiments on the effect of bergenin on powdery mildew development under glasshouse conditions revealed that it can control powdery mildew of pea at 2000 mg mL ¹1 by postinoculation treatment, the results being comparable with those of carbendazim (1000 mg mL ¹1 ) and wettable sulfur (2000 mg mL ¹1 ). It affected hyphal elongation and the number of primary and secondary branches.