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Rhizospheric bacteria are soil bacteria inhabiting the near-root zone, with multifarious activities including the promotion of plant growth, nutrient mobilization, and biological control of pests and diseases. Rhizobacteria produce microbial volatile organic compounds (mVOCs) that can be utilized as biocontrol components against phytopathogenic fungi. Here, we analyzed the mVOCs produced from cotton rhizobacteria and their role in biological control of the fungus Macrophomina phaseolina. Twelve endospore-forming rhizobacterial strains were isolated from the cotton rhizosphere and screened for their biocontrol potential. Three rhizobacterial strains, Bacillus cereus CICR-D3, Bacillus aryabhattai CICR-D5 and Bacillus tequilensis CICR-H3 were evaluated for mVOCs using gas chromatography-mass spectrometry (GC-MS). Major antifungal mVOCs i.e. Benzene, 1, 3-diethyl- and Benzene, 1, 4-diethyl followed by naphthalene, m-ethylacetophenone and ethanone, 1-(4-ethylphenyl) were produced by these strains. The relative abundance of mVOCs released was highest from CICR-D3 followed by CICR-D5 and CICR-H3. Bi-compartmental Petri plate assay against M. phaseolina showed that the CICR-D3 strain was the most effective in inhibiting the mycelial growth (86.70 ± 0.50%), followed by the CICR-D5 (69.27 ± 0.17%) and CICR-H3 (62.84 ± 0.50%) strains. Furthermore, in vivo co-inoculation in a polyhouse revealed that severity of root rot caused by M. phaseolina was reduced by 72.74% in potted cotton plants inoculated with CICR-D3 strain, followed by strains CICR-D5 (69.04%) and CICR-H3 (66.60%). To the best of our knowledge, the specific volatiles are being reported for the first time from native cotton rhizobacterial strains, which provides new insight into cotton rhizobacteria and their antifungal mVOCs as an eco-compatible strategy for cotton root rot management. [ABSTRACT FROM AUTHOR]

The pink bollworm Pectinophora gossypiella (Saundars) (Lepidoptera: Gelechidae) has recently emerged as a serious menace on Bt cotton in India. Extensive roving surveys were conducted in 83 locations spread across 16 major cotton growing districts of Maharashtra State, India to assess the level of pink bollworm infestation in Bt cotton. The dynamics and severity of pink bollworm damage during the different stages of boll development (90–130 days of crop age) were assessed based on random sampling of green bolls, opened bolls and picked bolls per plant and number of locules damaged per boll. Survey results revealed a widespread infestation of pink bollworm on Bt cotton across the surveyed sites in a range of 40–95% which accounts for anticipated yield losses between 20 and 30%. A typical pattern of progressive increase in the level of pink bollworm infestation and intensification of locular damage with the advancement of the crop season was observed. The pink bollworm hitherto was supposed to be under control since the introduction of Bt cotton in India, now it appears to be widespread, especially on Bt cotton throughout the cotton growing areas of Maharashtra State which shares approximately 36% and 25% of the country's cotton area and production, respectively. This article discusses the implications of serious outbreak of pink bollworm infestations in Bt cotton and also suggest measures necessary to mitigate its potential threat to Indian cotton production. The modulation of management practices aimed at manipulation of cotton cropping pattern being followed in the country in general and Maharashtra in particular could strengthen the management of pink bollworm populations effectively. We discuss the practicality of several management options aimed at achieving this goal. [ABSTRACT FROM AUTHOR]

Soil and plant samples from black rot infected fields were processed to isolate wild type Xanthomonas campestris pv. campestris (Xcc) bacteriophages by overlay agar method. Various Xcc strains were employed as indicator hosts. The aim of this study was to isolate and purify potential bacteriophages for their ability to lyse plant pathogenic strains of Xcc in vitro. Bacteriophages were purified and selected for further characterization based on their ability to produce clear lysis on plaque assay. Seventeen strains of pathogenic Xcc were tested for sensitivity to 31 phages isolated during the study. Lysis was graded subjectively as per standard. A virulent phage Xcc9SH3 isolated from soil sample from Lucknow was found to lyse all tested strains of Xcc in vitro. Characterization of Xcc9SH3 was done based on plaque morphology, phage titre, organic solvent sensitivity, effect of temperature and transmission electron microscopy. The size of long noncontractile tail of the phage was 100 nm in length and 10 nm in width with 20 nm diameter of head. The isometric head of the phage predicted to belong to Siphoviridae (dsDNA viruses) family of bacteriophages. These phages may be useful tool in specific and efficient detection and control of Xcc causing black rot disease in cole crops. [ABSTRACT FROM AUTHOR]