No abstract

Entomopathogenic fungi Metarhizium species are generally employed to manage the soil-dwelling stage of insect pests, and are known for their rhizocompetency property. Since this fungus is typically recommended for use in soil, it could potentially be investigated as a bioinoculant to reduce abiotic stress, such as salinity, along with improved plant growth promotion. Salt stress tolerance potential of native Metarhizium isolates was evaluated based on mycelial fresh weight, dry weight, and spore yield. All the isolates were found to tolerate NaCl concentrations (50 mM, 100 mM, 150 mM, 200 mM, 250 mM, and 300 mM) supplemented in the culture medium. Metarhizium anisopliae (AAUBC-M15) and Metarhizium pinghaense (AAUBC-M26) were found to be effective at tolerating NaCl stress up to 200 mM NaCl. These two isolates were analyzed in vitro for plant growth-promoting traits at elevated salt concentrations (100 and 200 mM NaCl). No significant effect on IAA production was reported with the isolate M. pinghaense (AAUBC-M26) (39.16 µg/mL) or in combination with isolate M. anisopliae (AAUBC-M15) (40.17 µg/mL) at 100 mM NaCl (38.55 µg/mL). The salinity stress of 100 mM and 200 mM NaCl had a significant influence on the phosphate solubilization activity, except in the co-inoculation treatment at 100 mM NaCl. The isolates were positive for ACC deaminase enzyme activity. An increase in salt concentration was accompanied by a steady and significant increase in chitinase enzyme activity. Total phenolics (149.3 µg/mL) and flavonoids (79.20 µg/mL) were significantly higher in the culture filtrate of Metarhizium isolates at 100 mM NaCl, and gradual decline was documented at 200 mM NaCl. M. pinghaense (AAUBC-M26) proved to be promising in reducing the salt stress in tomato seedlings during the nursery stage. In the pot culture experiment, the treatment comprising soil application + seedling root dip + foliar spray resulted in improved growth parameters of the tomato plant under salt stress. This study shows that Metarhizium, a fungus well known for controlling biotic stress brought on by insect pests, can also help plants cope with abiotic stress, such as salinity.

No abstract

Field surveys were conducted during kharif, 2019 and rabi, 2019-20 to document the fall armyworm (FAW) incidence and damage in maize fields of Anand district of Gujarat. The highest pest incidence and damage was recorded in maize fields of Khambhat taluka of Anand district during the study, while the lowest pest incidence and damage was recorded in Tarapur taluka. During kharif season, the highest pest incidence and damage was recorded in August month and during rabi season, the highest incidence of FAW and its damage in various maize fields was observed in November. It was noticed that the pest incidence was high in kharif season compared to rabi season. The significant differences were noticed with regard to FAW larval population and plant damage levels between the two seasons of the study. During the survey, the natural enemies of FAW viz., Chelonus sp., Coccinellids, Forficula sp., Eocanthecona sp., Cosmolestes sp., Spider (Oxyopes sp.) and Geocoris sp. were recorded. Similarly, Bacillus thuringiensis, Metarhizium (Nomuraea) rileyi and Nucleo Ployhedrosis Virus (NPV) infected FAW larvae were also noticed.

During November 2021, a new invasive thrips Thrips parvispinus was recorded in chilli growing areas of Telangana state. In India, this pest was first reported on papaya (Carica papaya L.) and later on Brugmansia sp. (Solanaceae) and Dahlia rosea Cav. (Asteraceae). Based on these reports and alert received from ICAR-NBAIR, Bengaluru, a survey was carried out on new invasive thrips in major chilli growing areas of Anand district of Gujarat state. Incidence of T. parvispinus was noticed during the survey. The high population of invasive thrips (14-16 thrips/flower/plant) was recorded in chilli fields of Umreth taluka of Anand district and low population (4-6 thrips/flower/plant) was recorded in chilli fields of Anand, Anklav, Borsad, Petald, Sojitra and Tarapur talukas. It is highly essential to adopt IPM based strategies for the management of this invasive pest in chilli.

Bio-efficacy of different biological control agents for the management of chilli fruit rot/anthracnose disease ABSTRACT: Chilli (Capsicum annum L.) an important economic crop worldwide is severely infected by fruit rot disease which may cause yield losses of up to 100%. Although different chemical fungicides are being recommended and used for the management of the disease, biocontrol-based strategy attracts considerable attention and offers great potential of novel biocontrol agents. Further, biological control methods for chilli fruit rot/anthracnose disease have not received much attention. Therefore, an investigation was carried out to assess the efficacy of different biological control agents against chilli fruit rot/anthracnose disease. Antagonistic yeast isolates Pichia guillermondii (Y-12), Hanseniaspora uvarum (Y-73) and Trichoderma asperellum (Th-3), Pseudomonas fluorescens (Pf-1) were tested through seed treatment, seedling dip and foliar spray at concentration of 2 × 10 8 cfu/g. The pathogens viz., Colletotrichum capsici, Alternaria alternata and Periconia byssoides were found associated with fruit rot during the study. Lowest mean disease intensity (MDI), highest disease control (DC) over untreated control was recorded in the treatment P. guillermondii (Y-12) (5.39% MDI, 64.72% DC) and this was found at par with the treatment P. fluorescens (Pf-1) (5.92% MDI, 65.52% DC). However, T. asperellum (Th-3) showed satisfactory results. The present study highlights the efficacy of antagonistic yeast species against chilli fruit rot pathogens and these findings serve as base for further exploration and exploitation of yeast species for eco-friendly management of crop diseases.

No abstract

No abstract