ANTIFUNGAL activities of cyanobacterial filtrate, compost tea, H 2 O 2 , garlic oil, barnyardgrass root exudates and Premis fungicide were tested against Cephalosporium maydis, the pathogenic fungus of late wilt disease of maize plants. In vitro and two field trials were carried out during 2015 and 2016 growing seasons under disease nursery conditions. In vitro, cyanobacterial filtrate and 30% premis fungicide were the superior treatments, by them linear growth of C. maydis were prevented totally and fulfillment inhibitions (100 %) were resultedwith lowest IC 50 values. Cyanobacterial filtrate and 3% H 2 O 2 were more effective in developing grain germination. Disease incidence showed better efficacy due to use 30 % Premis fungicide followed by 3 % H 2 O 2 with massive disease reductions reached 83.21 and 75.37 %, respectively during 2015 season. Effectiveness of the 3 % H 2 O 2 dose was extended to the 2016 season with 5.11 % disease incidence and 73.39 % disease reduction. For grain productivity, remarkable enhancements in the weights of both 10 ears and 1000 grains due to all treatments compared to control were recorded in both seasons. Due to their antifungal activities, qualitative analysis of Cyanobacterial filtrate and barnyardgrass root exudates was assayed on Gas chromatography mass-spectrum (GC-MS). Malonic acid, 2,3-Butandiol, Hexestrol, 12-Crown-4-ether and cis-Vaccenic acid were the major compounds extracted from the cultured blue-green algae. Whereas, Nadolol, Quinine, α-Methylionol, Phyllocladene, alcohols, acids, phenols and 2,6-dihydroxy benzoic acid were the most abundant antimicrobial agents in the barnyardgrass root exudates.
In the present study, cell-free cultures of four isolates of Rhizobium leguminosarum, an isolate of Azotobacter chroococcum and compost tea were investigated for their biocontrol potential against the root parasitic weed Orobanche crenata. Individual cell-free cultures of Azotobacter chroococcum or Rhizobium sp., dual and mixture of cell-free cultures of Rhizobium spp. or compost tea were applied to infested pots in greenhouse conditions. The treatments showed variable effects on many developmental parameters of both faba bean and broomrape. Significant decrease in the number of broomrape attachments, dry weight of the attached tubercles on faba bean roots and the reduction in percentage of broomrape seed germination were recorded. Compost tea, individual and mixture of R. leguminosarum isolates were more reducing on broomrape germination and growth than A. chroococcum alone did; being the former treatment is the best. The reduction in broomrape incidence by compost tea was due to certain phenotypic mechanisms, which acted alone or in combination. These mechanisms included negative effect of natural stimulant broomrape on seed germination, prevention of radical penetration inside the host roots, parasite yield reduction, and thus increasing the growth and vitality of faba bean. In vitro experiment indicated that seed germination percentage of broomrape was also negatively affected by the combination of root-exudates and compost tea. Radical apexes of the germinated seeds were distorted. These distortions may prevent the radicals to follow up the infestation. In conclusion, the study presents the potential of R. leguminosarum isolates and compost tea in biocontrol of broomrape. More investigations should be carried out with viable bacterial cells on the parasite plant before use in sustainable agricultural systems.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.