Possibility of recovering fusarium wilt affected eggplants by Trichoderma

The efficacy of Trichoderma suspension on the recovery of fusarium wilt infected eggplant was studied at Bangladesh Agricultural University Farm during July 2014 to April 2015. Suspension of Trichoderma asperellum CP (IPM 33) (5.8×107 CFU ml-1) was applied to rhizosphere soils of eggplants @ 0, 20 and 40 ml plant-1. Fusarium oxysporum f. sp. melongenae was inoculated to flowering and fruiting stages of healthy plants by soil drenching method 48 hrs before and after application of Trichoderma suspension. Observations were made on the severity and recovering of wilting. The eggplant variety BAU Begun 1 was found resistant to fusarium wilt while other two varieties BAU Begun 2 and Dohazari G showed susceptible reaction. Pre-inoculation application of Trichoderma @ 40 ml plant-1 significantly reduced the severity of the disease. The vulnerability to fusarium wilt was higher at flowering stage of eggplant. Thus, the experimental results have opened up a possibility of using Trichoderma suspension over conventional farming inputs for sustainable and organic production of eggplant.Int. J. Agril. Res. Innov. & Tech. 7 (1): 38-42, June, 201

RAPD analysis of Sclerotium rolfsii isolates causing collar rot of eggplant and tomato

Eight isolates of Sclerotium rolfsii from four strategically geographical sites of Bangladesh were characterized and their cultural properties like average linear mycelial growth, colony colour, colony consistency, growth pattern and sclerotia formation were studied. Isolates varied in mycelial growth and other growth characteristics and were grouped into three. The highest linear growth was displayed by S8. DNA concentration of eight isolates varied from 1150-7200 ng/?l. DNA fingerprinting by RAPD prompted the grouping of isolates. Selected 3 primers generated 20 bands with size ranging from 100-1500 bp. Out of the 20 bands, 9 bands (45%) were polymorphic and 11 bands (55%) were monomorphic among the eight isolates of Sclerotium rolfsii. The co-efficient of gene differentiation (Gst) was 1.000 reflecting the existence of high level of genetic variations among the 8 isolates. The lowest genetic distance and highest inter isolate similarity was found in S1 and S2 which would be homogeneous. The highest genetic distance and lowest inter isolate similarity found in S3, S7 and S3, S8 pair which would be most divergent isolates. The cluster analysis also revealed that S3, S7 and S8 belong to different clusters. All five varieties of eggplant and tomatoes were graded as susceptible when inoculated with eight isolates. Plant mortality 93.33% was recorded in S4, S6 and in S8. Considering the isolate factor the most virulent isolate would be S8 whereas the less virulent isolate would be S2 and S7. Host plant of S8 was tomato collected from Thakurgaon. S2 and S7 were collected from BAU farm and Dinajpur and host plants were lentil and tomato respectively. It is evident that Sclerotium rolfsii from Thakurgaon on host tomato is more virulent.Int. J. Agril. Res. Innov. & Tech. 6 (1): 47-57, June, 201

Possibility of recovering fusarium wilt affected eggplants by Trichoderma

The efficacy of Trichoderma suspension on the recovery of fusarium wilt infected eggplant was studied at Bangladesh Agricultural University Farm during July 2014 to April 2015. Suspension of Trichoderma asperellum CP (IPM 33) (5.8×107 CFU ml-1) was applied to rhizosphere soils of eggplants @ 0, 20 and 40 ml plant-1. Fusarium oxysporum f. sp. melongenae was inoculated to flowering and fruiting stages of healthy plants by soil drenching method 48 hrs before and after application of Trichoderma suspension. Observations were made on the severity and recovering of wilting. The eggplant variety BAU Begun 1 was found resistant to fusarium wilt while other two varieties BAU Begun 2 and Dohazari G showed susceptible reaction. Pre-inoculation application of Trichoderma @ 40 ml plant-1 significantly reduced the severity of the disease. The vulnerability to fusarium wilt was higher at flowering stage of eggplant. Thus, the experimental results have opened up a possibility of using Trichoderma suspension over conventional farming inputs for sustainable and organic production of eggplant.Int. J. Agril. Res. Innov. & Tech. 7 (1): 38-42, June, 201

Soil supplementation with Si, B and Zn and their synergetic effects in reducing severity of wheat blast (Magnaporthe oryzae Triticum)

Wheat blast (Magnaporthe oryzae Triticum) in Bangladesh and South America is recognized as one major limiting factor of wheat production. Its control using chemical pesticides raises concerns about food safety and pesticide resistance, which have dictated the need for alternative blast management approach, nutrient supplementation could be an ecofriendly alternative. Experiments were carried out under confined net house condition for two consecutive cropping seasons. Single doses of the nutrients (Si, B and Zn) were incorporated during soil preparation. Plants of the wheat blast susceptible variety BARI Gom-26 were inoculated with spores (1 x 107 spores ml-1) of Magnaporthe oryzae Triticum at blast vulnerable pre-heading stage of 52 days age. Typical wheat blast symptoms of spike bleaching from top to downward appeared on sight 14 days after inoculation i.e., 66 days age of the crop. Incidence and severity of blast bleaching of spike were scored for four times starting from 68 days age @ three day’s interval. None of the nutrients could stop the incidence of blast on wheat; however, some nutrients reduced the blast incidence significantly. Solo application of Si, B and Zn or combination of two caused significant reduction of spike bleaching. With the mixed application of Si, B and Zn, > 47% reduction of wheat blast severity was obtained. The results revealed that the soil application of silicon, zinc and boron had a synergistic effect on the intensity of blast disease of wheat

Soil supplementation with Si, B and Zn and their synergetic effects in reducing severity of wheat blast (Magnaporthe oryzae Triticum)

Wheat blast (Magnaporthe oryzae Triticum) in Bangladesh and South America is recognized as one major limiting factor of wheat production. Its control using chemical pesticides raises concerns about food safety and pesticide resistance, which have dictated the need for alternative blast management approach, nutrient supplementation could be an ecofriendly alternative. Experiments were carried out under confined net house condition for two consecutive cropping seasons. Single doses of the nutrients (Si, B and Zn) were incorporated during soil preparation. Plants of the wheat blast susceptible variety BARI Gom-26 were inoculated with spores (1 x 107 spores ml-1) of Magnaporthe oryzae Triticum at blast vulnerable pre-heading stage of 52 days age. Typical wheat blast symptoms of spike bleaching from top to downward appeared on sight 14 days after inoculation i.e., 66 days age of the crop. Incidence and severity of blast bleaching of spike were scored for four times starting from 68 days age @ three day’s interval. None of the nutrients could stop the incidence of blast on wheat; however, some nutrients reduced the blast incidence significantly. Solo application of Si, B and Zn or combination of two caused significant reduction of spike bleaching. With the mixed application of Si, B and Zn, > 47% reduction of wheat blast severity was obtained. The results revealed that the soil application of silicon, zinc and boron had a synergistic effect on the intensity of blast disease of wheat. Int. J. Agril. Res. Innov. Tech. 11(2): 76-84, Dec 202

RAPD analysis of Sclerotium rolfsii isolates causing collar rot of eggplant and tomato

Eight isolates of Sclerotium rolfsii from four strategically geographical sites of Bangladesh were characterized and their cultural properties like average linear mycelial growth, colony colour, colony consistency, growth pattern and sclerotia formation were studied. Isolates varied in mycelial growth and other growth characteristics and were grouped into three. The highest linear growth was displayed by S8. DNA concentration of eight isolates varied from 1150-7200 ng/?l. DNA fingerprinting by RAPD prompted the grouping of isolates. Selected 3 primers generated 20 bands with size ranging from 100-1500 bp. Out of the 20 bands, 9 bands (45%) were polymorphic and 11 bands (55%) were monomorphic among the eight isolates of Sclerotium rolfsii. The co-efficient of gene differentiation (Gst) was 1.000 reflecting the existence of high level of genetic variations among the 8 isolates. The lowest genetic distance and highest inter isolate similarity was found in S1 and S2 which would be homogeneous. The highest genetic distance and lowest inter isolate similarity found in S3, S7 and S3, S8 pair which would be most divergent isolates. The cluster analysis also revealed that S3, S7 and S8 belong to different clusters. All five varieties of eggplant and tomatoes were graded as susceptible when inoculated with eight isolates. Plant mortality 93.33% was recorded in S4, S6 and in S8. Considering the isolate factor the most virulent isolate would be S8 whereas the less virulent isolate would be S2 and S7. Host plant of S8 was tomato collected from Thakurgaon. S2 and S7 were collected from BAU farm and Dinajpur and host plants were lentil and tomato respectively. It is evident that Sclerotium rolfsii from Thakurgaon on host tomato is more virulent.Int. J. Agril. Res. Innov. & Tech. 6 (1): 47-57, June, 201