http://localhost:8080/xmlui/handle/123456789/6 Fri, 24 Apr 2026 13:49:43 GMT 2026-04-24T13:49:43Z http://localhost:8080/xmlui/handle/123456789/504 EFFECTIVENESS OF NEWER CHEMISTRY INSECTICIDES AGAINST CITRUS LEAFMINER (Phyllocnistis citrella) INFESTING JARA LEMON IN SYLHET REGION NANDI, MOHON The study on the effectiveness of newer chemistry insecticides against Citrus leafminer (Phyllocnistis citrella) was conducted in the farmer’s Jara lemon field at Bagerkhal under Fatehpur Union, Jaintapur Upazilla, Sylhet during January to August, 2016. The insecticide treatments were imidacloprid (Sapta 70 WG) (T1) applied at 0.5 g L-1 of water, bioneem plus (Azadirachtin 1 EC) (T2) applied at 1 ml L-1 of water, spinosad (Tracer 45 SC) (T3) applied at 1.25 ml L-1 of water, chlorfenapyr (Intrepid 10 SC) (T4) applied at 1 ml L-1 of water and untreated control (T5) with four replications. The treatments were randomly assigned to each replication and applied at 20-day intervals. Data of leaf infestation were collected from four canopies of one tagged plant. Each of four canopies was selected respectively from north, east, west and south direction of the tagged plant. The numbers of infested leaves were counted at 20-day intervals. The infestation rate was calculated from the mean data of four replicates for each treatment. The results revealed that highest leaf infestation reduction (22%) was obtained from the plant treated with bioneem plus (Azadirachtin 1 EC) (T2) followed by spinosad (Tracer 45 SC) (T3) (29.25%). The results indicate that bioneem plus and spinosad are most effective for the management of leafminer infesting Jara lemon. Bioneem plus treated plants offered highest fruit yield of Jara lemon (1.82 t ha-1), closely followed by spinosad (1.71 t ha-1). As regard to economic analysis, the highest Marginal Benefit Cost Ratio (MBCR) (9.55) was obtained from the treatment bioneem plus (T2), closely followed by spinosad (T3) (8.21). Based on crop protection level and economic returns, bioneem plus and spinosad may be recommended for the management of leafminer in Jara lemon. Thu, 01 Dec 2016 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/504 2016-12-01T00:00:00Z http://localhost:8080/xmlui/handle/123456789/503 DETERMINATION OF EFFECTIVE DOSE OF CLOVE POWDER FOR THE MANAGEMENT OF PULSE BEETLE (Callosobruchus chinensis L.) INFESTING CHICKPEA AT LABORATORY CONDITION DEBNATH, RONI A study was conducted to determine the effective lower dose(s) of clove powder against the pulse beetle, Callosobruchus chinensis L. on chickpea seeds kept in Petri Dishes, Laboratory of Entomology, Sylhet Agricultural University, Sylhet during the period from April to August, 2016. The effectiveness of different doses of clove powder as seed protectant was assessed at 1, 3, 5, 7, 9, 11 and 13 g kg-1 of chickpea seeds on the basis of adult mortality (%), total number of eggs laid (egg laying capacity), adult emergence (%) and seed weight loss (%) caused by the pulse beetle. Clove powder treated seeds did not host any egg on their surface and no adult was emerged when they were treated with 9, 11 and 13 g kg-1 of chickpea seeds. Seed weight loss was lowest (0.00%) at 11 and 13 g kg-1 of chickpea seeds, whereas the highest adult mortality (100%) was recorded at 9 and 13 g kg-1 of chickpea seeds. In contrast, control seeds had maximum number of eggs laid (229.67), adult emergence (77.86%) and seed weight loss (30.38%) with the minimum adult mortality of 6.7%. It was found that total number of eggs laid, adult emergence (%) and seed weight loss (%) were markedly reduced whereas adult mortality increased with increasing the doses of clove powder as seed protectant. Thu, 01 Dec 2016 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/503 2016-12-01T00:00:00Z http://localhost:8080/xmlui/handle/123456789/502 DEVELOPMENT OF EFFECTIVE MANAGEMENT PRACTICES AGAINST POD BORER (Helicoverpa armigera Hubner) IN CHICKPEA ALAM, SANJIDA The study was conducted to develop effective management practices against chickpea pod borer in the research field of Plant Pathology and Seed Science Department, Faculty of Agriculture, Sylhet Agricultural University (SAU), Sylhet from 25 November, 2014 to15 April, 2015. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. There were seven treatments including synthetic insecticides and botanicals. The treatments were lamda-chyhalothrin (Karate 2.5EC) applied @ 1.5 ml/L of water (T1), chloropyriphos + cypermethrin (Nitro 505EC) applied @ 2 ml/L of water (T2), chlorantranilprole + thiamethoxam (Virtako 40WG) applied @ 0.15g/L of water (T3), neem leaf extract (1:4) (T4), biskatali leaf extract (1:4) (T5), marigold leaf extract (1:4) (T6) and control (untreated) (T7). The 1st spray was applied at 50% of flowering stage, 2nd and 3rd sprays were applied at 10-day intervals after the 1st spray. Data on pod damage (%), reduction of pod damage over control (%) and seed yield (t ha-1) was recorded and analyzed statistically. Significant variations in pod damage and seed yield were observed among different treatments. The highest pod damage reduction (72.53%) over control was found from the plots treated with lamdachyhalothrin. The highest seed yield (1.6 t ha-1) and highest Marginal Benefit Cost Ratio (MBCR) (4.60) was also obtained from the same plots treated with lamda-chyhalothrin (T1). The 2nd highest MBCR (3.77) was found from the plots that were treated with neem leaf extract (T4). The results indicate that the use of lamda-chyhalothrin @ 1.5 ml/L of water is biologically effective and economically viable followed by neem leaf extract for the management of chickpea pod borer. Thu, 01 Dec 2016 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/502 2016-12-01T00:00:00Z http://localhost:8080/xmlui/handle/123456789/501 ASSESSMENT OF STORAGE FUNGI OF ONION AND ITS EFFECTS ON FIELD CONDITION AHSANUZZAMAN, MD. Two experiments were conducted to assess purple blotch disease in the experimental field (November, 2015 to April 2016) and association of storage fungi with onion bulb in the laboratory (July, 2016 to October, 2016) of the Department of Plant Pathology and Seed Science, SAU, Sylhet. A total of six onion where four Indian viz. Accession 1, Accession 2, Accession 3, Pusa Red and two deshi varieties Faridpuri and Zitka were used in these experiments. The experiments were arranged in Randomized Complete Block Design (RCBD) with three replications. In field experiment, three Indian accessions were sown in two different times as timely sown and late sown. Purple blotch disease was assessed in the field and disease incidence and severity was recorded at four different times (35 DAT, 50 DAT, 65 DAT and 80 DAT) at an interval of 15 days. Accession-1 showed the highest disease incidence 32.4% in timely sown (17 November, 2015) and 38.0% in late sown (21 January, 2015). Highest disease severity was 15.4% in timely sown and 22.27% in late sown among the accessions tested. Disease development was at the highest level in all the accessions at 80 DAT. All accessions showed significant disease development at aged plant and disease development less at timely sown compared to late sown. Disease development of stored onion bulbs was observed at 45 days of storage (DOS) using all six onions in the laboratory. Three important storage fungi namely Aspergillus niger, Penicillium spp. and Fusarium oxysporum were found to be associated with the onion bulbs that caused black mould, blue mould and Fusarium bulb rot disease, respectively. All onions were found to be susceptible to the storage fungi. The lowest (10.34%) disease incidence was found in Zitka variety where the highest (26.6%) was in Pusa Red variety. Black mould disease showed the highest disease incidence among the three diseases. Alternaria porri the causal agent of purple blotch disease was not found in the stored onion bulb. Percent weight loss was measured at three different time (15, 30, 45 DOS) for all the onions at an interval of 15 days. All varieties were significantly different regarding weight loss at 15 days interval in storage condition. Pusa Red variety showed the highest (35.7%) weight loss at 45 days of storage where the lowest (8.7%) was recorded in Zitka. All Indian onions showed higher weight loss compared to deshi onions. Thu, 01 Dec 2016 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/501 2016-12-01T00:00:00Z