 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Monitoring Insecticide Resistance Development in Beet Armyworm, Spodoptera exigua (H?bner) (Lepidoptera: Noctuidae)) ผู้เขียน: Md. Abdullah, Ouab Sarnthoy,  ดร.ศิริพรรณ ตันตาคม, รองศาสตราจารย์ , Somchai Isichaikul, ดร.สุดาวรรณ เชยชมศรี สื่อสิ่งพิมพ์:pdf AbstractField collected larvae of beet armyworm, Spodoptera exigua (H?bner) were reared and evaluated for resistance against cypermethrin 10 EC, neem extract (Azadirachtin 0.1%) and Bacillus thuringiensis Berliner var. kurstaki (53,000 SU per mg) for 12 generations under laboratory condition by using leaf dip bioassay. Cypermethrin showed LC50 value of 251 ppm at F1 generation and decreased gradually to onward generations resulting LC50 value of 90 ppm at F12 generation for non-selection, whereas LC50 increased rapidly with a value of 8625 ppm at F12 generation under selection pressure. Neem extract exhibited LC50 value ranging from 3.98 ppm to 9.99 ppm for non-selection, whereas under selection pressure LC50 ranged from 4.38 ppm to 13.04 ppm throughout the generations. Bacillus thuringiensis var. kurstaki showed LC50 value which ranged from 7.3 ? 106 SU/L to 15.9 ? 106 SU/L for non-selection, and selection for resistance monitoring gave LC50 value ranged from 7.6 ? 106 SU/L to 73.9 ? 106 SU/L . Compared with non-selection strain, selection strain exhibited 95.83-fold, 1.44-fold and 5.6-fold increase in the LC50 for 12 generations against cypermethrin, neem extract and Bacillus thuringiensis var. kurstaki, respectively. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Cypermethrin Insecticide Residues in Vegetable Soybean, Glycine max (L.) Merrill, at Different Days of Pre-harvest Interval) ผู้เขียน:Md. Abdullah, Ouab Sarnthoy, ดร.สุรัตน์วดี จิวะจินดา สื่อสิ่งพิมพ์:pdf AbstractThe experiments were conducted to investigate cypermethrin insecticide residues in vegetable soybean at different days of pre-harvest interval for two growing seasons. Soybean pods were collected at 0, 1, 3, 5 and 10 days after last application with cypermethrin. Residues were extracted from pods and determined using gas liquid chromatography with an electron capture detector. Cypermethrin when applied at the rate of 100 g ai/ha using a knapsack sprayer showed a mean residue level of 0.71 and 0.52 mg/kg at 0 and 1 day, respectively, in dry season (December- February) whereas the residues were 1.62 and 1.17 mg/ kg at 0 and 1 day, respectively, in early wet season (April-June). A pre-harvest interval of 3 days was found safe (0.42 mg/kg) for consumers in dry season whereas early wet st season soybean exhibited residue level of 0.48 mg/kg at 10 day which fell below maximum residue limit of 0.5 mg/kg as prescribed by Food and Agriculture Organization/World Health Organization. Therefore, a pre-harvest interval of 10 days should be considered for cypermethrin residues in vegetable soybean to avoid any health risk of consumers. The dissipation rates of cypermethrin on soybean pods were more or less similar at the same days for both seasons which was 70% (based on 0 day) at 10 days. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Efficacy of Cypermethrin, Neem Extract and Bacillus thuringiensis for Controlling Insect Pests of Vegetable Soybean) ผู้เขียน:Md. Abdullah, Ouab Sarnthoy, Somchai Isichaikul, ดร.ศิริพรรณ ตันตาคม, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractField experiments were conducted during dry and wet seasons (1999-2000) at Kamphaeng Saen Campus of Kasetsart University, Nakhon Pathom, Thailand to evaluate the efficacy of cypermethrin 10 EC, neem extract (Azadirachtin 0.1%) and Bacillus thuringiensis var. kurstaki (53,000 SU/mg) in controlling the major insect pests of vegetable soybean. Melanagromyza sojae, Spodoptera litura, Spodoptera exigua, Helicoverpa armigera, Lamprosema indicata, Etiella zinckenella and Bemisia tabaci were the most abundant species in both seasons. Insecticides were sprayed at 10 days interval until harvest. Cypermethrin showed significantly better control among the treatments. Neem extract moderately suppressed the insect pests with statistically significant efficacy over the control. B. thuringiensis var. kurstaki showed less efficacy than neem extract but exhibited statistically significant efficacy over the control in most cases. Highest yield was recorded in cypermethrin treated plot (9.83 t/ha) followed by neem extract (8.39 t/h), B. thuringiensis var. kurstaki (7.98 t/ha) and control (6.22 t/ha) in dry season whereas yields were 5.83, 4.83, 4.0 and 2.83 t/ha for cypermethrin, neem extract, B. thuringiensis var. kurstaki and control in wet season, respectively. Additionally, Menochilus sexmaculatus and spider were found less in cypermethrin treated plots whereas in other treatments they were significantly higher in number. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Comparative Study of Artificial Diet and Soybean Leaves on Growth, Development and Fecundity of Beet Armyworm, Spodoptera exigua (Hubner) (Lepidoptera : Noctuidae)) ผู้เขียน:Md. Abdullah, Ouab Sarnthoy, ดร.สุดาวรรณ เชยชมศรี สื่อสิ่งพิมพ์:pdf AbstractAn artificial diet and soybean leaves were used in rearing the larvae of beet armyworm, Spodoptera exigua (Hubner) (Lepidoptera : Noctuidae) in laboratory condition. The artificial diet was composed of soaked mungbean, baking yeast, methyl paraben, sorbic acid, ascorbic acid, casein, choline chloride, agar, vitamin, formalin and distilled water. Survival of larvae on artificial diet (96.67%) was higher than those reared on soybean leaf (63.64%). Weight of larvae and pupae reared on artificial diet were significantly higher than those of the larvae and pupae fed with soybean leaves. The larval and pupal periods of those fed with artificial diet were 15.7 ? 0.84 and 6.73 ? 0.51 days respectively, whereas, those fed with soybean leaf were 18.65 ? 0.83 and 8.5 ? 0.52 days respectively. The average number of eggs laid was 577.9, when the larvae were reared on artificial diet. However, it was 472.5 when the larvae were reared with soybean leaf. The female and male life spans were 14.6 and 11.4 days on artificial diet and were 13.1 and 10.2 days with soybean leaf. Without feeding, the adult showed a life span of 6.29 ? 1.42 and 5.3 ? 0.66 days in artificial diet and soybean leaf respectively. Three consecutive generations were reared on artificial diet. Pupal ratio from larvae was found closer among the generations. The sex ratio was more or less similar in the first and second generations but in the third generation males number increased considerably (1:1.72). |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Effects of planting times and plant densities of top-shoot cuttings on multiplication of breeder seed potato) ผู้เขียน:Md. Abdullah Al Mamun, Abdullah Al-Mahmud, Mohammad Zakaria, M. Mofazzal Hossain, Md. Tofazzal Hossain สื่อสิ่งพิมพ์:pdf AbstractTop-shoot cuttings were planted with the whole tuber (as a control) at different dates using three spacings at the Horticultural Research Farm of Bangabandhu Sheikh Mujibur Rahman Agricultural University to evaluate the performance of top-shoots as planting material and to determine the optimum time of planting and the optimum spacing for top-shoot cuttings as planting material for breeder seed production. The survival of top shoot cuttings was more than 97.8% irrespective of the planting time and plant spacing. Significant variations were found among the treatment combinations for plant height at 45 and 60 days after planting (DAP), foliage coverage at 45 and 60 DAP, number of branches per plant, number of tubers per plant, individual tuber weight, tuber yields per plant and per hectare yield. The highest mean yield (46.57 t/ha) was produced by whole tubers planted on 10 November with 50 10 cm spacing which was similar to whole tubers planted on 1 November with 50 10 cm spacing. On the other hand, plants from top-shoot cuttings yielded 34.82 t/ha in T3S2 followed by T1S1 (33.34 t/ha), T3S3 (30.70 t/ha). The total yield of potato increased 122.8% from a single, early crop due to taking two repeated cuttings compared with 89.6% from a single late crop. Early planting of top-shoot cuttings with closer spacing (50 10 cm and 50 15 cm) is recommended for the multiplication of breeder seed potato. |