Efficacy of Some Insecticidal Treatment Combinations for the Management of Flea Beetle and Leaf Folder of Mungbean
K N Islam, M M Islam, M M Uddin, and M M H Khan
The most effective way to manage insect pests is by using a combination of insecticides rather than using them separately. The objective of this study was to assess the effectiveness of insecticidal treatment combinations against flea beetle (Phyllotreta nigripes) and leaf folder (Cnaphalocrocis medinalis) of mungbean during late Rabi season 2018. The mungbean variety, BARI Mung-6 was grown in the field and five treatment combinations viz., TC1 = Nitro 505EC (Chlorpyrifos + Cypermethrin) + Bioneem plus 1EC (Azadirachtin), TC2 = Voliam flexi 300SC (Thiamethoxam + Chlorantraniliprole) + Bioneem plus 1EC (Azadirachtin), TC3 = Nitro 505EC (Chlorpyrifos + Cypermethrin) + Tracer 45SC (Spinosad), TC4 = Voliam flexi 300SC (Thiamethoxam + Chlorantraniliprole) + Tracer 45SC (Spinosad) and TC0 = Untreated control (water spray) were set in randomized complete block design (RCBD) with four replications. Insecticidal treatment combinations were applied at vegetative, flowering and podding stages of mungbean. All the treatments showed significantly different performance against flea beetle and leaf folder. TC4 was the most effective combination for the reduction of flea beetle population which was followed by TC2. On the other hand, TC3 significantly reduced the leaf folder population which followed by TC4. The highest yield (1589.63 kg ha-1) and maximum (1.60) marginal benefit cost ratio (MBCR) were obtained from TC4. It can be concluded that TC4 and TC3 were more effective among the insecticidal treatment combinations for management of flea beetle and leaf folder of mungbean, respectively.
Pest Status of Coconut Mite at Different Places in Barishal
M A Monim, M Ahmad, M A Haque, S N Alam and K N Islam
The coconut eriophyid mite was reported to cause damage in coconut homesteads at different places in Barishal. The pest status of A. guerreronis Keirfer was conducted during the month of February to May 2016 and 2017 in selected places in Barishal to documents the pest status of infested coconuts. The infestation of coconut eriophyid mites on the basis of percent plant infestation and coconut infestation was more in Bakergonj ranged between (Lakutia, 72.94 to Bakergonj, 91.44%), in the year 2015-2016. During the year 2016-2017 of coconut infestation was more in Rahmatpur ranged between (Sikerpur, 79.60 to Rahmatpur 91.40%). However, the pest’s status was the pooled mean of both years during 2015-2016/2016-2017 of coconut infestation was more in Bakergonj ranged between (Sikerpur, 77.08 to Bakergonj, 90.34%). The infestation level of coconut eriophyid mites on the basis of different places during the years 2015-2016/2016-2017 percent coconuts infestation as well as on the basis of coconut infestation was highest in Bakergonj (90.34%) followed by Rahmatpur (89.52%), Kalikapur (85.80%), Dehergoti (83.67%), Barisal Sador (83.54%), Joyshree (82.99%), Banaripara (82.65%), Punksha (81.78%), Lakutia (81.61%) and the lowest Sikerpur (77.08%). The grade wise infestation of coconuts confirms the severity of coconut eriophyid mite infestation at Bakergonj, where the infestation started much earlier than in rest of the places (25.29%) Grade I, (29.57%) Grade II and Barisal Sador, (39.04%) Grade III in 2015-16, at Banaripara, (36.25%) Grade-I, Lakutia (35.84%) Grade-II and Rahmatpur (52.04%) Grade-III. During the years 2015-2016/2016-2017 at Banaripara (28.21%) Grade I, Lakutia (30.08%) Grade II and Rahmatpur (45.42%) Grade III .
Effect of Levels of Rhizoctonian solanacearum Infected Seeds of Ginger on Wilt Incidence and Yield Loss
M M Islam, M I Faruk, A Hannan, M G F Chowdhury, and A N M E Karim
Ginger (Giniber officinalae Rosc.) is an important cash crop of Bangladesh. Bacterial wilt caused by Ralstonia solanacearum is the most important disease of the spice crop. The present experiment was conducted to assess the effect of different levels of seeds (rhizomes) infection with R. solanacearum on wilt incidence, germination and yield loss. The infection levels maintained in the experiment were 0, 5, 10, 20, and 100% and farmer’s saved seeds. The experiment was conducted in three consecutive years. The incidence of bacterial wilt, reduction in germination and yield loss of ginger were higher under higher levels of seed infection. Same trends in the results of the experiment were observed during three consecutive years. Average data of three consecutive years showed that wilt incidence was only 8.3% when R. solanacearum free seeds were planted and 10.3% at 5% infected seed. Disease incidence was 83.3% in 100% infected seed, 63.0% in farmer’s saved seed and 36.7% in 20% seed infection. The average seed germination ranged 67.0-9.01%. The highest germination was found under 100% healthy seed and the lowest in 100% infected seed. The yield of ginger varied 2.6 to 17.7 t/ha. The highest yield was recorded from 100% healthy seed and the lowest from 100% infected seed. The yield decreased with the increase of seed infection level. The highest yield loss (85.02%) was recorded from 100% seed infection followed by farmers saved seed (67.58%) and 20% seed infection (37.2%). The lowest yield loss of 3.5% was recorded from 5% seed infection followed by 10% seed infection showing 18.73%. The findings of the present study are in agreement with the findings of many other researchers.
Seed Health Effect on Phomopsis Blight and Fruit Rot Disease of Eggplant Caused by Phomopsis vexans
M M Islam, M T Hossain, M Afroze, M R Humauan and M A Wadud
Phomopsis blight and fruit rot caused by Phomopsis vexans is an important disease of eggplant (Solanum melongena L.) in Bangladesh. It decreases the production of eggplant to a great extent. The present research work was conducted to assess the effect of different levels of seed infection on phomopsis blight and fruit rot disease and yield of eggplant based on physical seed sorting at Plant Pathology Field, Bangladesh Agricultural Research Institute (BARI), Gazipur, Bangladesh during 2017-2018, 2018-2019 and 2019-20 cropping seasons. The levels of seed infected were 5, 10, 20, and 100%. Each level represented a treatment. Farmers saved seeds and apparently healthy seeds (0% infection) were also included which served as two controls. It was found that healthy seed effectively control the Phomopsis blight and fruit rot disease of eggplant. Same trend of the results was observed in all three consecutive years. In case of three years average, healthy seed showed the lowest disease incidence (8.33 %) whereas the highest disease incidence (84.33%) was observed in 100% seed infection. The highest yield of 44 t/ha of eggplant was found in treatment with 100% healthy seed. The highest disease incidence with lowest percentage of germination and yield were observed in 100% seed infection. The yield decreased with the increase of percent seed infection. The maximum yield incidence of disease and lowest yield were observed in 100% seed infection. The yield loss increased with the increase of percent seed infection.