Studies on Population Development on Pulse Grains and Eco-friendly Management of Pulse Beetle on Pigeon pea in Storage
Loading...
Date
2022
Authors
NAKAMBAM, SONALI
Journal Title
Journal ISSN
Volume Title
Publisher
Dr.RPCAU, Pusa
Abstract
In order to study the population development of pulse beetle on different pulse grains and eco-friendly management of pulse beetle on pigeon pea in storage, a series of laboratory experiments were conducted in the Entomology laboratory of Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur, Bihar during the two consecutive years viz., 2020-2021 and 2021-2022. Findings related to different aspects of the present investigation viz., ovipositional preference, adult emergence, mean developmental period, index of susceptibility, per cent and weight loss caused by C. chinensis on different pulse grains, efficacy of various oils, botanicals and insecticides and performance of different storage structures in pigeon pea storage have been outlined below:
For assessment of population development of pulse beetle and quantitative losses caused by pulse beetle on different pulse grains, the trials were conducted on six different hosts (lentil, field pea, green gram, bengal gram, pigeon pea and black gram) replicated four times under Completely Randomised Block Design.
The preference for egg laying by C. chinensis on different pulse hosts revealed that eggs laid per 50 grains ranged from 62.37 to 110.37 eggs/50 seeds and maximum oviposition was recorded on pigeon pea (110.37 eggs/50 seeds) while lowest was observed on lentil (62.37 eggs/50 seeds). Likewise, average egg count/seed was computed which resulted minimum and maximum number of eggs laid on lentil and pigeon pea with values 1.25 and 2.21 eggs per seed, respectively. Subsequently, emergence of adult beetles as well as per cent survival of adults emerged from different host grains recorded highest in pigeon pea with 99.88 numbers and 90.40 per cent while lentil recorded lowest in both the parameters recording 41.13 and 65.34 per cent, respectively.
The development period of pulse beetle (C. chinensis) on six different hosts revealed that shortest mean developmental period of beetles from egg to adult was found in pigeon pea (25.64 days) while beetle development in lentil took longest period (34.76 days). The result on index of susceptibility showed pigeon pea and lentil as the most and least susceptible to C. chinensis with susceptibility index of 7.79 and 4.56, respectively. On the basis of categorization given by Dobie (1974) pigeon pea falls in moderately resistant category while lentil comes under resistant category.
Assessment of grain damage as well as weight loss was carried out at different days interval. Per cent grain damage at 30 days after insect release (DAIR) revealed maximum grain damage in pigeon pea (16.84%) followed by green gram (14.97%), bengal gram (13.49%), black gram (11.77%), field pea (9.51%) and lentil (7.06%). At 60 days after insect release, pigeon pea recorded highest per cent grain damage with 37.62 per cent which was followed by green gram (32.07%), bengal gram (30.78%), black gram (22.71%), field pea (14.51%) and lentil (12.11%). Likewise at 90 and 120 days after insect release, pigeon pea recorded maximum with (60.41, 81.89%), green gram (54.56, 77.16%), bengal gram (50.63, 69.28%), black gram (31.24, 51.95%) and no significant difference was observed between field pea (16.87%) and lentil (15.45%) at 90 DAIR but at 120 DAIR, significant difference was recorded between field pea (31.45%) and lentil (23.83%).
Per cent weight directly correlated with the per cent grain damage in the present findings and there was significant variation among all the host grains. Starting from the initial month (30 DAIR) till 120 DAIR, pigeon pea recorded maximum weight loss followed by green gram, bengal gram, black gram, field pea and lentil. The order of per cent weight loss in all the four months study period is as follows: Pigeon pea (10.94, 17.00, 33.86, 62.63%), green gram (9.33, 15.55, 29.24,56.53%), bengal gram (7.89,13.44, 28.37%), black gram (6.88, 12.50, 20.04, 50.25%), field pea (4.76, 11.21, 14.72, 31.42%) and lentil (3.74, 8.07, 11.80, 17.88%).
Pigeon pea being widely cultivated pulse crop, the efficacy of various grain protectants including oils, botanicals and safer insecticides were assessed with regard to of reduced per cent egg laying, emergence of adult, per cent grain damage and weight loss for a duration of four months at monthly interval (30 to 120 DAIR). The series of experiments consisted of ten treatments including untreated control with three replications under Completely Randomised Block Design (CRBD).
Among all the treatments lowest number of eggs were laid on seeds treated with cypermethrin (10 EC) @ 0.05 ml/kg seeds (11.17 eggs/50 seeds) followed by spinosad (45 SC) @ 4 ppm/kg seeds (20.50 eggs/50 seeds). Among botanicals, lowest oviposition was recorded in mustard oil @ 5ml/ kg seeds (24.67 eggs/50 seeds) and all the treatments proved to be significantly effective in reducing the egg laying of Callosobruchus chinensis and superior over untreated control (98.67 eggs/50 seeds). Based on oviposition data, oviposition inhibition was computed which yielded maximum inhibition in seeds treated with cypermethrin (10 EC) @ 0.05 ml/kg seeds (88.67%) and minimum inhibition was recorded in seeds treated with YBSP @ 5g/kg seeds (39.91%). The data recorded on adult emergence and inhibition of adult emergence revealed that minimum adult emergence (12.93%) and maximum inhibition of adult emergence (84.54%) were recorded on seeds treated with cypermethrin (10 EC) @ 0.05ml/kg seeds while maximum adult emergence and minimum inhibition of adult emergence were recorded on seeds treated with YBSP @ 5g/kg seeds (67.43 and 18.93%).
Efficacy of oils, botanicals and insecticides against C. chinensis infesting pigeon pea indicated that 30 DAIR, seeds treated with cypermethrin (10 EC) @ 0.05 ml/kg seed recorded the least grain damage (by count) with maximum protection of 0.87 per cent while maximum damage was recorded in YBSP @ 5g/kg seed (8.70%). Cypermethrin (10 EC) @ 0.05 ml/kg seed proved to be the most efficient treatment in reducing grain damage till 120 DAIR with 1.19, 2.14 and 3.10% while maximum damage was recorded in YBSP @ 5g/kg seed (17.71, 27.35 and 28.45%) at 60, 90 and 120 days, respectively. Grain damage (by weight) nearly inferred same pattern with the previous grain damage (by count). Cypermethrin (10 EC) @ 0.05 ml/kg seed proved to be the best treatment with significantly less per cent grain damage from 30 DAIR till 120 DAIR. At 30 DAIR, cypermethrin (10 EC) @ 0.05 ml/kg seed recorded 0.53 per cent damage which was on par with spinosad (45 SC) @4 ppm/kg seed (0.84%). Among botanically derived grain protectants mustard oil @ 5ml/kg was the most efficient one in reducing per cent grain damage with 1.28 per cent which was on par with turmeric leaf oil @ 5ml/kg (1.47%). Intermediate protection of grains was provided by seed treatment with garlic extract @ 5% (1.96%), neem oil @ 5ml/kg (2.48%), NSKE @ 5ml/kg (3.85%) and maximum grain damage with least protection was observed in seeds treated with YBSP @ 5g/kg seed (5.94%) followed by YBSE @ 5ml/kg (4.99%). Even after 120 DAIR, cypermethrin (10 EC) @ 0.05 ml/kg seed was the most efficient treatment with 1.99 per cent and seed treatment with YBSP @ 5g/kg seed recorded maximum grain damage (12.57%).
The per cent weight loss also increased consequently with increased in storage period and corresponded with per cent grain damage. At 30 DAIR, cypermethrin (10 EC) @ 0.05 ml/kg seed provided maximum protection (0.54%) against C. chinensis. Among botanicals, mustard oil @ 5ml/kg (1.22%) also provided maximum protection and maximum weight loss was observed in YBSP @ 5g/kg seed (5.86%). All the treatments were found to be superior over untreated control (10.43%). From 60 to 120 DAIR, cypermethrin (10 EC) @ 0.05 ml/kg seed recorded lowest with values (0.65, 1.38, 1.81%) while maximum was observed in YBSP @ 5g/kg seed (14.20, 23.35%, 24.25%). All the treatments were superior over untreated control (10.43, 16.03%, 32.27 and 55.51 %) at 30, 60, 90 and 120 DAIR. YBSP @ 5g/kg seed was found to be on par with YBSE @ 5ml/kg seed and neem oil @ 5ml/kg seed with NSKE @ 5ml/kg seed at 120 days after insect release.
The effect of oils, botanicals and insecticides on germination and seed vigour of pigeon pea seeds were tested at the end of storage period (120 DAIR) and germination percentage varied from 22.67 to 77.00 per cent with minimum in untreated control and maximum in cypermethrin (10 EC) @ 0.05 ml/kg seed. No significant difference was observed between neem oil @ 5 g/kg seed (63.17) and garlic extract @ 5% (62.33%) which was followed by NSKE @ 5 ml/kg seed (59.09%). The lower per cent germination was recorded in YBSP @ 5 ml/kg seed (54.50%) which was on par with YBSE @ 5 ml/kg seed (54.84%) and all treatments were significantly superior over untreated control (22.67%). The data on seed vigour index revealed that maximum was recorded in seeds treated with cypermethrin (10 EC) @ 0.05 ml/kg seed (1600.22) which was statistically on par with spinosad (45 SC) @ 4ppm/kg seed (1584.18) followed by mustard oil @ 5 ml/kg seed (1442.96) and lowest seed vigour index was observed in YBSE @ 5 ml/kg seed (1103.76) followed by YBSP @ 5 g/kg seed (1138.89) as against untreated control (381.96).
For evaluation of the performance of various storage structures against C. chinensis, seven treatments including jute bag as check was taken which was replicated thrice under Completely Randomised Block Design. The data on per cent grain damage, weight loss, germination percentage and seed vigour index were recorded at two months interval i.e., 2 and 4 months after storage (MAS).
At 2 MAS, seeds stored in Polythene lined jute bag (PLJB) provided maximum protection with lowest grain damage (7.64%) and least protection of grain with maximum damage was recorded in jute bag (19.84%) while at 4 MAS, PLJB provided maximum protection with least damage of grains of 9.98 per cent. The next best treatment was recorded in plastic jar (12.16%) followed by earthen pot (14.30%), HDPE bag (16.63%), PP bag (18.46%). Among all the different treatments, least protection of grains was recorded in seeds stored in jute bag (30.91%). Data recorded on per cent weight loss at 2 MAS revealed maximum protection was recorded in pigeon pea seeds were stored in PLJB (3.65%) and maximum weight loss was recorded in jute bag (11.61%) followed by cloth bag (10.20%) and at 4 MAS, lowest weight loss was recorded in pigeon pea grains stored in PLJB (5.05%) and maximum weight loss was recorded in cloth bag (15.29%) and all the storage structures performed better than jute bag (19.05%) taken as check.
The data on germination and seed vigour index of pigeon pea seeds revealed that at 2 MAS, earthen pot performed best with maximum percent germination (91.33%) and was found to be on par with plastic jar (91.17%) and lowest was recorded in jute bag (77.33%) while at 4 MAS, germination percentage ranged from 65.17 to 90.33 per cent with minimum and maximum being recorded in jute bag and PLJB, respectively. At 2 MAS, maximum seed vigour index was recorded in pigeon pea seeds stored in earthen pot (1894.20), followed in decreasing order by PLJB (1877.06), plastic jar (1865.19), HDPE bag (1775.38), PP bag (1743.10), cloth bag (1659.46) and jute bag (1570.78) of which plastic jar, PLJB and earthen pot were on par and PP bag and HDPE bag were statistically similar while at 4 MAS, PLJB and plastic jar were on par and the most effective treatment in maintaining the seed vigour of pigeon pea seeds with values 1919.95 and 1850.77, respectively and all the storage structures were found to be significantly superior over check (1331.82) i.e., jute bag.