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Influence of temperature and CO2 levels on growth and development of Plutella xylostella Linnaeus on cauliflower
(Punjab Agricultural University, Ludhiana, 2018) Cheema, Rupinder Singh; Sandhu, Inderpal Singh
The studies on influence of different temperature and carbon dioxide levels on biology, food consumption and nutrional indices of Plutella xylostella Linnaeus on cauliflower were conducted by collecting insect population from two locations viz. Ludhiana and Malerkotla. Study was conducted at six different combinations of temperature and CO2 levels viz. 25:11ºC and 28:14ºC at 350, 400, 450 ppm carbon dioxide concentrations. The incubation period of eggs decreased non-significantly with increase in temperature and CO2 levels in population of both the locations. In Ludhiana population total larval duration, pupal duration, female adult longevity, male adult longevity decreased from 11.68, 4.32, 14.17, 20.51, respectively at 25:11ºC to 10.02, 3.71, 11.14, 16.62 days respectively, at 28:14ºC. Similarly when CO2 levels increased from 350 ppm to 450 ppm total larval duration, pupal duration, female adult longevity, male adult longevity decreased from 11.43, 4.22, 13.85, 20.17, respectively to 10.30, 3.77, 11.37, 16.90, respectively. Whereas fecundity P. xylostella increased significantly from 165.56 to 186.00 eggs female-1 with increase in temperature and from 167.50 to 183.67 with increase in CO2 levels which indicate reduced generation time ultimately more number of generations per year. Similar results were found in Malerkotla population. Likewise food consumption, consumption index, relative growth rate, approximate digestibility, efficiency of conversion of ingested food of third instar larvae of Ludhiana population increased significantly from 5.36, 0.92, 0.47, 50.96, 45.83 to 5.59, 1.20, 0.53, 55.29, 50.71, respectively with increase in CO2 levels from 350 ppm to 450 ppm. Similarly in fourth instar larvae of both the populations, value of food consumption, CI, RGR, AD and ECI increased significantly with the increase in temperature and CO2 levels. Thus it can be concluded that elevated temperature and carbon dioxide and their interactive effect influences the different biological and nutritional indices of P. xylostella.
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Effects of double stranded RNA in Bactrocera dorsalis (Hendel) on guava
(Punjab Agricultural University, Ludhiana, 2018) Simranpreet Kaur; Sandeep Singh
The present study entitled “Effects of double stranded RNA in Bactrocera dorsalis (Hendel) on guava” was conducted in the Fruit Entomology Laboratory, Department of Fruit Science and Fruit Biotechnology Laboratory, School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana during 2016-17 and 2017-18. Evaluation of impact of two genes NOA and V-ATPase D on maggots, pupae and adults of B. dorsalis revealed that these two genes were vital for growth and survival of B. dorsalis. Bacteria (Escherchia coli HT115) expressing dsRNA was successfully delivered to maggots and adults through artificial diet containing 10g agar, 120g sucrose, 10g soya peptone, 40g dry yeast, 1g sorbic acid, 6.6g ascorbic acid, 0.1g ampicillin, 0.03g tetracycline and 1000ml water. Silencing of NOA and V-ATPase D genes resulted in mortality of different life stages of B. dorsalis in a dose-dependent manner. Maximum moratlity was observed in maggot, pupa and adult stages of B. dorsalis after feeding of bacteria expressing dsRNA at 700µl concentration followed by bacteria expressing dsRNA at 350µl and 200µl concentrations for both NOA and V-ATPase D genes as compared to control (bacteria without dsRNA). Silencing of target genes had greater impact at higher concentrations of bacteria expressing dsRNA. Thus, utilization of this novel strategy might help to manage population of B. dorsalis in guava and may further strengthen the Integrated Pest Management module for B. dorsalis in Punjab after carrying out further research on these aspects.
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Estimation of residue of diafenthiuron in brinjal (Solanum melongena L.) and cabbage (Brassica oleracea L. var. capitata)
(Punjab Agricultural University, Ludhiana, 2018) Athulya R.; Kang, B. K.
Supervised field trials were conducted to study the residues of diafenthiuron in brinjal and cabbage following application @ 300 and 600 g a.i. ha-1. The samples of cabbage and brinjal were collected at 0 (2hrs), 1, 3, 5, 7 and 10 days after the second and third application. QuEChERS sample preparation was used for the determination of diafenthiuron residues. All the samples were quantified by High Performance Liquid Chromatography (HPLC) and confirmed by Liquid Chromatograph-Mass Spectrometry (LC-MS). Mean initial deposits of diafenthiuron at 300 and 600 g a.i. ha-1 on brinjal fruits were found to be 0.26 and 0.60 mg kg-1 reached below detectable level of 0.05 mg kg-1 after 5th and 7th day at single and double dosage, respectively. The average initial deposits of diafenthiuron in cabbage were observed to be 0.60 and 1.27 mg kg-1 following third application of diafenthiuron and reduced to below its limit of quantification of 0.05 mg kg-1 after 7 and 10 days at recommended and double the recommended dosages, respectively. Diafenthiuron residue in soil samples, collected from both brinjal and cabbage fields after third application was found to be below detectable level of 0.05 mg kg-1. The half-life value (T1/2) of diafenthiuron in brinjal was calculated to be 1.28 and 1.42 days and half -life in cabbage was 1.88 and 2.15 days at single and double the recommended dosages, respectively. The initial deposits were found to be below MRL of 1 mg kg-1, so one day waiting period is suggested for safe consumption of brinjal and cabbage. Among various household processing methods, cooking removed 100 percent of diafenthiuron residues on brinjal and cabbage in both the treatments.
Open Access
Avoidable crop losses, Economic Threshold Level and management of Helicoverpa armigera (Hübner) in chickpea
(Punjab Agricultural University, Ludhiana, 2018) Akanksha; Ravinder Singh
Field studies were conducted for two years during rabi 2016-17 and 2017-18 to determine the crop losses, to establish economic threshold level (ETL) and to evaluate the efficacy of various integrated pest mangement (IPM) modules for the management of Helicoverpa armigera (Hübner) in chickpea. The avoidable yield loss of 26.27 per cent was observed in chemical method as compared to 19.59 per cent in mechanical exclusion method over unprotected method. The avoidable crop losses due to H. armigera in chickpea var. PBG 7 was recorded to be 73.50 per cent by insect density method with larval population of six larvae per meter row length. The correlation coefficient for the larval infestation level and the per cent pod damage was significantly positive. However, significantly negative correlation was observed between larval infestation level per meter row and seed yield. On the basis of regression analysis and gain threshold, the EIL and ETL were determined to be 2.086 and 1.56 larvae per meter row, respectively. Among the different IPM modules tested for two years, to test the bioefficacy against H. armigera in chickpea, the treatment with three sprays of indoxacarb 14.5 SC @ 66 g a.i. ha-1 was found to be significantly superior over all other biointensive modules and untreated control but was at par with novaluron 10 EC @ 37.5 g a.i. ha-1 > chlorantraniliprole 18.5 SC @ 25 g a.i. ha-1 > emamectin benzoate 5 SG @ 11g a.i. ha- 1. Results of the study revealed that significantly lowest larval population of zero larvae per meter row, lowest pod damage of 1.41 per cent, highest seed yield of 1950 kg ha-1 and highest C:B of 1:6.9 were found in treatment with three sprays of indoxacarb 14.5 SC @ 66 g a.i. ha-1.
Open Access
Physiological influences of pyriproxyfen on whitefly, Bemisia tabaci (Gennadius)
(Punjab Agricultural University, Ludhiana, 2018) Savinderjeet Singh; Chandi, Anureet Kaur
Pyriproxyfen, a pyridine based juvenile hormone analogue with mode of action different from the conventional insecticides, was evaluated for its physiological influences on nymphs and adults of whitefly, Bemisia tabaci (Gennadius) during 2016 and 2017. Various toxicity values i.e. LC30 (0.020, 0.021%) and LC50 (0.043, 0.048%) for first instar nymphs; LC30 (0.026, 0.029%) and LC50 (0.055, 0.060%) for fourth instar nymphs; LC30 (0.031, 0.034%) and LC50 (0.061, 0.069%) for adults were worked out by employing standard methods of bioassay. Significant increase in 50 per cent red-eyed nymph formation (14.00 and 10.50 against 7.40 and 5.90 days in control) and nymphal period (15.20 and 12.20 against 8.50 and 6.80 days in control) was registered under influence of pyriproxyfen. In contrast, when first instar nymphs were treated with pyriproxyfen, there was reduction in adult emergence (49.78 and 50.19 against 76.05 and 79.38% in control); adult longevity (3.70 and 4.40 against 5.80 and 7.40 days in the control); oviposition period (1.70 and 1.90 against 3.10 and 3.20 days in control); fecundity (10.80 and 11.83 against 19.70 and 20.85 eggs in control) and egg hatching (20.74 and 21.82 against 60.11 and 62.28% in control). Inhibition of fecundity (7.73 and 8.44 in treated; 15.48 and 15.83 in control) and curtailed egg hatching (24.56 and 26.90 in treated; 65.10 and 67.70 in control) was ascertained. Mortality of first instar nymphs (47.72 and 45.85%) on lower surface of cotton leaves indicates pronounced translaminar effect in both the years. Significant reduction in the total amino acids, increased level of total sugars and phenols of treated cotton plants could be correlated with lesser whitefly population density. Hence, pyriproxyfen, given to its several lethal and sublethal influences can be used as an effective tool for management of B. tabaci.
Open Access
Biological activity of horticultural mineral oils against thrips and mites on Kinnow
(Punjab Agricultural University, Ludhiana, 2018) Dhaliwal, Rajwinder Singh; Sharma, D. R.
The studies on biological activity of horticultural mineral oils against thrips and mites on Kinnow were carried out at Fruit Research Farm/Old orchard and Entomology Laboratory, Department of Fruit Science, Punjab Agricultural University, Ludhiana, during 2016 and 2017 with the objective to evaluate the biological activity and phytotoxicity of different HMOs against thrips and mites on Kinnow. Eight year old trees of Kinnow were sprayed with five different horticultural mineral oils (HMOs), viz. MAK All Season, Servo, Arbofine, Sparrow 888 Plus and HPHMO at different concentrations (0.75, 1.00, 1.25, 1.50 and 2.00% for efficacy and 3.00 and 4.00% for phytotoxicity) alongwith insecticide/acaricide i.e. triazophos 40 EC and fenazaquin 10 EC as check and untreated control (in which only water was sprayed) at 15 days interval during March, April, May and June with the help of Rocking/Foot pump sprayer. The results on the evaluation of HMOs against citrus thrips, Scirtothrips citri showed that triazophos (0.075%) was found to be the most effective treatment against thrips upto 15 days after spray. All the HMOs at different concentrations three days after spray reduced the thrips population marginally and provided about 40 per cent control of thrips upto seven days after treatment. Similarly, in case of mites, fenazaquin (0.015%) was found the most effective treatment as compared to different HMOs. As in case of thrips, HMOs also reduced the mite population by 40-50 per cent upto seven days after treatment. The results further showed that with the increase in concentration of each HMO, the efficacy against thrips and mites increased. Among different HMOs, Arbofine was found to be numerically better both against thrips and mites. Similar results were also found against predatory mite, Amblyseius spp. where population was reduced marginally with the application of HMOs. The rind scarring of fruits due to thrips and mites also decreased with the application of HMOs. Fruits free from scarring increased from 40.00-49.17 per cent at 0.75 per cent to 64.17-75.83 per cent fruits at 2.00 per cent of each HMO spray as compared to 12.50 per cent in untreated control. It was also found that with the increase in concentration of HMOs, there was an increase in the deformity of the leaves in terms of leaf hyponasty, epinasty and yellowing. Trees treated with 4.00 per cent concentration of HMOs had only 55.00-60.00 per cent normal leaves as compared to 90.00 per cent in untreated control. Thus, it is concluded that with the increase in the concentration of HMOs, though there was an increase in the efficacy against thrips and mites but there was more phytotoxic effect on leaves if the concentration of HMOs is more than 2.00 per cent.
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Diversity of natural enemies and efficacy of biopesticides for the management of Bemisia tabaci (Gennadius) in Bt cotton
(Punjab Agricultural University, Ludhiana, 2017) Khangura, Samreet Singh; Rabinder Kaur
The studies on "Diversity of natural enemies and efficacy of biopesticides for the management of Bemisia tabaci (Gennadius) in Bt cotton" were conducted during Kharif, 2016. The population of whitefly and its natural enemies were comparatively less in sprayed field as against unsprayed fields at Abohar and Muktsar. Among natural enemies of whitefly, Chrysoperla zastrowi sillemi, spiders and coccinnellids were observed in both sprayed and unsprayed fields. Diversity of natural enemies associated with whitefly in the cotton ecosystem was quite less without dominance of any particular specie. Under net house conditions, Neem oil 1 per cent @ 700 and 500 ml/acre (27.11 to 74.43 per cent reduction over control) was most effective in reducing number of nymphs of B. tabaci. It was followed by Metarhizium anisopliae @ 1200 g/acre (27.06 to 58.38 per cent reduction over control). Neem oil 1 per cent @ 700 and 500 ml/acre (32.00 to 67.54 per cent reduction over control) proved to be highly effective in minimising the population of whitefly adults under net house conditions, followed by M. anisopliae @ 1200 g/acre (23.71 to 51.01 per cent reduction over control). In field conditions, the order of efficacy of biopesticides in case of B. tabaci nymphs Neem oil 1 per cent @ 700 and 500 ml/acre (53.95 to 94.61 per cent reduction over control) ˃ M. anisopliae @ 1200 and 1000 g/acre (13.41 to 79.99 per cent reduction over control) ˃ Beauveria bassiana @ 1200, 1000 and 800 ml/acre (12.26 to 77.20 per cent reduction over control) and the order of efficacy of biopesticides in case of B. tabaci adults was Neem oil 1 per cent @ 700 and 500 ml/acre (53.12 to 95.05 per cent reduction over control) ˃ M. anisopliae @ 1200 g/acre (13.15 to 70.04 per cent reduction over control). It was concluded that Neem oil 1 per cent @ 700 and 500 ml/acre and fungal formulations (B. bassiana, M. anisopliae) being safer than chemical insecticides could be included in the IPM of whitefly in the Bt cotton in field condition.
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Bee pollination requirement and honey production potential of broccoli (Brassica oleracea var. italica Plenck) and turnip (Brassica rapa var. rapa L.)
(Punjab Agricultural University, Ludhiana, 2017) Shamsher Singh; Jaspal Singh
The studies on the „Bee pollination requirement and honey production potential of broccoli (Brassica oleracea var. italica Plenck) cultivar Palam Samridhi at Punjab Agricultural University (PAU), Ludhiana and University Seed Farm (USF) Ladhowal, and of turnip (Brassica rapa var. rapa L.) cultivar L-1 at PAU, Ludhiana and USF, Nabha revealed that out of total 13 flower visiting insect species recorded on both the crops, 69.7-70.2 per cent were Hymenopterans, predominantly Apis spp. and these were the most abundant during noon. On broccoli, the foraging intensity of the honey bees was in the order of Apis mellifera>Apis cerana>Apis dorsata>Apis florea while the foraging rate was in the order of A. cerana>A. mellifera>A. dorsata>A. florea. Mean pollen gathering A. mellifera, A. cerana, A. dorsata and A. florea bees ranged between 15.6-34.9, 10.3-22.2, 15.5-31.4 and 15.7-23.2 per cent, respectively. The mean proportion of top foragers was in the order of A. dorsata>A. mellifera>A. cerana>A. florea. The highest mean number („000) of loose pollen grains (17.7) was recorded from A. dorsata followed by that from A. mellifera (14.5) and A. cerana (12.6) at 0900 h while on A. florea (6.8) at 1100 h. Pollination of broccoli by A. mellifera resulted in 359.5 siliquae per plant, 10.5 seeds per siliqua and 3.1 quintal seed yield per hectare whereas there was no siliqua and seed setting under exclusion of pollinators. Five visits of A. mellifera resulted in the highest seed weight per siliqua i.e. 29.4 mg while it was nil when there was no bee visit. A. mellifera was ranked as the most efficient pollinator on the basis of its highest pollination index (3.48) while pollination efficiency of A. mellifera was 16.9. Pollination requirement of broccoli was worked out to be one 10 bee-frame A. mellifera colony per hectare. Mean quantity of nectar production was 560 μg per 25 flowers and the mean sugar concentration of the nectar was 20.6 per cent. Honey production potential of broccoli was 4.0 kg per ha. On turnip, the foraging intensity of the honey bees was in the order of A. mellifera>A. cerana>A. dorsata>A. florea while the foraging rate was in the order of A. cerana>A. mellifera>A. dorsata>A. florea. Mean pollen gathering A. mellifera, A. cerana, A. dorsata and A. florea bees ranged between 16.9-33.8, 10.5-21.3, 16.632.7 and 15.7-23.2 per cent, respectively. The mean proportion of top foragers was in the order of A. dorsata>A. mellifera>A. cerana>A. florea. The highest mean number („000) of loose pollen grains (9.4) was recorded from A. dorsata followed by that from A. mellifera (8.4) and A. cerana (8.0) at 0900 h while on A. florea (3.6) at 1100 h. Pollination of turnip by A. mellifera resulted in 84.5, 44.9 and 263.6 per cent increase in the number of pods per plant, number of seeds per pod and seed yield over exclusion of pollinators. Five visits of A. mellifera resulted in the highest seed weight per pod i.e. 25.9 mg while it was 5.9 mg when there was no bee visit. A. mellifera was ranked as the most efficient pollinator on the basis of its highest pollination index (3.50) while pollination efficiency of A. mellifera was 20.8. Pollination requirement of turnip was worked out to be one 10 bee-frame A. mellifera colony per 2 hectares. Mean quantity of nectar production was 435 μg per 25 flowers and the mean sugar concentration of the nectar was 39.1 per cent. Honey production potential of turnip was 3.5 kg per ha.
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Ovipositional preference and biochemical interaction of whitefly, Bemisia tabaci (Gennadius) with Gossypium species
(Punjab Agricultural University, Ludhiana, 2017) Sukhdeep Kaur; Pandher, Suneet
The present investigation, “Ovipositional preference and biochemical interaction of whitefly Bemisia tabaci (Gennadius) with Gossypium species” was conducted at Punjab Agricultural University Regional Research Station, Faridkot during the year 2016-2017 with three cultivars of Gossypium arboreum and G. hirsutum under multiple and no choice conditions. The results showed significant difference among Gossypium species in terms of settling of whitefly adults and fecundity per unit area. The maximum number of adults per leaf was observed on G. hirsutum var. F 2228 followed by G. arboreum FMDH 9 and FDK 124.Whitefly preferred G. arboreum var. FMDH 9 for oviposition as indicated by results followed by G. hirsutum var. F 2228, significantly different from each other. The minimum number of eggs was observed on G. arboreum var. FDK 124. The trichome density of 13.67 per five mm diameter leaf disc was the highest on the F 2228. Development time on FDK 124 was 19.79 days whereas in case of F 2228, it was 15.5 days. In the second experiment on insecticide induced resurgence, studies indicated that decline in predator population led to upsurge in Bemisia incidence for short period followed by little decline. This decline probably corresponded to eventual reestablishment of natural enemies depending on the persistence of the insecticide in the environment. Total sugars in Fipronil 5 SC treatments were significantly different at different days after spraying as compared to sampling done before first spray and corresponded with maximum resurgence of whitefly in these plots. Increase in total sugars was found in other treatments also with lesser per cent of resurgence but increase was not significantly different from initial sampling. Further, the surveys were conducted in the cotton growing areas of districts Faridkot and Muktsar at fortnightly interval from July 2016 to April 2017. Nearly thirty weed species belonging to different families were abundantly found during cotton season and off season. Ten weed species exhibiting variable symptoms showed positive results by molecular diagnostic technique (Polymerase chain reaction).The six samples were asymptomatic and also carrier of virus during off season. Two weed species Abutilon theophrasti and Achyranthes aspera having nymphs was not the carrier of virus. Twelve species of weeds neither having nymphs nor the virus, were regarded as the casual hosts of whitefly. Among the three weeds Verbesina encelioides, Solanum nigrum and A. theophrasti the total life cycle of male and female of whitefly was highest on Abutilon theophrasti which might be due to longer egg incubation period, first instar duration and adult female longevity.

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