The effect of seed rate (35, 40, 45, 50 kg/acre), time of sowing (Nov. 1, Nov. 15 and Nov. 30) and methods of sowing (flat and ridge sowing) on the powdery mildew of wheat was studied under the present investigation. Severity of the disease significantly reduced with less seed rate and delayed sowing. Ten fungicides viz., Tilt 25 EC (propiconazole), Folicur 25 EmC (tebuconazole), Folicur 430 SC (tebuconazole 430 SC), Bayleton 25 WP (triadimefon), Amistar Top 325 SC (azoxystrobin + difenoconazole), Amistar Extra 280 SC (azoxystrobin + cyproconazol), Picoxystrobin + Propiconazole 20 EC, Navito 75 WG (trifloxystrobin + tebuconazole), Opera 25 SC (pyraclostrobin + epoxyconazole) and Karathane 48 EC (Dinocap) were tested under laboratory conditions at different concentrations viz., 10 ppm, 25 ppm, 50 ppm, 100 ppm and 200 ppm. These fungicides were also evaluated under field conditions at recommended doses and all of them reduced the disease significantly in comparison to control.
Ascochyta blight caused by Ascochyta rabiei is a serious disease of chickpea world wide. Twenty five Indian isolates of A. rabiei were evaluated for their morphological variability and 91 chickpea cultivars were screened for their reactions to Ascochyta blight. The populations of A. rabiei showed variations in various morphological characters like conidia size and density, colony colour and growth rate. Colonies of the isolates on artificial media were flat, submerged with sparse mycelium. The mycelium was pale cream at first but later turned greyish white or green to greenish dark. In Chickpea dextrose agar (CDA) medium, the isolate AR1 (Delhi) grew the largest followed by the isolates AR14 (Punjab), AR5 (Himachal Pradesh), AR9 (Jammu and Kashmir) and AR20 (Rajasthan) with statistically similar colony diameter at 20 days after incubation. Thus, the growth rate was significantly highest in isolate AR1 (Delhi) followed by the isolates AR14 (Punjab), AR5 (Himachal Pradesh), AR9 (Jammu and Kashmir), and AR20 (Rajasthan). More or less similar growth patterns of the isolates were observed on PDA medium with comparatively less growth as compared to CDA. The size of the conidia in all the isolates ranged from 9.19–12.51 x 3.36–4.32 μm whereas the density of conidia in A. rabiei isolates ranged from 0.5–7.2 x 106 conidia ml−1. Three cultivars namely, ICC 76, ICC 3996 and ICC 15978were identified as highly resistant to Ascochyta blight. Thirty cultivars showed resistant and 14 cultivars showed moderately resistant reactions against the disease. These cultivars may be used for cultivation or resistant breeding programs.
The eggs present in the hard coated cysts of potato cyst nematodes (PCN) Globodera sp hatch out only in the presence of potato (Solanum tuberosum L) root exudates of host plants. Non-availability of host plant along with the application of synthetic chemicals is expected to control this hard coated soil borne pest without much negative impact on the environment. Thus, the effects of seven different two year crop rotations of susceptible (Kufri Jyoti) and resistant (Kufri Swarna) cultivars of potato along with three non-host crops (cabbage-Brassica oleracea, carrot-Dacus carota and radish-Raphanus sativus) of PCN, in different crop rotation combinations were evaluated with an aim to find out the best rotation suitable to manage the PCN population. Effective nematode reduction (47% in 2 years) could be achieved by rotating susceptible potato variety with the resistant (resistant to both G. pallida and G. rostochiensis) one, and application of carbofuran @ 2.0 kg a.i. ha−1 for each crop of potato. However, higher economic returns (BC ratio: 2.91) were recorded in the treatment potato-cabbage-carrot-potato, along with carbofuran application to potato, which could not contain the nematode buildup substantially (5%) in two years rotation. Alternating the resistant potato with non-solanaceous crop in between two susceptible potato crops could bring down the PCN population only to the extent of 20–25%. The effectiveness of growing non-solanaceous crops to contain PCN populations in rotation is comparatively lower (20 to 25%) when compared with resistant potato varieties (47%). This integrated strategy with negligible negative impact on environment is recommended for PCN management.
Worldwide, armored scale infestations are hitherto unreported to occur on seabuckthorn (Hippophae L.) a wonderful natural nitrogen fixer and a storehouse of many useful antioxidant compounds grown commercially in many countries. However, heavy infestations of an armored scale (Aulacaspis sp.) (Hemiptera: Diaspididae) cause havoc in the natural seabuckthorn stands flourishing in North West Himalayan regions. Its scientific cultivation in these cold deserts can immensely benefit the tribal inhabitants economically and be useful in preserving the fragile ecosystem provided armored scale infestations are effectively controlled. Results of present investigations aimed at controlling this armored scale indicated that two sprays of azadirachtin rich neembaan 10000 ppm (10 ml/L)/agro spray oil S (10 ml/L)/imidacloprid 70% WG (0.2 g/L)/deltamethrin 1% + triazophos 35 EC (2 ml/L)/thiamethoxam 25% WG (0.5 g/L) at 10 days interval initiated within 48 h after crawler emergence effectively controlled the crawlers and prevented colonization of new shoots. Thus, it was concluded that these insecticides could be used judiciously and rotated prudently to prolong their utility by delaying the possibility of resistance development by armored scale crawlers.
Bioefficacy of botanicals and microbial insecticides was evaluated against aphid, Aphis gossypii Glover on coriander during Rabi 2011–12 and 2012–13. All the treatments were significantly superior to the untreated check. Among the tested biopesticides, neem oil (0.3%), Neem Azal-T/S 1 EC @ 0.0006 per cent and Gronim 0.30 EC @ 0.0006 per cent effectively managed the pest. The effectiveness was also reflected on yield of coriander seeds. The lowest (413 kg/ha) yield was obtained from ardusi leaf extract, which was at par with Verticillium lecanii (438.3 kg/ha) and Metarhizium anisopliae (453 kg/ha) treated plots.
Rice grown under irrigation of Cauvery river channels are facing early and drastic infections of blast disease while, udbatta, an endemic disease of the area has taken upper hand and become severe in the area. Seed treatment with fungicide manages the pathogen borne in the seed and soil, also protecting the crop upto 25–30 days. The method of seed treatment also plays a role in eradicating the seated infection propagules in the seeds. (Treating of sprouted seeds with carbendazim at 4g/kg of seeds exhibited least per cent of blast (14.4) and udbatta (15.5)disease severity during summer and Kharif, 2012 respectively). Whereas, dry seed treatment was next effective when combination of carbendazim 25 + mancozeb 50WS at 4g/kg seed treatment was used with 16.6 and 13.3, 17.7 and 15.5 per cent for Summer and Kharif, 2012 respectively. Both the chemicals were superior in treatment for sprouted seeds for efficiently managing both the diseases for two seasons when used as seed treatment.
The bioefficacy of five insecticidal spray schedules against aphid, Lipaphis erysimi Kaltenbach in mustard was evaluated a field experiment in conducted at Instructional Farm, College of Agriculture, Junagadh Agricultural University (JAU), Junagadh during Rabi 2012–13 and 2013–14. The results revealed that schedule 4 consisting of flonicamid 0.02 per cent at seedling stage, flubendamide 0.014 per cent at pre-flowering stage, azadirachtin 0.15 per cent at 50% flowering stage and acephate + fenvalerate 0.028 per cent at 50% pod formation stage was significantly. The most effective treatment which recorded lowest aphid index (1.1) over stage of the crop and year, whereas the schedule S3 (1.4 aphid index) proved next better effective in comparison to control schedule S6. The highest grain yield was found in schedule S4 (1302 kg/ha) followed by S3 (1218 kg/ha) and schedule S5 (1172 kg/ha) yield. Significantly the lowest grain yield was recorded in untreated control schedule S6 (500 kg/ha). It showed highest gross realization in schedule S4 (29674 Rs/ha) followed by schedule S3 (26566 Rs/ha). The schedule S2 generated highest ICBR ratio (1: 6.7) followed by schedule S3 (1: 6.3) and schedule S4 (1: 6.3) whereas, schedule S1 (1: 3.1) gave significantly lower ICBR than other schedules. Thus, any one of the above effective and economical insecticidal spray schedule can be suggested for the control of mustard aphid.
A field trial was carried out for bioefficacy of three fungicides (iprodione, propiconazole, mancozeb) with four different doses (0.15.0.20, 0.25, 0.30% a.i.) on Alternaria blight of mustard during 2008–09 to 2009–10. All the three fungicides reduced the Alternaria blight of mustard in comparison to untreated control irrespective of their doses. The results showed that three sprayings at 15 days interval from 40 days after sowing showed minimum percent of leaf infection (13.0%), AUDPC (9.9), per cent of siliqua infection (9.9%), number of spots per siliqua (5.3) and increase in the number of siliqua per plant (106.0) and seed yield (kgha−1) in iprodione sprayed plots @0.25% (1682.6 kgha−1) similar as 0.3% a.i.of the same chemicals (1671.8 kgha−1) and followed by propiconazole @0.30% (1539.3 kgha−1) with maximum cost benefit ratio (1: 5.5, 1: 4.5 and 1: 3.5, respectively).
Results of an experiment aimed at reducing the yellow mosaic disease (YMD) and increasing the grain yield of mungbean cv. T44 carried out in 2012 involving nine treatments indicated that none of them was effective in reducing the incidence of YMD significantly, but three treatments viz., foliar sprays of an insecticide, Nurelle D 505 consisting of 50% chlorpyriphos and 5% cypermethrin @0.1% at 15 and 45 days after sowing, seed treatment with imidacloprid 17.8SL @5ml/kg seeds and seed treatment with Trichoderma @ 6g/kg were effective in increasing the grain yield. Efficacy of these treatments and their different combinations were tested during Kharif season of subsequent years, 2013 and 2014. The YMD incidence was relatively higher during Kharif 2013 ranging between 22.79–31.59% as compared to 11.92–13.08% in different treatments during Kharif 2014. Treatments did not result in reduction of YMD but increased grain yield. The best treatment was seed treatment with imidacloprid 17.8SL @ 5ml/kg seeds + two foliar sprays with Nurelle D505 @0.1% at 15 and 45 days after sowing as it resulted in highest grain yield of 666.7kg/ha in 2013 and 753.96 kg/ha in 2014 as compared to 300kg/ha and 575kg/ha in control during corresponding years. Based on three years experimentation, treatment involving seed treatment with imidacloprid 17.8SL @5ml/kg seeds and two foliar sprays with an insecticide consisting of 50% chlorpyriphos and 5% cypermethrin @0.1% at 15 and 45 days after sowing showed statistically significant enhancement of grain yield of mungbean cv. T44, hence this treatment is recommended for getting maximum yield advantage.
The studies on life fecundity table, age specific distribution and life expectancy of Maruca vitrata (Geyer) on green gram cv. Meha were carried out at a constant temperature of 26∓ 1°C during the month of July to October, 2013 at Anand Agricultural University, Anand (Gujarat). Pre-oviposition period was 22 and 23 days of pivotal age. Female started laying eggs after 23rd day and stopped after 34th day with lx values being 0.59 and 0.03, respectively. The females contributed the highest number of progeny (mx= 25.12) on 27th day of pivotal age, which decreased day by day. The net reproductive rate (Ro) of 62.91 was obtained with a mean length of generation (Tc) 27.03 days. Intrinsic rate of natural increase in number (rm) was 0.1551 females per female per day and the population would be able to multiply 2.36 times per week. The hypothetical F2 females were worked out to be 3957.67. The life expectancy of M. vitrata declined gradually with the advancement of development. The life expectancy of newly deposited eggs was 7.48 days. The expectancy of further life was 2.80 day at the time of adult emergence. The contribution of egg to stable age distribution was 54.42 per cent, whereas it was 41.61 per cent by larval stage. Contribution of pupal and adult stage was negligible as it found 2.51 and 1.46 per cent, respectively.
The toxicity and effect of Bt cotton (Bollgard and Bollgard II) against pink bollworm (PBW) was studied. Larval incidence was noticed in 2nd week of October, 2012 to 2nd week of February, 2013. There was no incidence of PBW larva in RCH-2 Bt. The maximum larval population of 0.46 nos./50 bolls was observed at 51st std week and 0.42 nos./50 bolls at 50th std week in Bunny non-Bt and RCH 2 non-Bt cotton hybrids, respectively. Larval population of 0.60 nos./50 bolls at 2nd std week and 0.52 nos./50 bolls during 1st std week were observed in MCU 12 and DCH 32, respectively while the green boll damage ranged from 16.84% (42nd std week) to 60.20% (2nd std week), respectively. Among the cotton genotypes tested, significantly less percentage of locule damage was registered in RCH-2 Bt (0.25–3.00%) followed by Bunny Bt (2.00 to 6.75%) during all pickings. Highest seed cotton yield was recorded in RCH-2 Bt (11.81 q/ha) followed by Bunny Bt (7.40 q/ha), which in turn was on par with RCH 2 non-Bt (7.40 q/ha). Seed cotton yield registered were Bunny non-Bt (6.17 q/ha), DCH 32 (5.65 q/ha) and MCU 12 (5.37 q/ha), respectively.
An investigation was carried out during Kharif 2012 and 2013 at Research Farm of School of Agricultural Sciences and Rural Developm ent, Nagaland University, Medziphema to evaluate fungicide, nutrients and soybean genotypes for managing the rust (Phakopsora pachyrhizi Sydow & Sydow.) disease. Two consecutive sprays of hexaconazole 5% SC @ 0.1% + multinutrients @ 1% found superior in reducing the disease severity and increasing the seed yield, pods/plant and 100 seed weight. Spray of multinutrients @ 1% was found most economic (6.15 and 7.52), followed by hexaconazole 5% SC @ 0.1% + multinutrients @ 1% (4.31 and 5.12) and MgSO4 @ 1% (3.62 and 4.53). Of the 74 germplasm accessions screened under natural epiphytotic condition, 11 entries, viz., DSb 22, RSC 01–05, VLS 85, NRC 91, KDS 726, PS 1539, RVS 2002-4, MAUS 609, RSC 10–17, RVS 2002–19 and DSb 23-2 were recorded as highly resistant and five viz., AMS 475, KDS 705, KDS 693, KDS 708 and KDS 722 were found to be moderately resistant.
In the study against diamondback moth (DBM), 11 field populations were collected from cabbage during 2012 and 2013 to monitor the level of resistance to organophosphorus compounds (acephate and chlorpyriphos), synthetic pyrethroid (cypermethrin), oxadiazine (indoxacarb), naturalyte (spinosad) and diflubenzoylureas (novoluron) by using leaf dip bioassay method. DBM showed moderate to high resistance to chlorpyriphos, cypermethrin and acephate where the Oddanchatram (PX-3) population being the most resistant (275.61-fold, 108-fold and 52.07-fold for chlorpyriphos, cypermethrin and acephate, respectively). Biochemical validation of enzyme activity was also investigated by quantifying carboxylesterase, glutathione S transferase (GST) and cytochrome P-450. Metabolic inhibitors viz., S, S, S-tributylphosphorotrithioate (DEF), piperonylbutoxide (PBO) and diethyl malate (DEM) clearly proved the role of carboxylesterase and cytochrome P-450 in conferring high level of resistance to Oddanchatram population (PX-3) for chlorpyriphos, cypermethrin and acephate.
Flonicamid 50WG was evaluated @ 50, 75 and 100 g a.i. ha−1 against sucking insect pests and predatory complex on Bt cotton during 2007, 2008 and 2009. Based on pooled analysis of three years, per cent reduction of leafhopper over control in flonicamid @ 75 g a.i. ha−1 was found to be higher or at par with standard checks after 3 and 7 days of spray. Flonicamid @ 75 g a.i. ha−1 provided up to 73.4 per cent reduction in whitefly population but was less effective than ethion @ 1000 g a.i. ha−1 with 80.1 per cent reduction. Per cent reduction of aphid was higher in flonicamid @ 75 g a.i. ha−1 after 3, 7 and 10 days of spray as compared to all other treatments. Seed cotton yield was significantly higher in treated plots than control. Among the treatments, flonicamid @ 75 and 100 g a.i. ha−1 recorded significantly higher seed cotton yield being at par with each other. Moreover, flonicamid was comparatively safer to predatory complex.
The Weed risk assessment (WRA) is a science-based quarantine risk analysis tool for determining weedy/invasive potential of a plant species in establishing, spreading, and/or causing harm in a new area. Ambrosia psilostachya D.C., which found entry in India, is presently contained and eradication of the weed is in progress. It is essential to analyse its weedy or invasive potential, to predict its establishment in areas outside the delimited range. WRA has been carried out using the USDA-APHIS-PPQ1 model to evaluate the potential endangered areas in the country where the weed might establish. The analysis provides support to policy makers to negate the probable adverse effects in production systems and anthropogenic areas.
Field experiments were carried out to evaluate the performance of four IPM modules against leaf miner and diseases like root rot/wilt and Ascochyta blight in Kullu valley of Himachal Pradesh during Rabi 2010–11 and 2011–12. The findings of two years experiments revealed that the IPM module (M3) consisting of seed treatment by seed soaking in streptocycline @ 200 ppm followed by seed treatment with carbendazim (Bavistin 50 WP) @ 2.5g/Kg seed succeeded by two foliar sprays with a mixture of lambda-cyhalothrin 5EC @ 0.8ml/L(0.04%) and carbendazim @ 0.1% (Bavistin 50 WP) at the 50% flowering of the crop (3.5 months of sowing, 3rd week of March) and by the 2nd spray of mixture of acetamiprid @ 0.005% (Polar 25 SP) and triademefon @ 0.05% (Bayleton 2%) after 15 days of the first spray, was found to be most effective in minimizing the leaf infestation by leaf miner and root rot/wilt incidence with 85.1% and 98.2% reduction over control, respectively. This module was also found to be the most economic resulting in highest mean marketable pod yield (138.6 q/ha) during the two years and maximum net returns of 21.7 per rupee spent. However, for the control of Ascochyta blight, module M1 was found to be the most effective in minimizing the disease incidence with 68.8% reduction over the control.
A field study was conducted at Horticultural Research Station, Lam, Guntur, Andhra Pradesh for two consequent years i.e 2007–08 and 2008–09 to evaluate the new insecticides for the management of chilli thrips. Among the eleven molecules evaluated, Spinosad 45 SC @125 ml/ha recorded lowest mean number of thrips/leaf (1.0) followed by Diafenthiuron 50WP @ 750g/ha (3.1), Fipronil 5 SC @ 1000 ml/ha (6.7) and Chlorfenpyr 10 EC @1000ml/ha (12.6) were found significantly effective against chilli thrips as compared to untreated control (30.6). Highest thrips population/leaf was recorded with Lufenuron 5 EC @ 500 ml/ha (31.5), Novaluran 10 EC @ 375 ml/ha (25.4) and Emamectin benzoate 5 SG @ 200 g/ha (24.1). Highest mean dry pod yield (Kg/ha) was recorded with Spinosad 45 SC @125 ml/ha (3157), next best treatment was Diafenthiuron 50WP @ 750 g/ha (2389). It was followed by Chlorfenpyr 10 EC @1000ml/ha (2342), Fipronil 5 SC @ 1000 ml/ha (2305). Spinosad 45 SC @125 ml/ha was found to be effective in reducing chilli thrips and recording higher yields.
