White Ear Head Research Articles

Efficacy of Insecticides Against Yellow Stem Borer (Scirpophaga incertulas Walker) and Rice Leaf Folder (Cnaphaocrocis medinalis Guenee) and Their Impact on Natural Enemies in Rice Ecosystem

The experiment was conducted at AAU-Assam Rice Research Institute, Titabor to test the efficacy of some insecticides against yellow stem borer and rice leaf folder. Out of 8 tested insecticides, Chlorantraniliprole 18.5 SC showed the best result in minimizing yellow stem borer and rice leaf folder infestation. The lowest infestation percentage of yellow stem borer (2.10%) was observed on Chlorantraniliprole 18.5 SC treated plots followed by treatment with Chlorantraniliprole 10% + Lambda Cyhalothrin 5% ZC (2.33 %) at 7 DAT. Similarly, white ear head (0.33%) was also recorded as the lowest on Chlorantraniliprole 18.5 SC treated plots. Chlorantraniliprole 18.5 SC recorded the lowest infestation percentage of rice leaf folder at 7 DAT (3.40 %) and 14 DAT (3.53 %) followed by Chlorantraniliprole 10% + Lambda Cyhalothrin 5% ZC. While, the highest number of spiders and coccinellids were recorded in Chlorantraniliprole 0.4GR (2.43 spider/plant and 1.33 coccinellids/plant) followed by Thiamethoxam 25WG (2.13 spiders/plant and 1.10 coccinellids/plant). In terms of yield, Chlorantraniliprole 18.5 SC was found to be the best insecticide which provided the highest yield of 5.83t/ha among all the tested insecticides.

Efficacy of different pesticides in suppressing yellow stem borer in spring rice (Oryza sativa) in Ratuwamai, Morang, Nepal

Rice, a staple food for over half the global population, is crucial for food security, economic stability, and cultural significance. Its production, however, is threatened by pests like the Yellow Stem Borer (YSB), which causes substantial yield losses, especially in rice-dominant regions like Nepal. This study focuses on evaluating the effectiveness of biological, botanical, and chemical pesticides against YSB in spring rice crops of Ratuwamai, Morang, Nepal. For this, we apply biological methods/pathogens like Bacillus thuringiensis, to target YSB; botanical pesticides, derived from plants like Azadirachtin and Mugworth, act as repellents; while chemical pesticides such as Cypermethrin, Chlorpyriphos and Cartap Hydrochloride offer rapid control but come with environmental risks. Among those six pesticides used, the present findings revealed that chlorpyriphos 20% EC have minimum mean dead heart with 4.92% and cypermethrin 10% EC have minimum mean white ear head with 2.44% respectively after application of first and second dose of treatments respectively. Likewise, most plant yield attributes were superior where chlorpyriphos was used. Though bacillus and azadirachtin reduced the dead heart and white ear head symptoms, they couldn’t give good yield than that of chemical pesticides. Thence, through our research we investigated the impacts of different biological, botanical and chemical pesticides in controlling YSB population densities, and influencing yield and yield attributing characters from the field experiment.

Effect of Organic Nutrient Management Practices on Growth, Yield and Pests Incidence of Scented Rice (Oryza sativa L.) in Rainfed Situation of Assam

The field experiment was conducted in organic block on experimental farm of AAU-Assam Rice Research Institute, Assam Agricultural University, Titabar, Assam during kharif season of 2019 and 2020 to study the effect of organic nutrient management practices on growth, yield and pests incidence of scented rice (Oryza sativa L.) in rainfed situation of Assam. Eight treatment combinations of organic inputs were laid out in Randomized Block Design with three replications including one control where no organic nutrients were added. The study revealed that combined application of different proportion of green manure, enriched compost, azolla, vermicompost, neem cake with bio fertilizer consortium and rock phosphate as different treatment significantly improved the growth behavior, yield and also reduced pests incidence of scented rice. Among the organic nutrient management treatments, combination of Green manure (2.5 t/ha)+ Vermicompost (2.5 t/ha)+ Biofertilizer consortium (4 kg/ha seedling) as root dip +Rock phosphate (17 kg/ha)+Azolla (20 kg/ha) recorded the highest yield (3.80 t/ha) by improving yield attributing parameters, viz., Panicles (276.3 /m2), Spikelet /panicle (25.50 number) and Panicle weight (3.37g). The organic treatments also significantly enhanced the growth physiology viz., leaf area index (4.32), and specific leaf weight (8.56 mg/cm2) at panicle initiation stage (90 DAT). In organic management treatments, pests and disease incidence significantly reduced compared to control plot. Highest reduction of dead heart (DH%) and white ear head (WEH%) infestation due to stem borer, gall midge (silver shoot) and leaf folder damage was noticed in the treatment combination of Green manure (2.5 t/ha) + Vermicompost ( 2.5 t/ha)+ Biofertilizer consortium (4 kg/ha seedling) as root dip+Rock phosphate (17 kg/ha)+Azolla (20 kg/ha).

Performance of Aromatic Rice Varieties Against Yellow Stem Borer <i>Scirpophaga incertulas</i>

A field experiment was carried out at the Rice Research Farm of Birsa Agricultural University, Ranchi, Jharkhand during kharif, 2018 and 2019 to assess the performance of some aromatic rice varieties against the yellow stem borer (YSB) Scirpophaga incertulas (Pyralidae: Lepidoptera) in Jharkhand. The damage caused was measured as deadheart- DH (30 and 45 DAT) and white earhead- WEH (70 and 90 DAT) at the vegetative and reproductive stages, respectively. At vegetative stage seven varieties scored 1 (PS-4, Pusa1176, PS-3, BVS-1, BR-9, BR-10, Assam culture) with 4.62 to 9.53% DH while at reproductive stage only two varieties (BR-10 and Assam Culture) scored 1 with 4.56 and 4.95% WEH. Yield potential of BR-9 (38.50 q/ ha) was significantly superior over other aromatic varieties except BR-10 and followed by Birsamati (34.30 q/ ha) and BVS-1 (33.25 q/ ha).

Pest Management Modules for Basmati Rice and Farmer’s Perception

The experimental trials were conducted to evaluate four IPM modules viz., M1-Integrated pest management, M2-Chemical module, M3-Farmer’s practice, and M4-untreated control against major insect pests viz., brown planthopper (BPH) Nilaparvata lugens (Stål), white backed planthopper (WBPH) Sogatella furcifera (Horvath), yellow stem borer (YSB) Scirpophaga incertulus (Walker), leaf folder (LF) Cnaphalocrocis medinalis L, in basmati rice in farmer fields at Hapur, Uttar Pradesh. These experiments were conducted in during kharif 2017 and 2018. The observations were made on the mean number of hoppers (plant and leafhoppers), % leaf damage, % dead heart and white earhead. Similarly, occurrence of spiders was also monitored. The results revealed that the M1- IPM module was observed as the best with minimum pest damage, and higher yield. This study concludes that integration of ecofriendly sustainable IPM practices not only minimize insecticide use and other input costs, but also increases the crop yield by safeguarding the natural enemy (spiders). Pre-season skill-oriented extension training programs, field demonstration-based farmer-first participatory approach, as well as regular communication through social media, would enhance their adoption in basmati rice production.

Population dynamics of rice yellow stem borer and sheath blight

Field experiments were conducted on the seasonal incidence of yellow stem borer (Scirpophaga incertulas) and sheath blight (Rhizoctonia solani). These revealed that maximum deadheart incidence (5.32 and 5.64%) was observed in the 33rd and 34th standard meteorological week (SMW) in 2018 and 2019, respectively. The incidence of white earhead was maximum (4.96 and 5.28%) during 40th SMW. Maximum incidence of sheath blight (50 and 46.67%) was noticed during 36th SMW. A significant positive correlation of minimum temperature and evening relative humidity was found with deadheart incidence. Conversely, maximum temperature and morning relative humidity had significant positive correlation with incidence of sheath blight. The model developed for ascertaining effect of weather factors on incidence of pest and disease showed a good relationship between predicted and observed data of % deadheart (R2=0.996), white earhead (R2=0.992) and diseased plants (R2=0.986).

Comparative efficacies of modules against major insect pests and natural enemies in rice (Oryza sativa)

A field experiment was conducted at regional Research and Technology Transfer Station (OUAT), Chiplima,Sambalpur, Odisha, during rainy season (kharif) 2019–20 to determine the comparative efficacies of variousinsecticides and botanicals modules against major insect pests and natural enemies of rice (Oryza sativa L.). Therewere 9 modules and overall data revealed that the all the treated plots recorded significantly lower per cent of deadheart; white ear-head caused by stem borer; silver shoot caused by gall midge; leaf folder infested leaves and planthoppers. Among them, module consists of fipronil 5 sc @1500 ml/ha at 25–30 DAT, rynaxypyr 20 sc @150 ml/ha at45–50 DAT and triflumezopyrim 106 sc @240 ml/ha at 65–70 DAT treated plot recorded significantly higher per centreduction of stem borer infestation, leaf folder, plant hoppers and produced higher grain yield than the other modules as well as highest benefit cost ratio B : C (1.89) and next best was carbosulfan 25 ec @875 ml/ha, rynaxypyr 20 sc @150 ml/ha and flonicamid 50 wg @150 g/ha containing module. So, the module containing fipronil, rynaxypyr and triflumezopyrim may be adopted for the effective management of major insect pests of rice and helps the farmers from unwanted spraying of insecticides many times.

Bioefficacy of Thiocyclam Hydrogen Oxalate 50 SP against Major Pests of Rice

Bioefficacy of thiocyclam hydrogen oxalate 50 SP, a new molecule of nereistoxin group, was evaluated against three major pests of rice viz. stem borer, leaf folder and whorl maggot during Sali (Kharif) and Ahu (Rabi) seasons, 2016–2017 at Instructional Cum Research (ICR) farm of Assam Agricultural University, Jorhat. Cartap hydrochloride 50 EC and trizophos 40 EC were used as standard check along with three doses of thiocyclam hydrogen oxalate 50 SP viz., 200, 350 and 500 g ai ha−1. The result showed that thiocyclam hydrogen oxalate 50 SP @ 200 and 500 g ai ha−1 recorded the lowest dead heart (2.3 and 2.0%), white ear head (1.4 and 1.3%) and leaf folder infestation (3.0 and 2.8%) with highest yield (5069 and 5097 kg ha−1) in Sali (Kharif) season 2016. Similarly, in Ahu (Rabi) season of 2017, the thiocyclam hydrogen oxalate 50 SP @ 200 and 500 g ai ha−1 recorded the lowest dead heart (1.9 and 1.8%), white ear head (1.0 and 0.5%) and leaf damage by whorl maggot (2.2 and 2.1%) with highest yield (4691 and 4861 kg ha−1), respectively. Moreover, thiocyclam hydrogen oxalate did not show any deleterious effect on natural enemies population of rice ecosystem.

Bio-efficacy of newer insecticide molecules against rice stem borer Scirpophaga incertulas on rice

Three new combi products (Flubendamide 240 SC + thiaclorprid 240 SC, spinetoram 6% + methoxyfenizide 30% @ 400 ml/ha, indoxacarb 14.5 SC + novaluron 7.7% SC) with two different doses and one new molecule (flubendiamide 480 SC) in two doses, alongwith cartap hypochloride and untreated control were evaluated in this experiment against S. incertuals. Spinetoram 6% + methoxyfenizide 30% @ 400 ml/ha recorded 0.75, 0.85 and 0.80% dead heart and was significantly superior to all treatments and showed lowest white ear head (1.62, 1.77 and 1.69% WEH). Maximum net profit of Rs. 24,541/- was obtained with the application of spinetoram 6% + methoxyfenizide 30% @ 400 ml/ha but highest B:C ratio found in novaluron 5.25% SC + indoxacarb 4.5 SC @ 750 ml/ha having B:C ratio 3.02:1.

RELATIVE EFFICACY OF SOME BIORATIONAL AND MICROBIAL INSECTICIDES AGAINST YELLOW STEM BORER AND WHORL MAGGOT OF BORO PADDY

A field trial was conducted at Rice Research Station, Hooghly of West Bengal during boro season to evaluate the effect of some biorational and microbial insecticides against rice insect-pests. Insecticides of different origins such as, Beauveria bassiana Balsamo-Crivelli, Bacillus thuringiensis Berliner, Metarhizium anisopliae Metchnikoff, spinosad, azadirechtin, and cartap hydrochloride as check, have been tested in different combinations against yellow stem borer (Scirpophaga incertulas Walker) and whorl maggot (Hydrellia spp. Robineau-Desvoidy). The lowest whorl maggot infestation was recorded in spinosad treated plots (1.84%) followed by B. thuringiensis var. kurstaki (2.58%) and azadirachtin treatment (2.59%). The lowest yellow stem borer infestation as dead heart was recorded in plots treated with spinosad (2.92%) followed by M. anisopliae (3.32%) followed by azadirachtin (3.44%). The white ear head damage was recorded lowest in spinosad (8.04%) followed by B. bassiana + B. thuringiensis var. kurstaki (9.25%) and M. anisopliae treatment (9.48%). The highest grain yield and straw yield of boro rice were obtained from the plots treated with spinosad (57.72 q ha-1 grain yield and 6958 kg ha-1 straw yield) followed by B. bassiana + B. thuringiensis var. kurstaki (54.31 q ha-1 grain yield and 6681 kg ha-1 straw yield) followed by B. bassiana + M. anisopliae (53.47 q ha-1 grain yield and 64.58 q ha-1 straw yield). The overall results revealed spinosad as the most effective insecticide against both the insect species whorl maggot and yellow stem borer, showing minimum white ear head and dead heart with higher grain and straw yield.

An entomopathogenic fungus and a natural extract benefit rice (Oryza sativa) by suppressing populations of insect pests while keeping high populations of their natural enemies

Sustainable and environmentally safe pest management often involves the use of natural enemies as an alternative to chemical means. For successful management of pests by natural enemies, a balanced population between insect pests and their natural enemies should be achieved. In this study, we compared such population balances in rice fields of Cambodia under the following conditions: no insecticide (NI), chemical pesticide-based conventional practice (CP), the use of a biopesticide (Beauveria bassiana, Bb), and the use of an orange oil extract (Oo). Treatment effects were evaluated by monitoring 17 species of insect pests and 15 species of natural enemies at two sites for two seasons. In the NI treatment, the level of natural enemies was the highest, however, the pest population density was also higher in this treatment than in the Bb and the Oo treatments, resulting in a low grain yield similar to that in the CP treatment notably in one trial. The Bb and the Oo treatments showed the lowest insect pest populations, although the Oo treatment had little impact on the populations of natural enemies. These results suggest that contributions of Bb and Oo treatments to decreasing pest populations were greater than those of the NI and the CP treatments, and that the Bb and the Oo treatments resulted in a favorable balance between populations of insect pests and their natural enemies. A high level of white earhead caused by stemborers resulted in significant yield losses in one trial. Among the four treatments in the trial, the Bb treatment resulted in the highest grain yield, and importantly, this treatment depressed the insect pest populations without much affecting the populations of their natural enemies. Overall, the results of this study suggest that the use of biopesticides in rice paddies is effective to keep the well-balanced population between insect pests and natural enemies by decreasing the serious pests such as stemborer and leaf folder that directly affect rice grain yields.

Critical role of potassium and sodium salts against insect-pest complex of rice

A field experiment was carried out at Rice Research Station, Chinsurah, Hooghly during rainy (kharif) season, 2016 and 2017 to evaluate the effects of potassium and sodium salts on whorl maggot, leaf folder and yellow stem borer of rice. The yield and yield attributing characters were observed and benefit cost ratio was calculated. The potassium salts viz. potassium chloride (KCl), potassium nitrate (KNO3), potassium sulfate (K2SO4), potassium dihydrogen phosphate (KH2PO4) and sodium salt as sodium chloride (NaCl) were applied by three modes viz. seed soaking for 12 hours before sowing, seedling root dipping for twelve hours before transplanting and foliar sprays at 30 and 50 days after transplanting (DAT). The experimental results revealed that the foliar spray with 1% potassium dihydrogen phosphate salt at 30 and 50 DAT was the best performer against rice insect-pests by lowering down the infestation of leaf folder, dead heart and white ear head and as well as responses for good yield. Maximum benefit was recorded with foliar spray of 1% sodium chloride salt.

Assessment of management modules against yellow stem borer in paddy

Yellow stem borer (YSB) is one of the most serious and monophagous pest of paddy in India. Field experiments were carried out to assess the different management modules against the yellow stem borer in paddy during the Kharif season of 2019 and 2020. The results on efficacy of modules revealed that during both the years the minimum ‘Dead Heart’ (DH) (10.1 and 11.4% during the year 2019 and 2020, respectively) was recorded in M3 (clipping of terminal shoots at the time of transplanting and application of cartap hydrochloride 50 SP) followed by M2 (11.9 and 14.5% during the year 2019 and 2020, respectively) in which 1st application was done with fipronil 0.3G and 2nd with NSKE 5% and M1 (19.6 and 20.9% during the year 2019 and 2020, respectively) i.e. farmers’ practice where only carbofuran 3G was applied. ‘White Ear Head’ (WEH) was also recorded minimum in M3 (11.6 and 12.1% in the year 2019 and 2020, respectively) followed by M2 (13.3 and 16.4% in the year 2019 and 2020, respectively) and M1 (20.8 and 22.4% in the year 2019 and 2020, respectively) in paddy. Maximum yield (33.8 and 43.1 q/ha during the year 2019 and 2020, respectively) was also recorded in Module 3 practiced clipping of terminal shoots and spraying with cartap hydrochloride 50 SP with the highest BC(Benefit: Cost) ratio 1.52:1 and 1.94:1 in the year 2019 and 2020, respectively. The overall results of the present study indicating the overall superiority of M3 (clipping of terminal shoots at the time of transplanting and two applications of cartap hydrochloride 50 SP at 40 and 60 DAT) in all the aspects i.e. DH, WEH, yield and BC ratio.

Host plant resistance against yellow stem borer and rice leaf folder through varietal screening of rice

Rice plant is attacked by many insect-pests of which yellow stem borer (dead heart at vegetative stage and white ear head at reproductive stage) and leaf folder are considered as prime devastator, responsible for major economic loss. To combat this problem, resistant varieties of rice are required for better production as well as better productivity. Host plant resistance is very much effective in integrated pest management (IPM) system, where negligible pesticidal hazard is present as well as environmental safety, low cost farming by without or minimum pesticide application and proper identification of resistant varieties for selection as parent in crossing programme to develop resistant varieties in future. The 78 rice varieties were screened out against Scirpophaga incertulas (yellow stem borer) and Cnaphalocrocis medinalis (rice leaf folder) of rice during Kharif, 2010-2012 at Rice Research Station, Chinsurah, Hooghly, under Government of West Bengal. The experiment was carried out to determine the level of resistance in early, mid-early, medium and late duration rice varieties, and shallow and semi-deep rice varieties. The pest infestation level was determined by counting dead heart, white ear head and damaged/folded leaves. The experimental results revealed that the early duration variety viz. Narendra 97 and IR 50, the mid-early duration variety i.e. IR 64 and IET 17904 proved resistant against both yellow stem borer (dead heart) and leaf folder. The medium duration variety, Ranjit was highly resistant against both yellow stem borer (dead heart) and leaf folder, and the variety, Pratiksha showed a fair degree of resistance against both yellow stem borer and leaf folder; while Jarava, the late duration variety exhibited high degree resistance against yellow stem borer (dead heart and white ear head). Besides, the varieties, Sashi and Giri recorded very low level of infestation of both lepidopteran pests while shallow and semi-deep variety such as Sashi was also considered resistant against the noxious pests.

Seasonal incidence of yellow stem borer, Scirpophaga incertulas Walker infesting rice and its correlation with weather parameters

The present investigation was conducted to study the seasonal incidence of yellow stem borer, Scirpophaga incertulas Walker infesting rice and its correlation with weather parameters at MAE farm, Regional Agriculture Research Station, Karjat (M.S.), during Kharif 2019. Results revealed that intiation of yellow stem borer infestation was observed with (3.06%) dead heart, (1.72%) white ears head during the 31st SMW (30 July - 5 Aug) and 40th SMW (1Oct – 7 Oct) respectively. The maximum dead heart was recorded with (6.31± 2.57%) infestation at 37th SMW (10 Sept- 16 Sept) and white ear head with (6.81± 2.38%) infestation during 42th SMW (15 Oct – 21 Oct). Among the all-weather parameters, yellow stem borer showed non-significant positive correlation with sunshine hours (r= 0.017) while, other parameters showed non-significant negative correlation.

Farmer participatory assessment of pest management modules for yellow stem borer and leaf folder in summer rice

Rice yellow stem borer, Scirpophaga incertulas (Walker) (Pyralidae: Lepidoptera) is the major pest of rice that causes extensive damage to the crop and its infestation is more severe in summer rice. Field experiment for two consecutive seasons (summer 2014 and 2015) at Bhadrak, Odisha (India) was carried out to assess the relative efficacy of some modules pest management against yellow stem borer and leaf folder in rice. The pest management module comprising of nursery treatment with fipronil 03 G @ 100 g/ cent nursery area at 7 days before transplanting, clipping of leaf tips at transplanting, installation of pheromone traps for mass trapping @ 50/ ha, soil application of chlorantraniliprole 0.4 G @ 10 kg/ ha at 30 DAT and foliar spray of indoxacarb 14.5 SC @500 ml/ ha at 60 DAT minimised the stem borer damage substantially (76.40 and 76.15 % reduction of dead heart and white ear head, respectively over control) and contributed to the highest grain yield ( 42.86 % increase over control) with maximum net return (Rs. 19899.05 per hectare) and B :C ratio (1.46). The current pest management module also reduced the infestation level of leaf folder in rice (60.72 % reduction over the untreated control).

Impact of Nitrogen and Potash on the Incidence of Scirpophaga incertulas and Cnaphalocrocis medinalis and Yield of Rice

The experiment was conducted at Rice Research Station, Chinsurah, West Bengal, India during June-November 2010, 2011 and 2012 to evaluate the different doses of nitrogen and potash fertilizers on the incidence of Scirpophaga incertulas and Cnaphalocrocis medinalis in Swarna (MTU 7029) variety. Among the three straight fertilizers, N was applied at three split doses while P2O5 and K2O were applied basally. Eight treatments with different doses of N:P2O5:K2O viz. 40:40:20, 40:40:40, 80:40:20, 80:40:40, 80:40:60, 120:40:40, 120:40:60 and 0:40:0 were laid out in RCBD with three replications. The observations on dead heart (DH), white ear head (WE) and leaf folded (LF) were noted down. The pooled data of three consecutive years revealed the lowest DH% and WE% in 80:40:40 (3.96% DH and 4.70% WE) while lower LF% was recorded in 80:40:60 (1.75%) and 80:40:40 (2.02%). Percent DH, WE and LF were comparatively higher in both 120:40:60and 120:40:40. However, the treatments supported higher plant height and tillers hill-1, panicles hill-1 and 1000 grain weight which resulted in the highest grain (4926 kg ha-1) and straw (6028 kg ha-1) yield in 120:40:60 followed by the treatment 80:40:60 with 4907 kg ha-1 and 5972 kg ha-1, respectively. The results reflected that higher pest damage due to N at the dose of 120 kg ha-1 could be compensated by K2O @ 60 kg ha-1 which boosted the yield. Based on benefit-cost ratios, the treatments 80:40:40 and 80:40:60 proved cost effective.

Influence of weather factors on incidence of yellow stem borer in aromatic rice under agro-climatic condition of Jharkhand

Field experiment was conducted to study the influence of weather factors on incidence of yellow stem borer, Scirophaga incertula under agro-climatic condition of Jharkhand.it was revealed that incidence of YSB started after one or two week of transplanting and it caused dead heart in vegetative stage and white ear head in reproductive stage of the crop. Dead heart had significant correlation with maximum temperature while white ear head had negative effect.

Evaluation of new generation granular insecticides against major lepidopteran pests of rice <em>Oryza sativa</em> L.

Field experiments were conducted during kharif season 2015-16 at Agriculture Research Station, Gangavathi. Two doses of Flubendiamide 0.7% Gr @ 70 and 85 g a.i./ha, two doses of Spinetoram 0.8% Gr @ 50 and 60 g a.i. ha-1 and standard check Cartap hydrochloride 4% Gr @ 1000 g a.i. ha-1 was tested against yellow stem borer infesting transplanted paddy. Results revealed that, flubendiamide 0.7% Gr at 100 g a.i./ha was found quite effective against YSB recording mean per cent dead heart (DH) and white ear head (WEH) of 1.59 and 1.40 respectively, followed by its next lower dose of 85 g a.i./ha (1.81 DH% and 1.96 WEH %), which was found superior to spinetoram 0.8% Gr @ 60 and 50 g a.i./ha during 2015-16. All the granular insecticides recorded the higher grain yield compared to the untreated check. However maximum yield was recorded in the treatment, flubendiamide 0.7% Gr @ 100g a.i./ha (66.29 qts/ha) and minimum yield was in untreated check plot (48.49qts/ha). Based on the evaluations it can be concluded that, the granular insecticide flubendiamide 0.7% Gr @ 85-100g a.i./ha found superior in reducing the dead heart and white ears and in obtaining higher grain yield Moreover, these new insecticide molecules are comparatively safer to non-targeted organism in comparison with other conventional insecticides.

Evaluation of some insecticide modules against major insect pests and their natural enemies in rice, Oryza sativa L.

During present studies nine insecticides modules were assessed against major pests of rice and their natural enemies. Amongst them eight modules consist of a basal application of chlorantraniliprole 0.4 G @ 40 g a.i./ha at 20 DAT and third application of flonicamid 50 WG @ 75 g a.i./ha at 65 DAT and module ten was untreated control. Whereas module nine consist of a basal application of cartap hydrochloride 4G @ 600 g a.i./ha at 20 DAT followed by acephate 75 SP @ 658 g a.i./ha at 50 DAT and third application dinotefuran 20 SG @ 40 g a.i./ha at 65 DAT which was taken as farmers practice. All first eight insecticide modules differed with each other only second treatment which was applied at 50 DAT. The second treatments included: acephate 95 SG @ 682 g a.i./ha; cartap hydrochloride 50 WP @ 375 g a.i./ha; rynaxypyr 20 SC @ 30 g a.i./ha; fipronil 5 SC @ 75 g a.i./ha; spinetoram 6% + methoxyfenozide 30% SC @ 135 g a.i./ha; flubendamide 48 SC @ 48 g a.i./ha; azadirachtin 0.03 EC @ 8 g a.i./ha and chlorantraniliprole 0.4 G @ 40 g a.i./ha. The overall data revealed that all the treated plots recorded significantly lower per cent of dead heart, white ear-head caused by stem borer and plant hoppers respectively. Module with rynaxypyr 20 SC @ 30 g a.i./ha or spinetoram 6 + methoxyfenozide 30 SC @ 135 g a.i./ha treated plot recorded significantly higher % reduction of stem borer infestation and gave higher grain yield (5.26 t/ha and 5.15 t/ha respectively) than the other modules. Module with fipronil 5 SC @ 75 g a.i./ha recorded significantly lower number of plant hoppers than other modules. Among the different treated modules, the maximum numbers of spiders and mirid bugs were found in rynaxypyr 20 SC @ 30 g a.i./ha and azadirachtin 0.03 EC @ 8 g a.i./ha containing modules.