Effect of herbicides on weed dynamics and yield of transplanted rice.pptx

Herbicides significantly impact weed dynamics by controlling various weed species, leading to reduced weed density and biomass, and ultimately increasing transplanted rice yield. Pre-emergence herbicides prevent weeds from establishing, while post-emergence options target escaped weeds. Effective herbicide use increases crop yield and provides a competitive advantage, though continuous use can lead to herbicide resistance and shifts in weed flora, necessitating integrated weed management strategies.

1. SEMINAR ON Effect of herbicides on weed dynamics and yield of transplanted rice ( Oryza sativa L .) Preeti Singh ID NO. – 3617 DEPARTMENT OF AGRONOMY SARDAR VALLABHBHAI PATEL UNIVERSITY OF AGRICULTURE & TECHNOLOGY, MEERUT-250110

2. SEQUENCE OF PRESENTATION

3. INTRODUCTION OF RICE Rice Species ( 24 ) 22 non cultivated species 2 cultivated species Oryza sativa (Asian rice) Oryza glaberrima (African rice) Indica Javanica Japonica

4. Area (million hectare) Production (million tonnes ) Productivity (kg/ha) World 162.06 757 - India 44 122.27 2700 U ttar P radesh 257.04 lakh tonnes 60 lakh hectares 975 Rice Statistics

5. Rice Producing Countries Highest production – China (211.86 million metric tones) followed by India (122.27 mt ) Largest acreage - India (44 million hectares) Highest productivity - China (6710 kg/ha) followed by Vietnam (5573 kg/ha)

6. Rice Producing States Highest Production- West Bengal (146.05 lakh tonnes ) Largest acreage – U ttar Pradesh (5.99 m ha) Largest productivity- Punjab (856 kg/ha)

7. NUTRIONAL VALUE PER 100 GRAMS Calories (kcal)- 364 Carbs (g.)- 81.6 Proteins(g.)- 6.7 Fats(g.)- 0.9 Fibers(g.)- 1.4 Calcium(mg.)- 14 Magnesium(mg.)- 31 zinc(mg.)- 1.5 (“ Anonymus , 2018)

8. Weeds in rice Weeds : weed is an unwanted plant. Weed problems are more severe in aerobic and direct-seeded rice as compared with transplanted rice. (Reason) Nearly 134 weed species are identified from rice which belongs to 32 taxonomic families. Grasses are dominant in transplanted and sedges are dominant in rain-fed system .

9. Some weeds of rice

10. Weeds Echinochloa colona Cynotis axillaris Cyperus iria Digitaria ciliaris

11. cont …. Echinocloa crussgali Cyperus difformis Cyperus rotandus

12. Effect of Weeds With weeds W ithout weeds Problem of yield loss in crop. Yield increases. Weed seeds buildup in soil may degrade the soil. Soil become healthy. Irrigation channel may clogged. Proper water management. Weed may attract insects & act as a host for diseases. Decrease the infestation of pathogens & insect attack. Reduce the quality of harvested produced. Harvest a g ood quality of produce. Increase cost of cultivation. Not a large proportion of cost incurred towards weed control.

13. Population of Weeds Species in Rice Crop Palampur , HP Abha Sharma, 2019

14. Herbicides in rice

15. Effect of herbicides Health risk to both humans and pests. Non-selective vegetation removal. Persistence in soil for long. Water runoff can carry herbicides into unintended areas. Weed resistance to the chemical . Increases cost of cultivation.

16. Table no. 1: Effect of weed management practices on total weeds density (m -2 ) in rice at 90 days after transplanting. Treatments Total weed density ( m -2 ) 90 DAT T1 Weedy check 16.2 T2 Weed free 2.36 T3 One HW at 40 DAT+ Bispyribac -Na (25 g a.i /ha) at 15 DAT 9.2 T4 Penoxsulam (22 g a.i /ha) at 20 DAT 9.8 T5 One HW at 15 DAT+ Penoxsulam (22 g a.i /ha) at 30 DAT 8.0 T6 One HW at 20 DAT+ Penoxsulam (22 g a.i /ha) at 35 DAT 8.7 T7 One HW at 25 DAT+ Penoxsulam (22 g a.i /ha) at 40 DAT 8.9 T8 Pretilachlor (750 g a.i /ha) at 3 DAT + Penoxsulam (22 g a.i /ha) at 20 DAT 6.0 T9 Pretilachlor (750 g a.i /ha) at 3 DAT+ Penoxsulam (22 g a.i /ha) at 25 DAT 6.8 T10 Pretilachlor (750 g a.i /ha) at 3 DAT+ Penoxsulam (22 g a.i /ha) at 30 DAT 7.2   SEm 0.31   C.D.(P=0.05) 0.90 Treatments Total weed density ( m -2 ) 90 DAT T1 Weedy check 16.2 T2 Weed free 2.36 T3 One HW at 40 DAT+ Bispyribac -Na (25 g a.i /ha) at 15 DAT 9.2 T4 Penoxsulam (22 g a.i /ha) at 20 DAT 9.8 T5 One HW at 15 DAT+ Penoxsulam (22 g a.i /ha) at 30 DAT 8.0 T6 One HW at 20 DAT+ Penoxsulam (22 g a.i /ha) at 35 DAT 8.7 T7 One HW at 25 DAT+ Penoxsulam (22 g a.i /ha) at 40 DAT 8.9 T8 Pretilachlor (750 g a.i /ha) at 3 DAT + Penoxsulam (22 g a.i /ha) at 20 DAT 6.0 T9 Pretilachlor (750 g a.i /ha) at 3 DAT+ Penoxsulam (22 g a.i /ha) at 25 DAT 6.8 T10 Pretilachlor (750 g a.i /ha) at 3 DAT+ Penoxsulam (22 g a.i /ha) at 30 DAT 7.2   0.31   C.D.(P=0.05) 0.90 Chaudhary et.al. (2020) SVPUA&T, Meerut

17. Table no. 2: Effect of weed management practices on grains, straw, biological yield ( q ha -1 ) and harvest index (%) of rice  Treatments Yield (q ha -1 ) Harvest index (%) Grains Straw Biological T1 Weedy check 22.33 40.30 62.63 35.65 T2 Weed free 44.73 53.40 98.13 45.58 T3 One HW at 40 DAT+ Bispyribac -Na (25 g a.i /ha) at 15 DAT 34.07 46.96 81.03 42.05 T4 Penoxsulam (22 g a.i /ha) at 20 DAT 33.73 46.90 80.63 41.83 T5 One HW at 15 DAT+ Penoxsulam (22 g a.i /ha) at 30 DAT 35.20 48.17 83.37 42.22 T6 One HW at 20 DAT+ Penoxsulam (22 g a.i /ha) at 35 DAT 35.14 48.04 83.18 42.25 T7 One HW at 25 DAT+ Penoxsulam (22 g a.i /ha) at 40 DAT 34.97 47.96 82.93 42.17 T8 Pretilachlor (750 g a.i /ha) at 3 DAT + Penoxsulam (22 g a.i /ha) at 20 DAT 38.80 49.37 88.17 44.01 T9 Pretilachlor (750 g a.i /ha) at 3 DAT+ Penoxsulam (22 g a.i /ha) at 25 DAT 38.47 49.25 87.72 43.86 T10 Pretilachlor (750 g a.i /ha) at 3 DAT+ Penoxsulam (22 g a.i /ha) at 30 DAT 37.40 49.20 86.60 43.19   SEm 1.27 1.70 2.97 1.51   C.D .(P=0.05) 3.68 4.93 8.60 4.36 Treatments Yield (q ha -1 ) Harvest index (%) Grains Straw Biological T1 Weedy check 22.33 40.30 62.63 35.65 T2 Weed free 44.73 53.40 98.13 45.58 T3 One HW at 40 DAT+ Bispyribac -Na (25 g a.i /ha) at 15 DAT 34.07 46.96 81.03 42.05 T4 Penoxsulam (22 g a.i /ha) at 20 DAT 33.73 46.90 80.63 41.83 T5 One HW at 15 DAT+ Penoxsulam (22 g a.i /ha) at 30 DAT 35.20 48.17 83.37 42.22 T6 One HW at 20 DAT+ Penoxsulam (22 g a.i /ha) at 35 DAT 35.14 48.04 83.18 42.25 T7 One HW at 25 DAT+ Penoxsulam (22 g a.i /ha) at 40 DAT 34.97 47.96 82.93 42.17 T8 Pretilachlor (750 g a.i /ha) at 3 DAT + Penoxsulam (22 g a.i /ha) at 20 DAT 38.80 49.37 88.17 44.01 T9 Pretilachlor (750 g a.i /ha) at 3 DAT+ Penoxsulam (22 g a.i /ha) at 25 DAT 38.47 49.25 87.72 43.86 T10 Pretilachlor (750 g a.i /ha) at 3 DAT+ Penoxsulam (22 g a.i /ha) at 30 DAT 37.40 49.20 86.60 43.19   1.27 1.70 2.97 1.51   C.D .(P=0.05) 3.68 4.93 8.60 4.36 Chaudhary et.al. ( 2020) SVPUA&T, Meerut

18. Table no. 3: Effect of Treatments on Economics analysis of rice cultivation Treatment s Cost of cultivation Rs/ha Gross return Rs/ha Net return Rs/ha Benefit : cost Weed check 36624 53066 16442 1.45 Weed free 44814 98100 53286 2.19 1 HW at 40 DAT + Bispyribac - Na (25 g a.i ./ha) at 15DAT 39564 76606 37042 1.94 Penoxsulam (22 g a.i ./ ha) at 30 DAT 37108 75965 38857 2.05 1 HW at 15 DAT + Penoxsulam (22 g a.i ./ ha) at 30 DAT 39494 79043 39549 2.00 1 HW at 20 DAT + Penoxsulam (22 g a.i ./ ha) at 35 DAT 39514 78894 39380 2.00 1 HW at 25 DAT + Penoxsulam (22 g a.i ./ ha) at 40 DAT 39534 78558 39024 1.99 Pretilachlor (750 g a.i ./ hac ) at 3 DAT + Penoxsulam (22 g a.i ./ ha) at 20 DAT 37852 86009 48157 1.27 Pretilachlor (750 g a.i ./ hac ) at 3 DAT + Penoxsulam (22 g a.i ./ ha) at 20 DAT 37872 85367 47495 2.25 Pretilachlor (750 g a.i ./ hac ) at 3 DAT + Penoxsulam (22 g a.i ./ ha) at 20 DAT 37892 83389 45497 2.20 SEm + - 2842.60 1496.54 0.07 C.D.(p=0.05) - 8221.91 4328.58 0.21 Chaudhary et.al., 2020 SVPUA&T , Meerut

19. Table no. 6: Effect of weed management Practices on plant height Treatments Doses(g/ha) TOA Plant height 90 days At harvest Penoxsulam + butachlor 717.5 7 DAT 94.7 108.4 Penoxsulam + butachlor 820 7DAT 94.4 107.2 Penoxsulam 25 8-12 DAT 93.2 106.6 Butachlor 1500 1-3 DAT 94.0 106.3 Bispyribac sodium 25 20 DAT 94.2 106.1 Weed free condition (25, 45 and 75) - - 93.8 106.4 HW twice (25and 45 DAT) - - 93.7 105.5 Weedy check - - 87.9 100.4 Natural farming (25 and 45 DAT) - - 84.2 96.9 SE(m=) 0.9 1.0 CD(P= 0.05) 2.7 3.0 Palampur , HP Abha Sharma, 2017

20. Treatments Doses(g/ha) Time of application Number of tillers 90 DAT Harvest Penoxsulam+butachlor 717.5 7DAT 285.0 Effective Total 274.2 320.8 Penoxsulam+butachlor 820 7 DAT 291.7 265.0 313.3 Penoxsulam 25 8-12 DAT 295.0 268.3 318.3 Butachlor 1500 20 DAT 283.3 257.5 305.8 Bispyribac sodium 25 20DAT 286.7 266.7 312.5 Weed free(25,45&75 DAT) - - 296.7 267.5 310.8 HW twice(25 and 45DAT) - - 285.8 260.8 309.2 Weedy check - - 260.3 227.5 270.8 Natural farming(HW at 25 & 45) - - 265.0 236.7 280.0 SE (m ±) - - 5.5 6.0 5.8 CD(P=0.05) - - 16.4 18.1 17.5 Abha Sharma, 2017 Table no. 4: Effect of weed management on tillers (number/   Palampur , HP

21. Treatments Dose(g/ha) Time of application Cost of cultivation Gross return(₹/ha) Net return(₹/ha) Net return/ ₹ invested Penoxsulam + butachlor 717.5 7DAT 32080 106941 74861 2.34 Penoxsulam + butachlor 820 7 DAT 32330 103904 71574 2.21 Penoxsulam 25 8-12 DAT 32410 101983 69553 2.15 Butachlor 1500 20 DAT 31230 96965 65735 2.10 Bispyribac sodium 25 20DAT 32330 100810 68480 2.12 Weed free(25,45&75 DAT) - - 45810 103126 57316 1.25 HW twice(25 and 45DAT) - - 40410 94100 53690 1.33 Weedy check - - 29610 69675 40065 1.35 Natural farming(HW at 25 & 45) - - 38997 78826 39829 1.02 Price of grain : Rs. 14.7/kg Price of straw: Rs. 2.5/kg Table no.5: Effect of weed management on gross return, net return & net return per rupee invested Palampur , HP Abha Sharma, 2017

22. Table no. 7: Effect of weed Management practices on Length (cm ), no. of grains/panicle, grain weight/panicle(g) and T est weight (g) Treatments Dose (g/ha) Time of Application Panicle length (cm) Number of grains per panicle Grain weight per panicle 1000 grain weight Penoxsulam + Butachlor 717.5 7 DAT 24.4 104.5 2.63 24.6 Penoxsulam + Butachlor 820 7 DAT 24.2 101.0 2.51 24.3 Penoxsulam 25 8-12 DAT 24.5 99.6 2.52 24.9 Butachlor 1500 1-3 DAT 24.8 103.8 2.46 23.2 Bispyribac sodium 25 20 DAT 24.0 99.1 2.52 24.7 Weed free condition (25, 45 ,75 DAT) - - 24.0 100.6 2.57 24.4 HW twice (25, 45 DAT) - - 23.1 98.1 2.44 24.3 Weedy check - - 22.1 84.4 2.13 24.6 Natural farming ( hand weeding at 25 & 45 DAT) - - 22.9 92.1 2.25 24.0 SE (m ) - - 0.3 1.9 0.06 0.6 CD (p= 0.05) - - 0.84 5.6 0.17 NS Treatments Dose (g/ha) Time of Application Panicle length (cm) Number of grains per panicle Grain weight per panicle 1000 grain weight Penoxsulam + Butachlor 717.5 7 DAT 24.4 104.5 2.63 24.6 Penoxsulam + Butachlor 820 7 DAT 24.2 101.0 2.51 24.3 Penoxsulam 25 8-12 DAT 24.5 99.6 2.52 24.9 Butachlor 1500 1-3 DAT 24.8 103.8 2.46 23.2 Bispyribac sodium 25 20 DAT 24.0 99.1 2.52 24.7 Weed free condition (25, 45 ,75 DAT) - - 24.0 100.6 2.57 24.4 HW twice (25, 45 DAT) - - 23.1 98.1 2.44 24.3 Weedy check - - 22.1 84.4 2.13 24.6 Natural farming ( hand weeding at 25 & 45 DAT) - - 22.9 92.1 2.25 24.0 - - 0.3 1.9 0.06 0.6 CD (p= 0.05) - - 0.84 5.6 0.17 NS Abha , Sharma 2017 Palampur , HP

23. Table no. 8: Effect of weed Management Practices on Dry Matter Accumulation of crop Treatments Doses(g/ha) Time of application Dry matter accumulation 30 days 60 days 90 days Penoxsulam + butachlor 717.5 7 DAT 619.7 963.3 1320.0 Penoxsulam + butachlor 820 7DAT 615.7 930.0 1243.3 Penoxsulam 25 8-12 DAT 593.3 906.7 1270.0 Butachlor 1500 1-3 DAT 586.7 880.0 1213.3 Bispyribac sodium 25 20 DAT 576.7 946.7 1306.7 Weed free condition (25, 45 and 75) - - 581.7 936.7 1333.3 HW twice (25and 45 DAT) - - 573.3 841.7 1140.0 Weedy check - - 531.7 733.3 973.3 Natural farming (25 and 45 DAT) - - 500.0 731.7 1041.7 SE(m=) 16.3 34.8 50.7 CD(P= 0.05) 49.0 104.4 151.9 Abha Sharma, 2017 Palampur , HP

24. Treatments Dry matter of grassy weeds(g/ ) Dry matter of BLW weeds(g/ ) Dry matter of sedges(g/ ) Total weed density (no./ ) Weed control efficiency% Grain yield (kg/ha) 60 DAT 90 DAT 60 DAT 90DAT 60 DAT 90DAT 60 DAT 90 DAT Trisulfuron 20 WG@8g/ha 8.22 9.33 2.92 3.83 2.55 3.82 9.07 39.5 4808 Trisulfuron 20 WG@10g/ha 7.99 8.61 1.91 2.10 2.45 3.10 8.13 54.7 5384 Trisulfuron 20 WG@12g/ha 7.69 8.37 1.0 1.00 2.27 2.80 7.35 59.6 5786 Metasulfuron methyl 20 WG@4 g/ha 8.73 10.14 2.28 2.94 2.88 3.92 9.13 34.0 4417 Ethoxy sulfuron 15 WDG@15g/ha 8.36 9.80 2.95 4.28 1.00 1.00 7.80 42.3 5043 2,4-D@ 500 g/ha 8.44 10.15 2.46 3.18 2.60 3.58 9.21 34.6 4707 Weed free 1.00 1.00 1.0 1.0 1.00 1.00 1.0 100.0 6513 Weedy check 8.53 9.97 5.84 8.75 2.90 3.91 12.19 0.0 2705 S.Em ± 0.14 0.11 0.21 0.13 0.11 0.18 0.25 - 57 CD at 5% 0.43 0.34 0.63 0.40 0.33 0.52 0.76 - 173 Treatments Weed control efficiency% Grain yield (kg/ha) 60 DAT 90 DAT 60 DAT 90DAT 60 DAT 90DAT 60 DAT 90 DAT Trisulfuron 20 WG@8g/ha 8.22 9.33 2.92 3.83 2.55 3.82 9.07 39.5 4808 Trisulfuron 20 WG@10g/ha 7.99 8.61 1.91 2.10 2.45 3.10 8.13 54.7 5384 Trisulfuron 20 WG@12g/ha 7.69 8.37 1.0 1.00 2.27 2.80 7.35 59.6 5786 Metasulfuron methyl 20 WG@4 g/ha 8.73 10.14 2.28 2.94 2.88 3.92 9.13 34.0 4417 Ethoxy sulfuron 15 WDG@15g/ha 8.36 9.80 2.95 4.28 1.00 1.00 7.80 42.3 5043 2,4-D@ 500 g/ha 8.44 10.15 2.46 3.18 2.60 3.58 9.21 34.6 4707 Weed free 1.00 1.00 1.0 1.0 1.00 1.00 1.0 100.0 6513 Weedy check 8.53 9.97 5.84 8.75 2.90 3.91 12.19 0.0 2705 S.Em ± 0.14 0.11 0.21 0.13 0.11 0.18 0.25 - 57 CD at 5% 0.43 0.34 0.63 0.40 0.33 0.52 0.76 - 173 Samartha Tewari et.al. , 2018 GBPUA&T, Pantnagar Table no. 9: Effect of treatments on dry matter of grassy weeds, broadleaf weeds, sedges, weed density, WCE and rice grain yield

25. Treatments Grain yield (t/ha) Straw yield (t/ha) % increase of grain yield over control Weed index (%) Butachlor (T1) 2.39 3.21 26.45 36.09 Penoxsulam (T2) 2.86 3.77 51.32 23.52 Penoxsulam (T3) 3.12 4.19 65.07 16.57 Penoxsulam (T5) 3.32 3.59 75.77 11.22 Penoxsulam (T6) 3.53 4.73 88.67 5.61 HW Twice(T7) 3.74 4.95 97.88 Non Weeded control(T8) 1.89 2.52 49.46 SE (m)± 0.14 0.30 - - CD (P=0.5) 0.30 0.65 - - Table no. 10: Effect of different treatments on yield of rice (Pooled data of two years) Nadia, West Bengal Pal et. al.(2009 )

26. Treatments Weed density (no.) Weed biomass(g/ ) Weed control efficiency(%) 90 DAT 90 DAT 90 DAT Butachlor (T1) 1.5 kg a.i ./ha 32.60 15.05 40.27 Penoxsulam (T2) 0.0225 kg a.i ./ha 27.50 14.15 43.84 Penoxsulam (T3) 0.0250 kg a.i ./ha 20.75 11.77 53.57 Penoxsulam (T5) 0.0200 kg a.i ./ha 30.59 14.75 41.46 Penoxsulam (T6) 0.0225 kg a.i ./ha 17.25 9.50 62.30 HW Twice(T7) 15.68 7.10 71.82 Non Weeded control(T8) 50.45 25.20 SE (m)± 1.21 0.50 - CD (P=0.5) 2.62 1.08 - Treatments Weed density (no.) Weed control efficiency(%) 90 DAT 90 DAT 90 DAT Butachlor (T1) 1.5 kg a.i ./ha 32.60 15.05 40.27 Penoxsulam (T2) 0.0225 kg a.i ./ha 27.50 14.15 43.84 Penoxsulam (T3) 0.0250 kg a.i ./ha 20.75 11.77 53.57 Penoxsulam (T5) 0.0200 kg a.i ./ha 30.59 14.75 41.46 Penoxsulam (T6) 0.0225 kg a.i ./ha 17.25 9.50 62.30 HW Twice(T7) 15.68 7.10 71.82 Non Weeded control(T8) 50.45 25.20 SE (m)± 1.21 0.50 - CD (P=0.5) 2.62 1.08 - Table no. 11: Effect of different treatments on weed density, weed biomass & weed control efficiency (pooled data of two years) Pal et.al. (2009) Nadia, West Bengal

27. Table 12: Effect of Acetachlor + Bensulfuron -methyl on weeds and transplanted rice Treatment Total weed population (No.m -2 ) Weed dry weight (g m -2 ) Panicles (No. m -2 ) Grain yield (kg ha -1 ) Acetachlor+Bensulfuron-methyl 59.3 (7.7)* 73.5 (8.6) 137 3215 Acetachlor + Bensulfuron -methyl 53.3 (7.3) 70.4 (8.4) 142 3965 Acetachlor+Bensulfuron-methyl 46.6 (6.8) 64.3 (8.0) 154 4015 Acetachlor+Bensulfuron -methyl 47.3 (6.9) 59.9 (7.7) 167 4565 Acetachlor + Bensulfuron -methyl 42.3 (6.5) 42.1 (6.5) 176 5480 Pretilachlor 58.7 (7.6) 100.2 (10.0) 135 3480 Butachlor 48.0 (6.9) 81.4 (8.9) 162 4050 Weed-free 0.0 (0.7) 0.0 (0.7) 182 5925 Unweeded 92.3 (9.6) 152.3 (12.3) 116 3030 LSD (P=0.05) 0.8 1.3 24 505 Jabalpur Dubey et al. (2015)

28. Table 13: Effect of herbicide application on weed growth in transplanted rice Treatment Total weed density at 40 DAT (no. m -2 ) Total weed dry matter at 40 DAT (gm -2 ) Weed control efficiency(%) Bispyribac -sodium @ 20 g a.i ./ ha at 25 DAT 4.90 1.39 93.58 Bispyribac -sodium @ 25 g a.i ./ ha at 25 DAT 4.50 1.30 94.67 Bispyribac -sodium @ 30 g a.i ./ ha at 25 DAT 3.97 1.17 96.08 CFB @90g a.i ./ha at 15 DAT fb 2,4-D-Na@ 0.8 kg a.i ./ha at 30 DAT 6.56 1.68 91.84 CFB @90g a.i ./ha at 15 DAT fb MSM + CME ( Almix ) @4g a.i ./ha at 30 DAT 5.75 1.52 89.69 Hand weeding at 20, 40 DAT 0.71 0.71 100 Weedy check 9.51 4.77 - LSD (P=0.05) 0.86 0.25 NA West Bengal Das et al. (2017)

29. Table 15: E ffect of herbicide application on yield and yield attributing factors in transplanted rice Treatment Effective tillers m -2 Panicle length (cm) Grains panicle -1 Grain yield (kg ha -1 ) Bispyribac -sodium @ 20 g a.i ./ ha at 25 DAT 345 2.97 122 4998 Bispyribac -sodium @ 25 g a.i ./ ha at 25 DAT 368 3.10 126 5176 Bispyribac -sodium @ 30 g a.i ./ ha at 25 DAT 373 3.28 133 5549 CFB @90g a.i ./ha at 15 DAT fb 2,4-D-Na@ 0.8 kg a.i ./ha at 30 DAT 318 2.83 112 3772 CFB @90g a.i ./ha at 15 DAT fb MSM + CME ( Almix ) @4g a.i ./ha at 30 DAT 331 2.92 120 4376 Hand weeding at 20, 40 DAT 400 3.45 148 6143 Weedy check 247 2.43 96 2961 LSD (P=0.05) 36.71 0.27 18.40 575.57 West Bengal Das et al. (2017)

30. Table no.16: E ffect of herbicide application on economics of transplanted rice Treatment Net profit (₹ ha -1 ) Benefit: cost ratio Bispyribac -sodium @ 20 g a.i ./ ha at 25 DAT 45256 2.21 Bispyribac -sodium @ 25 g a.i ./ ha at 25 DAT 47101 2.26 Bispyribac -sodium @ 30 g a.i ./ ha at 25 DAT 52148 2.41 CFB @90g a.i ./ha at 15 DAT fb 2,4-D-Na@ 0.8 kg a.i ./ha at 30 DAT 33757 1.94 CFB @90g a.i ./ha at 15 DAT fb MSM + CME ( Almix ) @4g a.i ./ha at 30 DAT 26334 1.69 Hand weeding at 20, 40 DAT 50615 2.33 Weedy check 14318 1.39 LSD (P=0.05) 8055.46 0.21 West Bengal Das et al. (2017)

31. Improper usage of dosages. Improper mixing with sand. Faulty use of chemical. Wrong maintenance of water. Using sprayer for herbicide application which was earlier used for insecticide or fungicide application without proper cleaning. General m istake made by f armers while herbicide application

32. Conclusion It is conclusively inferred that combination of herbicide penoxsulam + butachlor @ 717.5 g/ha is an effective substitute of the recommended herbicide. penoxsulam + butachlor @ 717.5 g/ha combination product did not show any phytotoxic effect on rice crop. Appliction of petrilachlor (750g a.i .) at 3 DAT + penoxsulam (22g a.i ./ha) at 20 DAT most effective for weed control and resulted into higher weed control efficiency.

33. Future work 1. M ore combinations of herbicides with various doses should be studied in different crops. 2. Keeping in view the soil health the organic sources of the herbicides should be considered so that the resistant species of the weeds can be overcome. 3. Herbicide mixtures should be worked upon keeping in view the importance of different modes of action.

34. Thank you