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AICRP on Weed Management
(AICRP-WM)

Achievements

Achievements (2019-20)

WP 1. Development of sustainable weed management strategies in diversified cropping systems

  • Under different tillage and residue management scenarios, population density and dry weight of P. minor was lower in case of zero till wheat with or without residue compared to conventional tillage, while, it was reverse in case of broad leaved weeds at Hisar and Ludhiana.
  • Application of mesosulfuron-iodosulfuron at 14.4 g/ha along with one hand weeding resulted in more grain yield as compared to alone application of the same herbicide. Rice grain yield was similar under all the treatments in Kharif conventional till-puddle transplant rice (CT-PTR).
  • Significantly higher grain yield and economics were recorded in zero tillage in ZT+R-ZT+R system and in PE pendimethalin at 1.0 kg/ha + HW on 45 DAS in sunflower crop. Whereas, in maize, ZT-ZT+R system and in PE atrazine at 0.5 kg/ha + HW resulted in higher productivity and income in maize under maize–sunflower cropping system at Coimbatore.
  • In rice-wheat-cowpea fodder cropping system, CT had 6.3% higher resource use efficiency (RUE) over ZT; transplanting  had 12.5% higher RUE over direct seeding; chemical weed control higher RUE by 69.2% over unweeded, while, IWM found to be 85.1% more efficient over unweeded. Significantly lower weed dry matter was recorded under ZT (DSR) + R-ZT+R-ZT+R treatment in Summer-cowpea fodder at Raipur. Among different tillage practices, highest net return and benefit: cost ratio was obtained under ZT (Direct seeded) + R-ZT +R-ZT+R followed by ZT (Direct seeded) – ZT+R-ZT. ZT+R had 17.4% higher efficiency over CT; weed control by 145.1% over unweeded and integrated weed control by 161.3% over unweeded.
  • The practice of CT (transplanted rice) in Kharif followed by ZT in maize in Rabi and ZT in cowpea in summer with recommended herbicides resulted in the highest system productivity with minimum weed dynamics (weed count & dry matter). Increase of 20% of grassy weed population in ZT-ZT-ZT system and 15% in CT-ZT-ZT system was found in comparison to the base year of (i.e 2014) in CT-CT system at Bhubaneswar.
  • Among the different establishment methods, wheat grain yield and B: C ratio (3.2) was highest under conventional wheat after direct seeding of rice without residue and sesbania incorporation at Pantnagar. Whereas, significantly highest grain yield, net return and B:C ratio of rice was achieved under conventional transplanting of rice followed by ZT wheat along with residue and sesbania incorporation. Among weed management practices, IWM resulted in maximum grain yield of rice and B:C ratio.
  • The lowest dicot weed density and maximum seed yield was recorded with early post emergence application of atrazine 500 g/ha fb tembotrione 120 g/ha + HW at 40 DAS in maize which was statistically at par with early post-emergence application of atrazine 500 g/ha with topramazone 25.2 g/ha fb hand weeding at 40 DAS (4.48 t/ha) and two manual weeding at 15 & 35 DAS (4.10 t/ha) Udaipur, Bhubaneswar, Kalyani and Akola.
  • In CA based rice-wheat system, CT (-residue) had highest soil weed seed bank; residue incorporation with MB plough had lower density of P. minor than incorporation with rotavator. All CT and ZT (+/- residue) gave similar wheat yield at Ludhiana.
  • The grain yield of rice of the system significantly increased under MT (DSR) and CT (TR) compared to CT (DSR) at Jorhat under rice-mustard cropping system at Jorhat. Higher phosphate solubilising bacteria, azotobacter and azospirillum population were observed under MT (DSR).
  • Amongst all tillage and weed management combinations, highest net returns and B: C ratio were recorded in ZT-DSR+R and integrated weed management (Pendimethalin 1.0 kg/ha as PE fb bispyribac-sodium 25 g/ha at 25 DAS fb HW at 45 DAS) in rice. In wheat, ZT-wheat + crop residue with integrated weed management (sulfosulfuron + metsulfuron 30+2 g/ha at 30 DAS + HW at 45 DAS) gave higher grain yield and B: C ratio with lowest weed density, weed biomass and weed control efficiency in rice-wheat-greengram cropping system under CA at Jammu.

 

WP 1.2 Weed management in organic cropping systems

  • At Anand, significantly higher rturmeric rhizome yield of 24.2 t/ha was found under wheat straw mulch 5 t/ha (0-3 DAP) fb HW at 30, 60 and 90 DAP. Maximum gross return, net return and benefit cost ratio (2.15) was achieved under wheat straw mulch 5 t/ha (0-3 DAP) fb HW at 30, 60 and 90 DAP which was closely followed by paddy straw mulch 5 t/ha (0-3 DAP) fb HW at 30, 60 and 90 DAP which recorded.
  • At Hyderabad mulching with polysheet (25 microns) + HW in the inter row at 30 DAS  proved effective followed by cultural practice involving MW at 20 & 40 DAS (2631kg/ha) and straw mulch (5t/ha) fb intra row weeding and SSB preparation fb HW at 20 & 40 in okra under okra-carrot under organic cropping system.
  • The highest weed control efficiency (WCE) was recorded in paddy straw mulch +1 hand weeding at 30 DAT along with significantly higher curd yield of broccoli than rest of treatments in basmati rice-broccoli-Sesbania (green manure) cropping system at Jammu. In rice, stale seedbed + one hand weeding at 30 DAT recorded highest WCE along with highest benefit cost ratio thus found suitable for weed control in organic farming.
  • At Jorhat, green leaf yield of tea under organic management was found to be the highest at all the plucking stages in case of bio-degradable film mulching due to effective management of weeds.
  • Lowest weed density and dry matter at 30 and 60 DAS was recorded by summer ploughing with plastic mulching at sowing in sweet corn. Maximum values of green cob yield and green fodder yield of sweet corn were recorded with crop sown with treatment of soil solarization with plastic mulch at Udaipur.
  • Mulching with polythene sheet controlled weed growth effectively under turmeric- cowpea organic cropping system. Among organic mulches, mulching with grass clippings and coconut fronds reduced weed dry matter production to the greatest extent at 90 and 135 days after planting. Highest rhizome yield and B:C ratio were obtained on mulching with polythene sheet Thrissur.
  • Seed yield of foxtail millet was significantly higher in hand weeding at 20 and 40 DAS which was on par with Stale seed bed technique + intercultivation twice at 25 & 45 days after sowing at Bengaluru.

WP 2 Weed dynamics and management under the regime of climate change and herbicide resistance

  • High infestation of Argemone mexicana was observed in different parts of Gujarat. Fumeria parviflora in wheat crop in north Gujarat zone was recorded during survey work.
  • A broad-leaved weed Nicandra physaloides has extended its distribution from Tinsukia district to Jorhat district.
  • Severe infestation of Alternanthera philoxeroides in peach orchard and Aeschynomene indica and Phasalis minima in soybean was found at Palampur.
  • One new weed species found in Kodicherla village of Kothur mandal of Mahabubnagar district and identified as Solanum melongena var. insanum(L.).
  • In Punjab, Phalaris minor populations from farmers’ field showed moderate to higher level of resistance to sulfosulfuron, clodinafop, pinoxaden and/or mesosulfruon + iodosulfuron, however, no resistance to pre-mix of clodinafop plus metribuzin was recorded. GR50 values confirmed presence of high levels of resistance in minor to herbicides commonly used for its control in wheat.
  • On the basis of Taxonomic and Phyto-geographic assessment, 10 taxa of Spilanthes under eight species have been recognized in India that belonged to Acmella.
  • Heavy infestation of Hyptis suoveolenc was observed along the road sides in Eastern Vidarbha. Heavy Infestation of Cuscuta was observed in farmers field in soybean and pigeonpea crop in western vidarbh districts.
  • Celosia argentea is observed to be a severe problem in Odisha. Cuscuta chinensis was found to be a major parasitic weeds in the niger crop in the North eastern ghat zone.
  • New weed, Ethulia gracilis: belongs to Astraceae family was first noticed at Nippani, Belgavi district in maize and groundnut crop and fallow land.

WP 3 Biology and management of problem weeds in cropped and non-cropped areas

  • Application of sulfosulfuron 25 g/ha at 30 DAT fb 25 g/ha at 60 DAT resulted in the lowest number of Orobanche/plant, lowest total weed density at 60 and 90 DAP at Bhubaneswar.
  • Maximum fruit yield was recorded with the use of ethoxysulfuron 50 g/ha at 60 and 90 DAP in tomato which was at par with sulfosulfuron treatments at Udaipur. Similarly, application of ethoxysulfuron twice; 20 g/ha at 45 DAT fb 15 g/ha at 90 DAT found effective in reducing the Orobanche infestation and increasing brinjal yield by 11% over farmers practice at Hisar.
  • Neem cake 200 kg/ha fb glyphosate 30 g/ha was effective in controlling Orabanche Mulching with polysheet delayed emergence and lowered the incidence of Oranbanche at Hyderabad,
  • At Gwalior, early post emergence application of pendimethalin 1.0 kg/ha (after 10 DOS) produced higher fodder and seed yield with total three cuts and application of imazethapyr 40 g/ha after 1st cut + again applied after last cut were also found effective to control the Cuscutta reflexa and other weeds, higher berseem fodder yield (74 t/ha) with seed yield (248 kg/ha) and B:C ratio.
  • Soil application of Mycorrhizal consortium 8 kg along with 200 kg of compost/acre at the time of planting, resulted in an increased sugarcane yield up to 5% with a  B: C ratio of 2.51 for control of Striga in sugarcane.
  • Effective control of Water hyacinth was found by Neochetina bruchi introduced in 2016 and reoccurrence of water hyacinth has not been observed in the ponds of Morena district till 2020.

WP 4 Monitoring, degradation and mitigation of herbicide residues and other pollutants in the environment

  • Dissipation of imazethapyr was positively correlated with soil pH & temperature and negatively correlated with soil organic matter. Half-life of bispyribac-sodium decreased in rice husk and its biochar amended soils and ranged from 23.1 to 28.6 and 7.5 to 18.4 days in unamended and amended soil. The enzymatic and bacterial activity increased in amended soils and initial inhibition in activity after herbicide application was observed at Ludhiana .
  • More than 75% tembotrione applied at 60, 120 and 240 g/ha, dissipated from  soil within 15 days after herbicide application. Residues of bispyribac-sodium in rice and, metsulfuron-methyl and clodinafop in wheat were found BDL in the samples collected from farmers fields of Kangra district at the harvest of the crop.
  • Residues of bispyribac-sodium in the soil samples, rice grain and straw samples collected at harvest were below the detectable limit of 0.010 ppm in aerobic and transplanted rice treatments at Hyderabad.
  • Effect of herbicides on dehydrogenase enzyme activity at the time of flowering or harvest was non-significant in rice. Residues of pendimethalin in okra samples was below the detection limit of 0.05 mg/kg.
  • At Coimbatore, the residues of atrazine and pendimethalin in soil and maize grain were below 0.01 mg/kg irrespective of the tillage management practices followed for weed control. Residues of oxyfluorfen were not detected at the  time of harvest in soil aswell as in onion plant top.

WP 5 On-Farm Research and Front Line Demonstration

  • Pre-emergence use of pyroxasulfone at 127.5 g/ha demonstrated in rice-wheat growing areas of Haryana provided 84% control of multiple herbicide resistant P. minor whereas integration of this herbicide with pendimethalin at 1.5 kg/ha (PRE) and post emergence herbicides at 35 DAS provided 92% control of P. minor with higher grain yield.
  • At Udaipur, demonstrations on Orobanchae management in tomato and bringal were conducted with single application of ethoxysulfuron 20 g/ha at 45 DAT provided effective weed control up to 70-75 DAS, however, supplementation of second spray of ethoxysulfuron 15 g/ha at 90 DAT  not only prolonged the effective period of weed control, but also increased 10.6% tomato and brinjal fruit yield in comparison to farmers practice of manual control.
  • Demonstrations on weed management in maize at village Kanthoda and Bootwas were conducted showed maximum grain and straw yield with the application of atrazine fb tembotrione (500 g/ha as PE + 120 g/ha at 3-4 leaf stage 15 DAS) and it was 10.5% higher over farmers practice.
  • FLDs were conducted on transplanted rice and Kharif maize in villages of Puri district resulted in 20-  30% yield increase with the application either pre-emergence pretilachlor or post emergence application of  bispyribac-sodium at 25 DAT in rice and application of pendimethalin 750 g/ha in maize over farmers’ practice (One HW).
  • Application of atrazine 1000 g/ha PE fb topramezone 25.2 g/ha PoE was found effective with higher B:C ratio (2.21) as compared to farmers practices IC+HW at 20 and 40 DAS (1.94) under FLD. In wheat, B:C ratio of 2.82 achieved by the application of clodinafop-propargyl + metsulfuron-methyl 64 g/ha PoE (RM) as compared to farmers  practices IC+HW at 20 and 40 DAS (2.26) at Anand .
  • Post emergence application of glyphosate 25 g/ha at 30 DAS followed by its use at 50 g/ha at 50-60 DAS provided 79.5% control of Orobanche in mustard with yield gain of 33.6% over untreated control based on 199 FLDs conducted at Bhiwani, Hisar and Mahendergarh districts.
  • At Coimbatore under OFR and FLDs, PE oxyflourfen 200g/ha + Hand weeding on 25-30 DAP recorded higher bulb yield (13.8 to 14.7 t/ha) and net return (Rs. 1.90 – 2.10 lakh/ha). On an average, the tomato yields increased ranging from 21.2 to 38.9% over farmers practice (two HW). Higher income also obtained by improved practice over farmers practice.
  • In pearlmillet, chemical weed management practices gave higher grain yield over farmers practice. Maximum yield of 2.01 t/ha was obtained with the application of atrazine 500g/ha PE + 2,4-D 500g/ha (PoE)  fb atrazine 500 g/ha alone, which was 40% higher than farmers practice. Similarly higher B:C ratio of 1.45 was recorded in atrazine 500g/ha PE + 2,4-D 500g/ha (PoE).