Weed management

Tamil Nadu Agricultural University > Regional Research Station - Paiyur > Weed management

Weed management

Weed Management

  • In wet seeded rice, pre-emergence application of pendimethalin 1.0 kg /ha at 8 DAS fb POE bispyribac sodium 25 g/ha at 25 DAS fb HW on 45 DAS resulted in higher weed control efficiency (60.9 %) and grain yield of 5550 kg/ha which was 5.64 and 9.58 % higher than PE pendimethalin 1.0 kg/ha at 8 DAS fb hand weeding 25 DAS and cono weeder weeding at 10 and 25 DAS respectively. This treatment gave higher net return (Rs. 52209/ha) with Benefit Cost ratio of 2.45.
  • Pre-emergence application of pyrazosulfuron ethyl 10% WP @ 200 g ha-1 on 3 DAS followed by mechanical (cono weeder) weeding on 25 DAS is recommended for weed management in direct seeded puddled rice to meet the challenges against labour scarcity and weed infestation.
  • In the rainfed ecosystem of Ragi, Samai, Mochai , three groups of weeds were observed. Among the three groups, the broad leaved weeds registered higher weed density (25.3 No/m2) and was followed by grasses (10.4 No/m2). The only one sedge weed present in the survey  was  Cyperus rotundus
  • Application of Pendimethalin 30% EC + Imazethapyr 2% EC @ 1.0 kg a.i. ha-1 on 3 days after sowing of Green gram with one hand weeding at 30 days after sowing registered the highest growth attributes, yield attributes and grain yield (333 kg ha-1)  due to reduced weed density along with the highest net income (Rs.20,879 ha-1) and B:C ratio (2.32).
  • Pre-emergence application of pendimethalin 30% EC + imazethapyr 2% EC (Ready-mix) @ 1.0 kg/ha on 3 DAS + one hand weeding at 30 DAS was found to be an effective weed management practice for greengram, which recorded lower weed density (5.6 Nos./m2) and weed dry weight (61.9 kg/ha) at harvest stage and higher number of pods/plant (53.0), seeds/pod (10.3), grain yield (990 kg/ha) and registered maximum net return (Rs.30,612/ha) and Benefit Cost ratio (2.34).
  • In Redgram, foliar spray with 0.5% mono ammonium phosphate (MAP) at first  flowering and  15 days after first spray recorded higher grain yield ( 2483 kg ha-1) with higher  growth and yield attributing characters like number of branches plant‑1, no. of pods plant-1, no. of seeds pod‑1 and 100 seed weight. Intervention of this management technique enhanced the net income as Rs. 95215/ha with the B:C ratio of 2.97.
  • Late sowing of horsegram after November failed to flower and set seeds. The integrated nutrient management practices (FYM@12.5tha-1+ recommended dose of inorganic fertilizer 44:22:0 kg ha-1 N, P2O5 and K2O + seed treatment with bio-fertilizers) applied to samai increased  the yield of residual horsegram over absolute control recording 413 kg ha-1 , which was  60.1 percent over absolute control.
  • Application of 100% RDF (200:150:150 kg NPK/ ha) + Vermicompost (5 t/ha) + ZnSO4 @ 25 kg/ha as soil application to African Marigold,recorded the yield per plant (790.7 g), duration of flowering for 109 days and yield of 19.7 t/ha with highest Benefit Cost Ratio of 3.5 when compared to the control recorded the lowest yield of 11.6 t/ha with BCR of 2.7. The Xanthophyll content (1.75 g/1000 g) was also highest in the same treatment. The yield increase was also 69.8% over the control.
  • In Thinai, Panivaragu and Kudiraivali,  seed priming with 2% KH2PO4 and 20 % Pseudomonas fluorescens improved the productivity better than unprimed and hydroprimed seeds
  • Horse gram seeds primed with 100ppm ZnSO4 (soaking duration of 3 hrs with seed to solution ratio of 1:1) recorded higher productivity than unprimed and hydroprimed seeds recorded 18.9 and 11.4 per cent increase in productivity respectively and was followed by the seeds primed with 200ppm ZNSO4, 10 and 20% P.fluorescens with higher resultant  seed quality. Primed seeds also stored well upto seven  months with higher germination and vigour (more than minimum seed certification standard  – MSCS).
  • The finger millet entry KRI 009-01 recorded the maximum morphological growth and growth attributes like crop growth rate and relative growth rate. In addition it had the maximum photosynthetic pigments, leaf proline content with more RWC and yield .Hence could be highly considered for the tolerance study for drought under rainfed conditions.
  • Foliar application of 1% KCl with 50 ppm BAP and 0.5 ppm BR at 60 days after sowing registered highest ragi grain yield of 23.03 Q ha-1 with BC ratio of 2.42 followed by foliar spray of 1% KCl + 0.5 ppm BR with the grain yield of 21.95 Q ha-1 and BC ratio of 2.33.
  • In red gram, foliar application of 0.5% Mono Ammonium Phosphate (MAP) twice at flowering and 15 days thereafter registered higher yield parameters like number of pods/ plant (1210), number of seeds / pod (5.1) and 100 seed weight (12.7 g) resulting in higher grain yield of 2512 kg/ ha, net income of Rs. 95215/- and B:C ratio of 2.97.
  • In mango, fruit yield was the highest (198.45 kg/tree) with the foliar application of  KH2PO4 @ 1%  and was  followed by the spray of KNO3 @ 2% (186.22 kg/tree) .The yield of control plot was 134.80 kg/tree
  • Foliar application of 2% urea with 100 ppm salicylic acid at 30 and 60 days after transplanting registered highest fruit yield of 33.10 tonnes ha-1 with BC ratio of 3.86 followed by foliar spray of 2% MAP + 100 ppm salicylic acid with the fruit yield of 32.97 and BC ratio 3.42.
  • In production of organic finger millet under irrigated ecosystem application of Vermicompost @ 3.0 tonnes/ha (equivalent to 40 kg of recommended N) as basal  + seed treatment  with  Azophosmet + foliar spray of 3  per cent Panchagavya   at 20  and 40 DAS followed with another foliar spray with PPFM @ 500 ml ha-1 at flowering stage improved the productivity by  1010 kg/ ha.
  • Studies on the native mycorrhizal strains associated with root and soil samples of redgram, revealed that the  percentage colonization of micorrhiza was maximum in samples of M.Savalur and Pannihalli than Pochampalli, Velampatti, Karimangalam, Kallavi, M. Savalur, Varattampatti, Mittahalli, Santhoor, Mathur, Pannihalli and Melpaiyur