Search

A field experiment was conducted during the rabi season of 2020-21 in Kurnool district of Andhra Pradesh in a farmers's field to access the efficacy of integrated weed management on weed dynamics in blackgram (Vigna mungo L.). Data on weed dynamics revealed that significantly lesser weed density, weed dry weight and high weed control efficiency were obtained with application of Pendimethalin 30% EC @ 1.0 kg a.i. ha-1 as PE + Imazethapyr 10% SL @ 50 g a.i. ha-1 at 25 DAS as post-emergence. The higher values of all the weed dynamics except weed control efficiency were registered with the treatment Weedy check. Growth and yield parameters of blackgram viz., plant height, number of branches plant-1, number of leaves plant-1, LAI, CGR, RGR, number of pods plant-1, length of pods, number of seeds pod-1, test weight, grain yield, stover yield and harvest index were significantly higher with the application of Pendimethalin 30% EC @ 1.0 kg a.i. ha-1 as PE + Imazethapyr 10% SL @ 50 g a.i. ha-1 at 25 DAS as post-emergence. The highest net returns and benefit-cost ratio were also recorded with the application of Pendimethalin 30% EC @ 1.0 kg a.i. ha-1 as PE + Imazethapyr 10% SL @ 50 g a.i. ha-1 at 25 DAS as postemergence. [ABSTRACT FROM AUTHOR]

Field experiment was conducted to study the bio-efficacy of different herbicides on growth and yield of Coriander (Coriandrum sativum L.) at Zonal Agricultural Research Station, UAS, GKVK, Bengaluru during rabi 2020-21. The experiment was laidout in RCBD design with 12 treatments replicated thrice. Major weed floras in the experimental plots were Digitaria sanguinalis L., Echinochloa colonum L., Ageratum conyzoides L. and Mollugo verticillata L. At harvest lower weed density (37.48 no. m-2), weed dry weight (12.64 g m-2) and higher weed control efficiency (81 %) were recorded from intercultivation and hand weeding at 20 DAS and 40 DAS and among herbicides pendimethalin 38.7 EC @ 1000 g a.i. ha-1 (PE)-imazethapyr 10% SL @ 25 g a.i. ha-1 (PoE) recorded significantly lower weed density (60.45 no./m²), weed dry weight (21.73 g/m²) and higher weed control efficiency (67.51 %). Intercultivation and hand weeding at 20 DAS and 40 DAS recorded significantly higher seed yield (816 kg ha-1), gross return (Rs.66027 ha-1) and net return (Rs.27527 ha-1). Among the herbicides pendimethalin 38.7 EC @ 1000 g a.i. ha-1 (PE) - imazethapyr 10% SL @ 25 g a.i. ha-1 (PoE) recorded significantly higher seed yield (676 kg ha-1), gross return (Rs.53106 ha-1) and net return (Rs.25005 ha-1), was on par with Pendimethalin 38.7 EC @ 1000 g a.i. ha-1 (PE). The cost-benefit ratio was recorded higher in pendimethalin 38.7 EC @ 1000 g a.i. ha-1 (PE) followed by pendimethalin 38.7 EC 1000 g a.i. ha-1 (PE) - imazethapyr 10% SL @ 25 g a.i. ha-1 (PoE). Weedy check recorded lower seed yield, gross return, net return and cost-benefit ratio. [ABSTRACT FROM AUTHOR]

A field experiment was conducted during Kharif season of 2021 at research farm, Department of Agriculture Dev Bhoomi Uttrakahnd University, Dehradun, Uttrakhand, in order to investigate the response of different weed management strategies on growth & yield of black gram at Dehradun. The layout of experimental field was laid randomized blockdesign (RBD) with 10 treatments and 3 replications. Consisting of T1 Pendimethalin PE@(1000g/ha), T2 Pendimethalin PE@(500g/ha), T3 Pendimethalin PE@(500g/ha)+ Hand Weeding @ 40 DAS, T4 Imazethapyr P.OE @(500g/ha), T5 Imazethapyr P.OE @(1000g/ha), T6 Pendimethalin PE@(1000g/ha)+ Hand Weeding @ 20 DAS, T7 Hand Weeding @ 20 DAS& 40 DAS, T8 Hand Weeding @ 40 DAS, T9 Hand Weeding @ 20 DAS, T10 Weedy check (control plot). The results indicated that among all the treatments, T6 (Pendimethalin PE@(1000g/ha)+ Hand Weeding @ 20 DAS) overall was found best for farmer point of view with respect to plant height (60.66cm), branches/plant (15.66), seed yield (13.66q/ha), straw yield (81.00 q/ha). Based on present investigation, it can be concluded that the combination of both Pendimethalin PE@(1000g/ha)+ Hand Weeding @ 20 DAS are applied that improved growth and yield of black gram crop under present agro-climatic conditions. [ABSTRACT FROM AUTHOR]

Effects of various herbicides applied at different rates as pre-emergence or as post-emergence were studied on symbiotic parameters, growth, productivity and nutrient accumulation in mungbean. Pre-emergence application of pendimethalin 30 EC at 0.75 kg ha−1, pendimethalin 30 EC at 0.45 kg ha−1 + hand weeding (HW) at 4 weeks after sowing (WAS) and pendimethalin 30 EC + imazethapyr 2 SL (pre-mix) at 0.45 kg ha−1 + HW at 4 WAS had no/little inhibitory effect on symbiotic parameters (nodule number, nodule dry weight and leghaemoglobin content). Among herbicide treatments, pendimethalin 30 EC at 0.45 kg ha−1 + HW proved to be the best in influencing grain yield (1574 and 1246 kg ha−1 in 2016 and 2017, respectively) and nutrient uptake by crop (130.0–150.9 kg nitrogen, 13.6–16.4 kg phosphorus and 75.9–87.9 kg potassium ha−1) followed by pendimethalin 30 EC + imazethapyr 2 SL (pre-mix) at 0.45 kg ha−1 + HW (1528 and 1177 kg ha−1 grain yield, 123.9–140.9 kg nitrogen, 12.8–15.2 kg phosphorus and 71.5–81.5 kg potassium ha−1). Application of imazethapyr at 50 or 75 g ha−1 at 15 or 25 DAS had adverse effect on symbiotic parameters, grain yield and nutrient uptake. [ABSTRACT FROM AUTHOR]

A field experiment was conducted to study the effect of different land configuration and weed management treatments in greengram (Vigna radiata L.). The raised bed and ridge sown crop recorded significantly lower dry matter of weeds and significantly higher weed control efficiency (WCE) (78.4% and 78.1%, respectively ) than flat sown crop (68.5%). Raised bed sowing provided higher grain yield to the tune of 4.0 and 16.1% over ridge and flat sowing, respectively and gave significantly higher gross returns, net returns and B:C ratio than ridge and flat sowings. Application of pendimethalin @ 0.75 kg/ha as pre-emergence (PE) + imazethapyr @ 55 g/ha as post-emergence (POE) 15-20 days after sowing (DAS) and imazethapyr @ 55 g/ha (POE) 15-20 DAS recorded significantly lower dry matter of weeds and significantly higher WCE than pendimethalin @ 0.75 kg/ha (PE). The application of herbicides (pendimethalin as PE and imazethapyr as POE) had no adverse affect on symbiotic parameters. Pendimethalin @ 0.75 kg/ha (PE) + imazethapyr @ 55 g/ha 15-20 DAS provided significantly higher grain yield than the other treatments and gave the highest gross returns, net returns and B:C ratio. It can be concluded that sowing of greengram on raised bed land configuration along with application of pendimethalin @ 0.75 kg/ha (PE) + imazethapyr @ 55 g/ha 15-20 DAS was found to be effective for controlling weeds as well as improving the grain yield and providing higher net returns and B:C ratio.

The herbicides may have adverse effects on the soil microorganism. The aim of the study was to investigate the effects of herbicides pendimethalin and imazethapyr and mixture thereof on the growth of Rhizobium leguminosarum M-1, Rhizobium leguminosarum LSMR-1 and Strenotrophomonas maltophilia RB-3 in vitro and on soil microflora (bacteria, fungi and actinomycetes) at field conditions. The tolerance of Rhizobium and Stenotrophomonas to pendimethalin at 180–1980 mg/L and imazethapyr at 26–200 mg/L and mixtures thereof in nutrient media was tested. The tolerance for pendimethalin was higher than for imazethapyr. In field experiments with mungbean, the effects of pendimethalin alone as well as in mixture with imazethaypr at 0.45 and 0.75 kg ha−1 (applied as pre-emergence) and imazethapyr at 50 and 75 g ha−1 (applied at 15 and 25 days after sowing) in the rainy and summer season were tested. Pendimethalin and its mixture with imazethapyr did not influence the population of fungi and actinomycetes in rhizosphere (0–10 cm soil depth) at 35 days after sowing and at harvest. Imazethapyr treatments recorded inhibitory effects on bacterial population in rhizosphere at 35 days after sowing but no adverse effect was observed at harvest. Pendimethalin alone and in mixture with imazethapyr were found safe to investigated microorganism groups. [ABSTRACT FROM AUTHOR]

A field experiment was undertaken at PAU, Regional Station (Bathinda) to evaluate the effect of weed management practices on the performance of cluster bean [(Cyamopsis tetragonoloba (L.) Taub] under AICRP on Arid Legumes during the kharif season of 2015 and 2016. Data revealed that weed dry matter was lowest in case of weed free check (T8) as plots were kept weed free as per the treatment. Among other treatment combinations Pendimethalin @ 0.75 kg a.i./ha as PE + Imazethapyr+ Imazamox @ 40g a.i./ha at 2-3 leaf stage of weeds (T7) produced the lowest weed dry matter closely followed by Pendimethalin @ 0.75 kg a.i./ha as PE+ One Intercultivation at 20-25 DAS (T6) and Pendimethalin @ 0.75 kg a.i./ha as PE + Imazethapyr @ 40g a.i./ha at 2-3 leaf stage of weeds (T5). WCE was highest in weed free followed by Pendimethalin @ 0.75 kg a.i./ha as PE + Imazethapyr+ Imazamox @ 40g a.i./ha at 2-3 leaf stage of weeds (T7). Highest seed yield was recorded in weed free check followed by Pendimethalin @ 0.75 kg a.i./ha as PE + Imazethapyr @ 40g a.i./ha at 2-3 leaf stage of weeds (T5), Pendimethalin @ 0.75 kg a.i./ha + One Intercultivation at 20-25DAS (T6) and Pendimethalin @ 0.75 kg a.i./ha as PE + Imazethapyr+ Imazamox @ 40g a.i./ha at 2-3 leaf stage of weeds (T7). [ABSTRACT FROM AUTHOR]

Summary: Variable dormancies result in periodicity in the germination of weeds and make weed control a repetitive practice. Under some conditions, repeated applications of selective herbicides can lead to the dominance of perennial weeds like Cyperus rotundus. Our hypothesis was that applying a chemical dormancy breaker (DB) plus herbicide mixture would better control a mixture of weed species. Three experiments were designed to develop a cost‐effective DB treatment and to evaluate its dose with herbicides tank‐mixtures for effective weed management. KNO3 and gibberellic acid GA3 as dormancy breakers offered comparable effects, but KNO3 was more economical than GA3. KNO3 at a 6% concentration was more effective in promoting weed germination than a 3% concentration in soyabean. A combination of KNO3 (6%) and pre‐emergence pendimethalin 0.75 kg a.i. ha−1 + imazethapyr 0.10 kg a.i. ha−1 controlled annual weeds by 99% and reduced C. rotundus growth by 83%. This treatment gave significantly higher soyabean yield and net returns. Similarly, a tank‐mixture comprising of clodinafop 0.06 kg a.i. ha−1 + metsulfuron 0.006 kga.i. ha−1 was more effective against weeds than pre‐emergence tank‐mix application of pendimethalin 0.75 kg a.i. ha−1 + carfentrazone‐ethyl 0.02 kg a.i. ha−1 and isoproturon 0.75 kg a.i. ha−1. The use of pre‐emergence tank‐mixture of pendimethalin 0.75 kg a.i. ha−1 + imazethapyr 0.10 kg a.i. ha−1 should exhaust seed/tuber bank if repeated and reduce the application cost of herbicides by 50% and the dose, residue and cost of pendimethalin by 25%. [ABSTRACT FROM AUTHOR]

An experiment was conducted at Agronomy Research Station, Barkacha, Mirjapur 201–14 to assess the effect of mulching and weed management practices on weeds and nutrients uptake by greengram under agri-horti system. Three mulch treatments were taken in main plot (no-mulching, dust-mulching and paddy straw-mulching) and five weed control treatments (weedy check, weed free, pendimethalin pre-emergence (PE) 1000 g ha-1, imazethapyr post-emergence (PoE) 100 g ha-1 and pendimethalin (PE) 1000 g ha-1 followed by (ƒb) imazethapyr (PoE) 100 g ha-1) was randomly allocated to subplots and these were replicated thrice in split plot design. The results revealed that dust mulching recorded lowest density and dry weight of weeds, N, P, K depletion by weeds and resulted significantly the highest growth parameters (pant height, crop dry weight and branches palnt-1), N, P, K content and their uptake by crop, grain and straw yield, gross and net returns of greengram over paddy straw mulching and no-mulching, respectively. Pre-emergence application of pendimethalin (1000 g ha-1) ƒb post-emergence application of imazethapyr (100 g ha-1) recorded lowest density and dry weight of weeds, N, P, K depletion by weeds and recorded the highest growth parameters, grain and straw yield, N, P, K contents and their uptake, gross and net returns by crop as compared to alone application of pendimethalin (PE) 1000 g ha-1 and imazethapyr (PoE) 100 g ha-1, respectively. However, no mulching recorded maximum B: C ratio in among the mulches and among weed management practices alone application of pendimethalin recorded maximum B:C ratio. [ABSTRACT FROM AUTHOR]