Highest Weed Control Efficiency Research Articles

Performance of Various Weed Management Approaches on Weed Dynamics, Yield Attributes and Yield of Puddled Rice under Different Planting Techniques

Background: Rice is a major food source worldwide and direct seeding can shorten crop duration and reduce labour. The system of rice intensification (SRI) can boost yields with fewer inputs. Weed management is crucial for high yields, but chemical herbicides may not be necessary with SRI. A study evaluated herbicide performance based on rice establishment methods. Methods: An field experiment was conducted in January to May, 2021 (Navarai) to find out the efficient weed control techniques in puddled rice. The experiment has been carried out in split-plot design, which included two planting techniques viz., drum seeded rice and system of rice intensification (SRI) in main plot, as well as eight weed control techniques viz., hand weeding, cono weeding, pretilachlor, bispyribac sodium and fenoxaprop - p - ethyl as pre and post emergence application in sub plot. Result: The results of the experiment demonstrated that among the planting techniques and weed management practices tested, the system of rice intensification and sequential application of pretilachlor @ 0.5 kg a.i ha-1 fb bispyribac sodium @ 20 g a.i ha-1 has revealed lowest weed density and highest weed control efficiency, yield attributes and yield and energetics.

Effect of weed management practices on weeds, nutrient depletion and yield of rice (Oryza sativa)

Field experiments were conducted during Navarai (rabi) seasons of 2011 and 2012 with ADT-36 rice (Oryza sativa L.) variety to evaluate the effect of weed management practices. Pooled data of the two years revealed that application of butachlor @ 1.5 kg a.i/ha followed by weekly cono-weeding from 21 to 42 days after transplanting (DAT) resulted in least weed count, dry-matter production and nutrient removal which resulted in the highest weed control efficiency, productive tillers/hill, grains/panicle, number of filled grains/panicle and enhanced the grain yield, which was 0.73 and 0.46 t/ha more compared to twice hand weeding and conventional method of butachlor application followed by hand weeding.

Chemical weed management in wheat (Triticum aestivum) using ready-mix and tank-mix herbicides

A field experiment was conducted at the Bichpuri, Agra, Uttar Pradesh during the winter (rabi) seasons of 2011–12 and 2012–13, to evaluate the effect of different grass and broad-leaf herbicides as sole and ready-mix application on weed control in wheat (Triticum aestivum L.). Ready-mix application of herbicides proved better than their alone application in suppressing weed number and dry weight. Application of sulfosulfuron + metsulfuron (25 + 4 g/ha) resulted in the highest weed-control efficiency (WCE) as well as herbicide efficiency (HEI) and lowest weed index of 94.8%, 2.97 and 3.3 respectively. The highest grain and stover yield of 4.05 and 6.39 t/ha were obtained from weed-free treatment, although this remained statistically at par with sulfosulfuron + metsulfuron (25 + 4 g/ha) and both the treatments resulted in an increase of 34.6 and 30.2% in grain yield as compared to weedy check respectively. The highest net returns ( 43,200/ha) and benefit: cost ratio (2.40) were obtained with ready-mix application sulfosulfuron metsulfuron (25 + 4 g/ha) among the tested herbicide treatments.

Enhancing Summer Soybean Yield through Evaluation of Herbicidal Weed Management Options

The farmers of Gujarat have turned to soybean cultivation as soybean demand is increasing promisingly. Improper weed management is one of the reasons for the large yield gap between the potential and the actual yield of soybean harvested by the farmers. So, the selection of different herbicides in soybean is necessary for effective management of complex weed flora. An experiment was plotted with an aim of enhancing summer soybean yield through evaluation of herbicidal weed management options on medium black calcareous soil at Junagadh Agricultural University, Junagadh during summer season of 2021. The experiment comprised 12 treatments that were arranged in randomized block design with 3 replications. The outcomes of the results revealed that following to weed-free treatment, pre-mix pendimethalin + imazethapyr 750+50 g/ha as pre-emergence (PE) fb hand-weeding (HW) & inter-culturing (IC) at 30 days after sowing (DAS), HW at 15 DAS fb pre-mix propaquizafop + imazethapyr 50+75 g/ha as post-emergence (PoE) at 30 DAS, HW at 15 DAS fb pre-mix fluazifop-p-butyl + fomesafen 125+125 g/ha (PoE) at 30 DAS and pre-mix pendimethalin + imazethapyr 750+50 g/ha (PE) fb pre-mix fluazifop-p-butyl + fomesafen 125+125 g/ha (PoE) at 30 DAS enhanced growth parameters viz., plant height, branches per plant; yield attributes i.e., number of pods per plant and ultimately lead to greater seed yield and stover yield. These herbicidal weed management options also reduced population in addition to dry matter of weeds and had less reduction in yield due to better control of weeds, less crop-weed competition and higher weed control efficiency.

Impact of Different Doses of Herbicides on Weed Density and Weed Control Efficiency in Maize

A field experiment was conducted at Chandra Shekhar Azad University of Agriculture and Technology, Kanpur during Kharif season of 2021. To evaluate the effect of different doses of Mesotrione 2.27% w/w + Atrazine 22.7% w/w SC on growth and yield of maize (Zea mays L.). The experiment was laid down in the Randomized block design with ten treatments which was replicated three times. Experimental Field was infested with Echinochloa colona, Digitaria sanguinalis, Dactyloctenium aegyptium, Commelina benghalensis, Trianthema and Cyperus rotundus. Ready-mix herbicide, Mesotrione 2.27% w/w + Atrazine 22.7% w/w SC (Calaris Xtra) manufactured by Syngenta was used in the experiment. Among the herbicidal treatments, the application of Mesotrione 2.27% w/w + Atrazine 22.7% w/w SC @ 1.750 kg a.i. ha-1 recorded the lowest weed density and highest weed control efficiency (approx. 90%) at every growth stage of maize. However, among herbicidal treatments, grain yield of maize was maximum with the application of Mesotrione 2.27% w/w + Atrazine 22.7% w/w SC @ 1.0 kg a.i. ha-1(T4) which might be due do toxicity effect of herbicide.

IMPACT OF ORGANIC WEED MANAGEMENT PRACTICES ON WEEDS CONTROL, GROWTH AND YIELD OF MAIZE (Zea mays L.)

This field experiment on organic weed managament practices was conducted during rabi,2021-22 at wetland farm of S.V. Agricultural College, Tirupati, with 10 management practices in arandomized block design and replicated thrice. Among all the organic weed management practices,lower weed density and dry weight with higher weed control efficiency and weed control indexwas recorded with corn gluten meal 3.5 t ha-1 as pre-emergence (PE) followed by hand weeding(HW) at 30 days after sowing (DAS), however, it was statistically comparable with HW twice at 15DAS and 30 DAS. Significantly higher growth parameters, yield attributes and kernel and stoveryield of maize were recorded with corn gluten meal 3.5 t ha-1 as pre-emergence followed by HWat 30 DAS over rest of the treatments. The next best treatment in reducing density and dry weightof weedswith higher growth parameters, yield attributes and yield was HW twice at 15 DAS and30 DAS, which was however, at par with groundnut shells mulch 12.5 t ha-1 and mango leavesmulch 5 t ha-1.

Evaluation of Weed Management Practices in Maize (<i>Zea mays</i>) at Metu, Ethiopia

A field experiment was conducted at Metu Agricultural sub – centre on station in 2015 and 2016 cropping seasons to evaluate the effectiveness and economic feasibility of weed management methods on maize grain yield at Metu area. BH 661 at 25 kg/ha used as seed source. The experiment comprised of nine treatments laid out in randomized complete block design (RCBD) with three replications. The result revealed that the highest average grain yield 62.8 q/ha was obtained from Integrity EC 668g/l 1.0 liter with two supplementary hand weeding followed by 61.6 q/ha from Integrity EC 668g/l 1 liter with one hand weeding. Similarly, the minimum above ground wee dry biomass mean 0.07q/ha, 1.5 q/ha obtained from three hand weeding at 30, 60 and 90 days after planting and Integrity EC 668g/l 1.0 liter with two supplementary hand weeding respectively. Consequently highest weed control efficiency 99.93% and 98.5%obtained from the same treatment. In economic feasibility aspect the highest net benefit Accordingly the highest net benefit 61296.4 ETB ha<sup>-1 </sup>was obtained from Integrity EC 668g/l at 1.0 L/ha + two time supplementary hand weeding with 3042.86 MRR% followed by 60146.2 ETB ha<sup>-1 </sup>net benefit with 5661.90% MRR obtained from Integrity EC 668g/l at 1 l/ha + one times supplementary hand weeding whereas the minimum net benefit 50551.2 ETB ha<sup>-1</sup> and 53224.2 ETB ha<sup>-1</sup> obtained from one hand weeding at 30 & 454 days after planting respectively. Therefore, Integrity EC 668g/l at 1 l/ha + two times supplementary hand weeding and Integrity EC 668g/l at 1 l/ha + one time supplementary hand weeding treatment consecutively more profitable weed management practices to control weeds in maize and there by improve crop production up to 56.94% than other treatments and can be recommended for maize production at Metu area.

Studies on Chemical Weed Management Practices on Growth and Yield of Blackgram [Vigna mungo (L.)

An investigation was carried out at Zonal Agricultural Research Station, Kalaburagi, University of Agricultural Sciences, Raichur during kharif 2021-22 entitled studies on chemical weed management practices on growth and yield of blackgram [Vigna mungo (L.)]. The experiment was laid out in randomized complete block design with nine treatments and three replications. Among all the treatments, hand weeing at 25-30 DAS, recorded significantly lower weed density, higher weed control efficiency that favoured higher growth and yield parameters. Whereas, among the chemical weed management practices, application of sodium acifluorfen 16.5% + clodinafop propargyl 8% EC @ 1.0 kg a.i. ha-1 at 20-25 DAS as post emergent recorded significantly lower weed population (2.71/0.25 m2), lower weed dry weight (1.53/0.25 m2) and higher weed control efficiency (90.31 %) compared to other chemical weed management treatments. The treatment sodium acifluorfen 16.5% + clodinafop propargyl 8% EC @ 1.0 kg a.i. ha-1 at 20-25 DAS as post emergent also recorded significantly higher growth parameters viz., plant height (40.18 CM), number of branches (9.18), and dry matter production at harvest (23.50 g plant-1) and yield components viz., number of pods plant-1 (46.69 ), number of seeds pod-1 (7.89), 100 seed weight (4.7 g), seed yield (1059 kg ha-1) compared to other treatments. Significantly higher net returns (Rs.48,406) were recorded in hand weeding at 25-30 DAS and intercultivation at 45 DAS, which was on par with application of sodium acifluorfen 16.5% + clodinafop propargyl 8% EC @ 1.0 kg a.i. ha-1 at 20-25 DAS (Rs.45,066 ha-1). The higher benefit cost ratio was recorded with application of sodium acifluorfen 16.5% + clodinafop propargyl 8% EC @ 1.0 kg a.i. ha-1 at 20-25 DAS (3.08) followed by hand weeding at 25-30 DAS and intercultivation at 45 DAS.

Effect of crop residue and weed management on weed incidence, soil moisture and yield of chickpea

Chickpea is a major pulse crop which is grown and consumed by the Indian people. Due to poor weed competition ability of chickpea and very few weed management options, yield of chickpea is drastically reduced under vertisols. Therefore, the present study related to weed management and crop residues on weed incidence, yield attributing character and yield of chickpea was conducted at Research Farm of JNKVV, Jabalpur (MP), India. A field experiment was undertaken in split plot design with 3 replications and 4 weed-management treatment in main-plot and four crop residues as sub-plot. The main plot treatments were pendimethalin 38.7% CS at 1 kg/ha as pre plant incorporation (PPI), hand weeding at 30 days after sowing (DAS), hand hoeing at 30 DAS and weedy check. Four crop residues mulch (CRM) were, wheat straw (WSM), paddy straw (PSM) and soybean haulm (SHM) each at 5 t/ha and control where no mulch material was applied. Results revealed that imposition of hand weeding at 30 DAS recorded with least weeds with lesser weed biomass resulting in higher weed control efficiency (WCE). However, weedy check recorded maximum weed count and dry weight. Pendimethalin 1 kg/ha recorded lower weed prevalence and weed dry weight. It was similar to hand hoeing done at 30 DAS. Among applied CRM, PSM recorded lower weed density and dry weight with higher WCE and soil moisture at 30 DAS and was superior over control plots. Hand weeding at 30 DAS recorded with higher yield attributing traits viz, pods/plant, seed/pod and seed index resulted higher seed yield (1,604 and 1,731 kg/ha respectively in 2018–19 and 2019–20). It was at par with pendimethalin at 1 kg/ha. The lower yield attributes and yield was recorded in weedy check plots. Among CRM, spreading of PSM give more pods and seeds/pod with higher seed index resulted in higher seed yield (1515 and 1593 kg/ha in 2018–19 and 2019–20 respectively) over others. Thus, application of PSM at 5 t/ha with one hand weeding at 30 DAS or with pendimethalin can be suggested for significant weed control and higher seed yield in chickpea.

Effect of 2, 4-D sodium salt on weeds, growth and yields in rabi maize (Zea mays L.)

A field investigation was conducted during winter (rabi) season of 2021 at Agricultural Research Farm of Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, to study the efficacy of doses of 2, 4-D sodium salt 80% WP on weeds, productivity and economics of rabi maize (Zea mays L.). Application of 2, 4- D sodium salt 80% WP @ 1,250 g/ha at 25 days after sowing (DAS) resulted in to lesser weed density and weed dry weight of Physalis minima Roem. & Schult, Chenopodium album (L.), Melilotus indicus (L.) and Cichorium intybus (L.) as compared to 2, 4-D sodium salt 80% WP @ 1,000 g/ha and 2, 4-D sodium salt 80% WP @ 750 g/ha at 60 DAS, with higher weed control efficiency (77.3 %) and lesser weed index (34.9 %). At 60 DAS, 2, 4-D sodium salt 80% WP (applied @1250 g/ha at 25 DAS) produced higher plant height, number of leaves, chlorophyll content, leaf area index and plant dry-matter over other treatments except weed free and two hand weeding at 20 and 40 DAS. Application of 2, 4-D sodium salt 80% WP @ 1,250 g/ha at 25 DAS recorded higher number of cobs, number of kernels, number of kernels/row and seed index as compared to 2, 4-D sodium salt 80% WP @ 1,000 g/ha, and 2, 4-D sodium salt 80% WP @ 750 g/ha. Higher kernel (3.7 t/ha) and stover yield (4.7 t/ha) of maize was recorded due to application of 2, 4-D sodium salt 80% WP @ 1,250 g/ha at 25 DAS with higher harvest index (44.5%) and monetary returns (62.5 × 103 `/ha) as compared to 2, 4-D sodium salt 80% WP @ 1,000 g/ha, and 2, 4-D sodium salt 80% WP @ 750 g/ha.

Management of speargrass [<i>Imperata cylindrica (L.) Raeuschel</i>] in of southern agro-ecologies of Nigeria

Speargrass [Imperata cylindrica (L.) Raeuschel] infestation limits crop growth and yield. The effects of tillage methods, kenaf genotypes, and plant spacing patterns were studied for speargrass suppression at Eruwa (Derived Savanna) and Kishi (Southern Guinea Savanna) in 2015 and 2016. These were randomized in a Split-split plot design with three replicates. Agronomic data collected were analyzed, and the means were separated at P ≤ 0.05. Results showed that tillage enhanced weed control efficiency (10%), improved I. cylindrica suppression, and kenaf performance, relative to plant sown in no-till plots at both locations. The bast-fibre yield was higher in Ifeken DI 400 than in Ifeken 400 at Eruwa, but genotypes had similar bast-fibre yield at Kishi. Also, both genotypes had comparable I. cylindrica biomass and weed control efficiency at Kishi, while Ifeken 400 had higher weed control efficiency than Ifeken DI 400 at Eruwa, due to better suppression of I. cylindrica. The agronomic traits measured and weed control efficiency (WCE %) had a substantial inverse relationship with I. cylindrical growth at both locations. Tillage improved bast fibre yield (26 – 32%), core fibre yield (20 – 28%), and seed yield (26 – 59 %) relative to no-tilled plots. Ifeken 400 showed superior weed-suppressive traits and optimum fibre yield to Ifeken DI 400 at both locations. Tilling speargrass-infested land, with kenaf plant spacing of 50 cm × 10 cm and 50 cm × 15 cm with early canopy formation and better weed suppression are considered for an integratedspeargrass management scheme.

Controlling Phalaris minor with novel pyroxasulfone under conservation agriculture in the north-western Indo-Gangetic Plains

A field experiment was conducted during the winter (rabi) seasons of 2021–22 and 2022–23 at the research farm of ICAR-Indian Agricultural Research Institute, New Delhi to evaluate the effectiveness of pyroxasulfone in controlling resistant Phalaris minor within the maize (Zea mays L.)-wheat (Triticum aestivum L.) cropping system. The experiment consisted a split-plot design involving 3 crop establishment systems (Bed + R; ZT + R and CT + R) and 5 weed management strategies, viz. pyroxasulfone (W1); pyroxsulfone fb metsulfuron + carfentrazone (W2); Sulfosulfuron + metsulfuron (W3); UWC (W4); and WFC (W5), replicated thrice. The results from two-year analysis consistently favoured bed planting with residue, which exhibited the lowest P. minor density and total weed population compared to the other two methods with highest weed control efficiency. Among the various weed management options, the combination of pyroxasulfone fb metsulfuron + carfentrazone recorded significantly lowest P. minor density and higher weed control efficiency, similar to the weed-free check. Additionally, this treatment led to significantly higher dry matter accumulation (68.2 g/m2), ear length (12 cm), test weight (41 g) and grain yield (5.8 t/ha) compared to other herbicide treatments, underscoring its outstanding performance.

Effect of Pre and Post Emergent Herbicides on Weed Management, Yield and Economics in Irrigated Chickpea (Cicer arietinum L.)

A field experiment was conducted to study the effect of pre and post emergence herbicides on growth and yield of chickpea at College of Agriculture, Vijayapura, during rabi, 2021-22. The experiment was laid out in RCBD with three replications. The experiment consisted of 11 treatments involving two pre-emergence herbicides (Pendimethalin, Pendimethalin + Imazethapyr) and five post-emergence herbicides (Imazethapyr + Imazamox, Propaquizafop + Imazethapyr, Imazethapyr, Quizalofop ethyl and Aciflor + Clodinafop), intercultivation at 20 and 40 DAS, weed free check and weedy check. Among the herbicidal treatments, significantly lower weed population per m2 (2.40), lower total dry weight of weeds (3.18 g), higher weed control efficiency (84.98%), lower weed index (11.06 %), higher grain yield (2197 kg/ha), haulm yield (2766 kg/ha), net returns (₹ 80621/ha) and B:C ratio (3.01) was recorded with sequential application of Pendimethalin 38.7% CS @ 800 g a.i./ha as PE fb Propaquizafop 2.5% + Imazethapyr 3.75% W/W ME (RM) @ (125 g a.i./ha) as PoE at 25 DAS compared to all other treatments. Among herbicidal treatments lowest grain yield (923 kg/ha) and haulm yield (2098 kg/ha) were recorded with Imazethapyr 35% + Imazamox 35% WG (RM) @ 70 g a.i./ha as PoE at 25 DAS due to phytotoxicity and the results were almost near to weedy check which recorded 38.18 pods/plant, 100 seed weight of 22.36 g, 16.96 g of seed yield / plant, grain yield (896 kg/ha) and haulm yield (2056 kg/ha).

Evaluation of weed management approaches on weed dynamics, yield and economics of puddled rice under different plant techniques

A field experiment was conducted in January to May, 2022 (Navarai) to find out the effective weed management practices in puddled rice. The experiment was carried out in a split-plot design, which included two planting techniques viz., drum seeded rice and system of rice intensification (SRI) in main plot, as well as eight weed management practices viz., hand weeding, cono weeding, pretilachlor, bispyribac sodium and fenoxaprop - p - ethyl as pre and post emergence application in sub plot. The results of the experiment demonstrated that among the planting techniques and weed management practices tested, the system of rice intensification and sequential application of pretilachlor @ 0.5 kg a.i ha-1 fb bispyribac sodium @ 20 g a.i ha-1 has revealed lowest weed density (39.67, 71.25 and 17.02, 33.97 no m-2) and highest weed control efficiency (55.89, 65.78 and 84.99, 82.33 %) grain yield (4.55 and 5.47 t ha-1), gross and net income (Rs. 12116 and Rs. 64336 ha-1). However, drum seeded rice resulted higher return-1 rupee invested due to lower cost of cultivation. Hence, the SRI planting method with sequential application of pretilachlor @ 0.5 kg a.i ha-1 followed by bispyribac sodium @ 20 g a.i ha-1 has proven to be effective in controlling weeds and achieving higher grain yield and net income.

Weed Management Practices on Growth, Yield and Economics of Kharif Grain Sorghum

In the Kharif grain sorghum growing areas of Karnataka, the sorghum production suffers greatly due to weed problem, which offers limitations to crop. It was found that weed infestation become unmanageable throughout the growing period by the traditional methods of interculturing and manual weeding due to continuous and heavy rains during entire vegetative and early reproductive stages of Kharif sorghum. Hence, integration of herbicides with some cultural operations and use of pre-emergence, post-emergence herbicides in combination with mechanical methods can prove to be more successful. A field experiment entitled “Weed management in kharif grain sorghum” was conducted during Kharif 2019 at ARS, Hagari in deep black soil with neutral reaction (pH 7.50), organic carbon (5.5 g kg-1), available nitrogen (248.00 kg ha-1), available phosphorus (36.75 kg ha-1) and available potassium (312.00 kg ha-1). An experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. There were fourteen treatments comprising of weed management practices. The dominant weeds observed in the experimental fields were among grasses Brachiaria reptans, while in broad leaved weeds, Amaranthus viridis and among sedges, Cyperus rotundus. Significantly lower population of grasses, sedges, and broad leaved weeds, weed dry weight, weed index (%) and higher weed control efficiency throughout the crop growth period was noticed in sequential pre-emergence application of atrazine 50 WP @ 0.50 kg a.i. ha-1 as PE fb 2,4-D Na Salt 80 WP @ 0.75 kg a.i. ha-1 as PoE at 25 DAS except weed free treatment. Atrazine 50 WP @ 0.50 kg a.i. ha-1 as PE fb 2,4-D Na Salt 80 WP @ 0.75 kg a.i. ha-1 as PoE at 25 DAS recorded significantly higher plant height, dry matter accumulation, leaf area, test weight, grain yield, straw yield, harvest index, gross return, net return and benefit cost ratio (160.8 cm, 183.4 gplant-1, 24.1 dm2 plant-1, 30.53 g, 4195 kg ha-1, 9891 kg ha-1, 29.80 %, Rs. 1,03,675ha-1, Rs. 71,636 ha-1and 3.24, respectively) except weed free and it was on par with atrazine 50 WP @ 0.50 kg a.i. ha-1 as PE fb IC at 25 DAS and HW at 25 DAS and IC at 40 DAS.

Integrated Weed Management in Transplanted Rice (Oryza sativa L.): An Experimental Investigation

An experiment entitled Integrated Weed Management in transplanted rice (Oryza sativa L.)” was conducted at Shradhay Bhagwati Singh Agriculture Research Farm, Hajipur, Chandra Bhanu Gupta Post Graduate College, B.K.T., LUCKNOW (U.P.) during Kharif season of 2022-2023. The treatment comprised of 9 weed management practices. Weedy check till maturity, Weed free upto 60 DAT, Pretilachlor 50 % EC @ 1.25 kg a.i/ha (PE), Pendimethaline 30 % EC @1.0 kg a.i/ha (PE), Pendimethaline 30 % EC @ 1.0 kg a.i/ha + 1 hand weeding at 30DAT, Pendimethaline 30 % EC @1.0 kg a.i/ha (PE) + Bispyribac Sodium 10 % SC @ 25 g a.i/ha (POE), Pretilachlor 50 % EC @1.0 kg a.i/ha + 1 hand weeding At 35DAT, Two hand weeding at 20 and 40 DAT, Pretilachlor 5 0 % E C @ 1.0 kg a.i/ha (PE) + Bispyribac sodium 10% SC @ 25 g a.i/ha (POE). Weed free up to 60 DAT resulted in significantly higher growth, yield attributes and yield over result of the treatments. The highest weed control efficiency was recorded with weed free up to 60 DAT. However, the highest weed Index was recorded with weedy check and lowest being with weed free up to 60 DAT. The highest net returns (Rs. 58, 218.31/ha) was recorded by weed free up to 60 DAT and highest B:C ratio was recorded by Pretilachlor 50 % E C @ 1.0 kg a.i/ha (PE) + Bispyribac Sodium 10% SC @ 25 g a.i/ha (POE).

Effect of Drone Application of Pendimethalin on Microbial Population, Nodulation, Weed Control and Yield of Green Gram (Vigna radiata L.)

A field experiment was conducted at Anbil Dharmalingam Agricultural College and Research Institute, Tiruchirappalli, during Winter, 2023 to study the effect of pendimethalin application using drone on soil microbial population, nodulation, weed control and yield of green gram. The experiment was laid out in RBD with 12 treatments and 3 replications. The treatments consisted two levels of pendimethalin dosage (0.75 and 1.0 kg ha-1), five levels of spray fluids (40, 50, 60, 70 and 80 litres ha-1) for drone spray compared with manual spray of pendimethalin at 1.0 kg ha-1 with 500 litres ha-1 spray fluid and control. The results revealed that significantly higher microbial population such as bacteria (17.60 × 106 cfu/g of soil), fungi (14.90 × 103 cfu/g of soil), actinomycetes (42.60 × 104 cfu/g of soil) and rhizobium (21.30 × 105 cfu/g of soil) were recorded with no herbicide application (unweeded control) at 30 DAS than pendimethalin 1.0 kg ha-1 application either manual or drone. The lower dose of pendimethalin 0.75 kg ha-1 with spray fluid of 60 litres ha-1 was on par with no herbicide application treatment. Significantly higher root nodules per plant-1 (17.56 and 22.51) at 30 and 45 DAS was registered under drone spray of pendimethalin 0.75 kg ha-1 with spray fluid of 60 litres ha-1. Higher weed control efficiency (72.6 %) and grain yield (747 kg ha-1) were statistically superior under drone spray of pendimethalin 1.0 kg ha-1 with spray fluid of 60 litres ha-1 over 40 or 80 litres ha-1 spray fluids and was comparable with lower dose of pendimethalin (0.75 kg ha-1) with 60 litres ha-1. Thus, it can be inferred that pendimethalin at 0.75 kg ha-1 with spray fluid of 60 litres ha-1 was considered as ideal dose and spray fluid for drone application to get better soil microbial population, nodulation, weed control efficiency and grain yield of green gram.

Effect of Herbigation on Weed Control and Yield of Drip Irrigated Cotton

A field experiment was conducted during Summer, 2023 at Anbil Dharmalingam Agricultural College and Research Institute, Tamil Nadu Agricultural University, Tiruchirappalli to study the effect of herbigation on weed control and yield of drip irrigated cotton. The experiment was laid out in randomized block design with nine treatments and replicated thrice. The treatments consisted of herbigation of pre emergence (PE) herbicides (Pendimethalin 1.0 kg ha-1 and Oxyfluorfen 0.2 kg ha-1) combined with hand weeding at 45 DAS or manual spray or herbigation of post emergence (PoE) herbicide (Pyrithiobac Sodium + Quizalofop Ethyl 75 g ha-1 on 25 DAS) compared with recommended practice of manual spray of PE pendimethalin 1.0 kg ha-1 + HW at 45 DAS, HW twice on 20 and 40 DAS and unweeded control. The results revealed that among the different weed management practices manual spray of PE pendimethalin 1.0 kg ha-1 + HW at 45 DAS registered significantly lower total weed density (12.63 m-2), total weed dry weight (8.23 g m-2) and higher weed control efficiency (77%) at 20 DAS. This was followed by herbigation of PE pendimethalin 1.0 kg ha-1 + manual spray of PoE pyrithiobac sodium + quizalofop ethyl 75 g ha-1 on 25 DAS. Among the herbigation treatments, herbigation of PE pendimethalin 1.0 kg ha-1 + manual spray of PoE pyrithiobac sodium + quizalofop ethyl 75 g ha-1 on 25 DAS obtained lower total weed density (12.13 m-2), total weed dry weight (9.19 g m-2) and higher WCE (86%) at 40 DAS. This was followed by herbigation of PE oxyfluorfen 0.2 kg ha-1 + manual spray of PoE pyrithiobac sodium + quizalofop ethyl 75 g ha-1 on 25 DAS. At 60 DAS, application of manual spray of PE pendimethalin 1.0 kg ha-1 + HW at 45 DAS recorded lower total weed density (18.07 m-2), total weed dry weight (16.03 g m-2) and higher weed control efficiency (85%). However, this was comparable with herbigation of PE pendimethalin 1.0 kg ha-1 + manual spray of PoE pyrithiobac sodium + quizalofop ethyl 75 g ha-1 on 25 DAS and HW on 20 and 40 DAS. The highest seed cotton yield (2109 kg ha-1) was obtained with manual spray of PE pendimethalin 1.0 kg ha-1 + HW at 45 DAS and it was on par with herbigation of PE pendimethalin 1.0 kg ha-1 + manual spray of PoE pyrithiobac sodium + quizalofop ethyl 75 g ha-1 on 25 DAS and HW on 20 and 40 DAS. Hence, considering the labour scarcity, herbigation of PE pendimethalin1.0 kg ha-1 on 3 DAS followed by manual spray of PoE pyrithiobac sodium + quizalofop ethyl 75 g ha-1 on 25 DAS could be recommended for better weed control in drip irrigated cotton.

Weed Control by New Generation Herbicide and Its Influence on Yield and Nutrient Uptake in Transplanted Rice

A field experiment was conducted during kharif season 2019 and 2020 at research farm of Bihar Agricultural University, Sabour, Bhagalpur to evaluate the effect of different herbicide on weed attributes, yield attributes, yield and nutrient uptake in transplanted rice. The experiment comprised six treatment T1 (pyrazosulfuron ethyl 10 % WP 15 g a.i. ha-1), T2 (pyrazosulfuron ethyl 10 % WP 30 g a.i. ha-1), T3 (carfentrazone ethyl 25 g a.i. ha-1), T4 (carfentrazone ethyl 50 g a.i. ha-1), T5 (weed free) and T6 (weedy) with four replications in randomized block design. The significantly lesser weed density (37.75 No.m-2), weed dry weight (22.87 gm-2), weed index (3.41) and higher weed control efficiency (80.58 %) were recorded with the application of pyrazosulfuron ethyl 30 g a.i. ha-1 at 30 DAT than other treatments. Crop growth parameters (plant height, number of effective tillers, dry matter accumulation), yield attributes (panicle length, effective tillers, number of grains, test weight), nutrient uptake and grain yield were recorded highest in weed free plot (57.88 q ha-1) followed by pyrazosulfuron ethyl 10 % WP 30 g a.i. ha-1. However, least grain yield was recorded under weedy plot. The results suggested that pyrazosalfuron ethyl 10 % WP 30 g a.i. ha-1 were best broad spectrum effective herbicide in order to minimize the diverse weed flora in transplanted rice.

Effects of Integrated Weed Management Practices on Weed Parameters and Yield of Bt Cotton (Gossypium hirsutum L.)

Aim: To know the effect of integrated weed management on weed parameters and yield of bt cotton.
 Study Design: Randomized complete block design.
 Place and Duration of Study: College of Agriculture Farm, Bheemaraynagudi between July 2021 and Feb 2022.
 Methodology: The field experiment was conducted during Kharif 2021 at Experimental block, College of Agriculture, Bheemarayanagudi. The soil of the experiment field was deep black clayey in texture. The experiment comprises 11 weed management practices viz., T1: Pendimethalin 38.7% CS @ 750 g a.i./ha as PE + Hand weeding @ 20-25 DAS and Intercultivation @ 55-60 DAS, T2: Pendimethalin 38.7 % CS @ 750 g a.i./ha as PE fb Pyrithiobac Sodium 10 EC @ 75g a.i./ha + Quizalofop ethyl 5 EC @ 37.5g a.i./ha as PoE @ 25 DAS and Intercultivation @ 55-60 DAS. (Tank mix), T3 : Pendimethalin 38.7 % CS @ 750 g a.i./ha as PE fb Pyrithiobac Sodium 10 EC @ 50g a.i./ha + Quizalofop ethyl 5 EC @ 25 g a.i./ha as PoE @ 25 DAS and Intercultivation @ 55-60 DAS, T4 :Pendimethalin 38.7 % CS @ 750 g a.i./ha as PE fb Pyrithiobac Sodium 10 EC @ 75g a.i./ha + Quizalofop ethyl 5 EC @ 37.5g a.i./ha as PoE @ 25 DAS and Intercultivation @ 55-60 DAS, T5 : Pendimethalin 38.7 % CS @ 750 g a.i./ha as PE fb Pyrithiobac Sodium 10 EC @ 100g a.i./ha + Quizalofop ethyl 5 EC @ 50g a.i./ha as PoE @ 25 DAS and Intercultivation @ 55-60 DAS, T6 : Pyrithiobac Sodium 10 EC @ 50g a.i./ha + Quizalofop ethyl 5 EC @ 25g a.i./ha as PoE @ 25 DAS and Intercultivation @ 55-60 DAS, T7: Pyrithiobac Sodium 10 EC @ 75g a.i./ha + Quizalofop ethyl 5 EC @ 37.5g a.i./ha as PoE @ 25 DAS and Intercultivation @ 55-60 DAS, T8: Pyrithiobac Sodium 10 EC @ 100g a.i./ha + Quizalofop ethyl 5 EC @ 50g a.i./ha as PoE @ 25 DAS and Intercultivation @ 55-60 DAS, T9: Farmers practice (Hand weeding @ 25 DAS and 2 intercultivations @ 50 and 75 DAS), T10: Weedy check, T11: Weed free check.
 Results: Among the treatments, application of pendimethalin 38.7 % CS @ 750 g a.i./ha as PE fb pyrithiobac sodium 10 EC @ 100 g a.i./ha + quizalofop ethyl 5 EC @ 50 g a.i./ha as PoE (combi-product) @ 25 DAS and intercultivation @ 55-60 DAS recorded significantly lower weed density and higher weed control efficiency (82.39 %), also recorded higher seed cotton yield (2495 kg ha-1) and stalk yield (4056 kg ha-1) over other treatments.
 Conclusion: Application of Pendimethalin 38.7 % CS @ 750 g a.i./ha as PE fb Pyrithiobac Sodium 10 EC @ 100g a.i./ha + Quizalofop ethyl 5 EC @ 50g a.i./ha as PoE @ 25 DAS and Intercultivation @ 55-60 DAS was found effective in controlling the weeds with coupled with higher seed cotton yield .