Total Weed Dry Weight Research Articles

Evaluating the effects of manual hoeing and selective herbicides on maize (Zea mays L.) productivity and profitability

The objective of this study was to evaluate maize production and the economic profitability of weed management techniques. Field trials were conducted at the Kasapa farm during the 2021/22 growing seasons using a split-plot design with three repetitions. The main factor was the herbicides applied in pre-emergence alone (2L ha−1: acetochlor, bentazon, imazethapyr and 60 g ha−1 chlorimuron-ethyl), then mixed (1L ha−1: acetochlor plus bentazon plus imazethapyr plus 30g ha−1chlorimuron-ethyl), manual hoeing (3-5WAS) including the non-weeding. The secondary factor: maize varieties (GV672A, GV673A, GV664A and Sam4vita). The highest maize dry grain yield (7.66 t ha−1) was associated with imazethapyr, while those of acetochlor and chlorimuron-ethyl (6.86 and 6.92 t ha−1) compared to manual hoeing (7.62 t ha−1, respectively) were low, but much higher than no weeding (1.21 t ha−1). The yields of varieties GV672A and GV664A were higher (6.87 and 6.77 t ha−1), compared to Sam4vita (5.64 t ha−1). The total dry weight of weeds was negatively correlated with all crop parameters, with its maximum value (127.56 g m−2) characterizing non-weeding, and the minimum for manual hoeing (18.83 g m−2). The Ratio Cost Value showed that all treatments were profitable: imazethapyr > bentazon > chlorimuron-ethyl > combination > acetochlor > manual hoeing. However, imazethapyr was economically more profitable and could replace manual hoeing when the field to be weeded increases and labor is scarce.

Effect of Various Weed Management Options on Weed Dry Matter, Yield Attributes and Yield of Sweet Corn (Zea mays L. saccharata) under Organic Production System

A field experiment was conducted at Instructional cum Research Farm, Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.) during kharif 2019 entitled “Effect of various weed management options on weed dry matter, yield attributes and yield of sweet corn (Zea mays L. saccharata) under organic production system”. The soil of the experimental site was clayey in texture, neutral in reaction and low in nitrogen, medium in phosphorus and high in potassium. The experiment was laid out in Randomized Block Design with three replications. The weed flora of the experimental site was dominated by Echinocloa colona, Alternanthera sessilis, Parthenium hysterophorus, Cyperus iria. Results revealed that the highest green cob yield of sweet corn was recorded in stale seed bed + reduced spacing (upto 25%) + mulching with paddy straw + 20 DAS hand weeding (7.63t ha-1 ) which was 83.48% higher than the weedy check. The green cob yield in stale seed bed + reduced spacing (upto 25%) + mulching with paddy straw + 20 DAS hand weeding was found to be at par with mulching with waste polythene bags (ITK-practices) (7.45t ha- ), hand weeding twice carried out at 20 and 40 DAS (7.33 t ha-1) and soil solarization with 25µ polythene mulch during summer + one hand weeding at 20 DAS(6.94t ha-1). Although grain yield in other weed management practices was significantly lower than stale seed bed + reduced spacing (upto 25%) + mulching with paddy straw + 20 DAS hand weeding treatments but higher than weedy check. Similarly, As regards total weed dry weight at harvest, the total lowest weed dry weight was observed in stale seed bed + reduced spacing (upto 25%) + mulching with paddy straw + hand weeding at 20 DAS(3.45gm-2) followed by mulching with waste polythene bags (ITK- practices)(4.71 gm-2), hand weeding at 20 and 40 DAS (4.96gm-2)and soil solarization with 25µ polythene mulch during summer + one hand weeding at 20 DAS(5.08 gm-2). However, higher WCE was noticed in these treatment over weedy check. The weedy check was significantly inferior in all the yield attributes and green cob yield of sweet corn.

Weed control efficacy and dry bean response to preemergence herbicide incorporation timing

AbstractField experiments were conducted in 2021 and 2022 to evaluate the effect of irrigation timing on S‐ethyl‐N,N‐dipropylthiocarbamate (EPTC), flumioxazin, pyroxasulfone, and flumioxazin + pyroxasulfone weed control efficacy and safety in dry bean (Phaseolus vulgaris L.). Treatments consisted of EPTC (3430 g ai ha−1), flumioxazin (53.6 g ai ha−1), pyroxasulfone (119 g ai ha−1), and flumioxazin + pyroxasulfone (70.4 + 89.3 g ai ha−1) incorporated with overhead irrigation at 1, 4, and 8 days after herbicide treatment (DAT). A nontreated and hand‐weeded check were included for comparison. Delaying irrigation until 8 DAT resulted in 11% and 19% injury in the pyroxasulfone and flumioxazin + pyroxasulfone treatments, respectively, but the crop recovered within 5 weeks after treatment. Delaying irrigation until 8 DAT increased total weed dry weight by 52%. Generally, flumioxazin + pyroxasulfone provided better weed control compared to flumioxazin or pyroxasulfone applied alone. Irrigation timing did not influence dry bean yield. Seed yield was 160 kg ha−1 in the nontreated check and 2521 kg ha−1 in the hand‐weeded check. Seed yield in the flumioxazin + pyroxasulfone treatment (2425 kg ha−1) was similar to the hand‐weeded check. Flumioxazin + pyroxasulfone provided very good weed control with acceptable crop safety. While irrigation timing may play a role in flumioxazin or pyroxasulfone injury, other soil and environmental factors may influence dry bean response to these herbicides.

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).

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.

Effect of Mesotrione 40% SC on Weed Growth, Yield and Economics of Maize (Zea mays L.)

Newer herbicides are required to reduce the losses cause by the weeds in maize crop. Therefore, a field experiment was conducted during kharif 2019 at Research Farm, AICRP on Forage Crops, Department of Agronomy, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur (Madhya Pradesh) to study the effect of different weed management practices on productivity of Maize (Zea mays L.). The experiment was conducted in randomized block design with eight treatments (six herbicidal treatments with hand weeding twice at 20 and 40 DAS and weedy check) replicated thrice. Observations were recorded for various weed parameters and crop growth parameters. All the weed management treatments significantly reduced the total weed density and total dry weight of weeds as compared to weedy check. Among herbicidal treatments, mesotrione 350 g ha-1 recorded the lowest total weed density and total dry weight of weeds as compared to other herbicides. While highest total weed density and total dry weight were recorded under weedy check treatment. Significantly higher growth parameters and yield attributing traits were recorded with the application of mesotrione 350 g ha-1 which resulted in higher grain and stover yields (2447.22 and 21804.72 kg ha-1) followed by mesotrione 300 g ha-1. Maximum net returns and Benefit: Cost ratio was also obtained with the application of mesotrione 350 g ha-1.

Weed Dynamics of Fodder Maize as Influenced by Different Herbicides

The advancements in fodder maize cultivation practices over the past few years, has paved a change in the makeup of weed associations. This made it necessary to incorporate new, effective herbicides in the struggle against maize's primary weeds. Therefore, a field experiment was conducted at Research Farm, AICRP on Forage Crops, Department of Agronomy, JNKVV, Jabalpur (Madhya Pradesh) during Kharif season 2019 to devise an appropriate combination of herbicides required for the control of the complex weed diversity in fodder maize. The field experiment was laid out in randomized block design (RBD) with ten treatments (eight herbicidal combinations along with hand weeding twice at 20 and 40 DAS and a weedy check) and replicated thrice. Observations were recorded on the weed parameters and fodder yield of maize. Among monocots, the experimental field was infested with Echinochloa colona, Commelina communis and Digitaria sanguinalis. Phyllanthus niruri and Eclipta alba were dominated among dicots. Among all herbicidal treatment, topramezone 35 g/ha plus atrazine 250 g/ha was found to be significantly superior in reducing total weed density (9.49/m2, 11.50/m2) and total weed dry weight (6.43 g/m2, 7.91 g/m2) at 30 and 45 DAS, respectively and recorded the lowest weed index (1.82%). Also, the maximum green fodder yield (472.68 q/ha) was recorded in topramazone 35 g/ha + atrazine 250 g/ha compared to other treatments. Overall, this study indicated that the combination of topramazone 35 g/ha + atrazine 250 g/ha could be an alternative approach to hand weeding and alone herbicides in fodder maize.

Crop-establishment methods and weed management effects on weeds, wheat (Triticum aestivum) yield and economics under a conservation agriculture-based rice (Oryza sativa)–wheat system

A field experiment was conducted at the ICAR-Indian Agricultural Research Institute during the winter (rabi) season of 2018–19 and 2019–20 involving 6 tillage and residue practices, viz. T1 , zero-till (ZT) direct-seeded rice (Oryza sativa L.) (ZTDSR)–zero-till wheat [Triticum aestivum (L.) emend Fiori & Paol] (ZTW); T2 , ZTDSR + wheat residue (WR)–ZTW + rice residue (RR); T3 , ZTDSR + WR + brown manuring (BM) – ZTW+RR; T4 , ZTDSR–ZTW– ZT mungbean [Vigna radiata (L.) R. Wilczek] (ZTMB); T5, ZTDSR + mungbean residue (MBR) – ZTW + RR – ZTMB+WR; T6 , puddled transplanted rice (PTR)–conventional till wheat (CTW) in main plot; and 4 weed-control treatments, i.e. W1 , un-weeded control; W2 , Total (ready mix of sulfosulfuron + metsulfuron-methyl) 0.040 kg/ha at 30 day after sowing (DAS); W3 , tank-mixture of clodinafop-propargyl 0.060 kg/ha + metsulfuron-methyl 0.004 kg/ha at 30 DAS; W4 , tank-mixture of clodinafop-propargyl 0.060 kg/ha + carfentrazone-ethyl 0.02 kg/ha at 30 DAS in sub-plot under a split-plot design and replicated thrice. Treatment T6 resulted in significantly higher population and dry weight of littleseed canarygrass (Phalaris minor Retz.), yellow sweet clover [Melilotus indica (L.) All.] and swine cress [Coronopus didymus (L.) Smith] than other treatments, whereas, population and dry weight of common lambsquarter (Chenopodium album L.), sour dock (Rumex dentatus L.) and annual sowthistle (Sonchus oleraceus L.) were significantly higher under T1 and T4 treatments. The treatment T5 registered ~62, 44, 35, 31 and 24% lower population of P. minor than T6 , T1 , T4 , T2 and T3 treatments, respectively. Similarly, total weed population and total weed dry weight were ~38 and 33% lower under T5 compared with T6 treatment respectively. Better wheat growth and lower weed interference under T5 treatment led to 14.6% higher wheat grain yield under this treatment than T6 . The tank- mix of clodinafop-propargyl + metsulfuron significantly reduced the population and dry weight of all weeds compared to UWC and it led to 88.9% weed-control efficiency (WCE) and 89.4% weed-control index (WCI) in wheat. Therefore, growing of wheat under zero-till triple cropping system with rice, wheat and mungbean residues (T5 ) combined with tank-mix application of clodinafop + metsulfuron at 30 DAS may be recommended for better weed management, and higher productivity and profitability from wheat in Indo-Gangetic Plains (IGP) of India and in similar agro-ecologies of the tropics/ sub-tropics.

Management of weed diversity through organic mulching and alternative weed suppression practices on ginger (Zingiber officinale)

A field experiment was conducted at the Regional Research Station (Hill Zone), Uttar Banga Krishi Viswavidyalaya, Kalimpong, Darjeeling, West Bengal, during 2019 and 2020 to study the effect of weed diversity, growth and yield of ginger (Zingiber officinale Rose) as influenced by organic mulching and alternative weed management practices. The randomized block design, having seven varying treatments with three replications was used. The treatments consisted of dry weed biomass mulch @ 5.0 t/ha (T1), paddy straw mulch @ 5.0 t/ha (T2), FYM Mulch @ 5.0 t/ha (T3), dry leaves of Schima wallichi@ 5.0 t/ha (T4), dry leaves of Artimesia sp. and Eupatorium sp. @ 5.0 t/ha (T5), hand weeding (twice) at 45 and 90 DAS (T6) and unweeded control (T7). The result showed that hand weeding twice at 45 and 90 DAS (T6) appreciably reduced the total weed population/m2 and total dry weight of weeds than unweeded control plot (T7) at all the stages of crop growth. The highest plant height (82.10 cm), number of leaves/clump (65.41), number of pseudo stem/clump (5.17), rhizome length (7.22 cm), rhizome width (5.50 cm), number of fingers/rhizome (6.42), yield/plant (0.268 kg/plant), yield (20.33 t/ha) and weed control efficiency were recorded under the hand weeding twice at 45 and 90 DAS (T6) compared to other treatments. The results showed that it is necessary to cover the soil surface with different mulch materials and manual weed control practices to achieve a good control of weeds along with enhanced yield attributes and yield.

Screening of Herbicides in Transplanted Finger Millet [Eleusine coracana (L.) Gaertn

Background: Weeds smother the finger millet due to crop’s slow growth during the initial stages which reduces the yield substantially by 5-70%. Intensive use of herbicides is gaining popularity among the farmers now a days due to its effectiveness in controlling weeds, timeliness and reduced cost. Methods: The current field experiment was conducted at Tamil Nadu Agricultural university during kharif season, 2021 under irrigated condition with twelve herbicide treatments laid out in Randomized Complete Block Design (RCBD) with three replications. Result: Pre-emergence application of pyrazosulfuron ethyl 15 g ha-1 significantly reduced the total weed density and total weed dry weight at 90 days after transplanting over all the other herbicides used. This treatment also considerably improved the plant parameters such as plant height, total number of tillers, plant dry matter production, Grain and stover yield and yield parameters such as productive tillers, ear head weight of transplanted finger millet which was statistically followed by the application of pendimethalin 750 g ha-1 as pre-emergent spray. Similar trend was followed in case of net returns and B: C ratio. while lower plant parameters were observed with the application of tembotrione 12 g ha-1.

Bio‐efficacy of different post‐emergence herbicides in mungbean

AbstractWeeds result in a significant yield loss in mungbean (Vigna radiata[L.] R. Wilczek). However, post‐emergence (POST) herbicides are limited in mungbean for broad‐spectrum weed control. Therefore, we evaluated the efficacies of different herbicides in mungbean to find a suitable broad‐spectrum POST herbicide. Nine herbicides, weed‐free check, and unweeded control treatments were tested in a randomised block design with three replications for two consecutive years. Among the tested herbicides, clodinafop‐propargyl + sodium‐acifluorfen 122.5 g a.i. ha−1applied at 15 days after sowing (DAS) reduced the broad‐leaved weed dry weight at 35 DAS and harvest by 55.8% and by 58.6% (p < 0.05) compared with the unweeded control respectively. Notably, it minimised the total weed dry weight by 23.1%–30.3% compared with the recommended herbicide pendimethalin 1 kg a.i. ha−1– quizalopfop‐p‐ethyl 100 g a.i. ha−1(p ≤ 0.05). Clodinafop‐propargyl + sodium‐acifluorfen had higher weed control index (58.2% at 35 DAS and 62.1% at harvest) over the remaining tested herbicides. Unweeded controls resulted in 51% yield loss compared with the clodinafop‐propargyl + sodium‐acifluorfen that did not differ from pendimethalin − quizalofop‐p‐ethyl for seed yield of mungbean. Decreasing order of treatment efficacy on mean grain yield across two years comprised the weed‐free check, clodinafop‐propargyl + sodium‐acifluorfen and pendimethalin − quiza‐lofop‐p‐ethyl, imazethapyr + imazamox, tembotrione, and topramezone. [Correction added on 10 November 2022, after first online publication: In the preceding sentence, changes have been made to the article content to improve clarity in this version.] Application of clodinafop‐propargyl + sodium‐acifluorfen led to the greatest increase in soil microbial biomass carbon, indicating higher levels of soil biological and rhizospheric activity. We suggest that clodinafop‐propargyl + sodium acifluorfen is a suitable broad‐spectrum option for weed management of mungbean.

Weed Management in Direct Seeded Rice under Different Row Spacing

A field study to evaluate the weed management in direct seeded rice under different row spacing was carried out at Agronomic Research Area, University of Agriculture, Faisalabad during summer 2018. Two herbicides Butachlor @ 118.61 g a.i. ha-1 (pre-emergence) was applied within 24 hours of sowing of direct seeded rice and combination of two herbicides Butachlor @ 118.61 g a.i. ha-1 (pre-emergence) within 24 hours after sowing sequentially followed by Bispyribac Sodium + Bensulfurin Methyl @ 26.7 g a.i. ha-1 + 17.8 g a.i. ha-1 (post-emergence) was applied 15 days after sowing. Bispyribac Sodium @ 26.7 g a.i. ha-1 was applied 15 days after sowing. A weedy check and weed free treatment were also run for comparison. A fine rice cultivar (Basmati 515) was sown during the last week of June in 22.5 cm and 11.25 cm spaced rows using a seed rate of 29 kg ha-1. To fulfill the requirement of nutrients 135 kg N, 88 kg P and 61 kg ha-1 K were applied. The experiment was replicated thrice in a randomized complete block design under split plot arrangement. The net plot size was 3 m × 2.25 m. Date regarding weed density (15, 30 and 45 DAS), weed biomass before harvesting and yield components of rice were recorded by following standard procedures and statistically analyzed by applying Fisher’s analysis of variance technique. Least significant difference test (LSD) at 5% probability was used to compare treatments means. Results of the study showed that total weed density and weed dry weight were significantly influenced by different row spacing and weed control treatments. Significantly lower weed density and weed biomass were observed under narrow row spacing (11.25 cm) as compared to wider row spacing (22.5 cm). Among weed control treatments application of Butachlor @ 118.61 g a.i. ha-1 (pre-emergence) within 24 hrs after sowing of DSR and Bispyribac Sodium @ 26.7 g a.i. ha-1 (15 DAS) reduced the total weed density and weed dry weight. Similarly, paddy yield was also significantly influenced by different row spacing and weed control treatments as weed free at 11.25 cm row spacing gave maximum paddy yield (4.0 t ha-1).

Nutrient Availability and Nutrient Uptake by Crop and Weed as Influenced by Stale Seedbed, Mulching and Mechanical Weeding in Okra

Background: Weeds are the major biological constraint in okra due to its slow initial growth and wider row spacing. Due to severe crop weed competition, weeds removed considerable amount of nutrients from the soil. Competition exists between the crop and weed for nutrients results in nutrient deficiencies in crop. Hence the present experiment is formulated to assess the effect of stale seedbed, mulching and mechanical weeding on nutrient availability, nutrient uptake by crop and weed in okra. Methods: Experiment was conducted at Coconut Research Station, Balaramapuram, Thiruvananthapuram, Kerala during Rabi 2020-21. Design adopted for the study was RBD with two factors. The first factor was seedbed preparation (S) and the second factor was weed management (W). Stale seedbed (S1) and normal seedbed (S2) were the two different seedbed preparation methods and dried banana leaf mulch @10 t ha-1 alone (W1), dried banana leaf mulch @10 t ha-1 fb wheel hoe weeding at 30 and 45 DAS (W2), dried banana leaf mulch @10 t ha-1 fb hand weeding at 30 and 45 DAS (W3), wheel hoe weeding at 15, 30 and 45 DAS (W4), hand weeding at 15, 30 and 45 DAS (W5) and weedy check (W6) were the six different weed management options tried. Soil samples were collected after the harvest of the crop to determine the nutrient availability. Weed samples at 30 and 60 DAS and plant samples at harvest were analyzed to determine the NPK content and respective uptake of nutrients were calculated by multiplying the nutrient content with DMP. Result: Stale seedbed significantly enhanced the dry matter production and nutrient uptake by okra at harvest and lowered the nutrient removal by weeds at 30 and 60 DAS. Compared to non-stale, stale seedbed recorded significantly higher fruit yield. Among the weed management, wheel hoe weeding at 15, 30 and 45 DAS, recorded the lowest total weed dry weight at 30 and 60 DAS and resulted in the highest NPK uptake by crop and fruit yield. Uncontrolled weed growth resulted in a loss of 81.33, 18.16 and 50.84 kg N:P:K ha-1 at 30 DAS and 102.09, 57.90 and 55.31 kg N:P:K ha-1 at 60 DAS, respectively. Nutrient removal by weeds was the lowest in wheel hoe weeding at 15, 30 and 45 DAS and the highest in weedy check. It could be concluded that, wheel hoe weeding at 15, 30 and 45 DAS was the best option for the management of weeds, higher nutrient availability and uptake and yield in okra.

Weed Management Practices on Crop Productivity and Economics in Dry-Direct Seeded Rice under Hill and Plateau Region of Eastern India

In direct seeded rice, weeds are the major problems limiting the crop productivity. Sesbania with direct seeded rice (DSR) as well as seeding rates of rice affects the weed density by smothering effect and therefore, it can be a better weed management practice. Two year on farm trials were conducted at the Kusma, Boarijore Block and Bhaluka, Sundarpahadi block of Godda from 2020 and 2021 to assess the effect of weed management on yields and economics in DSR. The results revealed that significantly the lowest density of grasses, broad leaved weeds (BLWs), sedges, total weed density, total weed dry weight and the highest weed control efficiency were recorded with the treatment of DSR + Sesbania over DSR (pre-sowing irrigation followed by tillage and rice seeding) followed by first post-sowing irrigation at 15 DAS and the farmer’s practice. Weed management practice, DSR + Sesbania was found significantly higher grain yield, gross returns, net returns, B: C ratio, production efficiency and economic efficiency over to followed by first post sowing irrigation at 15 DAS and farmer’s practice. While the farmer’s practice was recorded higher weed index and lowest weed control efficiency. Thus, on the basis present study it is concluded that weed management practice i.e. DSR + Sesbania could be a better option to reduced the weed infestation as well as improves the productivity of DSR in rainfed agro-ecosystem of Jharkhand.

Influence of weed control methods on the yield and yield components of cowpea (Vigna unguiculata (L.) Walp.) varieties in Sokoto, Nigeria

Field trial was carried out during the 2017 wet season (July to October) at the Dryland Teaching and Research Farm of the Faculty of Agriculture, Usmanu Danfodiyo University, Sokoto to determine the effect of weed control methods on the yield and yield components of three (3) cowpea (Vigna unguiculata (L.) Walp) varieties sourced from Sokoto Agricultural Development Project (SADP). Treatments consisted of factorial combination of four (4) weed control methods [Control (no weeding), Chemical weeding (Pendimethalin), Chemical + Hoe and Hoe weeding] and three (3) cowpea varieties [Dan Gidan Yunfa (Local), IT-288 and IT-277-2)]. Treatments were laid out in Randomized Complete Block Design (RCBD) replicated three (3) times. Data were collected on pod yield, grain yield, and haulm yield, total dry weight shelling percentage, 100-grain weight and weed dry weight. Dan Gidan Yunfa recorded higher pod and grain yield than the other varieties. Weed control had significant effect on weed dry matter, the control plot where no weeding was done throughout recorded the highest (103.50 kg ha-1, 114.32 kg ha-1, 139.45 kg ha-1) weed dry matter at 4, 8 and 12 WAS, respectively. Therefore, it could be concluded that Dan Gidan Yunfa performed better than other varieties in the study area. The pod and grain yield of the crop in the weeding treatments were not different from the control (no weeding).

Response of Cowpea [Vigna unguiculata (L.) Walp.] as Succeeding Crop to Residual Effect of Extreme Levels of Atrazine Administered in Preceding Maize (Zea mays L.)

Background: Globally, grain legumes are the paramount family of agricultural crops following cereals. Generally, sequence cropping has manifested effectual in increasing farm productivity and profitability. However, sometimes herbicides administered in previous crop may be associated with phytotoxic effects that can later cause damage to the succeeding crops. The present study aimed to understand the residual effect of extreme levels of atrazine on succeeding cowpea under maize-cowpea cropping system. Methods: Field experiments were conducted during Kharif and rabi season of 2019-20 and 2020-21 in a randomized block design with eleven treatments, replicated thrice. Result: Residual effect of pre-emergence atrazine at 0.50 kg a.i. ha-1 followed by tembotrione at 120g a.i. ha-1 as post-emergence at 25 DAS recorded the lowest total weed density (4.41), total weed dry weight (9.81 g m-2) and highest weed control efficiency (39.25%) during rabi 2019-20 while during rabi 2020-21 lowest total weed density (5.03), total weed dry weight (10.68 g m-2) and highest weed control efficiency (39.65%) were noticed in pre-emergence atrazine 50% WP at 2.00 kg a.i. ha-1. Highest seed yield (788.67 and 842.33 kg ha-1) was obtained in weed free treatment.

Weed Control, Growth, Nodulation, Quality and Storability of Peas as Affected by Pre- and Postemergence Herbicides

Weeds represent a major constraint for successful pea cultivation, resulting in loss of green pea yield and quality. Two field experiments were carried out during the winter seasons of 2018/2019 and 2019/2020. The objectives of the current study were to evaluate the efficacy of pendimethalin, butralin, fluazifop butyl, bentazon, and hoeing on weed control, and their impact on pea growth, nodule formation, yield, quality, and storability. The results indicated that hoeing and fluazifop butyl were the most effective treatments for weed control in terms of the lowest values of total weed dry weight. The bentazon and fluazifop butyl herbicides didn’t affect active nodules number, plant height, plant weight, root length, or number of leaves and branches. Additionally, bentazon and hoeing resulted in the highest total yield per plant and protein content. Butralin and pendimetalin achieved the lowest yield, and butralin also resulted in the lowest plant height and weight. Bentazon-treated peas had the highest chemical compositions in terms of chlorophyll, carotenoids, total sugar, and vitamin C contents in pea pods at harvest and during cold storage at 4 °C and 95 RH for 45 days. No detectable residues of the four herbicides under study were detected in green pods, suggesting that pods can be safely consumed at the time of harvesting. It can be concluded that nodules formation in pea was not affected significantly by the application of the tested herbicides, except pendimethalin and butralin. Furthermore, bentazon had a positive impact on nodules formation and pods quality and could be used effectively for controlling the broadleaf weeds, and it was simultaneously a selective and safe herbicide in pea cultivation.

Weed-competition effects on proso millet (Panicum miliaceum L.): implications for the farmers

Climate resilient proso millet (Panicum miliaceum L.) is viable option to mitigate increasing abiotic stresses due to climate change and food security in the long run. An experiment was conducted at research area of MNS-University of Agriculture, Multan in 2019 to evaluate the impact of weed competition on growth and yield of proso millet. Proso millet variety Upea was sown in the last week of February 2019 with 20 cm row to row spacing using 5 kg seed per acre. Experiment was comprised of treatments of weeds competition period for viz; zero competition, competition for 2 weeks after emergence (WAE), competition for 3 WAE, competition for 4 WAE, competition for 5 WAE and competition for full season. Result indicated that maximum number of weeds (plants m-2) were noted when weeds competed with proso millet for full period. Increase in total weed-dry weight was recorded when allowed the weeds to compete with crop for whole season. Highest plant height (16.18), 100-grain weight (74.72 t ha-1), crop dry matter and chlorophyll contents (16.62 t ha-1) were noted where, weeds were kept weed free throughout whole season. Highest economic yield of crop was observed where weeds were competed with crop for five weeks after emergence, and it was statistically similar with control. Maximum yield and yield components were recorded from C2 (competition for 2 weeks after emergence) was provided significant results. Likewise, highest grain yield (1890 kg/ha) were recorded under C2. Farmers should remove weeds from proso millet in two to three weeks after emergence. Extension agents should persuade farmers for the post emergence control in first 2-3 weeks of the crop.

Evaluation of herbicide alachlor for weed dynamics, growth and yield of maize NAC-6002 (Zea mays L.)

A field experiment was conducted in a randomized complete block design with triplicates to evaluate the effects of herbicide alachlor on weed, growth and yield parameters of maize. The seeds were subjected to preliminary germination study and the selected concentrations were applied (1.0, 2.5, 5.0, 7.5 and 10.0 ppm) followed by seed sowing and the treatments were compared with control. The maximum weed growth was recorded in the experimental site without herbicide treatment. At higher concentrations of the herbicide treatment the maize plants showed different types of morphological changes like improper leaf curling, malformation of leaf, stunted growth. The total weed dry weight showed considerable difference in all the concentrations treatments and least fresh weight was observed in weed free check (1.9 g) plot and the dry weight of weeds was also significantly different in different concentrations of herbicide. The weed control efficiency was increased as the concentrations of the herbicide increased and the maximum and minimum WCE (97.67% and 28.97%) was recorded in 10.0 and 1.0 ppm respectively. The weed index also found to be significantly increased from 6.87 to 91.7% as the herbicide concentrations increased from 1.0 to 10.0 ppm respectively. The yield associated parameters like height of the plants, number of leaves and cobs, length of cobs, weight of cob and grains weight were found to be significantly different under different concentrations of herbicide treatment.

Residual Effect of Weed Management Practices Executed in Preceding Maize on Succeeding Greengram

Background: Maize followed by summer pulses is the emerging cropping system in many places in India. Herbicides are the efficient tools for checking weed infestation and their usage is increasing throughout the globe due to increased labour cost and quick weed control. Some herbicides do not degrade quickly and may remain in the soil for weeks, months or years after application and may inhibit the growth of succeeding crops. Methods: Field experiment was conducted in a randomized block design (RBD) during rabi and summer seasons of 2017-18 and 2018-19 to know the residual effect of different herbicides applied in maize on succeeding greengram. Result: The present study revealed that lower density and dry weight of total weeds and higher yield attributes and yield was recorded with the practice of adopting two hand weedings at 15 and 30 DAS, which was however, at par with atrazine 1.0 kg ha-1 as PE fb one HW at 30 DAS, atrazine 1.0 kg ha-1 as PE fb topramezone 30 g ha-1 as PoE and atrazine 1.0 kg ha-1 as PE fb tembotrione 120 g ha-1 as PoE, without any significant disparity among them. Herbicides applied in maize did not alter statistically the enzyme activity and microbial count in the soil at harvest of succeeding greeengram.