Maximum Weed Control Efficiency Research Articles

Integrated Weed Management in Turmeric (Curcuma longa)

The experiment was conducted at Regional Spices Research Centre, BARI, Magura during the cropping season of 2021-22 and 2022-23 to find out the best management practices for controlling the weed of turmeric. The experiment was laid out in a randomized complete block design with three replications. Nine different treatments and a control plot were studied. Significant differences regarding yield and yield attributes were observed among different treatments. The results revealed that Cyperus rotundus was the major weed constituting 51% of the total weed flora. All treatments brought significant reduction in the count of weeds over control. The lowest number of these weeds was recorded in glyphosate @ 10 ml/L+ 1 HW at 70 DAP + straw mulch @ 5 t/ha treated plot. The highest fresh yield (64.63 t/ha in 2021-22 and 58.28 t/ha in 2022-23) was found from treatment T5 (glyphosate @ 10 ml/L+ 1 HW at 70 DAP + straw mulch @ 5 t/ha) and the lowest yield (20.16 kg/ha in 2021-22 and 20.07 in 2022-23) was found from control plot T10. Maximum weed control efficiency (91.97%) was found from treatment T5 (glyphosate @ 10 ml/L+ 1 HW at 70 DAP + straw mulch @ 5 t/ha). Benefit cost ratio (BCR) was highest under glyphosate @ 10 ml/L+ 1 HW at 70 DAP + straw mulch @ 5 t/ha (3.75) followed by T6 (Paraquat @ 10 ml/L+ 1 HW (70 DAP) + straw mulch 5 t/ha (3.33).

Effects of Herbicides and Nano Urea Mixture on Weeds, Yield Attributes and Yield of Wheat (Triticum aestivum)

Wheat (Triticum aestivum) is second most important staple crop in India after rice. Weeds have emerged as the major biotic stress in wheat. Post-emergence herbicidal combinations are used widely to control the complex weed flora in wheat crops. A field experiment was carried out to study the “Effects of herbicides and nano urea mixture on weeds, yield attributes and yield of wheat (Triticum aestivum)”. The experiment was performed in randomized blocked design with three replications and fourteen treatments in Rabi season 2022-23 at Agronomy Research Farm, CCS Haryana Agricultural University, Hisar. Significantly minimum weed count (1.52 m-2) and dry weight (1.49 g m-2) and maximum weed control efficiency (88.6%) of Phalaris minor and broadleaved weeds (87%) was recorded with application of clodinafop + metribuzin 60 + 210 g ha-1 with nano urea 3 ml L-1 followed by clodinafop + metribuzin 60 + 210 g ha-1 at 90 DAS. In case of yield attributes i.e. number of effective tillers per meter row length (92.5), spike length (11.4 cm), number of grains spike-1 (55.9) and 1000-grain weight (43.8) were higher with application of clodinafop + metribuzin 60 + 210 g ha-1 with nano urea 3 ml L-1 followed by clodinafop + metribuzin 60 + 210 g ha-1. Grain yield (5876 kg ha-1) and B:C (1.94) was recorded higher with application of clodinafop + metribuzin 60 + 210 g ha-1 with nano urea 3 ml L-1 followed by clodinafop + metribuzin 60 + 210 g ha-1 which was significantly higher than weedy check but at par with the weed free treatment.

Integrated Weed Management in Summer Sesame (sesumun indicum L.)

A field research was evaluated at the Seed Technology, S. D Agricultural University, Sardarkrushinagar-385506, Banaskantha (North Gujarat) in the year between summer 2019 to 2021 to study the effect of weed management practices in summer sesamum. Experimental plot was loamy sand in texture with low organic carbon and available N, medium in available P2O5 and high in available K2O.
 Treatments were weed free (IC fb HW at 20 and 40 DAS), weedy control, pendimethalin 30 EC 0.750 kg/ha PE application fb IC+HW at 30 DAS, pendimethalin 30 EC1.0 kg/ha PE application fb IC+HW at 30 DAS, oxadiargyl 6 EC 75 g/ha PE fb IC + HW at 30 DAS, oxadiargyl 6 EC 90 g / ha PE fb IC+HW at 30 DAS, quizalofop-ethyl 5 EC 40 g/ha PoE 20 DAS fb IC+ HW at 40 DAS, quizalofop-ethyl 5 EC 50 g/ha PoE at 20 DAS fb IC+ HW at 40 DAS, pendimethalin 30 EC 0.75 kg/ha PE fb quizalofo-pethyl 5 EC 40 g/ha at 30 DAS and pendimethalin 30 EC 1.0 kg/ha PE fb quizalofop-ethyl 5 EC 40 g/ha at 30 DAS.
 The results revealed that significantly maximum seed yield (0.90 t/ha), stalk yield (2.14 t/ha), number of capsules per plant (73.1) and number of branches per plant (5.2) were obtained under weed free (IC fb HW at 20 and 40 DAS) treatment with maximum net realization (₹52322/ha).
 Minimum weed density at harvest/m2 and weed dry weight/m2 (67.17/m2 and 32.51g/m2) and maximum weed control efficiency (71.62%) were found under weed free (IC fb HW at 20 and 40 DAS).

Weed Dynamics and Crop Productivity as Influenced by Weed Management Practices and Fertility Levels in Groundnut (Arachis hypogaea L.)

Background: Groundnut or peanut (Arachis hypogaea L.) is known as the “King of Oilseeds” which belongs to family Fabaceae (Leguminosae). It is highly susceptible to weed infestation because of its slow initial growth up to 40 DAS and small foliage cover. However, study on use of mechanical weed control methods with different fertility regimes for improving the productivity of groundnut was limited. Therefore, the objective of this study was to find a suitable method for optimising the productivity of groundnut. Methods: A field experiment was conducted at Odisha University of Agriculture and Technology, Bhubaneswar for two consecutive years of 2020 and 2021. The field experiment comprised 16 treatment combinations of four weed management practices and four fertility levels. The weed management practice included W1-Pre-emergence (PE) application of pendimethalin @ 0.75 kg ha-1, W2-Pre-emergence (PE) application of pretilachlor @ 0.5 kg ha-1, W3-Manual weeding (20 and 40 DAS), W4-Twin wheel hoe at 20 DAS followed by (fb) hand weeding at 40 DAS and four fertility levels includes T1-100% RDF (20:40:40) (N: P205: K2O kg ha-1), T2- 75% RDF + 5 tonnes FYM ha-1, T3- 50% RDF + 10 tonnes FYM ha-1, T4- without fertilizer + without FYM. Result: Amongst the weed management practices, use of twin wheel hoe at 20 DAS followed by hand weeding at 40 DAS significantly reduced the weed density, weed dry weight, weed index and recorded the highest weed control efficiency (69.8%). Highest weed index (32.9) was recorded with the application of pretilachlor @ 0.5 kg ha-1 (PE), which was followed by weed index of (28.5) with application of pendimethalin @ 0.75 kg ha-1 (PE). The fertilizer management practice with application of 50% RDF + 10 tonnes FYM ha-1 gave the highest yield and considerably reduced the total weed density, weed dry weight and recorded the maximum weed control efficiency (71.8 % at harvest). We suggest that weed management with twin wheel hoe at 20 DAS followed by hand weeding at 40 DAS along with application of 50% RDF + 10 tonnes FYM ha-1 as the most effective strategy for controlling the weed menace in groundnut with the highest weed control efficiency.

Effect of Different Weed Management Practices on Growth and Yield of Cabbage (Brassica oleracea var. capitata L.)

As cabbage is cultivated with wide spacing, it is prone to profuse weed infestations, resulting in reduced crop yields and subsequent significant economic losses. A field experiment comparing different weed management treatments namely T1 (two hand weedings), T2 (paddy straw mulch), T3 (pre-emergent application of oxyfluorfen @ 1 kg a.i./ha), T4 (PE application of pendimethalin @ 1.5 kg a.i./ha), T5 (PE application of pendimethalin @ 1 kg a.i./ha + HW at 35 days after transplanting), T6 (PE application of oxyfluorfen @ 1 kg a.i./ha + HW at 35 DAT), T7 (weed-free) and T8 (weedy check) was conducted to evaluate their efficacy on growth, yield and economics of cabbage (Brassica oleracea var. capitata L.). The results revealed that the maximum value of plant height, number of unwrapped leaves, fresh weight of heads, dry weight of wrapped leaves and yield per hectare was obtained in plots under treatment T7 (weed free). Similarly, in terms of weed parameters minimum weed count, weed dry weight, weed index and maximum weed control efficiency were observed in treatment T7 (weed free). Maximum net return and benefit: cost ratio was observed under the treatment T5 (PE application of pendimethalin @ 1 kg a.i./ha + one HW at 35 DAT), making it an economically practical option for controlling weeds in cabbage.

Weed Management in Clusterbean under the Application of Different Agrochemicals and Phosphorus Levels

Among the Kharif legumes clusterbean (Cyamopsis tetragonoloba L. Taub) is important crop and popularly known as “Guar” in India. A field experiment was conducted during Kharif 2013 at Agronomy Farm, S.K.N. College of Agriculture, Jobner, Jaipur (Rajasthan) to evaluate the weed management in clusterbean under the application of different agrochemicals and phosphorus levels. The treatments comprising 6 weed control treatments (Weedy check, one hand weeding at 20 DAS, two hand weeding at 20 and 40 DAS, pendimethalin at 0.75 kg/ha, imazethapyr at 100 g/ha and fenoxoprop-p-ethyl at 70 g/ha and four levels of phosphorus (0, 20, 40 and 60 kg/ha) assigned to main and sub plots of spilt plot design, respectively and replicated thrice. Results showed that HW twice at 20 and 40 DAS and pre emergence application of imazethapyr at 100 g/ha resulted significant reduction in weed density and weed dry matter in comparison to most of the treatments. Results further indicated that application of 60 kg P2O5/ha in clusterbean recorded the highest density and dry weight of weeds at all the stages. Maximum weed control efficiency was recorded under two hand weeding at 20 & 40 DAS.

Enhancing profitability and sustainability through herbicides on weed control in wheat-greengram cropping system in Punjab, India

A field study was conducted during the two successive years of Rabi, 2020–21, 2021–22 and Kharif, 2020– 21, 2021–22 at the research farm of Lovely Professional University, Jalandhar, Punjab (India) in a RBD (randomized block design) with eight weed-controlling treatments with three replications. In wheat, seed yield, straw yield, and minimum total weed population and dry weight of weed in subsequent wheat were noted with Pyroxasulfone, with at equality Pyroxasulfone as (PE), followed by HW twice (20 and 40 days after sowing), and 2,4-D sodium salt with a combination of 1 HW (60 DAS). The minimum weed population and dry weight of weeds, maximum weed control efficiency and Greengram growth characteristics, number of pods per plant, number of seeds per pod, test weight, seed and straw yields were noted with Pendimethalin at 2 DAS (PE) and Imazethapyr at 30 DAS (PE), which was at par with Imazethapyr as (PE), followed by (fb) Pendimethalin as (PoE), and HW twice at 20 and 40 days after sowing. It can be used for extremely active weed control to increase the output of Greengram.

EFFECT OF TILLAGE AND WEEDING ON GROWTH AND YIELD OF MAIZE

The experiment was conducted to assess the effect of tillage and weeding practices on the growth, yield, and weed infestation of maize at the research field of the Bangladesh Institute of Nuclear Agriculture, Sunamganj substation, from December 2020 to April 2021. Three tillage (conventional tillage, zero tillage, strip tillage) and three weeding practices (pre-plant herbicide application, one manual weeding and no weeding) were tested using factorial randomized complete block design (RCBD) with four replications. The results revealed that maize growth, yield and its attributes as well as weed infestations were significantly affected by the tillage, weeding practices and their interactions. Weeds of all categories, including grass, sedge, and broad leaf, were present and affected by tillage and weeding activities. In the weed affected plots, Eleusine indica L., Fimbristylis maliaceae, Eclipta prostrata L., Echinochloa crusgalli L. were found prominent. It was observed that conventional tillage plots treated with herbicide produced the highest grain yield (10.78 t ha-¹) and benefit cost ratio (BCR) (2.26), as well as the lowest weed density (5.75 m-²) and maximum weed control efficiency (84.15%). The lowest yield was found in zero tillage plots with no weeding (4.89 t ha-¹) due to higher weed density (88.50 m-²). However, strip tillage along with herbicide treated plots produced yield of 8.01 t ha-¹ incurring a moderate cost of production (81,477 Tk.) and good BCR (2.13). As conventional tillage plots treated with herbicide resulted in higher plant growth and yield and lower weed density than conservation tillage practices with or without weeding it can be practiced in the field for better outcome. However, considering farmer’s income, strip tillage with herbicide application can be suggested for good yield and BCR with the low cost of production.

Effect of weed management practices under irrigated condition growth and yield of field pea (Pisum sativum L)

Field pea (Pisum sativum L) crop was conducted at the Agricultural Research Farm of B. H. U. Varanasi, during rabi season of 2010-11. The experiment was conducted in randomized block design (RBD) with 10 weed control treatments viz., pendimethalin 1.0 kg ha-1 (PE), pendimethalin 1.0 kg (PE) + imazethapyr 75 g ha-1 (PoE), quizalofop- ethyl 60 g ha-1 (PoE), quizalofop- ethyl 50 g ha-1 (PoE), imazethapyr 75 g ha-1 (PoE), imazethapyr 50 g ha-1 (PoE), chlorimuron- ethyl 4 g ha-1 (PPI), pendimethalin 1kg ha-1 (PE) + imazethapyr 50 g ha-1 (PoE) and weed free (HW at 30 and 60 DAS) were compared with weedy check and two irrigation were given to crop at critical stages of crop growth. The soil of experimental field application recommended dose of fertilizer at the time of sowing and soil sandy clay loam in texture, with slightly alkaline in reaction (pH 7.8). Field pea variety HUDP-15 was sown at row spacing of 30 cm apart on 11 November 2010. The observation on weed density and weed dry matter accumulations were recorded at 30, 60 and 90 DAS. Weed control efficiency was calculated at maximum weed dry weight stage (60 DAS) of crop growth. Among herbicidal treatments, sequential application of pendimethalin 1kg ha-1 (PE) + imazethapyr 50 g ha-1 (PoE) was proved to be the most effective in reducing the weed density and dry weight. It also recorded maximum weed control efficiency and lower weed index. The Observation on plant height, and yield attributes viz., pods plant-1, grains pod-1, seed index (100-grain weight), grain and straw yield. The crop growth, yield attribute, grain and straw yield, were maximum in pendimethalin 1kg ha-1 (PE) + imazethapyr 50 g ha-1 (PoE) treated plot followed by pendimethalin 1kg ha-1 (PE) + imazethapyr 75 g ha-1 (PoE) and quizalofop- ethyl 60 g ha-1 (PoE).

Impact of weed management practices on weeds and okra crop

A preliminary study was conducted during the summer of 2014 and 2015 at the N.M. College of Agriculture, Navsari Agricultural University, Navsari, Gujarat, India to evaluate the 10 treatments of weed-management, i.e. stale seedbed, pre- and post-emergence herbicides alone and in combination, integrated weed-management and hand-weeding in summer okra [Abelmoschus esculentus (L.) Moench]. Almost 73.2% of weed infestation was dominated by grasses and sedges, followed by broad-leaf weeds (26.8%). Uncontrolled weed growth caused significant reduction in mean green pod yield of okra by 67%. Weed-free plot [3 hand-weedings (HW) at 20, 40 and 60 days after sowing (DAS)] showed the maximum weed-control efficiency (WCE) (88.4%), resulting in higher green pod yield (16.8 t/ha) and net returns (`105,233/ha). Statistically at par yields were also obtained from plots treated with not incorporated and 2 HW at 20 and 40 DAS (14.3 t/ha) and pendimethalin 1.0 kg/ha followed by (fb) quizalofop-ethyl 0.04 kg/ha at 30 DAS (13.9 t/ha) with net returns of `83,442 and `82,277/ha respectively. Application of pendimethalin 1.0 kg/ha (pre) fb quizalofop ethyl 0.04 kg/ha at 30 DAS supressed the weeds effectively (71.3% WCE) which not only reduced the drudgery of farm labour but also found practically more convenient and economically feasible weed-management option for higher production of okra fruit crop.

Response of Weed Management Practices on Growth, Yields and Economics of Rabi Onion (Allium cepa L.)

The present investigation entitled, “Studies on weed management in Rabi onion (Allium cepa L.)” was carried out at the Vegetable Research Farm of Chandra Shekhar Azad University of Agriculture & Technology, Kanpur (U.P.) during Rabi season 2021with the objectives of relative efficacy of herbicides and hand weeding on weed control in onion. The experiment was laid out in Randomized Block Design for nine treatments with three replications. It was observed that the growth attributes viz., plant height (80.25 cm), leaves/plant (10.82), fresh weight of bulb (32.65 gm) and dry weight of onion (17.51 gm) were significantly higher in (T2) over rest treatments, respectively. The yields attributes viz., the polar diameter of bulb (56.70 mm), Equatorial diameter of bulb (68.58 mm) and total bulb diameter (5.97 cm) were significantly more recorded in T2, while the minimum was recorded in control. The bulbs yield (27.03 t / ha). TSS (15.43) was significantly highest in weed free check over remaining all treatments, respectively. Among the herbicidal treatment pre and post emergence application of treatment T8. The number of weeds (m2) and weed dry matter (g/ m2) were significantly noticed that weed free check (T2) was most effective treatment as it recorded less weed count 0.68/m2 and dry matter 1.25g followed by 3.63/m2 and 3.45g, respectively. The maximum weed control efficiency (93.3%) and minimum weed control index (0.00%) was significantly recorded by treatment T2, compared to remaining treatments, respectively. The gross monetary returns (Rs.3,24,360.00) were recorded higher in the treatment weed free check (T2) followed by among the herbicides T8 Rs 3,15,240/ ha and net monetary returns were recorded statistically higher in the treatment T8 Rs. 2,21,648.00. Whereas, the highest benefit cost ratio (1:3.71) was recorded in the treatment T7 followed by T6, in the present investigation.

Growth and productivity of maize (Zea mays L.) as influenced by organic weed and nutrient management practices in Western Rajasthan

An experiment was conducted during 2019 and 2020 at College of Agriculture, Sumerpur (Rajasthan) to study the effect of organic weed management and organic nutrient management treatments practices on maize (Zea mays L.)in split plot design with 3 replications.The two years mean data revealed that the minimum weed infestation (79.1%) and maximum weed control efficiency (93.1%) was recorded in weed free check as against weedy check among various weed management treatments at harvest. Most of the growth attributes, grain (3.36 t ha-1) and stover (6.26 t ha-1) yield of maize were significantly affected by weed management and nutrient management practices and found maximum in weed free check maintained up to 60 DAS closely followed by stale seedbed+ hoeing once at 20 DAS + straw mulch applied @ 5 t ha-1 at 30 DAS against weedy check. The application of vermicompost @ 75% of recommended dose of nitrogen (RDN i.e. 90 kg N equivalent) in two splits (75% at sowing +25% as top dressing at 30 DAS) along with seed treatment with fermented beejamurt and two sprays of jeevamurt registered significantly hgher growth parameters besides grain yield of 3.17 t ha-1as compared to 100% RDN through FYM. The mean gross return, net return and B:C ratio were significantly affected by various weed and nutrient management practice and maximum values were recorded with weedy check and 755% RDN through vermicompost + STB + JT, respectively.

Growth and productivity of maize (Zea mays L.) as influenced by organic weed and nutrient management practices in Western Rajasthan

An experiment was conducted during 2019 and 2020 at College of Agriculture, Sumerpur (Rajasthan) to study the effect of organic weed management and organic nutrient management treatments practices on maize (Zea mays L.)in split plot design with 3 replications.The two years mean data revealed that the minimum weed infestation (79.1%) and maximum weed control efficiency (93.1%) was recorded in weed free check as against weedy check among various weed management treatments at harvest. Most of the growth attributes, grain (3.36 t ha-1) and stover (6.26 t ha-1) yield of maize were significantly affected by weed management and nutrient management practices and found maximum in weed free check maintained up to 60 DAS closely followed by stale seedbed+ hoeing once at 20 DAS + straw mulch applied @ 5 t ha-1 at 30 DAS against weedy check. The application of vermicompost @ 75% of recommended dose of nitrogen (RDN i.e. 90 kg N equivalent) in two splits (75% at sowing +25% as top dressing at 30 DAS) along with seed treatment with fermented beejamurt and two sprays of jeevamurt registered significantly hgher growth parameters besides grain yield of 3.17 t ha-1as compared to 100% RDN through FYM. The mean gross return, net return and B:C ratio were significantly affected by various weed and nutrient management practice and maximum values were recorded with weedy check and 755% RDN through vermicompost + STB + JT, respectively.

Effect of herbicides on weed dynamics in transplanted rice (Oryza sativa L.) in Eastern U.P., India

A field experiment was conducted at Agricultural Research Farm, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, UP, India during kharif-2017 and 2018 to evaluate effect of herbicides on weed population and weed dry weight in transplanted rice in eastern UP. There were ten treatments in the combination of herbicides in varying doses, arranged in a randomized block design with three replications. Among dominant weed flora narrow leaf weeds like Cynodon dactylon, Echinochloa colona and Echinochloa crusgalli, sedges like Cyperus rotundus, Cyperus iria and Fimbristylis miliacea and broad-leaved weeds like Eclipta alba and Caesulia axillaris were recorded in the time of experimentation. Combined application of Bispyribac-Na 9.1% @ 24.57 g ha-1 + Metsulfuran methyl 1.2% @ 3.24 g ha-1 + Chlorimuron ethyl 1.2% SC @ 3.24 g ha-1 was recorded minimum weeds density and weeds dry weight and maximum weed control efficiency after weed free treatment at all the crop growth stage 30, 60 and 90 days after transplanting.

Integration effect of drip irrigation and mulching on weeds and spring maize productivity

A field experiment was carried out at Research Farm, Department of Agronomy, Punjab Agricultural University, Ludhiana during spring season of 2020 and 2021. The experimental design was split-plot with three replications. The main plots included the combination of two methods of drip irrigation, viz. surface drip irrigation (SD) and sub-surface drip irrigation (SSD) and three mulch treatments, viz. plastic mulch (PM), straw mulch 6 t/ha (SM) and no mulch (NM) along with furrow irrigation (FI) as a control treatment. The sub-plots consisted of four weed control treatments, viz. pre- emergence application (PE) of atrazine 1000 g/ha, hand weeding twice at 30 and 60 days after seeding (DAS), weed free and weedy check. The dominant weed species were Cyperus rotundus, Oenothera laciniata, Chenopodium album, Coronopus didymus, Rumex dentatus, Digitaria sanguinalis, and Dactyloctenium aegyptium. The maize emergence was 6 days earlier under plastic mulch than the crop under straw mulch. The SD-PM, SD-SM, SSD-PM, SSD-SM and SSD- NM resulted in maximum maize plant height when compared to FI. SD-PM, SD-SM, SSD-PM and SSD-SM treatments recorded significantly lower total weed density and biomass at 30 DAS than the atrazine treated FI treatment. Maximum weed control efficiency of 88.89% was recorded under integration of drip irrigation with plastic mulch. Integration of drip irrigation and mulches resulted in significantly increased maize grain yield as compared to FI. Crop raised under SD- SM treatment resulted in 20.62% higher grain yield than FI. The integration of drip irrigation with mulching resulted in effective weed management and higher maize grain yield than furrow irrigation method.

Effect Of Weed Management Practices On Weed Dynamics, Yield And Economics Of Spring Maize At Dhading Besi, Nepal

Weeds have been a major constraint in maize cultivation resulting in huge economic loss to farmers. A field experiment was conducted at Dhading Besi, Nepal to evaluate the effect of different weed management practices on weed dynamics, yield and economics of spring maize in 2020. The experiment was laid out in Randomized Complete Block Design (RCBD) comprising of eight treatments with three replications. Rajkumar hybrid maize variety was used in the experiment. The treatments consisted of weedy check, weed free, atrazine as PE @1.0 kg a.i./ha, pendimethalin as PE @1.0 kg a.i./ha, atrazine @ 1.0 kg a.i./ha as PE followed by (fb) 2,4-D EE @0.5 kg a.i./ha as PoE, pendimethalin @ 1.0 kg a.i./ha as PE fb 2,4-D EE @ 0.5 kg a.i./ha as PoE, 2 hand weeding @ 20 and 40 DAS and Farmer’s practice. The experiment result revealed that sequential application of atrazine fb 2,4-D EE treatment resulted in highest grain yield (11.37 t/ha) which was statistically similar with weed free (11.24 t/ha) and followed by the treatment atrazine (10.36 t/ha). 16 weed species belonging to 6 different families were identified. The broad leaf weeds and grassy weeds were more prominent than sedges. The total density and dry weight of weeds were found significantly lower in sequential application of atrazine fb 2,4-D EE than other treatments. Similarly, application of atrazine fb 2,4-D EE resulted in maximum weed control efficiency of 87.59 %, 95.91 % and 92.17% at 30, 45 and 60 DAS respectively. The lowest weed index (-1.27%) was also obtained in the application of atrazine fb 2,4-D EE. Yield loss due to weed in the weedy check treatment was found to be 50.99% followed by farmer’s practice (43.17%). The benefit cost ratio and increment in benefit over weedy check were highest in atrazine fb 2,4-D EE followed by atrazine and significantly better than other weed management treatments. The sequential application of atrazine fb 2,4- D EE was found to be the most effective in controlling weeds, high yielding and economical among the different weed control treatments. The application of atrazine one time as PE was found to be next better option for weed control in spring maize.

Efficacy of Herbicides for Weed Control in Cauliflower (Brassica oleracea var. botrytis L.)

A field experiment was conducted during Rabi, 2018-19 at Horticulture farm, RAK College of Agriculture, Sehore (M.P.) to study the effect of different weed management practices on growth and yield of cauliflower. The treatments namely - T1- Weedy check (control), T2- Weed free (through hand weeding) at 30 & 60 DAT, T3 -Pendimethalin 30% EC (PE) + one hand weeding at 30 DAT, T4 Oxyfluorfen 23.5% EC (PE) + one hand weeding at 30 DAT, T5 - Propaquizafop 10% EC (POE) + one hand weeding at 60 DAT, T6 -Wheat straw mulch 5kg/plot, T7- Black plastic mulch (150 mm) were evaluated in randomized block design with three replications. Results indicated that the there was no weed under T7 -black plastic mulch (150 mm) at all the stages. The maximum weed control efficiency (98%) was found with the treatment T7 - black plastic mulch (150 mm) at all the stages i.e. at 30, 60 and 90 DAT. The minimum weed index (0.00, 0.00 and 0.00%) was found with the treatment T7 (Black plastic mulch (150 mm) at all the stages. The maximum curd length, curd width, total curd weight (g) and curd yield (q ha-1) was recorded T7- black plastic mulch (150 mm) with the maximum net return (Rs. 75772.58 per ha).While the lowest net return was found under T1 (Weedy check) (Rs. 21405.34 per ha) treatment. The maximum B: C ratio (1:4.0) was recorded in case of treatment T3 [Pendimethalin 30% EC (PE) + 1HW at 30 DAT].

Efficacy of Herbicides in Controlling Wild Onion (Asphodelus tenuifolius L.) in Cumin Grown under Arid Climatic Conditions

A field experiment was conducted to investigate the effectiveness of different herbicides for controlling wild onion (Asphodelus tenuifolius) in cumin (Cuminum cyminum L.) during the rabi seasons (2018–2019 and 2019–2020) at Agricultural Research Station, Agriculture University, Jodhpur, Rajasthan. The experiment comprised eight herbicidal weed management treatments for wild onion applied to cumin in a three-replication randomized block design. Among the herbicidal weed management treatments, early post-emergence (8 DAS) application of oxyfluorfen 200 g/ha resulted in the lowest weed density and dry matter of Asphodilus tenuifolius, with maximum weed (Asphodilus tenuifolius) control efficiency at 40 days after sowing (DAS) during both experimental years. Likewise, the highest total efficiency of weed control was recorded with the application of oxyfluorfen 200 g/ha at 8 DAS. Oxyflourfen 200 g/ha used early post emergence (8 DAS) reduced the weed index more effectively than the other herbicides. It also recorded the highest number of branches/plant, plant height, umbels/plant, umbellates/umbel, seeds/umbellates, and seed yield. However, application of oxyflourfen @ 200 g/ha 8 DAS–early POE and pendimethalin 38.7 CS 500 g/ha + oxyfluorfen @ 150 g/ha 8 DAS–early POE were statistically similar in terms of plant growth, yield, and yield attributes. The net returns (366.49 USD/ha in 2018–2019 and 175.72 USD/ha in 2019–2020) and B:C ratio (1.70 and 1.33 in 2018–2019 and 2019–2020, respectively) were also superior, with oxyfluorfen 200 g/ha applied early post emergence.

Junglerice (<em>Echinochloa colona</em> L.) seedling emergence model as a tool to optimize pre-emergent herbicide application

Junglerice (Echinochloa colona), one of the worst and most problematic weeds globally, causes significant economic losses due to yield loss and control cost increase. Taking into account that this weed emerges in approximately five months - from September to January -, and considering that reducing herbicide use is key in the current intensification of agricultural production systems, the present study was carried out under the hypothesis that there should be an optimal moment for pre-emergent herbicide application to achieve maximum weed control effectiveness and efficiency. Therefore, experiments were carried out from August 2016 to January 2021 in Pergamino, Buenos Aires province, Argentina, using a double-logistic emergence model of junglerice seedlings. Bicyclopyrone plus s-metolachlor, clomazone, and pyroxasulfone plus saflufenacil were applied at different times between 92 and 478 growing degree days (GDDs). Single applications between 348 and 399 GDD were observed to reduce junglerice seedling emergence by 85-99%, depending on the herbicide used. Such a seedling emergence reduction could be a convenient strategy to provide significant weed suppression in the field in combination with a competitive crop and within a sustainable production system. The results of the present study lead to the conclusion that using predictive models for pre-emergent herbicide applications ensures more effective use of herbicides and reduces the amounts of herbicides used and the risks of selecting herbicide-resistant junglerice populations. Highlights - Weed occurrence indirectly increases the number of herbicide applications in Argentina. - Reducing the number and volume of herbicide applications contributes to mitigating environmental impact in the short term. - There is a critical time during weed emergence in which chemical control via herbicide application is most effective. - Seedling emergence models are useful management tools to predict critical timing for weed control.

Optimizing the Application Time of Pre-emergence Herbicide Pendimethalin and Oxyfluorfen Application for Effective Weed Management in Irrigated Blackgram (Vigna mungo L.) and Its Residue Persistence

Background: Time of pre-emergence herbicide application is an important factor that decides the efficiency of herbicide. If the pre-emergence herbicide is not applied at appropriate time, it may cause ineffective weed control or toxicity to crops. With this background, a field experiment was conducted at TNAU, Madurai to optimize the time of pre-emergence herbicides namely pendimethalin and oxyfluorfen application for effective weed management in irrigated blackgram. Methods: The experiment was laid out in randomized block design with three replication. Treatments were application of pendimethalin at 0.75 kg ha-1 and oxyfluorfen at 0.2 kg ha-1 on 1, 2, 3, 4 days after sowing, weed free check and unweeded check. Result: Results of the study revealed that oxyfluorfen gave maximum weed control efficiency as compared to pendimethalin, but toxicity to the crop was observed when oxyfluorfen was sprayed after 2 days of sowing. Yield and economics were achieved higher with application of 0.75 kg ha-1 of pendimethalin at 2 DAS, which was on par with application of 0.2 kg ha-1 of oxyfluorfen at 1 DAS due to lesser toxicity. Application of 0.75 kg ha-1 of pendimethalin and 0.2 kg ha-1 of oxyfluorfen didn’t leave any herbicide residue after harvest. Hence, application of 0.75 kg ha-1 of pendimethalin at 2 DAS and 0.2 kg ha-1 of oxyfluorfen at 1 DAS can be recommended for effective weed management in irrigated balckgram.