تاثیر الگوی کاشت و مصرف علفکش بر عملکرد دانه و کنترل علفهای هرز ذرت دانه ای (Zea mays L

به منظور بررسی اثرات تراکم و آرایش کاشت ذرت دانه‌ای در کاهش مصرف علف‌کش‌ها آزمایشی در سال زراعی 1386 در مزرعه تحقیقاتی بخش تحقیقات علف‌های‌هرز موسسه گیاهپزشکی کشور، واقع در ورامین به صورت کرت‌های خرد شده در قالب طرح بلوک‌های کامل تصادفی با چهار تکرار به اجرا درآمد. الگوی کاشت ذرت با چهار سطح تک‌ردیفه با تراکم معمول و دو ردیفه زیگزاگ با تراکم‌های معمول، 25% و 50% بیشتر از تراکم معمول به عنوان فاکتور اصلی و مصرف علف‌کش نیز با پنج سطح مخلوط آترازین به میزان 1 کیلوگرم در هکتار و ارادیکان به میزان 4، 5 و 6 لیتر در هکتار، مخلوط آترازین به میزان 1 کیلوگرم در هکتار و آلاکلر به میزان 5 لیتر در هکتار، ارادیکان به میزان 6 لیتر در هکتار به صورت پیش‌کاشت و به عنوان فاکتور فرعی اعمال گردید. کرتهای شاهد شامل شاهد بدون علفهرز و شاهد با علفهرز بود. تغییر الگوی کاشت ذرت از تک ردیفه با تراکم معمول به دو ردیفه زیگزاگ با تراکمهای 25% و 50% بیشتر از تراکم معمول موجب افزایش معنیدار عملکرد دانه ذرت شد. به غیر از تیمار شاهد با علفهرز عملکرد دانه سایر تیمارهای علف‌کشی اختلاف معنیداری با عملکرد دانه تیمار شاهد بدون علفهرز نداشت. در نتیجه میتوان از مقادیر کاهش یافته علفکشها استفاده نمود و در نتیجه میزان مصرف علفکشها را کاهش داد. افزایش عملکرد دانه نتیجه تأثیر معنیدار مصرف علفکش بر تعداد ردیف دانه در بلال، وزن صد دانه و قطر بلال بود.

Aims: The study aimed to evaluate the influence of different weed management approaches on weed density and weed control efficiency in apple nurseries.
 Study Design: The experimental method used in this study was a Randomized Complete Block Design with seven treatments, each replicated three times.
 Place and Duration of Study: The experiment was set up at the Experimental Farm, Division of Fruit Science, Faculty of Horticulture, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Shalimar Campus, Srinagar, Jammu and Kashmir, India during the year 2020.
 Methodology: Seven weed management treatments i.e. manual weeding, pendimethalin @ 1 kg a.i. ha-1, pendimethalin @ 1 kg a.i. ha-1 + manual weeding, paddy straw mulch – 6 cm thick, black polyethylene mulch - 200 micron, weed-free and weedy check were tested in apple nursery (Apple cv. Silver) Spur grafted on M-9 T337 was used as plant material for the study. Weed flora, density, dry weight, and weed control efficiency were all observed and recorded.
 Results: Among different weed management approaches tested, black polyethylene mulch (200 micron) resulted in the lowest weed density and weed dry weight, and the highest weed control efficiency followed by paddy straw mulch (6 cm thick) and pendimethalin @ 1 kg a.i. ha-1 + manual weeding.
 Conclusion: In apple nurseries on clonal rootstock M9-T337, black polyethylene (200 micron) was determined to be the most effective weed control strategy for reducing weed density while increasing overall control efficiency.

Weed management is one of the major constraints in the Zimbabwe smallholder farming sector contributing to smallholder poor yields, hence there is need to identify cropping systems that have potential to reduce weed pressure while improving crop yields. Conservation agriculture has been suggested as one of these farming systems. The implementation of CA three key principles reduces weed pressure even when the use of herbicides is minimised. Crops included in crop rotations, intercropping or relay cropping may have faster growth rate than weeds hence, have a comparative advantage over weeds. Maintenance of permanent soil cover through crop residues impedes weed germination thereby reducing weed population. Elimination of ploughing also reduces the chances of bringing buried weed seeds to the surface where their chances for germination are high. Hence, some seeds lose viability thus reducing weed density. Weed seeds accumulate at the surface, when allowed to set seed, increasing their exposure to predation resulting in reduction of weed density over time. The use of herbicides ensures that the fields are weed free as the season’s progress thus ensuring better yields at the end of each growing season. Hence, weeds are reduced in CA systems over time despite the weeding option used.

Based on a long-term experiment in the Changwu Agro-ecological Experimental Station in Xianyang, Shaanxi, China, we examined the effects of fertilization and planting patterns on soil aggregate quantity, aggregate stability and total carbon and organic carbon distribution in different aggregate fractions through dry and wet sieving methods, as well as the TOC combustion method. There were ten treatments, including uncultivated (R), wheat continuous cropping (CK/W), wheat-corn rotation (L), and nitrogen fertilizer (N), phosphorus fertilizer (P), nitrogen and phosphorus fertilizer (NP), organic fertilizer (M), nitrogen and organic fertilizer (NM), phosphorus and organic fertilizer (PM), nitrogen and phosphorus and organic fertilizer (NPM) for CK/W. The results showed that fertilizer application and planting patterns affected soil aggregate distribution and stability, the contents and contribution rates of total C and organic C. Force-stable aggregate was mainly constituted by >0.25 mm aggregate (>67%), which was reduced by fertilization. Continuous cropping decreased micro-aggregate while rotation facilitated it and the effect was larger than fertilization. Water-stable aggregate was mainly comprised of micro-aggregate (<0.25 mm), the contribution of which was larger than 61%. Both fertilizer application and planting pattern reduced water-stable micro-aggregate. Fertilizer application and planting pattern decreased the percentage of aggregate destruction rate (PAD) and increased macro-aggregate (>0.25 mm, R0.25) content. Organic fertilizer significantly improved total C and organic C concentrations in all the fractions of force-stable aggregates. Continuous cropping and rotation cropping increased total C concentration in all the aggregate fractions while rotation cropping significantly decreased organic C concentration. Single N and P fertilization decreased soil total C concentration, while mixed application of N and P fertilizers, and organic fertilizer significantly increased soil total C concentration. The effect of planting patterns on soil total C was lower than that of fertilization. Both continuous cropping and rotation cropping increased soil total C. Mixed application of N and P fertilizers, and organic fertilizer signifi-cantly increased soil organic C concentration while single N and P fertilization decreased it. The effect of planting patterns on soil organic C was lower than that of fertilization, while rotation cropping did not facilitate soil organic C. Micro-aggregate was the most notable size fraction to total carbon and organic C, with the contribution being 21.2%-33.6%. Fertilization and planting pattern increased the contribution rate of micro-aggregate in soil total C. NP and NPM significantly increased the contribution rate of micro-aggregate in soil total C and soil organic C. The effect of rotation cropping was most obvious in driving the contribution rate of micro-aggregate in soil total C and soil organic C.

Weeds caused serious problem on yield reduction of basmati rice worldwide. Losses caused by weeds varied from one country to another, depending on the presence of dominant weeds and the control methods practiced by farmers; therefore, suitable plant population and weed management practices should be adopted. Keeping these in mind, a field experiment was carried out during kharif seasons of 2009 and 2010 at crop Research Centre of SVPUA&T, Meerut, India comprising 4 planting geometries, viz. 20, 30, 40, and 50 hills m−2 as main plot factor, and 5 weed management practices (Butachlor @ 1.0 kg ha−1, Butachlor @ 1.0 kg ha−1 fb (followed by) one hand weeding, Butachlor @ 1.0 kg ha−1 fb Almix @ 4 g ha−1, two hand weedings and weedy check) in a split plot design with 3 replications. Experimental results revealed that plant population of 50 hills m−2 proved superior over that of 20 hills m−2 in respect of weed density, weed dry weight, number of tillers m−2, yield attributes, grain, straw, and biological yields. The maximum grain yield (29.00 and 31.00 q ha−1) and straw yield (51.30 and 52.50 q ha−1) were recorded in 50 hills m−2 followed by 40 hills m−2 during 2009 and 2010, respectively. In respect of nitrogen, phosphorus, and potassium removal, a reverse trend was observed: the highest in 20 hills m−2 followed by 30, 40, and 50 hills m−2. As far as the weed management practices are concerned, both chemical and mechanical methods of weed control were found superior over weedy check. The lowest weed density, dry weight, and highest weed control efficiency, maximum length of panicle−1, number of panicle (m2), and 1000-grain weight and grain yield of 30.40 and 32.60 q ha−1 were recorded with two hand weedings which was at par with Butachlor @ 1.0 kg ha−1 fb one hand weeding over rest of the weed management practices.

Experiments were conducted at the Teaching and Research Farm of the University of Ibadan in 1998/1999 and 1999/2000 cropping seasons to determine the effects of different crop associations and fertilizer types on the weed biomass. The results showed that crop associations did not significantly affect weed density and weed dry weight at 5 and 38 weeks after planting (WAP) in 1998/1999 and 1999/2000 cropping seasons. However, at 14, 21 and WAP, crop associations significantly reduced weed density and weed dry weight at P = 0.05. Fertilizer types significantly increased weed density and dry weight at 5, 14, 21, and 29 WAP, except in the 38 WAP in 1998/1999 and 1999/2000 cropping seasons. Key Words: Crop associations; fertilizer; weed biomass Moor J. Agric. Res. Vol.4(1) 2003: 46-49

An experiment was conducted during the spring seasons of 2022 and 2023 at Agricultural Research Station No. 1, College of Agriculture, University of Anbar, located in Ramadi district, Anbar province, Iraq. The study aimed to evaluate the impact of weed control methods and micronutrient spraying on weed traits and growth characteristics of three sunflower varieties. The experiment followed a randomized completely block design (RCBD) with a split-split plot arrangement and three replications. The main plots included weed control methods (no control, Treflan herbicide treatment and black plastic mulching). At the same time, the sub-plots consisted of three micronutrient spraying treatments (0, first combination and second combination). The sunflower varieties Aqmar, Sakha and Flami included the sub-sub-plots. Results indicated that the mulching treatment significantly reduced weed density and dry weed weight and achieved values ??of (5.96 and 4.33 plant m-1, 11.67 and 8.22 plant m-1, 123.97 and 91.02 g plant-1) for the two seasons, respectively, while enhancing: plant height, leaf area, stem diameter and chlorophyll index. The second micronutrient spray formulation gave the highest averages for most traits. Among the cultivars, Sakha showed the lowest weed density and dry weed weight, Qamar recorded the tallest plants (189.04 and 211.12 cm) for both seasons and Flame showed superior vegetative growth traits. Significant interactions were observed between the study factors, where the mulching combination and Flamy cultivar gave the highest leaf area, stem diameter and chlorophyll content and the three-way interaction of mulching, the second micronutrient formulation and Flamy cultivar achieved the highest chlorophyll content. and the triple interaction of mulching, second micronutrient combination and Flami variety achieving the highest chlorophyll content. In conclusion, black plastic mulching effectively reduced weed density and improved sunflower growth, with the second micronutrient combination and Flame variety showing the best results.

به منظور بررسی تأثیر فاصله ردیف و تراکم بوته بر عملکرد کمی و کیفی سویا در شرایط رقابت علف‌های هرز، آزمایشی در مزرعه دانشکده کشاورزی یاسوج در تابستان 1389 اجرا شد. این آزمایش به‌صورت اسپلیت فاکتوریل در قالب طرح بلوک‌های کامل تصادفی با سه تکرار انجام شد. عامل اصلی شامل رقابت علف هرز (در دو سطح کنترل و عدم کنترل علف‌های ‌هرز طبیعی مزرعه) و عامل فرعی شامل فاکتوریل فاصله ردیف سویا (با سه سطح 30، 45 و 60 سانتی‌متر) و تراکم کاشت (با سه سطح 40، 50 و 60 بوته در مترمربع) بود. نتایج حاصل از این آزمایش نشان داد که با افزایش تراکم کاشت سویا و کاهش فاصله ردیف آن عملکرد دانه این محصول به طور معنی داری افزایش می گردد، به طوری که بیشترین عملکرد دانه در تراکم 60 بوته در متر مربع (2405 کیلوگرم در هکتار) و فاصله ردیف 30 سانتی متر (2368 کیلوگرم در هکتار) به دست آمد. همچنین رقابت علف های هرز باعث کاهش معنی دار 37 درصدی عملکرد دانه سویا شد. افزایش تراکم و کاهش فاصله ردیف سویا، عملکرد روغن را افزایش داد در حالی که رقابت علف های هرز منجر به کاهش 38 و 41 درصدی عملکرد روغن و پروتئین گردید. همچنین با افزایش تراکم و کاهش فاصله ردیف سویا، وزن خشک علف های هرز کاهش یافت، به طوری که کمترین وزن خشک از فاصله ردیف 30 سانتی-متری (3/531 گرم) و تراکم کاشت 60 بوته در مترمربع (2/523 گرم) به دست آمد. نتایج به دست آمده حاکی از موثر بودن افزایش تراکم کاشت و کاهش فاصله ردیف سویا برای کنترل علف های هرز می باشد

Cowpea (Vigna unguiculata L. Walp.) production in Nigeria is limited mainly due to weed and insect infestations. The effects of insecticide spray regime and weed control on the productivity of cowpea were evaluated in the early and late seasons of 2020. Two insecticide sprays produced increased growth and yield in the late cropping season. However, in the early cropping season, optimum growth and yield of cowpea were obtained with four insecticide sprays. Regardless of the cropping season, preemergence (PRE) application of metolachlor or propaben plus manual weeding (MW) provided 71–80% reduction in weed density and biomass and resulted in cowpea growth and yields similar to the weed-free control. In the late season, two MWs resulted in cowpea growth and yield similar to the weed-free control. However, in the early season treatment, two MWs resulted in 51% lower yield than the weed-free control. The results showed that four insecticide sprays in the early cropping season or two insecticidal sprays in the late cropping season integrated with metolachlor or propaben application plus MW improved the productivity of cowpea.

A field study was conducted during the winter seasons of rabi 2000-2001 and 2001-2002 to investigate the comparative efficacy of herbicidal and manual weed control in cumin (Cumimum cyminum L.) at different levels of nitrogen. All the weed-control treatments significantly reduced the density and dry weight of weeds and nutri- ent depletion as compared to weedy check. Two hand-weedings at 25 and 50 days after sowing was found to be the best treatment in reducing the above weed parameters. It attained the maximum weed-control efficiency (87.9%) and seed yield of cumin (5.50 qlha). Among herbicides, the lowest density and dry weight of weeds and the maximum weed-control efficiency (84.3%) was obtained with pre-plant Trifluralin at 2.1 6 kglha. For seed yield (4.94 q/ha) and weed-competition index (10.2%), Trifluralin at 1.08 kg/ha was found the best herbicidial treat- ment. Pendimethalin at 1.0 kglha (pre-emergence) also controlled the weeds more effectively (79.3%) than lower doses of Trifluralin and Fluchloralin at 1.125 kg/ha and resulted 242.9% higher seed yield than the control. Appli- cation of 30 kg N/ha was the most remunerative dose for cumin with respect to seed yield.

In order to investigate the effect of weed control with common herbicides on yield and components of soybean yield (Glycin max L.) in the second crop, two experiments were conducted as a randomized complete block design with three replications at the Agricultural and Natural Resources Research Center of Moghan during 2016-2017 and 2017-2018. The treatments consisted of Ethalfluralin, Imazethapyr, Trifluralin, Metribuzin, Bentazone and Alacolor herbicides with and without weed control. The results showed that the number of pods per plant, biological yield, grain yield and soybean protein percentage were statistically significant, but for chlorophyll index, 1000 seed weight and oil percent grain, the difference was not statistically significant. The highest number of pods per plant (333.92), biological yield (1221 g.plant-1) and grain yield (2792 kg.ha-1) were obtained from hand weeding. The results of the analysis of variance showed that the treatments had a significant difference in terms of the percentage of the effect of herbicide, density and total weed dry weight. The results showed that one month after spraying, the Trifluralin and Ethalfluralin herbicides had the highest effect on the weed control and two months after spraying, the rest of the treatments also showed their effect and all herbicide treatments were in one group. In this study, all weed control treatments significantly reduced the density and dry weight of weeds than without control, but their effect was less than hand weeding. The highest grain yield (1896 kg.ha-1) and the highest biological yield (784.9 kg.ha-1) were observed from Ethalfluralin herbicide

Study was carried out in two different locations (L1: Yüzbaşılar village and L2: TUAM (Iğdır University Agricultural Application and Research Center) in 2020 to determine the effect of different waste mulch materials on weed control and tomato yield. In the study, five different mulch materials (tree of heaven, fine sawdust, wood chips, shredded paper and sheep wool) were used. Each plot has weed and weed-free control group. The effects of mulching on weeding, weed dry weight, yield (kg/da), fruit weight (gr) and number of fruit per plant (pieces) were investigated. Three counts were made to determine the weed density in the plots. As a result of the study, a total of 17 weed species belonging to 9 families were determined in the experimental areas. As a result of the counts, it was observed that Sorghum halepense L., Convolvulus arvensis L. and Xanthium strumarium L. weeds emerged the most in the plots where the mulch materials were laid. Depending on the location, the lowest density among the weed density counts was obtained from the paper plots. In the study, the lowest average weed dry weight among the mulch materials was paper (L1: 97.63; L2: 73.12 gr/m2), the highest average was tree of paradise (L1: 191.87; L2: 165.27 gr/m2) plots. As a result of the study, the best results in tomato yield (L1: 6.078.50; L2: 6.807.87 kg/da) and fruit weight (L1: 142.67; L2: 147.35 gr)) were obtained in the use of paper mulch. The highest number of fruits per plant was obtained in the use of wood chips (L1: 45.774.83/ pieces) and tree of heaven leaves (L2: 46.627.41/pieces). The fact that mulch applications give better results than control groups suggests that mulches will be much more beneficial for controlling weeds and improving fruit yield and quality.

A field experiment was conducted during the summer season of 2020 and 2021 at Agricultural Experimental Farm of Calcutta University, Baruipur, South 24 Parganas, West Bengal to find out the effect of plastic mulch and herbicides on weed dynamics, productivity and economics of sesame. Among different weed management treatments, plastic mulch was found very effective in reducing weed density and dry weight at 30 and 60 DAS and registered highest weed control efficiency at 30 DAS in 2020 and 60 DAS in both the years and lowest weed index. Sequential application of pendimethalin + imazethapyr 250g / ha at 2 DAS fb pendimethalin + imazethapyr+ fenoxaprop-p-ethyl 100 g a.i./ ha at 20 DAS recorded significantly lower density and dry weight of weeds than application of pendimethalin 750 g/ ha at 2 DAS, pendimethalin + imazethapyr 250g/ ha at 2 DAS and fenoxaprop-p-ethyl 100 g/ ha at 20 DAS. Weed free resulted in maximum seed yield which did not vary significantly from plastic mulch during both the years. The uninterrupted weed growth caused 49.37% and 46.67% yield loss in sesame during 2020 and 2021, respectively. However, the highest B:C ratio was 2.00, observed in plastic mulch + dibbling (considering only 2021, as the yield was highly damaged by “Amphun storm”) which was closely followed by weed free plot (1.69 and 1.14 in both the years 2020 and 2021 respectively).

به‬منظور بررسی عوامل مؤثر بر تراکم علف‬های‬هرز و کاهش عملکرد ناشی از آنها در گندم دیم، آزمایشی به‬صورت پیمایشی با استفاده از 45 مزرعه گندم در شهرستان بندرگز(روستای سرمحله) در سال 1391 انجام گردید. نمونه‬برداری از گندم و علف‬های‬هرز در دو مرحله (سنبله‬دهی و رسیدگی) به‬صورت تصادفی از پنج نقطه از هر مزرعه با استفاده از کوادراتی به ابعاد 1*1 متر انجام شد. در این تحقیق کلیه اطلاعات مربوط به مدیریت زراعی شامل مساحت اراضی، تجربه کشاورزان، عملیات تهیه بستر بذر، تاریخ‬کاشت، روش کاشت، رقم مورد استفاده، محل تهیه بذر، میزان بذر مصرفی، روش مبارزه با علف‬‬هرز، نوع، مقدار و زمان مصرف علف‬کش و قارچ‬کش و زمان برداشت گندم، در قالب پرسش‎نامه و در طول فصل رشد از طریق پرسش از کشاورزان جمع‎آوری و تکمیل شد. در پایان فصل رشد میزان عملکرد واقعی برداشت‬شده توسط کشاورزان، ثبت گردید. از میان پارامترهای مختلف مورد بررسی تراکم بوته، تراکم سنبله، سابقه کشاورز، نوع رقم و استفاده از علف‬کش تاپیک+گرانستار تأثیر معنی‬داری بر جمعیت علف‬های‬هرز داشتند. با افزایش تراکم بوته گندم در واحد سطح، تراکم علف‬هرز کاهش یافت. هم‬چنین در مزارع کشاورزان با سابقه بیشتر تراکم علف‬هرز کمتر بود. در مزارع تحت کشت رقم N8118در مقایسه با N8019 تراکم علف‬های‬هرز کمتر بود و عدم استفاده از علفکش تاپیک+گرانستار، منجر به افزایش تراکم علف‬هرز شد. در میان گونه‬های مختلف علف‬هرز ، یولاف‬وحشی، علف‬خونی و خردل‬وحشی، بیشترین تأثیر منفی بر عملکرد گندم را در پی داشتند. بررسی مدل نشان می‬دهد که در شرایطی که تراکم بوته گندم در حد مطلوب باشد و این علف‬های‬هرز نیز وجود داشته باشد عملکرد حاصله برابر 2713 کیلوگرم در هکتار خواهد بود و در صورت حذف آنها عملکرد به 2877 کیلو گرم در هکتار افزایش می یابد (خلأ عملکردی معادل 164 کیلوگرم در هکتار). در میان گونه‬های حاضر، 12 بوته علف‬خونی در مترمربع، 3 بوته خردل‬وحشی در مترمربع و 2 بوته یولاف‬وحشی در مترمربع به ترتیب با 65، 18 و 17 درصد کاهش عملکرد قوی‬ترین رقبا برای گندم بودند.

A field trial was conducted for two consecutive years, 2021-2022, to assess the performance, crop safety and proitability of soybean on the effects of pre-mix herbicide combinations and residual effect on green gram. Weed management in soybean faces signiicant challenges due to the prevalence of diverse and competitive weed species, the limited availability of effective post-emergence herbicides, and the necessity to balance effectiveness with crop safety and proitability. The higher dose combination of Metamifop -1 8% + Imazethapyr 4% + Imazomox 3% ME + Ammonium Sulphate @ 1250 ml ha (T ) demonstrated superior performance, 6 achieving remarkable weed suppression with a reduction in weed density ranging from 79-95%, 78-86%, and 80-90% at 15, 30 and 45 DAA, alongside a decrease in weed dry weight by 79-86%, 87-93%, and 77-93% compared to untreated control plots. The weed control eficiency for T surpassed 77% at all intervals recorded. Correspondingly, soybean plants in T plots reached average heights 6 6 -1 of 33-34 cm, produced between 6.9 and 7.6 lateral branches, set 8.8 to 9.3 pods per plant, and yielded between 1.95 and 1.98 t ha , values statistically on par with hand weeded control (T ), which measured 35.6-36.3 cm in height, 7.3-8.0 branches, 9.3-9.7 pods, and 10 -1 yielded 2.15-2.23 t ha . The moderate dose combination of Metamifop 8% + Imazethapyr 4% + Imazomox 3% ME + Ammonium -1 Sulphate @ 1000 ml ha (T ) recorded almost similar agronomic results, with plants measuring 33.0–33.8 cm in height and 5 -1 -1 achieving a seed yield of 1.94-1.98 t ha , suggesting that an application dose of 1,000 ml ha is optimum for effective weed management. Economic analysis indicated that T has recorded the highest net returns and beneit-cost ratio, followed by treatment 5 T . These results suggest that the post-emergence application of the Metamifop-Imazethapyr-Imazamox mixture combined with 6 -1 Ammonium Sulphate at 1,000-1,250 ml ha helps in effective weed control and achieves higher grain yield and economic returns in soybean cultivation. The study identiies an optimal herbicide dose for effective weed suppression, ensuring crop safety and proitability, thus providing a viable alternative to labour-intensive manual weeding in soybean production systems.