Weed Control Treatments Research Articles

Evaluation of cultural practices for weed management in maize-based cropping system in Palam valley, Himachal Pradesh

A study was carried out during 2017-19 at Palampur in an ongoing experiment under All India Coordinated Research Project on Weed Management (AICRP-WM). Ten weed control treatments based on hoeing, stale seed bed + hoeing, raised stale seed bed (RSSB) + hoeing, mulch, stale seed bed + mulch, raised stale seed bed (RSSB) + mulch, intercropping, crop rotation, intensive cropping and herbicide check (pendimethalin in pea/garlic and atrazine in maize) were tested during Rabi 2017-18 to Kharif 2019. There were 22 weed species in garlic and 19 weed species in maize. Phalaris minor, Daucus carota and Anagallis arvensis were the major weeds, constituting 17.0, 14.0 and 12.0 per cent, respectively of the total weed flora in garlic during 2017-18. Commelina benghalensis L., Galinsoga parviflora and Ageratum sp. were the major weeds constituting 21.0, 17.0 and 11.0 per cent, respectively of the total weed flora in maize. Maximum bulb yield (3472 kg/ha) was recorded with RSSB + hoeing and was statistically at par with herbicide check and SSB + hoeing. In maize, the highest cob yield was recorded in RSSB + mulch followed by mulch. Maize equivalent yield was higher in intercropping followed by intensive cropping and RSSB + mulch treatments. In 2019, 22 and 13 weed species occurred in pea and maize, respectively. The maximum pea pod yield was with intensive cropping followed by herbicide check in Rabi 2018-19. Herbicide check gave highest green cob yield (10323 kg/ha) of maize and was statistically equivalent to RSSB + hoeing (9208 kg/ha green cobs yield). Higher productivity (maize equivalent yield of 11420 kg/ha) was realized with the herbicide check which was at par with RSSB + hoeing (10160 kg/ha). The B:C followed the trend of intensive cropping > intercropping > herbicide check > RSSB + hoeing > RSSB + mulch.

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.

Forecasting bean yield losses under weed and Fusarium impacts from field plot statistical modeling

A better understanding of bean dynamic threats and pathogens is needed to improve accuracy of field measurement for breeding and mitigation programs. Thus, a two-year field plot study examined associations of bean production, Fusarium root rot, and weed in two cultivars sown under different dates and weed control treatments. We examined six standard curves to model bean leaf area, disease incidence, and weed biomass development across 256 plots. Gaussian, linear-by-linear and exponential models were fitted to bean-disease-weed development data, respectively, and then model parameters besides maximum values were used in the remainder of analyses. There were significant correlations between bean-disease-weed development descriptors. Principal component analysis showed bean-disease-weed development descriptors accounted for 84% of total data variance. Using six principal components as variables, a multivariate regression model showed the descriptors leaf area, Fusarium root rot, and weed biomass development explained 31% of variations in bean yield.

Evaluation of atrazine 50% WP herbicide for weed control in Maize (Zea mays L.) of Jhabua hills zone of M.P

A field experiment was conducted during kharif season of 2015 at Zonal agricultural research station, Jhabua with the objective to assess the bio-efficacy of atrazine herbicide against complex weed flora and yield of maize crop. The experiment consisted of six treatments, was laid out in randomized block design with three replications. Results revealed that all the weed control treatments significantly reduce the weed density and weed dry matter at 30 and 60 DAS. Atrazine 50% WP @ 1 kg/ha significantly reduced the weed count of grassy as well as broadleaved weeds at 30 and 60 DAA and found at par with Atrazine 50% WP @ 1.5 kg/ha and Atrazine 50% WP @ 2.0 kg/ha. However, better efficacy was observed with higher dose of atrazine viz., Atrazine 1.5 kg and 2.0 kg/ha. Hand weeding was also found as an effective tool for controlling the weed biomass at early stage of observation (30 DAS) but on later stage of crop it proves less effective due to emergence of weeds which further reduce the yield. Further, maize yield (43.43 q/ha) was also found significantly superior in Atrazine 1.0 kg/ha as compared to Atrazine 0.5 kg/ha, hand weeding a 20 DAS and control plot and found at par with higher doses of atrazine. Highest net return of Rs 43203/ha and B:C ration of 3.43 was observed in Atrazine 1.5 kg/ha.

Efficacy, Energy Budgeting, and Carbon Footprints of Weed Management in Blackgram (Vigna mungo L.)

Weed management in blackgram is one of the most efficient ways to improve its yield, as uncontrolled weed growth causes a significant decrease in crop yield. A field experiment was performed at Berthin, Himachal Pradesh, India, to investigate the efficacy, energy use efficiency (EUE), and carbon footprints of weed management tactics. Twelve weed control treatments were tested applied alone or in combination at pre and post emergence stages. The most prominent weeds were Cyperus iria, Dactyloctenium aegyptium, and Echinochloa colona, which caused a 68.1% loss in unweeded conditions. The application of weed control treatments reduced the weed count at 60 DAS from around 50% to 90%. The most efficient weed control treatment was pre-emergence (PRE) use of ready mix imazethapyr 35% + imazamox 35% WG @ 80 g ha−1, which resulted in a minimum weed infestation (i.e., weed count and weed biomass) and consequently highest yield. Its efficacy in weed control treatment was on par with PRE use of ready mix imazethapyr (35%) + imazamox (35% WG @ 70 g ha−1. Maximum energy use efficiency was also obtained upon PRE use of imazethapyr (35%) + imazamox (35% WG) @ 80 g ha−1 (8.27), trailed by PRE use of imazethapyr + imazamox @ 70 g ha−1 (7.84), mainly because of the higher yield obtained in these treatments which shows their efficiency in energy conversion. The carbon footprints were observed to be the lowest in ready mix combination of imazethapyr (35%) + imazamox (35% WG) applied at 80 g ha−1 (0.11 kg CE kg−1 yield), followed by imazethapyr (35%) + imazamox (35% WG) applied at 70 g ha−1 (0.12 kg CE kg−1 yield), as it resulted in the lowest emission per unit output production.

Cultural Practices and Mechanical Weed Control for the Management of a Low-Diversity Weed Community in Spinach

Low-diversity weed communities are dominated by few species that are highly competitive to crops. The management of such weed communities should rely upon sustainable cultural and non-chemical practices, especially in crops such as spinach (Spinacia oleracea L.), where very few herbicides are available. A two-year field trial (2020 and 2021) was conducted to evaluate different fertilization practices (broadcast and banded), intra-row spacings (15 cm, 11 cm, 7 cm), and mechanical weed control treatments (untreated, one treatment, two treatments) for the management of a low-diversity weed community in spinach. Weed competition severely affected spinach commercial biomass (R2 = 0.845). Compared to broadcast fertilization, banded fertilization reduced weed biomass and improved spinach yield and nitrogen use efficiency. Narrow intra-row spacing (7-cm) reduced weed biomass by 28 and 45% compared to intra-row spacings of 11-cm and 15-cm, respectively. Two mechanical weed control treatments resulted in 49% lower weed biomass compared to a single treatment. Commercial biomass increased with decreasing intra-row spacing (R2 = 0.881) and increasing the number of mechanical treatments (R2 = 0.911). More cultural and non-chemical practices should be evaluated for weed management in spinach, especially at sites infested with low-diversity weed communities.

Effect of integrated weed management on turmeric under mid hill conditions of Himachal Pradesh

A field experiment was carried out on silty clay loam soil, acidic in reaction, high in available phosphorus, medium in available potassium and low in available N during kharif 2017 at the Research Farm of Department of Agronomy, CSKHPKV, Palampur to study effective weed control strategy for this important crop. The results revealed that Alternanthera philoxeroides was the major weed constituting 16% of the total weed flora. This was followed by Cynodon dactylon and Echinochloa colona with 14 and 12% of total weed population, respectively. The count of Echinochloa colona, Alternanthera philoxeroides, Commelina benghalensis, Digitaria sanguinalis and Ageratum conyzoides was maximum at 120 DAP and there after it gradually decreased. All herbicide treatments brought significant reduction in the count on Echinochloa, Alternanthera and Ageratum over weedy check. The lowest count of these weeds was recorded in metribuzin fb straw mulch fb hand weeding and the maximum count was in case of weedy check. All the weed control treatments significantly reduced the total weed count and dry weight of weeds as compared to the weedy check. Amongst different herbicide treatments application of metribuzin @ 0.70 kg/ha fb straw mulch fb hand weeding resulted in significantly lowest weed count at all stages of observation as well as at harvest though this treatment was at par with metribuzin @ 0.70 kg/ha fb two hand weedings and treatments in which atrazine 0.75 kg/ha and hand weedings were applied with or without the use of straw mulch resulted in significantly lower dry matter accumulation by weeds as compared to other herbicide treatments. Weed index calculated at 120 DAP was highest with use of metribuzin @ 0.70 kg/ha and atrazine @ 0.75 kg/ha used along with straw mulch and one or two hand weedings proving effective as compared to other herbicides tested. From the present study it seems that mulching must be included in any effective weed management strategy for turmeric. Also among different herbicides metribuzin and atrazine are effective and their integration with mulching and/or hand weeding gave good control of weeds in turmeric.

Weed dynamics, grain yield and quality of basmati rice (Oryza sativa) under organic agriculture system

There is a growing demand for organically produced food including basmati rice (Oryza sativa L.) worldwide and organic farming is continuously gaining importance. The objectives of study were to manage weeds in organically grown basmati rice with non-chemical weed management approaches including tillage, plant density and green manuring. The two year experiment was conducted at Punjab Agricultural University, Ludhiana during summer (kharif) of 2017 and 2018. The combinations of conventional tillage (CT) or deep tillage (DT) with green manure levels at 50, 75 and 100 kg/ha plus 25% higher plant density and one hand pulling including one weedy check and weed-free treatment were studied for weed control in basmati rice. The lowest weed density and biomass was observed in plots with green manuring at 100 kg/ha. Weed density was statistically similar in weed control treatments including CT or DT with green manuring at 50-100 kg/ha plus 25% higher plant density along with one hand pulling and it was significantly lower than weedy check. Crop growth, yield attributes and grain yield was found statistically similar in non-chemical weed management treatments and conventional agriculture treatment. Different quality parameters such as physical and milling properties of paddy and eating and cooking parameters of milled rice grains were statistically similar in differential tillage, green manuring and plant density treatments. Thus, weeds in organically grown-basmati rice may be controlled by using green manuring and higher plant density.

Improving Some Vegetative Growth Characters, Yield and its Components by the Effect of Weed Control Treatments and Plant Densities in Sesame (Sesamum indicum L.)

A field experiment was carried out in the summer season in the field of a farmer in the Zankora/Ramadi/Anbar Governorate, located at longitude 43° E and latitude 38° N, in silty loam texture soil to study the effect of weed control treatments and different plant densities on growth characteristics, yield and its components of sesame crop. The complete randomized block design (R.C.B.D) was used in a Split Plot arrangement with three replications. The plant densities allocated to the main plot (100000, 80000, and 66666 plants ha-1), and the sub plot included several weed control treatments, which are the use of the mechanical method with three levels, which is the manual hoeing process once, twice and three times during the growing season, in addition to the two control treatments (the weed free and the weedy treatments). The results showed that there is a clear effect of different weed treatments on all the traits under study. The weedy treatment achieved the highest mean number and density of weeds after 60 and 90 days of planting, which amounted to 25, 17.8 plants m-2, while the three hoeing treatments achieved the highest percentage of inhibition in the dry weight of the weeds, which was 93.27%, the free weeds treatment gave the highest mean of stem diameter, plant dry weight and 500-seed weight, and the individual plant yield was 1.43 cm, 163 gm, 2.05 gm, and 265.20 gm, respectively. Whereas the effect of plant densities showed that there was no significant effect on most of the studied traits. As for the two-way interaction between weed control treatments and plant densities, it had a significant effect on yield characteristics, as treatment W4D1 recorded the lowest mean of weeds after 60 days of planting (2.33 plants m-2), Also, treatment W3D3 recorded the highest inhibition rate of 94.61%, and treatment W4D2 recorded the highest mean leaf area index of 5.04, while weed free treatment W1 when interacted with plant density D3 had the highest mean of stem diameter trait that was 1.54 cm. The treatment W1D1 recorded the highest value of the dry weight of the plant, which was 196 gm. It also affected the yield of the individual plant when it was interacting with the highest mean of 291.70 gm, which was positively reflected in improving most of the vegetative growth characteristics and some yield traits.

Effect of Weed Control Treatments on some Maize Hybrids and its Associated Weeds

Effect of Weed Control Treatments on some Maize Hybrids and its Associated Weeds

Silvicultural intensification has a limited impact on tree growth in forest restoration plantations in croplands

Investigating the impact of silvicultural practices on tropical forest restoration plantations is highly relevant, as there is a growing global demand for large-scale ecological restoration. The objective of this study was to test the hypothesis that native trees respond positively to the intensification of fertilization and weed control in a forest restoration plantation on a site previously used as cropland in the Atlantic Forest region of Brazil. We carried out a study with 22 native tree species, 11 of which were classified as shade species and the other 11 classified as diversity species. We implemented a randomized experimental design in a split-plot design, with six replicates of four treatments: intensive weed control (glyphosate spraying every 3 months) with and without fertilization, and non-intensive control (mechanical control every 6 months), with and without fertilization. We performed fertilization by supplying the site with 53 kg ha−1 of nitrogen, 35 kg ha−1 of phosphorus, and 51 kg ha−1 of potassium. We evaluated individual tree crown areas and increments in basal diameter and height 16 months after planting. In general, growth varied more among species than in weed control and fertilization treatments. Overall, the method of controlling weeds did not influence tree growth, but interacted with species for all growth variables. Fertilization increased tree diameter increment, and interacted with species, leading to diameter and height increments; however, most of the species did not respond to fertilization. Contrary to our expectations and previous findings, silvicultural intensification did not promote higher overall tree growth, probably because the restoration planting was conducted on a cropland with decades of intensive management, which increased soil fertility and reduced weed abundance through periodical maintenance prior to restoration planting. Our results highlight the importance of considering local and historical conditions to decide whether and when management intensification is required to accelerate tree growth in tropical forest restoration plantations.

Comparison of the effects of ammonium nonanoate and an essential oil herbicide on weed control efficacy and water use efficiency of pumpkin

AbstractWeed management is one of the major challenges responsible for growers’ reluctance to switch from conventional to organic vegetable production. Competition from uncontrolled weeds can significantly reduce the yield and water use efficiency (WUE) of vegetable crops. A field study was conducted during the summers of 2019 and 2020 at the Quaker Research Farm of Texas Tech University, in Lubbock, TX, to determine physiology, plant growth, yield, soil water depletion pattern, and WUE of pumpkin as affected by five weed control treatments: 1) ammonium nonanoate 5% ai, 2) ammonium nonanoate 6% ai, 3) clove oil + cinnamon oil 4.5% ai, 4) clove oil + cinnamon oil 9% ai, and 5) an untreated control. Each plot received the same herbicide treatment at 20 and 30 d after planting (DAP). The experiment was conducted in a randomized complete block design with four replications of each treatment. Both herbicides resulted in significant weed suppression compared to the untreated control and weed control was 88% to 98% with ammonium nonanoate and 39% to 69% with clove oil + cinnamon oil. Photosynthesis rate, stomatal conductance, shoot dry biomass, average fruit weight, total fruit yield, and WUE of pumpkin were significantly higher in plants that were treated with ammonium nonanoate compared to the untreated control. All the aforementioned parameters were not significantly different between clove oil + cinnamon oil and the untreated control. Use of higher active ingredient concentration did not improve the performance of either herbicide. Soil water depletion and evapotranspiration were comparable among all the treatments. Based on the results, ammonium nonanoate at its lower concentration could be an option for effective weed control, and for improving fruit yield and WUE of pumpkin.

Sesame (Sesamum indicum L.) Response to Different Fertilizing System and Cover Crops in Weed Competition

AbstractBackground & objectives: This study was conducted to investigate the effect of different nutrition systems and cover crops on morphological traits, yield, yield components and competitive indices of sesame in competition with weeds. Materials & Methods: This research was carried out in the research farm of Sari Agricultural Sciences and Natural Resources University in 2016 as a randomized complete block design with three replications and eight treatments. Experimental treatments include: 1- sesame + soybean cover crop + without fertilizer, 2- sesame + millet cover crop + without fertilizer, 3- sesame + soybean cover crop + vermicompost, 4- sesame + millet cover crop + vermicompost, 5- sesame + soybean cover crop + chemical fertilizer, 6- sesame + millet cover crop + chemical fertilizer, 7- sesame + without weeding + without fertilizer (control) 8- sesame + weeding + chemical fertilizer (control). Also, two treatments of monoculture of sesame were considered as control (weed infestation and weed free). The traits studied in this experiment include weed density and weed biomass, competitive indices, yield and yield components, as well as morphological traits of sesame. Results: The results of weed sampling in three stages (10- leaf, seed dough and harvesting time) showed that the highest weeds density and biomass was in control with weed infestation and then in soybean cover crop with chemical fertilizer application. The results showed that fertilizer resources and cover crops had a significant effect on the grain yield, number of capsules per plant, seed number per capsule, 1000 seed weight, biological yield, as well as competition index (CI), so that the highest and lowest grain yields were observed in the treatment of millet with organic fertilizer (1630.22 kg.ha-1) and millet without fertilizer (413.33 kg.ha-1), respectively. The highest number of capsules per plant (41) was observed in weed control and the highest number of seeds per capsule (64.33 and 63.66) and 1000-seeds weight (2.56 and 2.53 g) in two treatments of weed control and millet cover crop with organic fertilizer application, respectively. Also, the highest rate of competition index (4.38%) was observed in millet cover crop with organic fertilizer, which showed significant effect of treatments on this index in sesame. Conclusion: The result of this experiment showed that millet cover crop, with decreasing weed density and biomass, increased sesame yield significantly. Furthermore, the use of organic fertilizers comparison to chemical fertilizers improves the properties of the soil and, also, the use of these fertilizers with the appropriate cover crops is a suitable strategy for sustainable agriculture in order to achieve greater yield and higher quality of the sesame. So, use of millet cover crop as well as organic fertilizer is recommended to improve sesame yield and proper weed management.

Efficacy of Weed Management Techniques on Weed Control, Biomass Yield, and Soil Herbicide Residue in Transplanted Wild Marigold (Tagetes minuta L.) under High Rainfall Conditions of Western Himalaya

A reduced herbicide rate with hand-weeding (HW) can act as a safer and sustainable approach for weed control. A field study was conducted at CSIR-IHBT, Palampur, India during 2018 and 2019 to analyze the efficacy of herbicides in combination with manual weeding on weed control and the yield of wild marigold (Tagetes minuta L). The experiment was laid with 12 treatments, consisting of two herbicide dosages with prescribed and reduced rates (R) of pendimethalin, imazethapyr, and carfentrazone-ethyl, along with integration of reduced-rate herbicide treatments with HW. The weed population, dry matter, and the crop biomass yield had a significant effect on different weed-control treatments. Imazethapyr (R) with HW recorded a reduced weed number (9.64 m−2) and weed dry matter (13.64 g m−2) and a greater biomass yield (235.03 q ha−1). All the herbicides with integration with HW decreased the weed infestation and enhanced the biomass yield. The weed control efficacy of imazethapyr was higher than pendimethalin and carfentrazone-ethyl. Weed infestation in reduced doses of herbicides with HW was lower than in recommended doses. Herbicide residues in the soil of all herbicides at both the dosages were below the detectable limit (<0.001 μg g−1). Therefore, a reduced dose of imazethapyr integrated with HW can be prescribed to T. minuta growers as a more sustainable approach.

Influence of Biofertilizers and Weed Control Treatments on Weeds and Soybean Productivity تأثير الأسمدة الحيوية ومعاملات مکافحة الحشائش على الحشائش وانتاجيه فول الصويا

This work was conducted during the 2019 and 2020 seasons at the Agricultural Research Station in Sakha, Egypt to study the effect of various biofertilizers (Rhizobacterin and non-fertilized) and weed control treatments (pendimethalin 1.7 L/acre, Prometric n 1.25 L/acre, Pendimethalin). 1.7 L/acre + Fluazifob-p-butyl 1.5 L/acre, Prometrine 1.25 L/acre + Fluazifob-p-butyl 1.5 L/acre, scrabble 15 days after sowing (DAS) + Fluazifob-p-butyl 1.5 L/acre wice manual hoeing and control (untreated assay) on soybean nodules, weeds and yield. The results indicated that biofertilization (Rhizobacterin) and weed control treatments increased the nodule number, weight, plant height, number of branches, number and weight of pods, seed yield and seed yield/acre. of soybeans in the two years compared with un-Rhizobacterin plants. Moreover, the content of protein, oil, nitrogen and protein in soybean seeds increased in the two seasons. From the results obtained, bendemethalin 1.7 L/acre + fluazifob-p-butyl 1.5 L/acre, manual hoeing twice at 21, 35 days post-seeding (DAS) and cribbing 15 days after sowing + fluazifob-p-butyl 1.5 L / Feeding was the best treatment which gave the best weed control. Therefore, it is recommended to search using the Rhizobacterin in vivo fertilization, soybean plants were treated with pendimethalin 1.7 L/acre + fluazifop-p-butyl 1.5 L/acre, manual hoeing twice at 21, 35 days after sowing (DAS) and scribbling 15 days after Sowing + fluazifob-p-butyl 1.5 L/acre gave the highest soybean seed yield and the best weeding control under experimental conditions

Pamuk ekim alanlarında Ipomoea triloba L. (pembe çiçekli akşam sefası)’nın mücadele olanaklarının belirlenmesi

Cotton (Gossypium hirsutum L.) is used as the raw material in more than fifty industries and is also the main source of raw materials used in the textile, the oil, the animal feed, and the paper industries. Additionally, it is a crop of great economic importance for its producer countries with the added value and employment opportunities. Cotton is among the crops sensitive to weed competition and its yield decreases with the weeds. For this reason, weed control treatments should be employed effectively to obtain high yields in cotton fields. In the recent years, Ipomoea triloba (IPOTR), which has increased in its importance in the agricultural areas of the Mediterranean Region, prevents the development of the cotton because of its invasive features and causes the harvest difficulties during by hand or machine harvest. The aim of this study is to create an effective control program against IPOTR in cotton. Field experiments were carried out in Ceyhan, Adana, Turkey in 2018 and 2019. For this purpose, impact of the treatments including Pyroxasulfone 85% (PYRS) Trifloxysulfuron sodium 75% (TRFS), Pyrithiobac-sodium 383 g/l (PYBS), Glyphosate isopropylamine salt 480 g/l (GLYI), S-metolachlor 915 g/l + Benoxacor 45 g/l + hand hoe (SMEC), inter-row rotary hoe + intra-row hand hoe (FÇEÇ) were investigated 28 day-after treatment and at the harvest during two years. It has been determined that TRFS and PYBS have an efficacy over 90%, while FÇEÇ, SMEÇ, TRFS and PYBS applications have an efficacy over 60%. Applications against IPOTR have increased the cotton lint and yield. However, crop injury was observed after GLYI application (20%).

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.

Post‐sowing weed control technique can affect woody seedling numbers, with early hand‐weeding potentially more beneficial than early spraying

SummaryDirect seeding is increasingly being used as a cost‐effective revegetation technique. Successful outcomes from direct seeding rely on effective weed control, particularly during the vulnerable seedling establishment phase. Post‐sowing weed control options are constrained by the need to protect seedlings from damage and few studies have compared the effectiveness of different weed control techniques. We evaluated the effect of preliminary hand weeding (with subsequent spraying), spraying monthly or spraying quarterly with glyphosate, on woody seedling emergence, survival and growth in trials sown either in spring or autumn at a riparian site in Victoria, southeastern Australia. Seedling numbers were recorded monthly for 6 months and at 12 months after sowing, with seedling survival and heights assessed at 12 months. Total seedling numbers were higher in subplots initially hand weeded than in subplots sprayed on either a monthly or quarterly basis, regardless of when direct seeding occurred, but weed control treatment had no effect on seedling survival. These results indicate that post‐sowing spraying limited rates of seedling emergence, either directly or indirectly. For direct seeding, hand weeding in the first few months after sowing may maximise rates of woody seedling emergence, while spraying with glyphosate may inhibit seedling emergence.

Effect of sunnhemp (Crotalaria juncea L.) green manuring on weed dynamics in puddle transplanted rice-based systems

Effects of Crotalaria juncea green manure on weed dynamics in transplanted rice-based systems were investigated in a field study conducted over two cropping seasons, 2016 and 2017, at Ludhiana, India. The major weed species in the field, during the green manuring phase, included Cyperus rotundus, Digitaria ciliaris and Eleusine indica. The use of cover/green manure crops and their residues to suppress weeds has shown potential to manage weeds. In this context, green manuring/cover cropping has great potential and is feasible in a rice-wheat system in northern India as there is a 45 to 60 days’ fallow period between wheat harvest and transplanting of rice. C. juncea with 50 and 100 kg seed ha-1 recorded significantly lower density and biomass of aerobics weeds and weed density as compared to without green manure in both years; GM with 100 kg seed ha-1 had a more suppressing effect on weeds than green manuring with 50 kg seed ha-1. The residual effects of weed control treatments, applied during 2016 to succeeding transplanted rice crops, did not have any specific trend on weed density in 2017. The major weeds in green manuring crop were C. rotundus, D. ciliaris and E. indica. But in transplanted rice, Echinochloa colona, E. crus-galli and Leptochloa chinensis were major weeds

Effect of New Pre-Emergence Herbicides on Quality and Yield of Potato and Its Associated Weeds

Potato is an economically important vegetable crop in Egypt. Weed infestation, especially broad-leafed, during the vegetative growth stage substantially affects both crop yield and tuber quality. In the current study, the impact of new ready-mix pre-emergent herbicides on broadleaf weeds, tuber yield, and quality was evaluated. The two-year field experiment comprised the following treatments: (1) Un-weeded control, (2) Hand hoeing, (3) Sencor, (4) Ecopart, (5) Zeus, (6) Kroki, and (7) Flomex. The results showed that weed control treatments significantly reduced the weed density compared to un-weeded control and the herbicides efficacy reached over 90%. The herbicidal treatments also significantly increased the activity of antioxidant enzymes peroxidases (POX) and catalase (CAT) and improved the non-enzymatic antioxidant (carotenoids) compared to un-weeded control. Conversely, the higher content of malondialdehyde (MDA) in potato leaves was obtained for un-weeded control. Moreover, weed control treatments caused significant enhancement in plant growth parameters, yield, and its components in addition to tuber quality of potato. Compared to the un-weeded control, maximum tuber yield was observed in Flomex followed by Ecopart, Kroki, Zeus, and Sencor, respectively. The higher number of tubers and total yield were recorded in plants treated with Flomex plus compared to all the other treatments. Higher content of total soluble sugar, total soluble protein, and total starch content was observed in weed control treatments compared with un-weeded control. Based on Pearson’s correlation and heatmap analysis, the changes in agro-physiological parameters data are linked to the herbicidal treatments. The results indicate that the applied herbicides could be alternative products for Sencor and an option for controlling broadleaved weeds. However, further studies are needed to ensure their efficacy and safety under other conditions.