Weed-free Treatment Research Articles

Evaluation of herbicides for selective weed control in cutleaf groundcherry (Physalis angulata L.)

Cultivation of cutleaf groundcherry (Physalis angulata L.) is increasing due to its potential nutritional and medicinal use. Lack of registered herbicides is a main constrain for efficient weed control and consequently successful production in cutleaf groundcherry. To evaluate the efficacy of eight herbicide treatments for weed control and crop injury in cutleaf groundcherry, field experiments were conducted in two consequent years (2017 and 2018). Treatments consisted of PRE application of pendimethalin and POST application of foramsulfuron, oxadiazon, nicosulfuron, rimsulfuron, sulfosulfuron, iodosulfuron-methyl-sodium + mesosulfuron-methyl-sodium + mefenpyr-diethyl (IMM), and iodosulfuron-methyl-sodium + mesosulfuron-methyl-sodium + diflufenican (IMD). Weed-free and weedy plots were also considered for comparison in both years. Although, density and biomass of broadleaf weeds were decreased in all treatments compared to the weedy check, grass weeds did not affect by the herbicides. In both years, the lowest broadleaf weed dry weight of (12 g m−2) was found in plots treated by IMD and IMM. Different levels of herbicide injury was found in cutleaf groundcherry plants. Of the herbicides tested, the minimum crop injury was related to plots treated with foramsulfuron (1.4%), rimsulfuron (2.7%) and sulfosulfuron (6%). Notice that the yield in rimsulfuron treatment (38,160 kg ha-1 and 18,053 kg ha-1 in 2017 and 2018) was just about 62% and 48% of that in weed free treatment in 2017 and 2018, respectively, although rimsulfuron treatment improved crop fruit yield compared with the weedy treatment. Overall, although none of the tested herbicides could provide fruit yield similar to the weed free condition, an herbicide program consisting of rimsulfuron and sulfosulfuron would therefore provide both high weed control and crop safety.

Efficacy of Herbicides, Their Effects on Rice Yield Under Saturated Soil Condition

This study was carried out in containers which were placed outdoor to evaluate the efficacy of different herbicides with different mixtures on weed growth suppression in rice and their effects on rice grain yield under saturated soil water regime in two consecutive seasons (cropping season and off season) at the Universiti Putra Malaysia Farm, Serdang, Selangor, Malaysia during 2016 to 2017. Eight combinations of different herbicides, viz. T1, T2, T3, T4, T5, T6, T7 and T8 along with weed free and non-weeded treatments were used in the study following a RCBD. Weed composition in the experimental containers and their summed dominant ratio (SDR) at 60 days after planting were recorded from non-treated containers. Naturally grown eleven weed species mainly under the families of Poaceae, Cyperaceae and Pontederiaceae were found in the experimental containers. Based on the SDR values the dominant weed species were Monochoria vaginalis, Echinochloa crus-galli, and Fimbristylis miliacea in both the seasons. Results revealed that four herbicide treatments viz. Pretilachor fb Bentazon/MCPA (T1), Pretilachor+Pyribenzoxim fb Bentazon/MCPA (T2). Bispyribac-sodium fb Bentazon/MCPA (T2), Fenoxaprop+Ethoxysulfuron (T3), fb Bentazon/MCPA (T7) were superior in their effectiveness for weed control in both seasons and gave better rice grain yield with high economic return. Bangladesh J. Bot. 52(1): 37-44, 2023 (March)

Impact of Some Herbicides on Growth Indicators of Some Wheat Cultivars and Weight of Companion Weeds

An experiment was implemented in the experimental field of the Department of Field Crops, College of Agricultural Engineering Sciences, University of Baghdad, Jadriya during the year 2020-2021. The study aimed to investigate the effect of some herbicides (Crash + U46-Combifiluid) combination and Axial, Weed Free and Weedy, on the companion weeds and growth indicators for three cultivars of wheat (Shame6, Samur, and GRAIME). The experiment was conducted according to a RCBD (in a split-plot arrangement with three replicates), while the cultivars represent the main treatments and herbicide treatments. The results showed the superiority of cultivar GRAIME in the trait of the number of tiller. meters 2 and the flag leaf area (centimeter2), as it recorded averages of 469.90 meters2 and 22.61 centimeter2 respectively. The cultivars did not differ significantly between them in terms of the dry weight of plants. In comparison, the cultivar Samur recorded the highest plant height of 135.12 centimeter and the lowest weed dry weight was 40.44 gram. meters-2, recording the highest inhibition ratio in the weed dry weight amounted to 62.60%. The combination treatment (Crash + U46-Combifiluid) for all traits was superior to the weedy treatment, which recorded the lowest averages, as it recorded 459.9 tiller.meters2, 124.89 centimeter, 22.70 centimeter 2, and 1344 gram. meters -2 for the number of tillers, plant height, flag leaf area, and the dry weight of wheat plants, respectively. Besides, the lowest average weed dry weight was 6.55 gram. meters -2 and the highest inhibition ratio in the weed dry weight was 93.97%, it was close to the results of the weed-free treatment. The treatment of cultivar GRAIME with (Crash + U46-Combifiluid) combination achieved the highest mean for the number of tillers, flag leaf area, and dry weight of wheat plants reaching 515.70 tiller. meters 2 and 25.20 centimeter 2 and 1371.20 gram. meters-2 respectively, In comparison, the lowest weed dry weight was achieved in the treatment of cultivar Samur and Shame6 with the combination of (Crash + U46-Combifiluid) reached 0.00 and 5.80 gram. meters-2 respectively and recorded the highest inhibition ratio of weed dry weight reached 100% and 94.44% respectively.

Chemical Weed Control in Grain Sorghum (Sorghum bicolor L.)

A field experiment was conducted at the Demonstration Farmof the Faculty of Agriculture, University of Khartoum, Sudan, during2012/2013 and 2013/2014 seasons, to determine the magnitude of growthand yield losses in grain sorghum crop due to weed competition, and toevaluate the effects of three herbicides viz, sorgoprim, gesaprim and tankmixture of 2,4-D and gesaprim at three rates of each in addition to aweed-free and a weed- infested treatments i.e. eleven treatments. Theexperiment was laid out in a randomized complete block design with fourreplications. The results showed that when the weeds were left to competewith the sorghum crop throughout the season, the reduction percentages inthe seedlings’ dry weight, plant height and plant shoot dry weight in2012/13 were 55.4, 39,2 and 47.2 respectively; reductions in the sameparameters were 74.4, 39.1 and 45.4 respectively in 2013/14. Untreatedweeds – infested control, coupled with weed index (WI) of 65%–66%,inflicted considerable reductions in crop grain number/ plant of 60.1% in2012/13 and 61.4% in 2013/14, grain weight/plant of 66.3% in 2012/13and 66% in 202013/14 and on yield( ton/ha) by 65% in 2012/13 and by66% in 2013/14. All herbicide treatments irrespective of rate ofapplication, resulted in a good to excellent weed suppression. Herbicidesweed control efficiency (WCE) for 2012/13 and 2013/14 ranged from56% to 99% for broad-leaved weeds and from 39% to 97% for grassyweeds. The mixture tank of 2, 4-D + gesaprim @ 0.76L/ha + 0.6 Kg/hatreated sorghum reduced the WI to 2.5% in 2012/13 and to 3.2% in2013/14 and resulted in values of crop grains number/plant, grains weight/plant and yield significantly comparable to weed-free treatment.

Weed Management in Ajwain (Trachyspermum ammi L.) at Farmer’s Fields in South East Rajasthan

The field experiments were conducted during kharif (July–October) seasons of 2014–15 and 2015–16 at KVK, Rajsamand, Rajasthan and farmers’ field with objective to explore and test other alternative and economical methods of weed control. On-farm Trial, technology option Oxadiargyl applied 50 g a.i. ha-1 applied as early post emergence at 20 DAS proved the best over farmers’ practice as well over recommended practice of 1.0 kg a.i. ha-1 pendimethalin pre-emergence in terms of growth and yield attributing characters viz., plant height, primary and secondary branches, number of umbels, number of umbellets umbel-1, number of seeds umbel-1 and remained statistically at par with weed free treatment. Weed indices namely weed count, weed dry weight, weed index and weed control efficiency were statistically significant by oxadiargyl applied 50 g a.i. ha-1 as early post emergence at 20 DAS and pre-emergence application of pendimethalin 1.00 kg a.i. ha-1 pendimethalin over farmer’s practice. Lower WI and higher WCE was observed by oxadiargyl applied 50 g a.i. ha-1 followed by pendimethalin 1.00 kg a.i ha-1. Grain and starw yield recorded in weed free plot was statistically at par with yield obtained by application of oxadiargyl 50 g a.i. ha-1. Net returns and B:C were also high in refined technology option i.e. of 50 g a.i. ha-1 oxazdiargyl (` 127570 ha-1 and 4.77) over recommended practice of 1.0 kg a.i ha-1 pendimethalin pre-emergence (` 107930 ha-1 and 4.19) and farmers’ practice (` 75930 ha-1 and 3.49).

Effect of crimson clover on the critical period of weed control in conservation tillage corn

An increasing number of herbicide-resistant weeds, in addition to troublesome weeds, pose a significant challenge for chemical weed control in corn. Simultaneously, high-biomass cover crop adoption has gained popularity among farmers as an efficient weed control strategy. While the critical period of weed control (CPWC) following conventional tillage has been well documented, there is little knowledge of CPWC following high residue cover crops in corn. A two-year field experiment was conducted to estimate the influence of a high biomass crimson clover cover crop and conservation tillage on the critical period of weed control (CPWC) in corn. The experiment was implemented in a split-plot design in which the main plots were conventional tillage (CVT), conservation tillage following winter fallow (CT + WF), and conservation tillage following crimson clover (CT + CC), and the subplot included multiple durations of weedy plots (estimation of critical timing of weed removal (CTWR), i.e., beginning of weed control) and weed-free plots (estimation of critical weed-free period (CWFP), i.e., end of weed control). The results described that the estimated duration of CPWC in three systems, included CT + CC, CT + WF and CVT equals 2.8 weeks, 3.5 weeks, and 4.9 weeks respectively in 2019. In 2020, the predicted value of CTWR under CT + CC equals 3.8 weeks after planting and the predicted values of CWFP were 5.1 and 5.7 weeks after planting under CT + WF and CVT systems, however, the model did not predict some values within the fitted 8 weeks of time. In conclusion, the presence of a crimson clover cover crop delayed the CTWR and caused the early beginning of CWFP and hence shortened CPWC in 2019. During most of the growing season, weed biomass production was less under CT + CC plots than CVT and CT + WF systems of weedy treatment in both years. While weed biomass production fluctuated in CT + CC, CVT and CT + WF systems in weed-free treatment.

Weeds Enhance Insect Diversity and Abundance and May Improve Soil Conditions in Mango Cultivation of South Florida.

This study examined if weeds could serve as insectary plants to increase beneficial insect abundance and diversity in mango cultivation in southern Florida. Additionally, we examined how weed presence affects mango tree soil health. We found that weeds significantly increased pollinating and parasitoid insect abundance and diversity. Eight insect orders and eighteen families were significantly more abundant on mango trees with weeds growing beneath them than those where weeds were removed. There was no difference in predatory insects between treatments, and slightly more herbivorous insects on weedy mango trees. Pollinating insects visiting mango flowers in the weed treatment were significantly greater, as well as spiders on weedy mango trees. However, there were more lacewings (Neuroptera) observed on the mango trees without weeds, and leaf chlorophyll in the old and new mango leaves was significantly greater, in the weed-free treatment. Soil conditions, however, significantly improved in soil carbon and a greater pH reduction in the presence of weeds, though weeds affected neither soil nitrogen, phosphorous, nor chlorophyll in productive green leaves. These results show that a tolerable level of selective weed species' presence may benefit insect, plant, and soil biodiversity in farms. This is important in increasing production, sustainability, and biodiversity in agriculture, which otherwise may be deficient in non-crop life.

Efficacy of p-hydroxy-phenyl-pyruvate dioxygenase (HPPD) enzyme-inhibitive tembotrione and topramezone herbicides for weed-management in rainy season grain sorghum (Sorghum bicolor)

A field experiment was conducted during the rainy season (kharif) of 2019 and 2020 at Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan, to ascertain the weed-management efficacy of postemergence (PoE) tembotrione and topramezone at 25 days after sowing following pre-emergence (PE) atrazine in the kharif grain sorghum [Sorghum bicolor (L.) Moench]. Eight treatments (6 herbicidal along with weed-free and weedy check) were evaluated in randomized block design (RBD) with 3 replications. Results showed that, uncontrolled weeds have inflicted a grain, stover yield and net income penalty of 63.7, 55.5 and 69% over weed-free check (3.47, 12.34 t/ha and `135,216). Pre-emergence (PE) application of atrazine @ 0.5 kg a.i./ha was found to be the most promising herbicide in terms of benefit: cost ratio (5.76) despite having 12.4, 6.2, and 6.71% lower grain, stover and net income than weed-free treatment (5.03). Both PE and PoE application of atrazine did not bring any yield and profit gains over its PE application. Topramezone and tembotrione (PoE) controlled weeds as effective as weed-free treatment and their impacts persisted up to crop maturity. However, on account of crop phytotoxicity that is dependent on dose (2.83–5.17) severe yield losses (60 and 51.9% grain and stover) were recorded. Both tembotrione and topramezone at their higher dose (0.0242 and 0.0363 kg a.i./ha) resulted in at par grain yield (1.18 t/ha) as weedy check (1.26 t/ha).

Response of different weed management practices on growth and yield of black gram (Vigna mungo L.) under irrigated conditions of Punjab

The field experiment was carried out during the summer season of 2021-2022 to study the response of different weed management practices on growth and yield of black gram. Cyperus sp., Phyllanthus niruri, Trianthema portulacastrum, Amaranthus viridis were the dominant weeds. It was observed that besides weed free treatment the lowest weed count, dry weight of weeds (3.66 g m-2), weed index (2.73%) as well as highest weed control efficiency (60.06%) were found with the pre-emergence (PE) application of pendimethalin1 kg ha-1 followed by one hand weeding at 40 days after sowing (DAS). The maximum growth attributes, yield attributes and yield were found with the pre-emergence application of Pendimethalin 1 kg a.i. ha-1 followed by one hand weeding at 40 DAS which was statistically at par with pre emergence application of Pendimethalin 1 kg a.i. ha-1 followed by post emergence application of imazethapyr 75 g a.i. ha-1 at 40 days after sowing. The economics parameters were recorded highest with the application of Pendimethalin (PE) 1 kg a.i. ha-1 followed by one hand weeding at 40 days after sowing. Hence Pendimethalin is most effective treatment among the other treatments.

Influence of Different Weed Management Practices on Weed Indices and Growth Parameters of Summer Moong (Vigna radiata L.Wilczek) Under Irrigated Conditions of Punjab

A field experiment was conducted during summer season of 2019-20 at the Campus for Research and Advanced Studies Dhablan ofGeneral Shivdev Singh Diwan Gurbachan Singh Khalsa College, Patiala, Punjab. A set of 12 different treatment combinations werelaid out in randomized block design with 3 replications. Different weed management practices significantly influenced weed indices,growth and economics of summer moong crop. Besides weed free treatment, weed indices like total weed population (3.13 m-2), weeddry weight (4.07 gm-2) and weed index except weed control efficiency (%) were recorded significantly minimum with applicationof Pendimethalin @ 1.0 kg ha-1 pre emergence (PE) followed by hand weeding (H.W.) at 30 date after sowing (DAS), followed by theapplication of Imazethapyr @75 gm ha-1 (PE) followed by one hand weeding at 30 DAS at all growth stages. All growth parameters viz.,plant height (36.28 cm), number of branches plant-1 (10.16) and dry weight (76.63 g) plant-1 significantly increased with application ofPendimethalin @ 1.0 kg ha-1(PE) followed by H.W. at 30 DAS. The benefit cost ratio (2.68) was significantly maximum with applicationof Pendimethalin @ 1.0 kg ha-1 (PE) followed by H.W. at 30 DAS.

Effect of Herbicide Combinations on Growth and Yield of Kharif Maize (Zea mays L.)

The present investigation entitled “Effect of Herbicide Combinations on Growth and Yield of Kharif Maize (Zea mays L.)” was carried out during kharif 2019 at College Farm, College of Agriculture, Badnapur, Dist.-Jalna. Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani, Maharashtra (India). Randomized Block design was used for study comprised of ten treatments. Among treatments, weed free treatment attributed more number of leaves, maximum plant height, dry matter production and leaf area per plant followed by treatment of topramezone 33.6 % SC @ 25.2 g a.i.ha-1 + atrazine 50 % WP @ 250 g a.i. ha-1. Poor growth attributes were recorded in weedy check. Significantly maximum values of yield attributes were recorded in treatment of topramezone 33.6 % SC @ 25.2 g a.i.ha-1 + atrazine 50 % WP@ 250(g)a.i.ha-1 followed by treatment of tembotrione 42 % SC @ 105 g a.i. ha-1+ atrazine 50% WP @ 250 g a,i. ha-1. Minimum values of yield attributes were attributed in weedy check. Treatment of topramezone + atrazine @ 25.2 + 250 g a.i ha-1 as PoE (T6) found effective in limiting weed growth and recorded lower weed index, weed dry matter with higher weed control efficiency followed by tembotrione +atrazine @105 + 250 (g) a.i.ha-1as PoE (T7) at all growth stages of crop. The benefit cost ratio was highest (2.94) with application of topramezone + atrazine @25.2 + 250 g a.i ha-1 followed by tembotrione + atrazine @ 105 + 250 g a.i. ha-1 as PoE (2.81) whereas weedy check recorded significantly lower B:C ratio(1.50) over other treatments.

Response of Weed Management on Growth, Yield and Yield Attributes of Kharif maize (Zea mays L.)

The present investigation entitled “Weed management in kharif maize (Zeamays L)” was carried out during kharif 2019 at College Farm, College of Agriculture, Badnapur, Dist.- Jalna. Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhnai Maharashtra (India). Randomized Block design used for study which comprises ten treatments. Among treatments, weed free treatment attributed more number of leaves, maximum plant height, dry matter production and leaf area per plant followed by treatment of topramezone 33.6% SC @ 25.2g a.i.ha-1 + atrazine 50% WP @ 250g a.i.ha-1. Poor growth attributes were recorded in weedy check. Significantly maximum values of yield attributes were recorded in treatment of topramezone 33.6 % SC @ 25.2g a.i.ha-1 + atrazine 50% WP @ 250 (g) a.i. ha-1 followed by treatment of tembotrione 42% SC @ 105g a.i.ha-1 + atrazine 50% WP @ 250 g a,i. ha-1. Minimum values of yield attributes were attributed in weedy check. Treatment of topramezone + atrazine @ 25.2 + 250g a.i ha-1 as PoE (T6) found effective in limiting weed growth and recorded lower weed index, weed dry matter with higher weed control efficiency followed by tembotrione + atrazine @ 105 + 250(g) a.i.ha-1 as PoE (T7) at all growth stages of crop. Lower uptake of nitrogen, phosphorous and potassium by weeds were recorded in treatment of topramezone + atrazine @ 25.2+ 250g a.i.ha-1 as PoE followed by tembotrione + atrazine @ 105 +250g a.i. ha-1 as PoE. The benefit cost ratio was highest (2.94) with application of topramezone + atrazine @ 25.2 + 250g a.i ha-1 followed by tembotrione + atrazine @ 105 + 250g a.i. ha-1 as PoE (2.81) whereas weedy check recorded significantly lower B:C ratio (1.50) over other treatments.

The Influence of Different Row Spacing and Weed Control Intervals on Weed Infestation and Yield-Related Traits of American (Gossypium hirsutum L.) and Desi (Gossypium arboreum) Cotton

Narrow row spacing has attracted significant attention due to its beneficial impacts on weed management in cotton. This study compared the effects of normal and ultra-narrow row spacing on critical periods of weed control in American (Gossypium hirsutum L.) and ‘Desi’ (Gossypium arboreum) cotton. Two different row spacings (i.e., recommended (75 cm) and ultra-narrow (30 cm)) and three weed control intervals (i.e., weed control at 30, 60 and 90 days after sowing (DAS)) were included in the study. Weedy-check and weed-free treatments were included in the experiment as controls for comparison. ‘Desi’ cotton grown under ultra-narrow spacing recorded the lowest weed density and individual density of Trianthema portulacastarum L., Cyperus rotundus L., Cynodon dactylon L., Echinochloa colona (L.) Link and Digera muricata (L.) Mart. Moreover, ‘Desi’ cotton sown under ultra-narrow spacing with weed-free and weed control at 30 DAS resulted in the highest leaf area index (LAI), leaf area duration (LAD), net assimilation late (NAR), root elongation rate (RER) and root growth rate (RGR) at all sampling dates. Likewise, ‘desi’ cotton sown under recommended row spacing and weed-free conditions produced the highest number of sympodial and monopodial branches, number of flowers and bolls per plant, whereas the highest seed cotton yield of ‘Desi’ cotton was noted under ultra-narrow spacing and weed-free conditions. It is concluded that sowing both cotton types in ultra-narrow row spacing and controlling weeds at 30 DAS will result in lower weed infestation and higher seed cotton yield.

Fresh-marketable tomato yields enhanced by moderate weed control and suppressed fruit dehiscence with woodchip mulching

The use of plastic film imposes various environmental risks in agroecosystems. The replacement of plastics with organic materials for mulching has been suggested to enhance the sustainability of agroecosystems. However, whether woodchip mulch can be used for annual crops needs to be verified. We examined the effects of mulberry woodchip mulches on tomato-fruit yields over two successive years. Mulberry is the unique food plant of silkworms, and it will be better if its pruned shoots can be recycled rather than incinerated as waste. Setting three treatments, including woodchip mulch, weed-free and weedy (i.e., unweeded) treatments, we compared the amounts of fresh-marketable and unmarketable tomato fruits. The yields of fresh-marketable tomato fruits in the woodchip mulch treatment were significantly 16–57% higher than those in the weed-free treatment and comparable to those in the weedy treatment. The yields of unmarketable dehiscent tomato fruits in the weed-free treatment were significantly 46–86% higher than those of the other two treatments. The woodchip mulches extensively suppressed the weed density, while the grown weeds became large, preventing strong sunlight exposure and dehiscence of tomato fruits. Current results suggest that woodchips could be a possible alternative to plastics, facilitating climate change mitigation with agroforestry practices.

Bio-efficacy of pre and post-emergence herbicides on lentil yield, weed control efficiency, weed index, nutrient uptake and economics

Lentil (Lens culinaris Medikus) is an important grain legume crop. Among all the biotic factors, weed infestation is being an adverse impact on growth, yield, nutrient uptake and economics due to lentil short stature, low branching, lack of protective canopy and it’s unable to smother the weeds. Although, applying pre emergence herbicides, in many situation early weed control herbicides are not that much efficient for attaining higher yields due to lentil is long duration crop and critical weed competition upto 40-60 DAS. Sequence use of pre and post-emergence herbicides and application of early post-emergence herbicides may help in controlling the weeds at later stages of crop growth period. To understand resources distribution in lentil a field experiment was laid out at BAU research farm, Sabour during Rabi of 2019-20 in RCBD replicated thrice with 13 treatments to assess the effect of various pre and post-emergence herbicides in lentil. Out of 13 treatments, weed free treatment produced significantly higher grain yield and haum yield and new generation herbicides application of pendimethalin fb quizalofop-ethyl + imazethapyr and oxyflurofen fb quizalofop-ethyl + imazethapyr were statistically at par with weed free treatment. Weed control efficiency, Weed index, Nutrients uptake and Economics by different weeds treatments were recorded significantly higher in pendimethalin fb quizalofop-ethyl + imazethapyr, oxyflurofen fb quizalofop-ethyl + imazethapyr and imazethapyr + imazomox at 60 DAS and at harvest. Ultimately, it can be concluded that, application of pendimethalin fb quizalofop-ethyl + imazethapyr and oxyflurofen fb quizalofop-ethyl + imazethapyr in lentil brings in enhancing grain yield and achieving more net returns, B:C ratio apart from suppressing the weeds through higher weed control efficiency and lower weed index.

Weed Management in Direct Seeded Rice under Different Row Spacing

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

Impact of different mulching treatments on weed flora and productivity of maize (Zea mays L.) and sunflower (Helianthus annuus L.)

The concerns on weed control through herbicides are increasing due to their negative impacts on environment and human health. Therefore, alternative weed management methods are inevitable for sustainable crop production and lowering the negative consequences of herbicides. Mulching is an environment-friendly weed management approach capable of substituting herbicides to significant extent. Therefore, this study evaluated the role of different mulching treatments on suppressing weed flora in maize (Zea mays L.) and sunflower (Helianthus annuus L.) crops. Furthermore, the impact of different mulching treatments on the productivity of both crops was also investigated. Three mulch treatments, i.e., plastic mulch (PLM), sorghum mulch (SM) and paper mulch (PM) along with two controls, i.e., weed-free (WF) and weedy-check (WC) were included in the study. Different mulch treatments significantly altered weed flora in both crops. The PLM and PM resulted in the highest suppression (43–47%) of weed flora compared to WC treatment in both crops. The highest and the lowest weed diversity was recorded for WC and WF treatments, respectively. Different allometric traits, i.e., leaf area index, crop growth rate and root length of both crops were significantly improved by PLM as compared to the WC. Overall, maize crop recorded higher density of individual and total weeds compared to sunflower with WC treatment. The density of individual and total weeds was significantly lowered by PLM compared to WC treatment in both crops. Similarly, higher growth and yield-related traits of both crops were noted with PLM compared to the rest of the mulching treatments. Results of the current study warrant that PLM could suppress weed flora and improve the productivity of both crops. However, PLM alone could not provide 100% control over weed flora; therefore, it should be combined with other weed management approaches for successful weed control in both crops.

The Impact of Different Weed Management Systems on Weed Flora and Dry Biomass Production of Barley Grown under Various Barley-Based Cropping Systems.

Weeds are among the major issues responsible for reduction in yield and profit in any crop production system. Herbicides are the easiest and quickest solution of weeds; however, their frequent use exert negative consequences on environment, human health, and results in the evolution of herbicide-resistant weed species. Due to these reasons, alternative weed management methods that are less harmful to environment and human health are needed. This two-year study evaluated the impact of different weed management options, i.e., false seedbed (FS), allelopathic water extracts (AWE), chemical control (CC), weed-free (WF) weedy-check (WC) on weed spectrum in various barley-based cropping systems, i.e., fallow-barley (FB), maize-barley (MB), cotton-barley (CB), mungbean-barley (M*B), and sorghum-barley (SB). Data relating to density, diversity, and biomass production of weed species prevailing in the studied cropping systems were recorded. Interactive effect of weed management methods and barley-based cropping systems significantly altered weed diversity, and densities of individual, broadleaved, and grassy weeds. A total 13 weed species (ten broadleaved and three grass) were recorded during both years of study. The highest dry biomass, diversity, and density of individual, broadleaved, and grassy weeds were noted in WC treatment, whereas WF treatment resulted in the lowest values of these traits. Chemical control resulted in the highest suppression of weed flora and improved dry biomass production of barley followed by AWE. The SB cropping system with CC or AWE resulted in the least weed flora. The M*B cropping system with CC or AWE produced the highest dry biomass of barley. It is concluded that including sorghum crop in rotation and applying AWE could suppress weeds comparable to herbicides. Similarly, including mungbean in rotation and applying AWE could increase dry biomass production of barley. In conclusion, herbicides can be replaced with an eco-friendly approach, i.e., allelopathy and inclusion of sorghum crop could be helpful in suppressing weed flora.

Productivity of Groundnut + Pigeonpea Relay Intercropping System as Influenced by Weed Management Options

Background: Weed management is one of the most important agronomic constraints leading to severe losses in the cropping system. Intercropping has several advantages to mitigate the losses faced by monocropping in addition to which if there is a proper control of weeds then the advantages of the intercropping system can be multiplied. Methods: An investigation was conducted on medium black clayey soils at Junagadh during kharif 2019-20 and 2020-21 in randomized block design with 10 treatments replicated thrice, to evaluate the effect of different weed management options on the growth and yield of groundnut + pigeonpea relay intercropping. The treatments were: pendimethalin 0.9 kg ha-1 as PE fb interculture and hand weeding at 45 DAS (T1), pendimethalin 0.45 kg ha-1 + oxyfluorfen 0.09 kg ha-1 as PE fb interculture and hand weeding at 45 DAS (T2), interculture and hand weeding at 15 DAS fb sodium acifluorfen 16.5% + clodinafop propargyl 8% (ready mix) 1 kg ha-1 at 45 DAS as POE (T3), interculture and hand weeding at 15 DAS fb quizalofop p ethyl 40 g ha-1 at 45 DAS as POE (T4), interculture and hand weeding at 15 DAS fb propaquizafop 70 g ha-1 at 45 DAS as POE (T5), pendimethalin 0.9 kg ha-1 as PE fb sodium acifluorfen 16.5% + clodinafop propargyl 8% (ready mix) 1 kg ha-1 at 45 DAS as POE (T6), pendimethalin 0.9 kg ha-1 as a PE fb quizalofop p ethyl 40 g ha-1 at 45 DAS as POE (T7), pendimethalin 0.9 kg as ha-1 PE fb propaquizafop 70 g ha-1 at 45 DAS as POE (T8), weed free (T9) and unweeded control (T10). Result: The results of the experiment revealed that weed free registered significantly higher plant height, number of branches, dry matter per plant and number of root nodules per plant in groundnut and pigeonpea and was statistically on par with to intercultureand hand weeding at 15 DAS fb sodium acifluorfen 16.5% + clodinafop propargyl 8% (ready mix) 1 kg ha-1 at 45 DAS as PoE, pendimethalin 0.9 kg ha-1 as PE fb sodium acifluorfen 16.5% + clodinafop propargyl 8% (ready mix) 1 kg ha-1 at 45 DAS as PoE. The data on yield attributes and yield of both the crops depicted that significantly superior results were obtained with weed free treatment, which was statistically at par with intercultureand hand weeding at 15 DAS fb sodium acifluorfen 16.5% + clodinafop propargyl 8% (Ready mix) 1 kg ha-1 at 45 DAS as PoE and pendimethalin 0.9 kg ha-1 as PE fb sodium acifluorfen 16.5% + clodinafop propargyl 8% (Ready mix) 1 kg ha-1 at 45 DAS as PoE. While in case of groundnut equivalent pod and haulm yields, statistically superior yields were registered with weed free treatment, which was statistically at par with intercultureand hand weeding at 15 DAS fb sodium acifluorfen 16.5% + clodinafop propargyl 8% (Ready mix) 1 kg ha-1 at 45 DAS as PoE.

Yield and Seed Quality of Summer Green Gram as Influenced by Weed Management under Zero Tillage

Background: Weeds are primary factors that adversely affect growth, yield and seed quality of summer green gram, which can be minimized with adoption of proper weed management practices. This field experiment was conducted to find out the effective weed management practice in summer green gram (Vigna radiata) under zero tillage condition. Methods: In this field-laboratory investigation conducted during summer season 2019 on different herbicides were applied to manage weeds in summer green gram. Eight treatments were applied based on various application windows. In the field and laboratory, the collected samples were determined for growth parameters, nutrient uptakes, seed yield and seed quality of summer green gram. Result: The result revealed that weed free treatment recorded higher growth parameters like, plant height, number of branch/plant, number of leaves/plant and root biomass which was statically at par with Shaked (Propaquizafop + Imezathyper) as post-emergence (POE) at 20 DAS and Pendimethalin as pre-emergence (PE) followed by one hand weeding 20 DAS. Same trends were also observed in seed yield, nutrient content and uptake by seeds. Seed quality parameters like germination per cent (98.00), shoot (25.63 cm) root (14.20 cm) and seedling length (39.83 cm), seedling dry weight (0.16 g), vigour index I (3903.33) and vigour index II (14.96) was higher under weed free followed by Shaked (Propaquizafop + Imezathyper) and Pendimethalin as (PE followed by one hand weeding 20 DAS over weed check.