Weed-free Plots Research Articles

Herbicidal weed management options for pigeon pea(Cajanus cajan) grown in southeastern Rajasthan

A field experiment was carried out during the kharif seasons of 2020–21, 2021–22 and 2022–23 at Kota, Rajasthan, to study the effect of post-emergence herbicides on productivity of pigeonpea [Cajanus cajan (L.) Millsp]. The results indicated that the minimum weed density and dry weight, and the highest yield attributes, yields, and net return of pigeonpea were obtained under weed free plot. All the herbicidal treatments significantly reduced the weed density and biomass compared to the weedy check. However, application of pendimethalin 30 EC @ 0.75 kg /ha (PE) fb Imazethapyr 10 SL @ 100 g/ha at 20–25 DAS + one inter-cultivation at 50 DAS recorded significantly higher plant height (1.82 m), pods/branch (22.96), pods/plant (206.3), weed control efficiency (84.39% at 60 DAS), grain yield (1,868 kg/ha), net return (` 87.66 x 103 /ha) and B: C ratio (3.35) over weedy check. This leads to the 61.73% higher pigeonpea grain yield over the weedy check plot. Hence it can be inferred that the ap- plication of pendimethalin 30 EC @ 0.75 kg /ha (PE) fb Imazethapyr 10 SL @ 100 g/ha at 20–25 DAS + one inter- cultivation at 50 DAS is an efficient weed control method for profitable cultivation of pigeonpea in south eastern Rajasthan.

Impact of weed control methods and staking on the growth, yield, and weed response of cucumber (Cucumis sativus L.) in Kano, Sudan Savanna, Nigeria

Cucumber growing is becoming increasingly popular in Nigeria's Sudan savanna region due to its health benefits and minimal impact on the soil. However, weed infestation is a major challenge that can significantly reduce yields, by up to 45-95%. In view of this, two trials were conducted at the Teaching and Research farm of the Faculty of Agriculture and the net house of the Centre for Dryland Agriculture of the Bayero University Kano to examine the effects of weed control and staking on cucumbers during the 2021 dry season. The trial consisted of eight weed control treatments and two staking methods which were arranged in a split plot design with three replicates, with staking assigned to the main plot while weed control was assigned to the sub plots. The study analyzed data on growth and yield, using Genstat (17th edition) and significantly different means were separated using the Student Newman-Keuls Test (SNK) at a 5% level of probability. Results showed a higher composition of grass and broadleaf weeds in open fields compared to controlled net house environments. Weed Control Efficiency (WCE) was greater in weed-free plots, but Butachlor and metolachlor significantly outperformed other treatments, providing higher WCE. The herbicidal treated plots significantly resulted in longer days to 50% emergence than other treatments, while it also resulted in a shorter number of days to 50% flowering and fruiting than weedy check. The vine length, number of leaves, leaf area, and chlorophyll content were highly significant (p<0.01) in weed free, butachlor at 1.5 + Imazethapyr 1.5 kg a.i.ha-1 post emergence ( POE) and metolachlor at 1.5 + Imazethapyr 1.5 kg a.i.ha-1 POE. Similarly, yield and yield attributes followed the same pattern as obtained in growth components. Staking of vines on the other hand significantly resulted in greater growth and yield of cucumber. Based on these findings, farmers in the study area are advised to grow cucumber staked with the application of Butachlor at 1.5 + Imazethapyr 1.5 kg a.i.ha-1 POE and metolachlor at 1.5 + Imazethapyr 1.5 kg a.i.ha-1 POE for sustainable weed management.

Enhancing productivity and profitability of quinoa through optimization of plant spacing and weeding regimes

ContextWeeds are a major constraint to quinoa production since no herbicide tolerant variety is available worldwide. This raises the importance of cultural practices for controlling weeds. Optimizing plant spacing and implementing effective weeding practices may help to enhance quinoa productivity and profitability. ObjectiveThe objective of current study was to utilize the plant spacing as an alternate option for ensuring effective weed management and profitable quinoa production for the irrigated plains. MethodsThe effect of planting spacing on weed flora in quinoa was evaluated for two consecutive years (2021–22 and 2022–23). Two weeding regimes (weedy and weed-free) along with three plant spacings viz., 10, 20, and 30 cm were tested using a randomized complete block design in split-plot arrangement with three replications. In the weedy plots, no weeding was done, while in the weed-free plots, manual weeding was performed to keep them weed-free throughout the growing season. Results and conclusionsDifferent plant spacing significantly influenced weed biomass and density in quinoa. Narrow spaced plants (10 cm) gave maximum weed suppression as against widely spaced plants (30 cm) and a concomitant yield increase. Medium plant spacing (20 cm) gave maximum grain yield by attaining the optimum plant population under weed-free conditions during both years. Economic analysis also revealed that medium plant spacing with weed-free conditions was beneficial compared to other treatments regarding gross returns, net returns, and benefit-cost ratio. SignificanceThis study highlights that quinoa spacing primarily determined quinoa-weed competition and can be a tool for weed management in this crop.

Induced mutation in the SiALS gene offers new weed management opportunities for sesame crop

Weeds are the primary biotic constraint affecting sesame growth and production. Here, we applied EMS mutagenesis to an elite sesame cultivar and discovered a novel point mutation in the sesame SiALS gene conferring resistance to imidazolinone, a group of acetolactate-synthase (ALS)-inhibitors. The mutant line exhibited high resistance to imazamox, an ALS-inhibitor, with hybrid plants displaying an intermediate response. Field-based validation confirmed the mutant line’s substantial resistance, leading to a significantly higher yield under imazamox treatment. Under pre-emergence application of imazapic, the mutant plants sustained growth, whereas wild-type and weed were effectively controlled. Field trials using s-metolachlor and imazapic combined resulted in weed-free plots compared to untreated controls. Consequently, this treatment showed a significantly greater yield (2280 vs. 880 Kg ha−1) than the commercial practice (s-metolachlor). Overall, our study unveils the potential of utilizing this point mutation in sesame breeding programs, offering new opportunities for integrated weed management strategies for sesame cultivation. Developing herbicide-resistant crop plants holds promise for supporting sustainable production and addressing the challenges of weed infestations in sesame farming.

Effect of Different Doses of Herbicides on Growth and Yield in Maize (Zea mays L.)

A field experiment was conducted at Chandra Shekhar Azad University of Agriculture and Technology, Kanpur during Kharif season of 2021, to evaluate effect of different doses of Mesotrione 2.27% w/w + Atrazine 22.7% w/w SC on growth and yield of maize (Zea mays L.). The experiment was laid down in the Randomized block design with ten treatments which was replicated three times. At 45, 60 and 90 DAS among different herbicidal treatments maximum plant height was observed in Mesotrione 2.27% w/w + Atrazine 22.7% w/w SC) @ 1.0 kg a.i. ha-1. Among the herbicidal treatments, highest cob length (15.67 cm), grain rows per cob (13.26), grains per row (26.93) and grains per cob (370.83) was observed in the treatment T4 (Mesotrione 2.27% w/w + Atrazine 22.7% w/w SC) @ 1.0 kg a.i. ha-1) followed by treatment T3 (Mesotrione 2.27% w/w + Atrazine 22.7% w/w SC) @ 0.875 kg a.i. ha-1). Data from experiment revealed that significantly highest grain yield was recorded in weed free plot (35.65 q ha-1). While among herbicidal treatments, application of Mesotrione 2.27% w/w + Atrazine 22.7% w/w SC @ 1.0 kg a.i. ha-1 (35.18) resulted in significantly higher grain yield followed by (T3) Mesotrione 2.27% w/w + Atrazine 22.7% w/w SC @ 0.875 kg a.i. ha-1 (34.38 q ha-1). Among all the treatments all the parameters of crop growth and yield was highest in the weed free treatment (T9).

Effect of Tillage and Weed Management Practices on Growth and Yield of Green Gram [Vigna radiata (L.) Wilczek

A field experiment was conducted during 2023 at Karunya Institute of Technology and Sciences, Coimbatore, Tamil Nadu, to find out the effect of different tillage management [Minimum tillage (primary tillage only) and Conventional tillage (primary and secondary tillage)] and five weed control treatments [(PE Pendimethalin @ 1.0 kg ha-1, PE Pendimethalin + Imazethapyr (pre-mix) - Valor 32% EC 1.0 kg ha-1, Hand weeding on 15 and 30 DAS, Weed free plot and Un weeded control (weedy check)] on weeds and productivity of green gram (Vigna radiata (L.) Wilczek) during the winter (Rabi). Conventional tillage generally led to taller plants and higher leaf counts compared to minimum tillage, while effective weed management practices, particularly the combination of Pendimethalin and Imazethapyr, resulted in superior growth indices. Additionally, conventional tillage and weed-free conditions significantly enhanced dry matter production and yield parameters of green gram.

Reduced weeding shows potential to regulate nutrient leaching in a cabbage (Brassica oleracea, var. capitata) lysimeter trial

Agricultural land is the main contributor to nitrogen and phosphorus pollution of groundwater sources. Adopting agroecological management practices can support the transition towards sustainable farming systems. We investigated if reduced weeding could support nutrient retention in a nutrient demanding vegetable crop (Brassica oleracea, var. capitata), without causing unacceptable yield losses. We conducted a three-year study (2019–2021) with two cropping seasons (autumn and spring) using 1 m3 above-ground lysimeters, each containing four cabbage plants. Different vegetation covers, each with four replicates, were considered: 1) crop only 2) weeds only 3) crop + weeds from crop transplanting 4) crop + weeds after 20 days from crop transplanting 5) bare soil with fertilizer 6) bare soil without fertilizer. Each system received the recommended dose of mineral fertilizer for cabbage (130 kg ha−1 N, 80 kg ha−1 P, 150 kg ha−1 K), except for two bare soil lysimeters which were not fertilized. Water samples were taken throughout the growing season, in particular after each fertilization event, and analysed for nitrate (NO3-N), phosphorus (P) and potassium (K) concentrations. Cabbage yield in both weedy treatments was significantly lower compared to the weed-free plots only in spring 2020 and fall 2021. Weed cover contributed to explain NO3-N and K leaching, while P leaching was affected by crop cover. The results suggest that it is possible to reduce weed management intensity in cabbage while also obtaining some benefits concerning nutrient losses.

COST-BENEFIT ANALYSIS OF SELECTED PRE-EMERGENCE HERBICIDES FOR WEED CONTROL IN COCOYAM (Xanthosoma sagittifolium L.) PRODUCTION

Weed control being a very important operation in the production of cocoyam is costly, therefore, there is a need to evaluate the most economically viable method of weed control for the purpose of minimizing production cost to maximize profit. The experiment was conducted in 2018 at the Ido farm settlement in Ibadan, Oyo State. The experiment involved five pre-emergence herbicides (Diuron 3.2 kg a.i/ha, Indaziflam + Ixoxaflutole 300 g a.i/ha, Flumioxazin + Pyroxasulfone 0.32 kg a.i/ha, Sulfentrazone 600 g a.i/ha, S-Metolachlor + Atrazine 2.64 kg a.i/ha), weed free and weed check (control) laid out in a Randomized Complete Block Design with four replicates. Data were collected on corm and cormel yield parameters, inputs, and costs including revenue associated with herbicide and manual weeding treatments used in benefit: cost ratio analysis. Results showed that Diuron (6.7 t/ha) and Sulfentrazone (9.4 t/ha) gave better cormel and corm yield respectively than the other treatments. The highest benefit-cost ratio was achieved from Diuron-treated plots (4.97). Sulfentrazone and Flumioxazin + Pyroxasulfone treated plots also had a benefit-cost ratio of 2.86 and 2.76 respectively. Indaziflam + Ixoxaflutole and Metolachlor + Atrazine had a similar benefit-cost ratio of 2.71. A low benefit-cost ratio (1.99 ) was produced in weed-free plots while a benefit-cost ratio of less than 1 was observed in weedy check plots (0.76). Therefore, the highest net benefit with a high benefit-cost ratio can be achieved by using Diuron, Flumioxazin + Pyroxasulfone, Sulfentrazone as pre-emergence herbicides in cocoyam production.

Estimating the impact on maize production by the weed Parthenium hysterophorus in Pakistan

Parthenium hysterophorus L. (Asteraceae) is an aggressive annual herbaceous weed which causes severe yield losses on a global scale. However, the precise impact of this weed in several countries is not yet known. To assess the impact of P. hysterophorus on maize crop losses in Pakistan, a 2 year field experiment was carried out at the CABI Rawalpindi campus in 2019 and 2020. Yield was measured on maize plants planted along with different densities (0, 1, 2, 4, 8, and 16 plants per m2) of P. hysterophorus. The trial was laid in a randomized complete block design with five replicates per density each year. The highest maize seed yield was obtained in weed-free plots (4256.5 ± 118 kg ha−1), while maize yield at weed infestation levels of 1, 2, 4, 8 and 16 plants m−2 was reduced by 14, 22, 29, 38 and 46%, respectively, compared to weed free plots. In the light of these findings, to reduce yield losses to non-significant levels it is proposed to reduce P. hysterophorus densities below 2 plants per m2 in maize fields.

Results of Weed Density, Yield Attributes, and Yield on Wheat Crop were Influenced by Varying Broad-spectrum Herbicide Treatments in Eastern U.P., India

In the year 2015-16, a field experimental trial was conducted during the rabi season to assess the impact of various broad spectrum herbicide treatments on weed density and yield in wheat crops. The experiment followed a randomized block design with four replications, and a total of eight treatments were tested. The wheat cultivar DBW-17 was used as the test crop. Results showed that weed density and dry matter accumulation of weeds increased up to 90 days of crop growth, but decreased at 120 days in the weedy check treatment. In contrast, no weeds were recorded in the weed-free plot throughout the crop period. In terms of the wheat crop, the weed-free plot had the highest total dry matter accumulation at all stages (30 DAS-32.62, 60 DAS-278.26, 90 DAS-934.49 and 120 DAS-1276.28 g/m2), number of spikes (303.00/m2), number of grains/spike (51.00), test weight (40.40 g), length of spike (11.12 cm) and grain yield (5.422 t/ha). On the other hand, the weedy check treatment had the lowest total dry matter accumulation at all stages (30 DAS-28.78, 60 DAS-207.24, 90 DAS-679.82 and 120 DAS-932.76 g/m2), number of spikes (208.00/m2), number of grains/spike (42.00), test weight (36.41 g), length of spike (10.31 cm) and grain yield (2.641 t/ha).

Evaluation of the Impact of Herbicidal Weed Management Practices on Weed Density, Yield Attributes and Yield of Irrigated Chickpea (Cicer arietinum L.)

In the Rabi season of 2021-22, an experiment was conducted at the Agronomy Research Farm of CCS Haryana Agricultural University in Hisar. The aim was to examine how herbicidal weed management affects irrigated chickpea. The experiment was laid out in Randomised Block Design (RBD) with thirteen treatments, each repeated three times. The treatments included various herbicides applied at different stages, such as pre-plant incorporation (PPI), pre-emergence (PRE), and post-emergence (POE). Interestingly, the Ready mix (RM) herbicide application of pendimethalin + imazethapyr (RM) @ 1000 g a.i ha-1, applied both as PPI and PRE, outperformed the herbicides applied solely as PPI, PRE, or POE. Among the herbicidal treatments, the combined during PPI and PRE stages exhibited excellent control over a diverse weed population, leading to a significant increase in chickpea yield compared to the weedy check. The number of seeds per pod, pods per plant, and branches per plant varied significantly with different weed control treatments. Weed-free plots showed the highest values in these parameters. The uncontrolled growth of weeds in the weedy check resulted in a 55.2% reduction in seed yield as compared to weed-free plots. The maximum seed yield (1968 kg ha-1) and favorable yield attributes were observed in the weed- free treatment, statistically comparable to the yield obtained from two hand weeding at 30 and 50 days after sowing (1940 kg ha-1). Among herbicidal treatments, the highest seed yield was achieved with the PRE application of pendimethalin + imazethapyr (RM) @ 1000 g a.i. ha-1 (1827 kg ha-1). The dominant weed flora consisted of Chenopodium album, Fumaria parviflora and Anagallis arvensis. Density of different weed species was significantly influenced by different weed control treatments. All the weed control treatments significantly reduced the total weed density and dry matter accumulation by weeds in comparison to weedy check. Weed free and two hand hoeing reduced the weed population drastically which was statistically at par with PRE application of pendimethalin + imazethapyr (RM) at 1000 g a.i. ha-1. Chenopodium album, Fumaria parviflora and Anagallis arvensis were effectively controlled by RM irrespective of its time of application.

The influence of priming methods, planting dates, and weed interference levels on the vegetative growth, yield, and yield components of AS71 hybrid corn

By carrying out a laboratory experiment, the influence of priming methods, including ZnSO4, BSN, and hydropriming was evaluated on the seed germination of hybrid AS71 corn. Then, the main and interaction effects of the priming methods, planting dates, and weed interference levels were surveyed on the vegetative growth traits, yield, and yield components of corn in a field experiment. Based on the lab experiment, although the maximum germination percentage (100%) was observed in the treated plots by hydropriming 22 h after treatment (HAT), the greatest seedling vigor index (122.99) was recorded with treated seeds by ZnSO4 (0.03 mg L–1) at 8 HAT. The greatest emergence index was observed in the treated plots by hydropriming on both planting dates of June 1 and 11. The interaction of planting dates and weed interference levels revealed that the highest emergence index (14%–17%) occurred in the weed-free plots on both planting dates. BSN recorded the greatest corn 1000-grain weight that was significantly higher than the control plots by 28%. Furthermore, BSN enhanced the corn grain yield compared with the control plots by 63% and 24.9% on the planting dates of June 1 and 11, respectively. BSN, as a nutri-priming approach, by displaying the highest positive effects in boosting the corn grain yield in both weedy and weed-free plots as well as both planting dates, could be a recommendable option for growers to improve the crop yield production.

Weed Control by New Generation Herbicide and Its Influence on Yield and Nutrient Uptake in Transplanted Rice

A field experiment was conducted during kharif season 2019 and 2020 at research farm of Bihar Agricultural University, Sabour, Bhagalpur to evaluate the effect of different herbicide on weed attributes, yield attributes, yield and nutrient uptake in transplanted rice. The experiment comprised six treatment T1 (pyrazosulfuron ethyl 10 % WP 15 g a.i. ha-1), T2 (pyrazosulfuron ethyl 10 % WP 30 g a.i. ha-1), T3 (carfentrazone ethyl 25 g a.i. ha-1), T4 (carfentrazone ethyl 50 g a.i. ha-1), T5 (weed free) and T6 (weedy) with four replications in randomized block design. The significantly lesser weed density (37.75 No.m-2), weed dry weight (22.87 gm-2), weed index (3.41) and higher weed control efficiency (80.58 %) were recorded with the application of pyrazosulfuron ethyl 30 g a.i. ha-1 at 30 DAT than other treatments. Crop growth parameters (plant height, number of effective tillers, dry matter accumulation), yield attributes (panicle length, effective tillers, number of grains, test weight), nutrient uptake and grain yield were recorded highest in weed free plot (57.88 q ha-1) followed by pyrazosulfuron ethyl 10 % WP 30 g a.i. ha-1. However, least grain yield was recorded under weedy plot. The results suggested that pyrazosalfuron ethyl 10 % WP 30 g a.i. ha-1 were best broad spectrum effective herbicide in order to minimize the diverse weed flora in transplanted rice.

Effect of Herbicide on Root Nodules, Phytotoxicity and Economics of Chickpea (Cicer arietinum L.)

The field experiment was done during Rabi season of 2011-12 at Agronomy Research Farm of NDUA&T, Kumarganj, Faizabad, UP. The fresh biomass and dry biomass nodules plant-1 (mg), branches numbers and grain yield significantly supreme was noted in weed free plot. Fresh and dry biomass, branches number was obtained statically at par with treatments pendimethalin 1000 g ha-1 PE, or fb quizalofop 60 g ha-1 PoE or clodinafop 60 g ha-1 PoE at 45 and 60 DAS, 60 DAS and at 90 DAS. The minimum Fresh and dry biomass, branches number was noted with rest all the treatments. Whereas drastic toxicity was detected tracked by oxyfluorfen 200 g + fb clodinafop 60 g ha-1 PoE and pendimethalin 1000 g PE fb imazethapyr 75 g + quizalofop 60 g ha-1 PoE, separately. The greatest drop in grain yield of chickpea were noted in PE application of pendimethalin 750 g tracked by mutual PoE application of quizalofop-ethyl 60 g + oxyfluorfen 200 g ha-1 at 35 DAS. The utmost net economic returns and B-C ratio were noted in PE application of pendimethalin 1000 g and PoE application of clodinafop 60 g ha-1 and PE application of pendimethalin1000 g and PoE application of quizalofop-ethyl 60 g ha-1 at 35 DAS and the net monetary returns and B-C ratio were in negative with application of pendimethalin 750 g PE followed by mutual PoE application of quizalofop-ethyl 60 g + oxyfluorfen 200 g ha-1at 35 DAS and PoE application of oxyfluorfen200 g + quizalofop-ethyl 60 g ha-1 PoE.

Effect Of Sequential Application Of Pre And Post-Emergence Herbicides On Dynamics Of Weeds Associated With DSR System Andrice-Growth And Sustained Yield

The sustained rice yield plays an important role in the country’s GDP. The diverse weed flora is a potential biotic threat to the sustained yield in the DSR system. The crop faces severe competition the resources from its beginning (germination of crop seedlings) to the panicle initiation with the diverse weeds flora as it grows quickly in moist conditions, resulting in severe yield losses up to 65 per cent. Thus, an effective and economical weed control strategy in DSR is often required to overcome the losses. In such situations, sequential application of herbicides may provide broad-spectrum weed control in DSR. A field experiment was conducted on silty loam soils to assess the herbicidal effects on weed dynamics and growth & yield productivity of direct-seeded rainy (Kharif) rice at Agronomy Research Farm of Narendra Deva University of Agriculture and Technology, Kumarganj, Ayodhya (U.P.) during the years, 2016 and 2017. The field trial was carried out in Randomized complete block design (RCBD) with three replications and twelve treatments. The treatments consisted of nine pre & post-emergent herbicide combinations along with three distinct controls, i.e. a) Hand weeding (at 20 & 40 DAS), b) Weed Free (weeding at every 15 days interval from seedling to the PI stage), and c) Weedy Check. The results of the field study revealed that the weed-free plots recorded the highest weed control efficiency, and they registered the least weeds density and dry weight of weeds associated with direct seeded rice fields. However, the application of herbicides, namely, pendimethalin (1000 g a.i. ha-1) as pre-emergent and Bispyribac-Na (1000 g a.i. ha-1) as post-emergent coupled with a hand weeding at 40 DAS provided the statistically comparable results to weed-free and is effectively controlled the diverse weed flora by 81.9-84.5 per cent in DSR system. And both the treatments gave significantly better growth (plant height, number of tillers, dry matter, LAI) and yields (grain and straw) of rice as compared to the weedy-check. Among the diverse weeds associated with the DSR fields, sedges were dominant as compared to broad leaves and grasses. The study also recorded the rice-grain yield reduction by 40.9 per cent due to the presence of diverse weed flora in weedy check plot as to weed-free plot.

Effect of row spacing and weed management practices on dry direct-seeded spring rice

Weeds are the major burden for rice-growing farmers in the case of direct-seeded rice due to the preemptive competition of weed in the species early seedling stage. A field experiment was carried out during the spring season in 2021 to evaluate the effect of different weed management practices and row spacing on dry directed-seeded spring rice under the Prime Minister Agriculture Modernization Project (PMAMP) at Rice Super Zone, Kanchanpur, Nepal. The experiment was laid out in a two-factorial randomized complete block design (RCBD) with twelve treatments and three replications. The highest number of effective tillers per m2 was obtained in weed-free plots (531.67), which is statistically similar to Pretilachlor fb 1HW (505.42). Row spacing of 10 cm showed a significantly higher number of effective tillers per square meter (521.94). A higher grain yield was observed in weed-free plots (6397.87 kg.ha-1), which is followed by Pretilachlor fb 1HW, which is statistically similar to other management practices except for weed check. All the management practices were found effective in reducing weed parameters such as weed density, weed dry weight, and weed index as compared to weed checks. A positive relation was recorded between plant height at 90 DAS and grain yield, thousand-grain weight, and grain yield, and a negative relation was recorded between weed density, weed dry biomass, and grain yield. It is recommended to apply Pretilachlor fb 1HW with 10 cm row spacing for effective weed control and to increase the yield of dry direct-seeded rice.

Effect of Herbicides Combination on Weed Management and Yield of Direct Wet Seeded Rice (Oryza sativa L.)

Rice is the most stable food crop in the world, especially in Southeast Asia. Different types of methods are used in rice cultivation viz., conventional method and the no-till (direct seeding) method. Now a days, the direct seeding method of rice cultivation is gaining popularity among farmers due to its lower labour and energy requirements. In direct seeding rice weeds are the major hindrance, which compete with crops for important factors such as light, space, nutrient and moisture. To manage the weeds population in direct-seeded rice, a study was conducted in the summer, 2022 to find out the best herbicide combination. The design adopted for this experiment was Randomized Block Design (RBD) with 12 treatments and 3 replications. The results of the study revealed that a weed free plot (T11) followed by the application of Pretilachlor 50% EC @ 625 g a.i. ha-1 on 3 DAS (Days After Sowing)+ Bispyribac-sodium 10% SC @ 20 g a.i. ha-1 + Ethoxysulfuron 15% WDG (Water Dispersible Granule) @ 15 g a.i. ha-1 (Tank Mix) on 15 DAS and 40 DAS (T9) recorded higher weed control efficiency, lesser weed density and weed dry weight compared to all other treatments. A similar result was observed in yield attributes like number of tillers m-2, number of productive tillers m2, panicle length, number of grains panicle-1, test weight, higher grain and straw yield of direct wet seeded rice.

Drone-based herbicide application for energy saving, higher weed control and economics in direct-seeded rice (Oryza sativa)

A field experiment was conducted at Tamil Nadu Agricultural University, Coimbatore during kharif (rainy) and rabi (winter) seasons of 2022 and 2023 to evaluate the efficiency, energy and economics of drone-based herbicide application in direct-seeded rice (Oryza sativa L.). The study was carried out with application of pre-emergence, early post-emergence and post-emergence herbicides using drone and knapsack sprayer to assess the weed control efficiency. Treatments included pretilachlor followed by (fb) application of post-emergence herbicides, such as bispyribacsodium (Na), fenoxyprop ethyl + carfentrazone ethyl and early post-emergence herbicides, such as bispyribac-Na, fenoxyprop ethyl + carfentrazone ethyl, bispyribac-Na fb post-emergence of fenoxyprop ethyl + carfentrazone ethyl, weed-free check and unweeded check. Application of pretilachlor fb bispyribac-Na using knapsack sprayer reduced weed density from 83 to 87% and weed dry weight from 81 to 83% over unweeded plot. Moreover, it was found on par with drone application of same herbicides in both seasons. Pretilachlor fb bispyribac-Na application through knapsack sprayer and drone produced higher grain yield and it was comparable with weed-free plot. Higher net return, benefit: cost ratio (2.27 and 2.09), energy-use efficiency (10.86 and 9.55 MJ) and energy productivity (0.81 and 0.71 kg/MJ) were noticed with drone application of pretilachlor fb bispyribac-Na in both the seasons. From the experiment, drone application of pretilachlor fb bispyribac-Na is found as an effective strategy to manage weeds in direct-seeded rice and more advantageous in terms of energy-use and profitability.

Bio-efficacy of fomesafen + fluazifop-p-butyl mixture against weeds and its effect on productivity and profitability of soybean (Glycine max) in Central India

Grassy and broadleaf weeds are simultaneously growing in soybean (Glycine max L.) crop and there is a lack of herbicides to control all types of weeds in a soybean crop. Thus, a field experiment was conducted during rainy (kharif) seasons of 2017 and 2018 to evaluate efficacy of fomesafen + fluazifop-p-butyl mixture against weeds and consequent improvement in productivity of soybean. Bio-efficacy was evaluated with 10 weed control treatments comprising of 4-doses of fomesafen + fluazifop-p-butyl mixture (90+90, 110+110, 130+130 and 220+220 g/ha), alone application of imazethapyr (100 g/ha), market check – fomesafen + fluazifop-p-butyl (110 + 110 g/ha), combined application of imazethapyr + imazamox (35 + 35 g/ha) as early post-emergence, hand weeding twice at 15 and 30 DAS, weedfree and weedy-check, were laid-out in a randomized complete block design with three replications. Application of premix fluazifop-p-butyl + fomesafen (130+130 g/ha) as early-post-emergence resulted in lower density, dry weight of all individual weeds with 99.2% weed control efficiency (WCE) and higher value of yield parameters and yield (2.01 t/ha) of soybean which was statistically at par with weed-free plots (2.04 t/ha). The higher dose of fomesafen + fluazifop-p-butyl (220+220 g/ha) was found effective against weeds but caused phytotoxicity to soybean crop and reduced seed yield marginally (1.98 t/ha). The fomesafen residues up to 130 g/ha dose were found below the detectable limit in the soil with zero per cent persistence at harvest. However, the highest dose of fomesafen (220 g/ha) resulted in residues in soil (0.016 μg/g) with 4.44% persistence and half-life of 13 days. These results suggested that premixfomesafen + fluazifop-p-butyl at 130+130 g/ha as early-post-emergence can be safe for the application in soybean crop.

Efficacy of Herbicides on Weed Control & Growth Parameter on Wheat

Wheat (Triticum aestivum) is a globally significant crop and a staple food for millions of people. Weed infestation is one of the major constraints affecting wheat productivity worldwide. The purpose of this study was to assess the efficiency of Carfentrazone ethyl 5% + Clodinafop propargyl 15% DF as a post-emergence herbicide against predominant weeds in wheat crops. Wheat is a globally significant crop and a staple food for millions of people. Weed infestation is a major constraint affecting wheat productivity. The study was conducted using a Randomized Block Design with three replications and a total of 11 treatments. The herbicide treatments were applied using foliar spray at different doses. Weed control efficiency was evaluated at 30, 45, and 60 days after herbicide application.
 The results showed that the highest weed control efficiency was observed in the weed-free plot, followed by the treatment with Carfentrazone ethyl 5% + Clodinafop propargyl 15% DF at a dose of 800 g/ha. This treatment provided significant control against different weed species such as Phalaris minor, Avena ludoviciana, and Chenopodium album. The herbicide treatments showed varying degrees of control efficiency, with some treatments performing better than others.
 These findings highlight the importance of weed management for increasing wheat crop production. The judicious use of herbicides, such as Carfentrazone ethyl 5% + Clodinafop propargyl 15% DF, can effectively control weeds and contribute to higher yields. However, further research and field trials are necessary to optimize the herbicide application and determine its long-term effects on wheat crops. Overall, this study emphasizes the need for effective weed control strategies to enhance wheat productivity and meet the demands of a growing population.