Integrated Weed Management Practices Research Articles

Effect of integrated weed management practices on growth parameters, yield attributes and yield of Rabi groundnut

Effect of integrated weed management practices on growth parameters, yield attributes and yield of Rabi groundnut

Efficacy of integrated weed management practices on growth and yield of sweet corn

Efficacy of integrated weed management practices on growth and yield of sweet corn

Effect of Integrated Weed Management Practices on Weed Dynamics, Growth Performance and Yield of Direct Sown Finger Millet (Eleusine coracana L.)

Background: Finger millet is an important dryland crops since they can tolerate unfavorable weather and are frequently planted in soils with low nutrient and poor water holding capacity in soils. The main cause for yield loss is weed infestation which occurs in finger millet. Several integrated weed management techniques were carried out to control them particularly and to increase yield which benefits farmers. Methods: In this context a field experiment was conducted in Karunya Institute of Technology and Sciences, Coimbatore, during Rabi season of 2022-23 in direct sown finger millet under irrigated condition. The experiment was laid out in RCBD with ten treatments and three replications viz., PE pendimethalin @ 0.75 kg ha-1 8 DAS + Hand weeding @ 35 DAS, PoE 2,4-D @ 2 kg ha-1 40 DAS + Hand weeding @ 35 DAS, PE pretilachlor @ 0.75 kg ha-1 8 DAS + Hand weeding @ 35 DAS, PoE 2,4-D @ 2 kg ha-1 40 DAS + Twin wheel hoe @ 30 DAS, PE pendimethalin @ 0.75 kg ha-1 8 DAS + Twin wheel hoe @ 30 DAS, PE pretilachlor @ 0.75 kg ha-1 8 DAS + Twin wheel hoe @ 30 DAS, Hand weeding @ 25 and 40 DAS, Twin wheel hoe @ 25 and 40 DAS, Hand weeding @ 25 DAS + Twin wheel hoe @ 40 DAS and Unweeded control. The CO 14 finger millet was used a test variety with 110 days medium duration. Result: The result showed that pre-emergence pretilachlor @ 0.75 kg ha-1 8 DAS + Twin wheel hoe weeding @ 30 DAS significantly decreased weed density, importance value index and summed dominance ratio of weeds with higher weed control. The same treatment combination recorded higher plant height (115.8 cm) and grain yield (2368 kg ha-1) at harvest.

Integrated Weed Management in Minor Millets: A Review

Presently, agriculture is facing tremendous problem due to climate change and global warming. To ensure food and nutritional security at national level, there is an immediate need to promote the cultivation of millets as millets are considered climate smart and nature friendly crops because of high nutritive value and can withstand under warm and drought conditions with short life, low external inputs requirement, tolerance to water and temperatures stress. Ten millet crops have been declared as ‘Nutri Cereals’ which include three major millets i.e., pearl millet, sorghum and finger millet; five minor millets i.e. foxtail millet, proso millet, kodo millet, barnyard millet, little millet; and two pseudo millets i.e. kuttu (buckwheat) and amaranthus. Due to sluggish growth in initial phases of life, millets proved relatively poor competitors against weeds. Manual weeding is the most commonly adopted for weed control in millets. But the non-availability of labour and ever-increasing labour wages have compelled the farmers to seek alternate method of weed management. Herbicide use is the most viable method of weed control but their continuous and excessive use is not advisable due to its ill effects on environment and development of herbicide resistance in weeds. Very limited options are available in literature for weed control in minor millets. Thus, integrated weed management practices should be followed on site and time specific basis for effective and efficient weed management in minor millets. For integrated weed management in minor millets, 2-3 times inter-cultivation and 1-2 time hand weeding during initial 25 days after sowing in addition to pre-emergence spray with Isoproturon @ 0.5 -1.0 kg a.i./ha and post emergence spray of 2, 4-D sodium salt @ 0.75-1.0 kg a.i./ha at 20-25 days after sowing should be done for effective weed control.

To Study the Effect of Integrated Weed Management Practices on Weeds Parameters of Transplanted Rice in Chhattisgarh Plains

The present experiment entitled “To study the effect of integrated weed management practices on weeds parameters of transplanted rice in Chhattisgarh plains” was studied during the 2022, kharif season at Agricultural Research Farm BTC, CARS, Bilaspur, Chhattisgarh. A randomized block design with ten treatments and three replications was used.  Treatment T5 (untreated control) had the highest weed density and dry weight measurements, whereas treatment T6 (weed-free) had the lowest.The weed index was lowest in T6 (weed-free). The stage with the highest percentage of weed control efficiency was T6 (Weed-Free), then T10 (Chlorimuron ethyl 10% WP + Metsulfuron methyl 10% WP @ 0.06g ha-1 (20 DAT) + mechanical weeding (20 & 40 DAT) by Ambika paddy weeder at all stages.

Integrated Weed Management Practices on Productivity and Profitability of Direct Seeded Rice under Aerobic Condition

At the research farm of RPCAU, Pusa, Samastipur, Bihar, a field experiment was carried out during the 2017 kharif season to examine the effects of integrated weed control on the profitability and productivity of direct-seeded rice grown in aerobic conditions. The experiment was laid out in Randomized Block Design having ten treatments with three replications. Both hand weeding and herbicidal treatments, out of all the weed control techniques, had noticeable effects on crop development and yield as well as their superiority to the weedy check. Hand weeding at 20, 40 and 60 days after sowing was found significantly superior over all the integrated weed management practices on productivity and profitability of dry direct seeded rice. Pendimethalin @ 1 kg/ha at 0–2 days after sowing, followed by two hand weedings at 20 and 40 days after sowing, outperformed the other herbicidal treatments in the trial for dry direct seeded rice.

Effect of Integrated Weed Management Practices on Growth and Yield of Green Chilli (Capsicum annum L.)

Weed infestation in chilli production, especially during early growth stages, is a major constraint leading to significant yield loss. Effective weed management during this critical phase is crucial for maximizing chilli crop productivity. Keeping this in view a field experiment was conducted at the research farm of Abhilashi University, Mandi (H.P) during the Kharif season of 2022-23. The main objective was to assess the impact of various integrated weed management strategies on the growth and yield of green chilli crops. The experiment consisted of seven treatments with control, laid out in Randomized Block Design with three replications. The treatment details viz., T1[Weedy check (Control)], T2(Weed free), T3[Hand weeding at 30 and 60 days after transplanting (DAT)], T4[organic mulch (paddy straw)], T5 (Oxyfluorfen 1.0 kg/ha, T6 Pendimethalin 1.0 kg/ha) and T7 (Pendimethalin 1.0 kg/ha. + HW after 60 DAT). The results of the study revealed that the "Weed-free" treatment (T4) exhibited the highest plant height (80.35 cm), number of leaves per plant (120), number of fruits per plant (85) with an average weight of fruits per plant (276.74 g), dry weight of fruits per plant (33.21 g) and yield (7.56 kg/plot and 189.05 q/ha). The treatment "Pendimethalin 1.0 kg/ha + Hand weeding after 60 DAT" (T7) followed closely, recording the plant height (75.78 cm), number of leaves per plant (114.66), number of fruits per plant (82.33) with an average weight of fruits per plant (251.56 g), dry weight of fruits per plant (32.7 g) and yield (7.12 kg/plot and 178.08 q/ha). The "Weedy check" treatment (T1) required the longest duration for 50% flowering and the first and final harvest, with 76, 108 and 124 days, respectively. On the other hand, the "Weed-free" treatment (T2) required the shortest period, with 66, 93, and 106 days, respectively. Regarding weed-related parameters, the "Weedy check" treatment (T1) demonstrated the highest weed count (110), fresh weight of weeds (2160.03 g) and dry weight of weeds (388.81 g), while the "Weed-free" treatment (T2) exhibited the minimum weed count (0.00), fresh weight of weeds (0.00 g) and dry weight of weeds (0.00 g). The highest weed control efficiency (WCE) of 100% and the lowest weed index (0.00%) were observed in the "Weed-free" treatment (T2), whereas the lowest WCE (0.00%) and the highest weed index (69.69%) were recorded in the "Weedy check" treatment (T1). Economically, the combined treatment of "Pendimethalin 1.0 kg/ha with hand weeding after 60 DAT" (T7) resulted in the highest net return of 4,39,192.78 ₹/ha, followed by the "Weed-free" treatment (T2) with 4,35,207 ₹/ha. The lowest net return was observed in the "Weedy check" treatment (T1) with 62,117.28 ₹/ha.

Effect of Integrated Weed Management Practices on Growth and Yield of Onion (Allium cepa L.)

A field experiment was conducted to study the effect of integrated weed management practices on growth and yield of onion at College Farm, Professor Jayashanker Telangana State Agricultural University, Rajendranagar, Hyderabad in Rabi 2021. The experiment consisted of eleven treatments and laid out in randomised block design (RBD) with 3 replications. Results revealed that growth parameters viz., plant height and number of leaves per plant were significantly influenced by weed   management practices. Significantly high growth parameters were recorded with mechanical weeding at 20 and 40 DAT and it was at par with  pendimethalin 38.7% CS 677.25 g ha-1 PE + polyfilm mulch and oxyfluorfen 23.5% EC  100 g ha-1 PE + polyfilm mulch. Similarly, higher yield was recorded with mechanical weeding at 20 and 40 DAT (183.2 q ha-1) and it was on par with pendimethalin 38.7% CS 677.25 g ha-1 PE + polyfilm mulch (176.3 q ha-1) and oxyfluorfen 23.5% EC  100 g ha-1 PE + polyfilm mulch T2 (173.2 q ha-1). On the other hand, lower growth parameters and yield was recorded in unweeded treatment. Hence it can be concluded that mechanical weeding at 20 and 40 DAT or pendimethalin 38.7% CS 677.25 g ha-1 PE + polyfilm mulch or oxyfluorfen 23.5% EC 100 g ha-1 PE + polyfilm mulch may be adopted for better growth and yield in onion.

Effect of integrated weed-management practices in direct-seeded autumn rice (Oryza sativa) on growth, yield and soil microflora

A study was carried out during the rainy (kharif) season of 2015 and 2016 at Assam Agricultural University, Jorhat, to evaluate the effect of 6 weed-management practices on growth, yield and soil microflora with 3 different direct-seeded upland rice (Oryza sativa L.) varieties. The percentage of grasses was higher, followed by broad leaf weeds in variety ‘Maizubiron’ followed by ‘Guni’ during the critical crop growth period. The lowest weed density as well as dry weight at 20, 40 and 60 days after sowing (DAS) was recorded in rice variety ‘Inglongkiri’ under integrated weed management of pretilachlor 1.5 kg/ha and mechanical weeding which resulted in higher weed-control efficiency (36.29 and 37.62%, respectively) at 20 DAS. The light transmission ratio was the lowest in ‘Inglongkiri’ followed by ‘Guni’. The fungal and bacterial populations were reduced at 25 days after herbicide application which gradually increased up to 50 days. Higher grain yield and harvest index among rice varieties were recorded in ‘Inglongkiri’ (1.98 t/ha and 43.09, respectively.) and application of pretilachlor 0.75 or 1.5 kg/ha combined with mechanical weeding 30 DAS resulted in the higher grain yield (1.95 t/ha) and harvest index (39.33%) over 2 years.

Effect of Integrated Weed Management Practices on Growth, Physiology and Yield of Direct Sown Finger Millet (Eleusine coracana L.)

To determine “Effect of integrated weed management practices in direct sown finger millet”. The field experiment was conducted during rabi 2022 at South Farm, Karunya Institute of Technology and Sciences, Coimbatore. The soil of the experimental field was sandy clay loam in texture, pH 6.9, level of organic content (0.37%),  available N (336 kg ha-1), P (91 kg ha-1) and K (261 kg ha-1). The experiment was laid out in completely randomized block design. T1 (PE pendimethalin @ 0.75 kg ha-1 8 DAS + Hand weeding (HW) @ 35 DAS), T2 (PoE 2,4-D @ 2 kg ha-1 40 DAS + Hand weeding (HW) @ 35 DAS), T3 (PE pretilachlor @ 0.75 kg ha-1 8 DAS + Hand weeding (HW) @ 35 DAS), T4 (PoE 2,4-D @ 2 kg ha-1 40 DAS + Twin wheel hoe weeding (TWHW) @ 30 DAS), T5 (PE pendimethalin @ 0.75 kg ha-1 8 DAS + Twin wheel hoe weeding @ 30 DAS), T6 (PE pretilachlor @ 0.75 kg ha-1 8 DAS + Twin wheel hoe weeding (TWHW) @ 30 DAS), T7 (Hand weeding (HW) @ 25 and 40 DAS), T8 (Twin wheel hoe weeding (TWHW) @ 25 and 40 DAS), T9 (Hand weeding (HW) @ 25 DAS + Twin wheel hoe weeding (TWHW) @ 40 DAS), T10 (Unweeded control). The result shows that the weed control practices significantly decreases weeds also higher control of weed infestation was observed in PE pretilachlor @ 0.75kg ha-1 8 DAS + Twin wheel hoe weeding @ 30 DAS. The maximum dry matter production, CGR, RGR, NPK uptake and grain yield (2368 kg ha-1) were also found higher in PE pretilachlor @ 0.75kg ha-1 8 DAS + Twin wheel hoe weeding @ 30 DAS. From this study it is concluded that application of pre emergence herbicide pretilachlor along with twin wheel hoe weeder increases the crop growth and yield.

Yield and Nutrient Uptake of Green Gram (Vigna radiata L.) and Weeds as Influenced by Different Integrated Weed Management Practices in Western Uttar Pradesh

The field experiment was conducted at Crop Research Centre of Sardar Vallabhbhai Patel University of Agriculture & Technology in Meerut (U.P.) during kharif 2021 to assess the performance of post-emergence application of Imazethapyr and Quizalofop-ethyl in combination with pre-emergence application of Pendimethalin on green gram (Vigna radiata L.). The experiment laid out in randomized block design with three replications and comprised of treatments Control (Weedy check) T1, Weed free T2, One hand weeding 20 DAS T3, Two hand weeding 20 and 40 DAS T4, Quizalofop-ethyl 50g a.i./ha Post-emergence (20 DAS) T5, Quizalofop-ethyl 50g a.i./ha Post-emergence (20 DAS) + one hand weeding 40 DAS T6, Imazethapyr 50g a.i./ha Post emergence (20 DAS) T7, Imazethapyr 50g a.i./ha 20 DAS + one hand weeding 40 DAS T8, Pendimethalin 1.0kg a.i./ha Pre emergence T9 and Pendimethalin 1.0kg a.i./ha Pre emergence + Imazethapyr 50g a.i./ha 20 DAS + one hand weeding 40 DAS T10. Treatments effects were evaluated in terms of weed dynamics growth and yield of green gram. The highest total NPK content and uptake by grain and straw found with weed free treatment followed by Pendimethalin 1.0kg a.i./ha Pre emergence + Imazethapyr 50g a.i./ha 20 DAS + one hand weeding 40 DAS was at par with Imazethapyr 50g a.i./ha 20 DAS + one hand weeding 40 DAS. Among the herbicides, the lowest total NPK content and uptake by weed was found with the application of Pendimethalin 1.0kg a.i./ha Pre emergence + Imazethapyr 50g a.i./ha 20 DAS + one hand weeding 40 DAS. The results revealed that treatment T2 (weed free) had the best financial return (Rs 91250 ha-1) and B:C ratio (2.72), while among the herbicides treatment T10 and T8 had the highest net financial return (Rs 92706 ha-1) and B:C ratio (3.14) respectively.

Date of Transplanting and Integrated Weed Management Effects on Growth and Yield of Black Rice (Oryza sativa L.) under SRI

Background: The date of transplanting which is related to the climatic condition is one of the major factor affecting the growth and yield of black rice. Weeds also pose serious threat to rice in SRI condition if not controlled during critical period of weed competition. Therefore, efficient integrated weed management practices are required in SRI. The experiment was carried out to assess the effect of date of transplanting and integrated weed management on black rice. Methods: The experiment was conducted in the experimental farm of SASRD, NU, Medziphema campus during kharif season of 2019 and 2020. The experiment was laid out in split plot design with three dates of transplanting in the main plots and five integrated weed management treatments in the sub-plots with 15 treatment combinations and three replications. Result: Minimum weed population and dry weight were recorded with transplanting black rice on 15th June. It also gave significantly highest growth attributes and yield of black rice. Among the integrated weed management, Pretilachlor 0.75 kg/ha t 3 DAT fb handweeding at 40 DAT recorded significantly lowest weed population and dry weight and highest plant height, number of green leaves plant-1, dry matter accumulation and yield of black rice.

Effect of Integrated Weed Management Practices on Microbial Population in Soil, Yield and Economics in Wet Direct Seeded Rice

An experiment had been conducted at the Agronomy Farm, Indira Gandhi Krishi Vishwavidyalaya, Raipur, (C.G.) in the kharif season of 2019, to determine the effects of integrated weed management practices on microbial population in soil, yield and economics in wet direct seeded rice. Pre-emergence herbicides (Oxadiargyl and Pretilachlor) were followed by post-emergence herbicide (Bispyribac-Na), mechanical and manual weeding. Plots treated with oxadiargyl performed better than pretilachlor. When Oxadiargyl was integrated with Hand Weeding (HW) at 35 days after sowing (DAS) gave results which were better than twice HW plot (T10). Oxadiargyl @ 70g/ha at 7-11 DAS fb HW at 30-35 DAS (T4) proved to be superior over all the treatments when yield and economics of wet direct seeded rice was concerned and was statistically at par with twice HW plot (T10) and oxadiargyl @ 70 g/ha at 7-11 DAS fb bispyribac-Na @ 25 g/ha at 30-35 DAS (T2). The unsprayed and two-hand weeding treatments had much lower levels of fungi, actinobacteria, and bacteria than the other weed control methods. The herbicidal treatments had much higher microbial populations at all stages of observation.

Productivity and profitability of zero till winter maize as influenced by integrated weed management practices

Productivity and profitability of zero till winter maize as influenced by integrated weed management practices

Growth and development of multiple waterhemp (Amaranthus tuberculatus) cohorts in corn and soybeans

Waterhemp is a troublesome weed species in cropping systems throughout Wisconsin and much of the US Midwest. Coupled with extended emergence window, rapid growth, high genetic diversity, and herbicide resistance to multiple sites of action, waterhemp represents a major challenge for chemical-based weed control. The objective of this experiment was to evaluate the impact of soybean and corn canopy on growth and development of multiple waterhemp cohorts in 2019 and 2020. Treatments consisted of narrow- (38 cm row spacing) and wide-row (76 cm row spacing) soybeans, corn (76 cm row spacing), and fallow (no crop), with 6 waterhemp transplant timings (cohorts) in 2019 and 2020, respectively. Waterhemp seedlings grown in the greenhouse were transplanted at the 2-3 true leaves growth stage to the field at 10-day increments throughout the typical waterhemp emergence season for Wisconsin (June-July). Waterhemp plants were measured for height and harvested for biomass when they reached the flowering stage. The number of days from the first transplant timing to result in 50% and 90% biomass and height reduction (ED50 and ED90) of subsequent waterhemp cohorts were estimated and used as indicators of weed suppression ability by the respective crop. Narrow-row soybeans required fewer days to suppress 50% growth of new waterhemp cohorts followed by corn, wide row soybeans, and fallow, respectively (4, 6, 9, and 14 d for 50% biomass reduction, and 10, 14, 18, and 42 d for 50% height reduction, respectively). Similarly, narrow-row soybeans required fewer days to suppress 90% biomass of waterhemp, followed by corn, wide-row soybeans, and fallow (11, 15, 18, and 78 d, respectively). Conversely, narrow and wide-row soybeans required fewer days to suppress 90% height of new waterhemp cohorts followed by corn and fallow (20, 26, 43, and 85 d, respectively). Rapid soybean canopy closure (e.g., planting soybeans earlier and in narrow row-spacing) combined with other integrated weed management practices have the potential to reduce reliance on POST herbicide application and mitigate herbicide resistance evolution. In corn, mid- to late-season monitoring and management of later emerging waterhemp cohorts is recommended due to longer time required to reach 90% waterhemp growth suppression.

Impact of integrated weed management practices on cotton economics and Palmer amaranth (Amaranthus palmeri) populations

AbstractThe threat of herbicide-resistant weed species, such as Palmer amaranth, has driven the development of robust weed management programs that rely on more than chemicals for weed control. Previous research has shown that zero-tolerance weed thresholds, cover crops, deep tillage, and diverse herbicide programs are effective strategies for controlling Palmer amaranth. Unfortunately, research investigating the integration of all four of these weed management strategies in a system is lacking. To better leverage these integrated weed management strategies in cotton production systems, a long-term study was initiated in fall 2018 near Marianna, AR, with zero tolerance, deep tillage, a cereal rye cover crop, and either a dicamba or non-dicamba in-crop herbicide program as factors. Results found that total Palmer amaranth emergence was reduced 76% as the result of deep tillage in 2019 and, in the absence of a zero-tolerance strategy, 73% in 2020. In the absence of a zero-tolerance strategy, the combination of a non–cover crop strategy and dicamba herbicide program decreased total Palmer amaranth emergence by 73%, while the combination of a cover crop strategy and dicamba herbicide program decreased total Palmer amaranth emergence by 78% compared to the combination of a cover crop and non-dicamba herbicide program. Under a zero-tolerance strategy in 2019, tillage reduced cotton yield by 12% and partial returns by US$370 ha−1. In 2020, tillage reduced cotton yield by 14% and partial returns of US$371 ha−1 under a non-zero-tolerance strategy, while a 12% yield reduction and a US$260 ha−1 decrease in partial returns were observed under a zero-tolerance strategy. In 2019, the non-dicamba program resulted in greater partial returns than the dicamba in-crop program because of greater yield and lower program costs. However, in 2020, partial returns were greater for the dicamba in-crop herbicide program owing to greater yields achieved by this program.

"Effect of Integrated Weed Management Practices on Flowering, Yield and Economics of African Marigold (Tagetes erecta L.) cv. Arka Bangara-2"

"Effect of Integrated Weed Management Practices on Flowering, Yield and Economics of African Marigold (Tagetes erecta L.) cv. Arka Bangara-2"

Pinoxaden resistance in Lolium perenne L. is due to both target-site and non-target-site mechanisms

Application of herbicides inhibiting acetyl CoA carboxylase (ACCase) has been one of the main strategies for selectively controlling grass weed species such as perennial ryegrass (Lolium perenne L.) in wheat and barley crops in New Zealand. In this study, we have confirmed and characterized resistance to pinoxaden, an ACCase-inhibiting herbicide, in a population of L. perenne. Dose-response experiments were conducted to assess the level of pinoxaden resistance, and based on the LD50 values, the studied population was 41.4-times more resistant to pinoxaden than a susceptible population. Application of malathion, an inhibitor of the cytochrome P450s, preceding pinoxaden treatment reduced the level of resistance to 9.7-fold. However, pre-treatment with the glutathione S-transferase (GST) inhibitor 4-chloro7- nitrobenzoxadiazole prior to pinoxaden treatment did not affect pinoxaden resistance. Partial sequencing of the ACCase gene revealed that the resistant population had an isoleucine to valine replacement at position 2041. These results suggest that both cytochrome P450-based and target-site mechanisms are jointly associated with this instance of pinoxaden resistance in L. perenne. The pinoxaden-resistant L. perenne individuals were also resistant to quizalofop-p-ethyl (108.6-fold), but they were susceptible to clethodim, which can, therefore, be used to manage this pinoxaden-resistant L. perenne. This is the first report of a L. perenne population in which a rare target-site mutation works in concert with enhanced cytochrome P-450 activity to confer pinoxaden resistance. Evolution of resistance to ACCase-inhibiting herbicides in this L. perenne population indicates that integrated weed management practices are required to prevent widespread resistance developing in New Zealand cereal crop systems.

System productivity, energetics and economics of soybean (Glycine max)-wheat (Triticum aestivum) cropping system as influenced by weed management practices

 A field experiment was conducted during 2015–16 and 2016–17 to assess the system productivity, energetics and economics of weed management practices in soybean (Glycine max L.)-wheat (Triticum aestivum L.) cropping system at ICAR-Directorate of Weed Research, Jabalpur, Madhya Pradesh. The experiment comprised 10 treatments having combinations of sole and sequential application of pre-emergence and post-emergence herbicides in both the crops, and their integration with hand weeding undertaken in randomized block design replicated thrice. The highest system productivity (8.04 t/ha) was obtained by employing two hand weedings, sequential application of pendimethalin followed by (fb) imazethapyr in soybean and pendimethalin fb mesosulfuron + iodosulfuron in wheat as well as by integrating either pre or post-emergence herbicides with one hand weeding. Among weed management practices, energy requirement was lowest in sole post-emergence herbicide treatment, however, integration of manual weeding required maximum energy. The energy input for hand weeding was a major share of integrated weed management practices, and it varied from 54–83% of the total treatment energy. Due to requirement of less energy for sole post-emergence herbicides, energy output, net energy return and energy ratio were the maximum. Total output energy was higher (258×103 MJ/ ha) in post-emergence herbicide fb hand weeding treatment because of higher system productivity (7.29 t/ha), and this treatment was more energy efficient and gave the highest economic returns among the weed management practices. The highest benefit: cost ratio (3.10) was obtained by the application of post-emergence herbicides in both the crops.

Conservation agriculture for increasing productivity, profitability and water productivity in rice-wheat system of the Eastern Gangetic Plain

There are increasing concerns about the negative effects of conventional tillage (CT), extreme climate events, increased weed incidence, and reduced availability of farm inputs on crop yield and yield stability, profitability, and water productivity in rice-wheat (R−W) systems of the Eastern Gangetic Plains (EGP) in South Asia. Conservation agriculture (CA)-based tillage practices have been proposed in the region to address these concerns. We analysed 84 on-farm trials’ data comparing CA-based practices with farmers’ CT practices in R−W systems of eastern Terai region of Nepal in the EGP. The objectives were to investigate crop and cropping systems productivity, profitability, yield stability, irrigation (WPi) and total water productivity (WP(r+i)), and fertilizer-use efficiencies of three CA- and one CT-based practices in R−W systems. Treatments included: (i) CT-based: puddled transplanted rice - conventional tillage wheat (PTR−CTW); (ii) CA-based: PTR − zero tillage wheat (PTR−ZTW); (iii) CA-based: direct-seeded rice − ZTW (DSR−ZTW); and (iv) CA-based: un-puddled transplanted rice − ZTW (UPTR−ZTW). Results showed that although there were no significant differences in yield of either rice or wheat or R−W system between CA-based and CT treatments, there was a significant reduction in production cost (by 245−369 USD ha−1) mainly due to reduced labor use and increased net gain (188−223 USD ha−1) in all CA-based R−W system. DSR−ZTW showed the highest yield stability and net profit, demonstrating its adaptability in the region. Among the irrigation applicators (35%) in rice, DSR used 107 mm (67 mm higher than PTR) irrigation water with WPi of 70% and 96% of PTR and UPTR, respectively due to the need of additional irrigation for crop establishment. In contrast, among the irrigation applicators (75%) in wheat, due to earlier sowing of ZTW, it required 18% less irrigation water resulting in 9% higher WPi compared to CTW. However, a follow-up study two years after completion of field trials revealed that no local farmers had continued CA-based practices mainly due to high weed pressure, lack of land leveling, inaccessibility of zero-till (ZT) drill machines, and lack of ZT service providers. Effective support systems incentivizing in land leveling, ZT machines, technical knowledge dissemination, and the development of integrated weed management practices for scaling-out strategies are essential to adopt CA-based practices. As the results have great implications to reduce production costs and increase farm profits, save energy and water, increase land and labor productivity, and improve food security of millions of smallholder farmers in the EGP, strong policy support to incentivize farmers to avoid the adoption barriers of CA-based practices is required.