Weed Management Options Research Articles

Herbicide Use Strategy and Its Economy as a Weed Management Option in Wheat Varieties

Weed pressure is an additional threat to high temperature stressed wheat crop for its optimum production. A field experiment was conducted at Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during Rabi 2017-2018 to assess the response of wheat varieties to different weed managements and its economical viability. As such three varieties i.e. BARI Gom-28, BARI Gom-29, and BARI Gom-30 along with five weed managements viz. control (no weeding), two hand weeding at 20 and 40 DAS, Panida 33EC (Pendimethalin) @ 2000 ml ha-1 spray at 5 DAS as pre-emergence, Affinity 50.75 WP (Isoproturon) @ 1500 g ha-1 spray at 25 DAS as post-emergence and Panida 33EC (Pendimethalin) @ 2000 ml ha-1 at 5 DAS + Affinity 50.75 WP (Isoproturon) @ 1500 g ha-1 at 5 & 25 DAS were treatment variables tested under split plot design.Cynodon dactylon, Cyperus rotundus, Echinochloa colona, Eleusine indica, Chenopodium album, Alternanthera philoxeroides, Brassica kaber, Leliotropium indicum, Vicia sativa,etc.werethe major weeds as determined based on their field intensity.Results revealed that BARI Gom-30 out-yielded other varieties with the highest grain yield (3.01 t ha-1). Pre-emergence application of Panida 33EC at 5 DAS proved as suitable weed management compared to other methods. BARI Gom-30 in combination with Panida 33EC @ 2000 ml ha-1 spray at 5 DAS as pre-emergence gave higher yield and yield attributes while BARI Gom-28 under no weeding check showed lower grain yield (2.09 t ha-1). Economically maximum gross return (Tk.75761.52ha-1),net income (Tk.21775.92ha-1), and BCR (1.41) were associated with Panida 33EC treatment when minimum values were obtained in the control plot (no weeding). So, the application of pre-emergence herbicide, Panida 33EC might be economically viable weed management ensuring a higher yield in wheat cultivation.
 Bangladesh Agron. J. 2020, 23(2): 119-125

Bio-efficacy of sequential herbicide application for weed management in dry direct seeded rice

Weeds are the major biotic constraint in dry-direct seeded rice (DDSR), mainly due to the concurrent emergence and absence of water layer to suppress weeds. Therefore, strategy needs to be developed to get broad-spectrum weed control in DDSR. Experiments were conducted in rice (var. MTU 1010) during 2015-16 where sequential applications of pre- and post-emergence herbicides were evaluated for providing broad-spectrum weed management options in DDSR. Both the years, employing two-hand weedings at 15 and 30 DAS provided the lowest weed densities and weed dry weight at 75 DAS, whereas the maximum values of weeds were recorded in un-weeded plots. Among the herbicide-based weed management practices, application of pendimethalin 1000 g/ha fb bispyribac sodium 25 g/ha fb fenoxaprop 60 g/ha + chlorimuron + metsulfuron 4 g/ha at 30 DAS provided excellent weed control at 75 DAS, with 4.3% higher rice grain yield than two hand weedings at 15 and 30 DAS, pendimethalin 1000 g/ha fb bispyribac sodium 25 g/ha also provided good weed control and higher grain yield. Un-weeded plots noticed with considerable yield reduction of 79.5-83.3% over two hand weedings. Therefore, sequential application of pendimethalin 1000 g/ ha fb bispyribac sodium 25 g/ha is recommended along with need-based application of post-emergence herbicides (fenoxaprop 60 g/ha + chlorimuron + metsulfuron 4 g/ha) or one hand weeding to improve the weed control efficiency and provides economically higher productivity in DDSR.

Weed flora composition of different barley‐based cropping systems under conventional and conservation tillage practices

Tillage is among the most important soil management practices, which exert strong impacts on weed flora composition in different cropping systems. The large-scale adoption of tillage and cropping systems warrants thorough investigation regarding their impacts on weed flora composition. Therefore, this study was aimed to assess weed flora composition of various barley-based cropping systems (BBCSs) under different tillage practices (TPs). Barley was sown in fallow-barley (F-B), maize-barley (M-B), cotton-barley (C-B), mungbean-barley (Mu-B) and sorghum-barley (S-B) cropping systems with zero tillage (ZT), conventional tillage (CT), minimum tillage (MT), strip tillage (ST) and CT with bed sowing (CTBS). Significant differences (p < 0.05) were recorded among study years and interactions among BBCSs and TPs. The C-B system with ST during 1st year recorded the highest density (35 m− 2) of broadleaved weeds, whereas the highest density (37.76 m− 2) of broadleaved weeds was noted for the same cropping system with MT. All TPs, except BS resulted in increased density of broadleaved weeds in 2nd year compared with 1st year of the study, whereas BS reduced broadleaved weeds’ density during 2nd year. Nonetheless, M-B cropping system with ST and S-B cropping system with CTBS recorded the lowest density of broadleaved weeds during 1st and 2nd year, respectively. Similarly, C-B cropping system with ZT (39.33 m− 2) and MT (24.00 m− 2) recorded the lowest density of grassy weeds during 1st and 2nd year respectively. Nonetheless, S-B system with CTBS and S-B and Mu-B systems with ST recorded no grassy weeds during 1st and 2nd year, respectively. The S-B and M-B cropping systems suppressed various broadleaved and grassy weed species due to their allelopathic potential. In conclusion, different BBCSs had varying weed flora composition under different TPs. Adapting ST and CTBS can lower weed infestation. Similarly, inclusion of sorghum in rotation could be a viable option for effective weed management of barley-based cropping systems. Moreover, long-term experiments are needed to infer the weed seed bank in different TPs and BBCSs.

Integrated Effect of Tillage and Herbicides on Wheat Crop

Combining tillage with herbicides is an economical and efficient method for weed management and yield improvement in wheat. A two-year study was conducted having three tillage levels viz. 2″ tillage (shallow tillage, ST), 4″ tillage (conventional tillage, CT) and 6″ tillage (deep tillage, DT). The weed control treatments were five including three herbicides i.e. bromoxynil + MCPA (a broad-leaf weed killer), fenoxaprop-p-ethyl (a grass killer) and isoproturon + carfentrazone (a broad-spectrum herbicide), along with a hand weeding (HW) and a weedy check (WC). Results showed that the recorded parameters were significantly affected by the varying tillage depths, herbicide applications and their interactions. The weed density and biomass were the highest in ST and the lowest in DT, while among the weed control treatments, the weed density and biomass were highest in WC and lowest in HW. On the other hand, the DT treatments resulted in highest number of spikes m−2, 1000-grain weight (TGW), biological yield and grain yield; while ST showed the lowest values. Among the weed control treatments, the number of spikes, TGW, biological and grain yields were the highest in HW and the lowest in WC treatments. The herbicide isoproturon + carfentrazone performed the best among the three applied herbicides in diminishing the weed population density and biomass, and improving the number of spikes, TGW, biological and grain yields. In conclusion, the combination of deep tillage and herbicide isoproturon + carfentrazone can prove to be the best option for optimum weed management in wheat at higher altitudes.

A novel pre‐emergence herbicide (Diclosulam) as an environmentally friendly weed management option in peanut and its phytotoxicity evaluation

AbstractA two‐season field experiment was conducted to evaluate the efficacy of diclosulam compared with recommended doses of pendimethalin and oxyfluorfen for weed management in peanut. Persistence of diclosulam in oil, de‐oiled cake, haulm of peanut, and soil was also studied. Diclosulam 22 and 26 g a.i. ha−1, and a weed‐free check had a high pod yield due to more mature pods and their mass. Pre‐emergence application of diclosulam 26 g a.i. ha−1 provided better weed management and enhanced peanut growth and yield with high net returns. Phytotoxicity studies indicated that the diclosulam application did not cause any phytotoxic symptoms (vein clearing, epinasty, hyponasty, wilting, and injury) on leaf tips and leaf surface of peanut. Diclosulam residues in peanut viz. oil, de‐oiled cake, haulm, and soil were below the detection level after harvesting of peanut from the experimental field. Further, germination percentage and seed cotton yield of cotton crop cultivated after peanut were also not affected significantly.

Integrated Weed Management Systems to Control Common Ragweed (Ambrosia artemisiifolia L.) in Soybean

As resistance to herbicides limits growers' weed management options, integrated weed management (IWM) systems that combine non-chemical tactics with herbicides are becoming critical. A 2 year integrated weed management (IWM) study was conducted at three locations in VA, USA. The factorial study evaluated: (1) soybean planting date (early or late planted) (2) with or without winter cover (cereal rye/wheat or no cover), and (3) with or without harvest weed seed control (HWSC). Prior to soybean planting in the first year, winter cover resulted in a 22% reduction in common ragweed density compared to no cover. At soybean harvest in the first year, the lowest common ragweed densities were in the late planted plots following winter wheat, and common ragweed aboveground biomass was reduced by 46 and 22% at two locations in late planted compared to early planted soybean. To evaluate the impact of the first year's treatments and HWSC, full season soybeans were planted across the trial in the second year. Prior to soybean planting in the second year, late planting in the first year common ragweed density was reduced by 83% at one location, but significant reductions were not observed elsewhere. When comparing winter cover to no cover, common ragweed densities were reduced by 31 and 49% at two locations and densities were similar at the third location. Harvest weed seed control reduced common ragweed density by 43% at one location compared to the conventional harvest plots but no significant reductions were observed at the other locations or at other rating timings. However, there was a significant location by planting date by winter cover interaction and the overall lowest common ragweed densities (4.1 to 10.3 plants m−2) were in the late planted plots with winter cover. This research indicated that winter cover, late planting, and HWSC can reduce common ragweed populations with late planting being the most influential. Therefore, double-cropping soybean after wheat is likely the most viable means to better control common ragweed using IWM as it combines both winter cover and late planting date.

Distribution and Control of Herbicide-Resistant Italian Ryegrass [Lolium perenne L. ssp. multiflorum (Lam.) Husnot] in Winter Wheat (Triticum aestivum L.) in North Carolina

Italian ryegrass is consistently ranked as one of the most problematic weeds of winter wheat in the Southeastern United States. To determine the distribution of resistant Italian ryegrass biotypes, seed was collected from locations throughout North Carolina and screened with diclofop, pinoxaden, mesosulfuron, and pyroxsulam. Results identified evidence of resistance to diclofop at all locations sampled throughout the state. Resistance to mesosulfuron, pyroxsulam, and pinoxaden were confirmed in 11, 19, and five percent of sampled locations, respectively. Additionally, Italian ryegrass biotypes resistant to multiple and all herbicides tested were identified, eliminating POST herbicide application as an option for control. Adjusting tillage practices may be an option for sustainable weed management to maintain effective control and maximize crop yield. Companion studies were established in the Coastal Plain and Piedmont regions of North Carolina in 2013 and 2014 to evaluate the effect of tillage on Italian ryegrass efficacy with herbicides. Herbicide treatments consisted of pyroxasulfone PRE only, mesosulfuron, or pinoxaden and POST only applications of mesosulfuron plus pyroxasulfone or pinoxaden plus pyroxasulfone. Tillage treatments included no-till and conservation tillage. Treatments containing pinoxaden provided the greatest Italian ryegrass control, regardless of tillage system. The use of pyroxasulfone PRE controlled a higher percentage of Italian ryegrass in the Piedmont when compared to the Coastal Plain, which is believed to be due to multiple flushes during the growing season in the Coastal Plain. Herbicide treatment was still a significant factor in Italian ryegrass control, but Italian ryegrass seed head density was consistently lower in the no-till system. Tillage may be stimulating germination, allowing greater control with PRE herbicides. An integrated system of herbicides and tillage may allow for greater yield and reduce selection pressure on POST herbicides.

Estimations and projections of Avena fatua dynamics under multiple management scenarios in crop fields using simplified longitudinal monitoring

Integrated weed management (IWM) is currently the most appropriate and effective method of agricultural weed control. To determine the most effective strategy, it is necessary to compare the effects of different control options and their rotation. Avena fatua (common wild oat) is one of the most common and economically threatening grass weed species of cereal crops worldwide. To examine the effects of non-chemical weed management options (farmland use, delayed sowing, and summer irrigation) on control of A. fatua, we recorded coverage levels and field conditions in 41 sites during the spring growing season of winter wheat for about 10 years. A transition matrix model was then constructed to project coverage levels of A. fatua under each management option using ordinal logistic regression. The results showed that farmland use had a remarkable effect on coverage; notably, planting of paddy rice and vegetables, which respectively eliminated the effect of coverage in the previous year and facilitated rapid convergence of coverage to 0%. Thus, although 90% of fields under continuous wheat cultivation were found to be at risk of A. fatua colonization, the risk was reduced to almost 0% with rotation of effective farmland use. As summer irrigation was also effective, more than 50% of wheat fields with the option continuously converged to no risk for A. fatua colonization. When the different management cycles were repeated, the effects were observed within 3 years, with a steady state reached in less than 10 years. Overall, these results suggest that simplified monitoring data could help decision-making on IWM, thereby helping to improve the efficiency of agricultural production.

Growth, yield and economics in summer groundnut sequenced with rice under different weed management options

Growth, yield and economics in summer groundnut sequenced with rice under different weed management options

Influence of Integrated Weed Management Practices on Yield and Yield Components of Chickpea in Southeastern of Ethiopia

The experiment was conducted on research field of Sinana Agricultural Research center and Goro sub site in the highlands of Bale, south eastern Ethiopia under rain fed conditions during main cropping season of 2018 and 2019 to evaluate the integrated effects of pre-emergence (Dual gold 960 EC), post emergence (Gallant super) herbicides and hand weeding frequencies on yield and yield components of chick pea. The experiment consisted of eight weed management options; sole dual gold 960 EC, dual gold 960 EC + one time hand weeding at two weeks after crop emergence, and dual gold 960 EC at four weeks after crop emergence, sole gallant super, gallant super and one time hand weeding, weedy check, one time hand weeding at two weeks after crop emergence and two times hand weeding at two and four weeks after crop emergence along with two varieties (Dhera and Habru) laid out in randomized complete block (RCBD) with three replications. Analysis of variance showed that a significant difference in number of branches per plant, biological yield (kg ha^-1), and grain yield (kg ha^-1) were observed on different herbicidal treatments and hand weeding at Sinana while at Goro significant effects of integrated weed management were observed on dry matter, plant height, biological yield, grain yield and harvest index. The remains parameters studied at both locations were no significant for the treatments studied. The highest net return obtained from the application of 1.5 lit ha^-1 dual gold 960 EC integrated with hand weeding at four weeks after crop emergence while the highest net return at Goro was obtained from two times hand weeding at two and four weeks after crop emergence and hence can be recommended for the end users. Moreover, similar experiments should be carried out in different cold and warmer regions of chickpea potential areas of the zone to confirm the present findings.

Influence of fertilizer application timing and reduced herbicide dosage on weed infestation and maize grain yield

A field trial was conducted in the southern Guinea savanna of Nigeria during 2018 and 2019 to determine the better time of fertilizer application and identify effective weed management options to manage weed infestation and increase maize grain yield. The treatments consisted of two fertilizer application timings and six weed control treatments. The experiment was a 2 x 6 factorial in a randomized complete block design and replicated three times. The fertilizer application at 0 and 6 weeks after seeding (WAS) was found better than application at 2 and 6 WAS in minimising weeds, however both the application timings had no significant influence on maize grain yield. The formulated ready-mixtures (RM) of metolachlor (373 g) + atrazine (375 g) at 1.5 kg/ha followed by (fb) one hoeing at 6 WAS, metolachlor (375 g) + atrazine (373 g) at 1.5 kg/ha fb nicosulfuron 0.03 kg/ha at 6 WAS, metolachlor + atrazine (RM) 1.5 kg/ha fb paraquat 0.7 kg/ha at 6 WAS and metolachlor + atrazine (RM) at 1.5 kg/ha fb 2,4-D (900 g) at 1.5 kg/ha significantly (p=0.05) reduced weed infestation by 89.3, 63.8, 48.2 and 39.8%, respectively. The use of metolachlor + atrazine (RM) 1.5 kg/ha fb one hoeing at 6 WAS, metolachlor + atrazine (RM) 1.5 kg fb nicosulfuron 0.03 kg/ha increased maize grain yield by 82.5 and 69.7%, respectively. These treatment combinations integrated with fertilizer timing application at 0 and 6 WAS may be used for efficient, economical and more eco-friendly management of weeds for increasing maize grain yield.

Weed management in finger millet in India- an overview

Eleusine coracana (L.) Gaertn (finger millet) is one of the most nutritious and major staple food in some states of India. Finger millet is cultivated by using broadcast seeding, row (drill) seeding, and transplanting. In this review, the weeds associated with finger millet in different parts of India are listed, information on reported weed management options in finger millet is synthesized and future weed management research needs are enumerated. Weeds smother the finger millet resulting in significant reduction in the yield by 5 to 70%. The critical period for weed competition in finger millet is the first 4–6 weeks from planting/seeding. Physical/mechanical methods such as hand weeding at 20 and 30 days after planting (DAP) or passing wheal hoe twice with one manual weeding were found to be equally effective. In majority of the studies, inter-cropping was found helpful in reducing weed population substantially. Pre-emergence application of bensulfuron-methyl + pretilachlor, butachlor, isoproturon and post-emergence application of 2,4-D, chlorimuron-ethyl either alone or in combination with other methods were found effective in managing weeds in finger millet. Future research needs are: continuous monitoring of weeds and their shifts, understanding weed ecology and biology, developing improved mechanical tools and weed competitive cultivars along with location specific cost-effective and eco-friendly weed management strategies.

Weed science as a new discipline and its status in some South Asian universities and colleges: examples from Bangladesh, Bhutan, Nepal and Pakistan

Abstract Agriculture is the most important sector of the economy and livelihood in South Asia. Of the many biotic stresses in agriculture, weeds pose a continuous threat and cause considerable yield losses in the major crops. In the past, ample human labour was available for weed management in South Asia. However, in recent years, there has been a steady decline in labour availability in this region due to migration to other better-paying sectors. Thus, farmers are rapidly adopting less labour-intensive, chemical weed control methods. Adoption of chemical control methods requires formal and nonformal education in herbicide mode of action, safety and weed biology. We emphasize that sound formal and nonformal education in weed science is thus a necessity for this region as adoption of herbicides increases. In this paper, we review existing problems with weeds, current weed management options, herbicide use trends and development of curricula in weed science in academic institutions in Bangladesh, Bhutan, Nepal and Pakistan. We emphasize that herbicide resistance management programmes need to be developed before it becomes a major problem in the region.

Financial comparisons of under‐vine management systems in four South Australian vineyard districts*

Conventional viticultural practice in Australia and elsewhere involves removal of under‐vine vegetation using herbicides or cultivation. Concerns over the long‐term effects of herbicides on soil health, evolution of resistant weeds and possible impacts on human health motivate the search for alternative weed management options. Industry‐supported trials on commercial vineyards in four South Australian regions investigated standard practices of straw mulch and bare earth created with herbicides, compared to under‐vine cover crops, focusing on soil health attributes (soil carbon, soil microbiological processes, etc.) and grape yields in 2016 and 2017. Measured yields with the Control (herbicide) treatment were combined with published district grape prices and yields over the 12‐year (2006–2017) period, defining multivariate distributions of gross revenues ($/ha). Assuming all treatments produce grapes of equal quality and price as the Control, our results showed median per‐hectare gross margins greater than the Control in the Barossa district, lower than Control in Riverland, and mixed results in Langhorne Creek and Eden Valley. Multi‐year risk profiles, based on decadal whole‐farm (50 ha) cash flows for each treatment, were calculated using Monte Carlo analysis, based on historical yield and price distributions. These risk profiles showed the under‐vine treatments may result in major differences in long‐term vineyard financial viability.

Allelopathy and allelopathic substances of mango (Mangifera indicaL.)

AbstractHomegarden, traditional agroforestry system in tropical and subtropical regions, sustains the availability of daily necessities. Mango (Mangifera indicaL.) is an essential tree in the homegardens and is used for multiple purposes such as food, folk medicine, fuel, timber, and apiculture. The interaction between mango and weeds or crops has been evaluated in terms of allelopathy and the evidence of the allelopathy accumulated in the literature over two decades. The leaf extracts and leachate of mango inhibited the germination and growth of several other plants species. Soil collected from mango orchard shows growth inhibitory activity. Residues of mango leaves also suppressed the growth of other plant species. Phytotoxic substances such as coumaric, vanillic, caffeic, cinnamic, gallic and protocatechuic acids, and methyl gallate and quercetin‐3‐O‐α‐glucopyranosyl‐(1 → 2)‐β‐D‐glucopyranoside were identified in mango leaves. Those compounds may be released into the soil through the leaf leachate and the decomposition of plant residues and they can inhibit the germination and the growth of neighboring plants as allelopathic substances. Therefore, the allelopathy of mango is potentially useful for the weed management options in homegardens and other agriculture settings to reduce commercial herbicide dependency.

Is Tillage a Suitable Option for Weed Management in Conservation Agriculture?

In Europe, conservation agriculture (CA) is currently challenged by higher weed pressure, potential glyphosate ban and reduced crop yield. Based on preliminary results and a critical analysis, we provide insights on how to assess the effect of introducing different levels of tillage intensity, after a long-term CA sequence, on weed communities and crop yield. The experiment compared three types of fallow management (ploughing (CT), reduced tillage (RT), no-till with glyphosate (NT)) on four fields after 17 years of no-plough, which ended with 7 years of CA. The introduction of tillage proved to be a major driver of weed communities before weeding (density, richness and composition) in winter wheat. Weed density and species richness before weeding was greatest in RT, intermediate in CT and lowest in NT. The number of grains per ear and crop yield increased with tillage intensity (+11% for RT, +31% for CT). We provide avenues for future research through detailed methods and key references. Differences in winter wheat productivity were possibly related to enhanced soil structure and increased mineralisation of soil organic matter. Potential benefits of occasional ploughing will depend on the density and composition of the newly upwelled weed seedbank, which will need to be assessed before implementing tillage. From a multicriteria perspective, the long-term benefits associated with CA could largely exceed short-term yield increases associated with occasional tillage. Future studies will need to characterize the impact of occasional tillage operations on the long-term multiperformance of CA systems.

Long-Term Effect of Cover Crops on Species Abundance and Diversity of Weed Flora.

Cover crops are gaining in popularity as an eco-friendly tool for weed control in organic and low-input agricultural systems. A 5-year study was carried out in a Mediterranean environment (Sicily, south Italy) to (1) quantify cover crop biomass production and (2) evaluate the effects on weed soil seed bank, aboveground biomass, species richness, species composition and associations between communities. Cover crop treatments included subterranean clover (Trifolium subterraneum L.) and spontaneous flora, both with and without burying dead mulch into the soil, compared to a conventional management treatment. Weed biomass was significantly reduced by subterranean clover, contrariwise to spontaneous flora, with season-dependent results. Cover crop biomass, which ranged from 44 to more than 290 g DW m−2, was negatively correlated to weed biomass. Moreover, subterranean clover decreased the size of the soil seed bank and species richness. Based on relative frequency, a low similarity was found between the conventional management and cover crop treatments. In addition, no significant differences in species composition across treatments were observed, whereas principal component analysis highlighted some associations. The results suggest that subterranean clover cover cropping is a good option for weed management in Mediterranean agroecosystems.

Eco-friendly weed management options for organic farming: A review

Weeds are the major biotic factor which cause significant reduction in crop yield. Weeds will compete with crop for nutrients, light, water etc. In accordance with weeds in organic production system, weeds as one of their most troublesome, time consuming and costly production problems. Application of high dose of inorganic herbicide led to more toxic accumulation besides causing degradation to the soil health, pollution of ground water table and extinct of natural enemies. Weeds are conventionally controlled by herbicides which led to herbicide persistence and resistance and shift of weed flora by alien weeds. So, organic weed management is much needed to exert higher crop productivity. In organic production weeds are be managed by use of clean seeds, composted manures and timely removal of weeds by cultural, physical, mechanical, thermal and biological means during critical crop-weed competition.

Flumioxazin soil persistence under plastic mulch and effects of pretransplant applications on strawberry

AbstractWeeds are managed in Florida strawberry production systems with plastic mulches, fumigants, and herbicides. There are limited post-transplant options to control weeds that emerge in the planting holes in the plastic-covered beds, but flumioxazin at 107 g ai ha−1 can be applied pretransplant under the plastic mulch to control broadleaf and grass weeds. Three research trials were conducted in Balm and Dover, FL, in 2017 and 2018 to evaluate tolerance of the strawberry cultivar ‘Radiance’ to flumioxazin rates ranging from 54 to 6,854 g ha−1 and to estimate herbicide persistence under the plastic mulch. Shoot damage was observed at 428 to 857 g ha−1 (4× and 8× the label rate, respectively), but a significant increase in the number of dead plants was not observed until the treatment rate was 857 g ha−1 at one site and 3,427 g ha−1 at a second site (8× and 32× the label rate, respectively). Berry yields were unaffected by rates lower than 857 g ha−1. Flumioxazin persisted throughout the growing season (approximately 150 d) with no reduction in soil concentration. We conclude that applied at the label rate, flumioxazin is a safe pretransplant weed management option for season-long weed control in strawberry with no yield reduction at rates below 8× the label rate. Caution is recommended for growers who plant a second crop on the same bed.

Transforming labor requirement, crop yield, and profitability with precision dry-direct seeding of rice and integrated weed management in Eastern India.

In many parts of Eastern India that have a very high prevalence of rural poverty and food insecurity, the prevailing rice establishment practice of 'beushening' is characterized by low yields and modest profitability, while labor and energy inputs are high. Beushening consists of broadcasting ungerminated rice seed at high rates (>100 kg ha-1) prior to the onset of monsoon rain, followed by ploughing at 4-6 weeks after crop emergence to control weeds with subsequent manual gap filling through seedling redistribution to ensure stand uniformity. Dry-direct seeding of rice (DSR), both drill-DSR and precision broadcast-DSR in combination with integrated weed management (IWM) may offer a pathway for simultaneously reducing costs and markedly increasing productivity. On-farm trials were conducted from 2016 to 2018 in four districts of Odisha (Mayurbhanj, Cuttack, Bhadrak, and Puri) to evaluate the yield and economic performance of dry-DSR (drill and precision broadcast), coupled with herbicide-based IWM strategies, in comparison with conventional beushening. Drill-DSR with IWM increased grain yield by 1.7 t ha-1 in Mayurbhanj and 1.3 t ha-1 in Cuttack, but not in Bhadrak, compared to beushening. The combination of increased yield and lower variable cost in drill-DSR increased net benefit by 550, 395, and 166 US$ ha-1 in Mayurbhanj, Cuttack, and Bhadrak, respectively. For farmers without access to seed drills, precision broadcast-DSR with IWM increased yields by 0.91, 1.22 and 0.60 t ha-1, and net benefits by 270, 312, and 188 US$ ha-1 in Mayurbhanj, Puri, and Bhadrak, respectively. Among the IWM practices evaluated in dry-DSR, application of pretilachlor + safener @ 500 g ai ha-1 as pre-emergence, followed by bispyribac-sodium @ 20 g ai ha-1 at 15-25 days after sowing as post-emergence, and then one spot hand weeding at 30-35 days after sowing was effective in controlling weeds. These results suggest that rice yield gaps in eastern India can be reduced, and farmers' income from rice can be increased by more than 50 % by replacing beushening with drill-DSR or precision broadcast-DSR. The results could be applicable to approximately 6.4 million ha of lowland rice where beushening is currently practiced in Eastern India.