On-farm research was conducted at Gouripur sub-district under Mymensingh district of Bangladesh during the boro (mid November-June) season in 2013-14 and 2014-15 to evaluate the performance of non-puddled rice cultivation with and without crop residue retention. The rice var. BRRI dhan28 was transplanted by two tillage practices viz., puddled conventional tillage (CT) and non-puddled strip tillage (ST) and at two levels of mustard residues, i.e., no residue (R0) and 50% residue (R50). The experiment was designed in a randomized complete block design with four replications. There were no significant yield differences between tillage practices and residue levels in 2013-14. But in the following year, ST yielded 9% more grain compared to CT leading to 22% higher BCR. Retention of 50% residue increased yield by 3% compared to no-residue, which contributed to 10% higher benefit-cost ratio (BCR). The ST combined with 50% residue retention yielded the highest grain yield (5.81 t ha-1) which contributed to produce the highest BCR (1.06).

This experiment carried out to determine the effects of using some alternative litter materials on the growth performance, litter conditions, airborne quality and health traits of broiler chickens, one hundred and eighty, 1 day old broiler chicks were reared for six weeks and housed in pens in six equal groups (3 replicates of 10 birds each).Wheat straw (control), wood shaving, rice hulls, corn stalks chips, chopped palm fiber and palm spines chips were used as litter materials in this the study.Wheat straw, wood shaving, rice hulls, corn stalks chips, chopped palm fiber and palm spines chips did not differ statistically for body weight, feed consumption, feed conversion ratio and survivability (p>0.05).However, body weight tended to increase on wood shaving and palm spines chips.Carcass weight and gizzard yield were significantly (p<0.001) higher for birds raised on corn stalks chips maintained approximately 10% lower moisture level in comparison to Wheat straw and wood shaving.The lowest bacterial counts and moisture content of used litter was found in corn stalks chips followed by palm spines chips, wood shaving, rice husk, wheat straw and chopped palm fiber.There was no statistically significant effect between type of litter on litter pH, litter temperature and body conformations.Depends on the price and availability palm spines can be used as litter material instead of wood shaving and wheat straw.In conclusion, corn stalks chips, chopped palm fiber and palm spines chips can potentially be used as alternative litter materials in New Valley for growing broilers.

When farmers first shift from conventional tillage (CT) to conservation agriculture (CA) practices, the control of weeds may be more difficult, due to the absence of tillage. However, continuous CA, over several years, may alter the weed seedbank. The nature of the weed seedbank changes over time, in intensively cropped rice-based rotations that are typical of the Eastern Gangetic Plain, are not well understood. Two on-farm CA experiments were sampled (in Beluapara after 3 years and Digram after 5 years) in Bangladesh for the effects of strip planting (SP) and bed planting (BP) at both the sites, plus no-tillage (NT) in Beluapara, and increased retention of the residue of previous crops (20% vs. 50%). The conventional tillage (CT) and 20% residue was the control treatment. The weed seedbank in 0–15 cm soil was quantified by assessing the emergence of weeds from soils collected from the field after irrigation, (Boro) rice in Digram and wheat in Beluapara, and they were allowed to emerge in trays in a shade-house experiment. The year-round count of emerged weeds at both the locations revealed the fewest number of weed species (especially broadleaf weeds), and the lowest weed density and biomass in SP, followed by CT, BP, and NT, with 50% crop residue mulch. Relative to CT, the SP, BP, and NT produced relatively more perennials weeds, as follows: Alternanthera denticulata ((R.) Brown.), Cyperus rotundus (L.), Dentella repens (L.), Jussia deccurence (Walt.), Leersia hexandra (L.), and Solanum torvum (Sw.), which was the opposite of CT that was enriched with the following annual weeds: Cyperus iria (L.), Digitaria sanguinalis (L.), Euphorbia parviflora (L.), Fimbristylis miliacea (L.), Lindernia antipoda (L.), L. hyssopifolia (L.), and Monochoria hastata (L.). The soil weed seed bank reduced by 13% in SP, while it increased by 19% and 76% in BP and NT, respectively, compared with CT. The species diversity reduced in SP and NT, by 24% and 11%, respectively, but increased by 2% in BP. In 50% residue, the soil weed seed bank and species diversity reduced by 16% and 14%, respectively, relative to that of 20% residue. The continuous practice of CA, for 3 or more years, in two rice-based crop rotations, decreased the size of the weed seedbank, but increased the relative proliferation of specific perennial weeds.

Exhaustive conventional tillage and removing residues of previous crops in the rice-based cropping system are labor intensive, costly, soil destructive and non-ecofriendly. In recent years, increased concerns for healthier food production and environmental quality, and increased emphasis on sustaining the productive capacity of soils, have raised concern in the maintenance and improvement of soil organic matter through appropriate land use and management practices. Strip tillage with the application of herbicides and crop residue mulching are being developed to overcome this challenge. A two-year experiment of the summer rice-mustard-winter rice (R-M-R) system was conducted at the farmers’ field in the northern Bangladesh during 2014-2016. Summer rice (BRRI hybrid dhan6), mustard (BARI Mustard 14) and winter rice (BRRI dhan28) were grown under, T1: Conventional tillage (CT) + three hand weeding (Control) and T2: Pre-plant herbicide (PRE) + strip tillage (ST) + pre-emergence herbicide (PE) + post-emergence herbicide (PO) with two levels of crop residue mulching, M0: no-mulch and M50: 50% standing mulch. The CT consisted of two primary tillage operations by a two-wheel tractor, and ST had done by a Versatile Multi-crop Planter in a single-pass process. The PRE (glyphosate) and PE (pendimethalin) in all crops and the PO (ethoxysulfuron-ethyl in rice and isoproturon in mustard) were applied at recommended dose and time. The combination of applied PRE, ST, followed by PE and PO herbicide and the retention of 50% mulch fetched the highest yield and economic returns of individual crop and the productivity of the summer rice-mustard-winter rice system.

When farmers first shift from conventional tillage (CT) to conservation agriculture (CA), weeds control may be more difficult due to the absence of tillage. However, in the longer term (3-5 years), CA changes to weed dynamics may alter the weed seedbank. The nature of weed seedbank changes over time in intensively cropped rice-based rotations typical of the Eastern Gangetic Plain of Bangladesh is not well understood. Three long term CA experiments were sampled (at Rajbari after three years and Rajshahi after five years) for effects of decreased soil disturbance strip planting (SP) and bed planting (BP) at both sites and Zero tillage (ZT) at Rajbari, increased retention of standing residues of previous crops (20 vs. 50%. The weed seedbank in 0-15 cm soil was quantified by assessing emergence from trays in a net-house experiment during January-December 2016. The year-round count of emerged weeds revealed the fewest number of weed species (especially broadleaf weeds) and lowest weed density in SP, followed by CT, BP, and ZT with 50% crop residues. The SP, BP, and ZT produced a higher number of perennials weeds than annual weeds, which was the opposite of CT. The continuous practice of SP and increased crop residue retention for three or more years decreased the size of weed seedbank but increased the relative proliferation of perennial weeds compared to CT. Weed seedbank size in SP was even smaller than BP and ZT.

A two year longer on-farm research on conservation agriculture was conducted at Bhangnamari area of Bangladesh during November-June in 2014-15 and 2015-16 to evaluate the performance of non-puddled rice cultivation under increased crop residue retention. The rice variety BRRI dhan28 was transplanted under puddled conventional tillage (CT) vs. non-puddled strip tillage (ST) with 50% standing residue (R50) vs. conventional no-residue (R0) practice. The treatments were arranged in a randomized complete block design with four replications. There were no significant yield differences between tillage practices and residue levels in 2014-15. But in the following year, ST yielded 9% more grain compared to CT leading to 22% higher BCR. Retention of 50% residue increased yield by 3% over no-residue, which contributed to 10% higher benefit-cost ratio (BCR). Results of this two year on-farm study confirmed that the ST combined with 50% residue retention yielded the highest grain yield (5.81 t ha-1) which contributed to produce the highest BCR (1.06).

Cropping under conservation agriculture (CA) has become increasingly attractive among farmers in recent years. However, weed control may be more difficult during the transition to CA from conventional establishment methods due to the reduction in tillage intensity. Conversely, CA changes to weed dynamics can alter the weed seed bank in the longer run. In Bangladesh’s intensively cropped rice-based rotations, the nature of weed seed bank shifts over time after adopting CA are poorly known. Two 2-year studies were sampled from on-farm CA experiments under wheat-mungbean-winter rice and monsoon rice-mustard-winter rice rotations. We investigated the effects of reduced soil disruption in the form of strip-tillage (ST) combined with increased deposition of standing reside from previous crops (0 vs. 50%). The weed seed bank in 0–5, 5–10, and 10–15 cm depths of soil were quantified in a shade-house experiment by measuring weed emergence over 12 months in seedling trays. After 2 years of field study, the year-round count of emerged weeds from the seed bank showed that ST plus 50% mulch had a lower weed abundance and biomass and fewer weed species than that of conventional tillage (CT) without residue. The perennial weeds Ageratum conyzoides L., Alternanthera philoxeroides L., Cynodon dactylon L., Cyperus rotundus L., Jussia decurrence Walt., Leersia hexandra L., Scirpus mucronatus (L.) Palla., and Solanum torvum Sw. were enriched in the smaller-sized ST seed banks in terms of both density and biomass. The CT, on the other hand, was dominated by annual weeds: Cyperus difformis L., Cyanotis axillaris Roem., Echinochloa crus-galli (L.) Beauv., Eleusine indica L., Fimbristylis miliacea (L.) Vahl., and Rotala ramosior L. Overall, ST plus 50% residue had a more diverse seed bank than CT without mulch. The majority of weed seeds were amassed in the 0–5 cm soil depth of the ST, while most of them were accumulated in the 10–15 cm layer of the CT. The wheat-mungbean-winter rice rotation had a more diverse floristic composition with many more weed species than the monsoon rice-mustard-winter rice rotation.

Crisis of agricultural laborers in South Asia’s rural zones is pushing to pursue a labor-saving conservation agriculture strategy for crop production and weed control. Non-puddled transplanting and mulching residues of the previous crop are being developed for rice-based cropping systems in Bangladesh to address this issue. Hence, the present study was undertaken to determine the effectiveness of strip tillage vs. conventional tillage combined with previous rice residues relative to herbicides and hand weeding on weed control and grain yield of winter rice during January-May in 2015 and 2016. Rice cv. BRRI dhan28 was transplanted with a combination of six treatments: puddled conventional tillage (CT)+3 hand weeding (HW) (Control); Preplant (PRE) herbicide (glyphosate)+non-puddled strip tillage (ST)+1HW; PRE+ST+pre-emergence (PE) herbicide (pendimethalin); PRE+ST+post-emergence (PO) herbicide (ethoxysulfuron-ethyl); PRE+ST+PE+PO; PRE+ST+weed-free (WF); and two levels of rice residues: no-residue (R0) vs. 50% standing residue (R50). The CT had done using a two-wheel tractor (2WT) by four ploughings and cross ploughings followed by levelling. A Versatile Multi-Crop Planter (VMP) was used for ST in a single pass operation. Over the two years, PRE+ST+PE+PO reduced weed density by 40% in the first year and 50% in the second year and weed biomass by 70% than CT+3HW in both years. Retention of 50% residue reduced weed density by 20% and biomass by 34%. The highest grain yield (12% higher than CT+3HW without residue) was obtained from PRE+ST+WF with 50% residue, while the highest BCR (47% higher over CT+3HW without residue) was obtained from PRE+ST+PE+PO with 50% residue.

Labour shortage is pushing the smallholder farms to seek for labour saving strategies for planting and weed control. With this point of view, this study was undertaken to determine the effectiveness of mulching from previous crop relative to herbicides and hand weeding on weed control and grain yield of rice transplanted in non-puddled soil after mustard in the northern Bangladesh during January to May in 2014 and 2015. Rice cv. BRRI dhan28 was transplanted with a combination of six weed control practices [Conventional tillage (CT)+3 hand weeding (HW) (Control); Glyphosate (Gly)+strip tillage (ST)+1HW; Gly+ST+pre-emergence (PE) herbicide (pendimethalin); Gly+ST+post-emergence (PO) herbicide (Ethoxysulfuron-ethyl); Gly+ST+PE+PO; and Gly+ST+weed-free (WF)], and two levels mulch of previous mustard [M0: no mulch and M50: 50% mulch (875 kg ha-1). Over the two years, CT produced 30% higher weed density and 40% higher weed biomass than ST. Spraying herbicides at PE followed by at PO in ST reduced weed density by 45% and weed biomass by 70%. Retention of 50% mulch reduced weed density by 20% and biomass by 34%. The combination of applied glyphosate, ST, followed by sequential application of PE and PO herbicides and the retention of 50% mulch achieved the highest weed control efficacy. Furthermore, this practice produced the 12% higher yield and 47% higher economic returns relative to manual weed control in conventional tillage. These results demonstrate the value of mulch integrated with pre-plant, PE and PO herbicides in controlling weeds and improving grain yield and return of rice transplanted in a non-puddled soil.

Weed seeds are introduced to agronomic systems naturally or through human-mediated seed dispersal, and introduced seeds have a high chance of being resistant to selective, in-crop herbicides. However, colonisation (invasion) rates for a weed species are usually much lower than rates of seed dispersal. The current research investigated colonisation of a winter annual wheat cropping system in Western Australia by a range of winter or summer annual weed species. The weed seeds were sown (at 100 seeds/m(2)) directly before seeding the crop in 2016 and allowed to grow in the following 3 years of wheat. Selective herbicides were not applied, to simulate growth of weed populations if the initial seed had been resistant to herbicide. Bromus diandrus, Hordeum leporinum, Rumex hypogaeus, Sonchus oleraceus, Polygonum aviculare, Lolium rigidum, Citrullus amarus and Tribulus terrestris colonised the crop, while Dactyloctenium radulans, Chloris truncata and Salsola australis failed to establish over 3 years. The most successful weed was B. diandrus, with a plant density of 1,170/m(2) by the third year and seed production of 67,740/m(2). The high density of B. diandrus reduced wheat density by 76% in the third year and reduced average yield by 36%. Lolium rigidum reduced average yield by 11%, and the other weed species did not affect crop yield. Further research is required on the invasiveness of these species in other regions, but it is clear that the spread of B. diandrus to new areas or the introduction of resistant B. diandrus seeds via contaminated grain should be avoided.

Development of integrated weed management strategies is dependent on a thorough knowledge of the demography of individual species. The current research established eight winter or summer weed species in a winter annual wheat cropping system at Wongan Hills, Western Australia, and investigated emergence of the first cohort of each species, survivorship, plant size, seed production and seed shedding over three years (2016-2019). The winter weedsBromus diandrusandLolium rigidumemerged at the same time as the wheat crop, and the initial cohort of marked plants had 100% survival to seed production in each year. By comparison, other winter weed species likeHordeum leporinum,Rumex hypogaeus,Sonchus oleraceusandPolygonum avicularefrequently emerged later than the crop and had a lower percentage of plants surviving to seed production. However, individualS. oleraceusandP. aviculareplants had the greatest seed production compared to other species. All winter weeds had variable patterns of seed shedding between years, with the exception ofL. rigidum. Summer weed species emerged at the same time, but plants in the initial cohort of each species did not always survive to produce seed. The early emergence and high survivorship ofB. diandrusindicates high competitive ability, but shedding commenced at a similar time toL. rigidumand harvest weed seed control may be a viable control method for this species.

On-farm research was conducted at Gouripur sub-district under Mymensingh district of Bangladesh during boro (mid November-June) season in 2013-14 and 2014-15 to evaluate the performance of unpadded rice cultivation with crop residue retention. The rice var. BRRI dhan28 was transplanted by two tillage practices viz., puddled conventional tillage (CT) and non-puddled strip tillage (ST) and two levels of mustard residues, i.e., no residue (R0) and 50% residue (R50). The experiment had designed in a randomized complete block design with four replications. There were no significant yield differences between tillage practices and residue levels in 2013-14. But in the following year, ST yielded higher grains (5.72 t ha-1), which was about 9.36 % higher compared to CT. The higher grain yield in ST, leading to 22.23% higher BCR compared to CT. Retention of 50% residue increased by 3.15 % yield compared to no-residue, which contributed to 10.58 % higher benefit-cost ratio (BCR). The ST combine with 50 % residue retention yielded the highest grain yield (5.81 t ha-1) which credited to obtain the highest BCR (1.06).

—Crisis of agricultural labors in the rural areas is pushing the smallholder farms in South Asia to seek for a mechanized planting system together with crop residue mulching and the application of herbicides. The present on-farm study was undertaken to determine the effectiveness of residue mulching relative to herbicides and manual weeding by hands for controlling weeds and yield of mungbean in strip planted soil in northern Bangladesh. In this experiment, mungbean cv . BARI Mungbean 6 was grown after wheat during the April-June in 2015 and 2016, under two tillage types combined with the two weed control practices [P 1 : conventional tillage (CT) + three hand weeding, P 2 : Pre-plant (PRE) herbicide + strip planting (SP) + pre-emergence (PE) herbicide + post-emergence (PO) herbicide]; and two levels of wheat straw mulch [M 0 : no-mulch and M 50 : 50% standing mulch]. The CT was done by two primary and two secondary tillage operations by a two-wheel tractor, while the SP was done by a Versatile Multi-crop Planter in a single-pass process. The PRE herbicide (glyphosate), PE herbicide (pendimethalin) and PO herbicide (fenoxaprop-p-ethyl) was applied at recommended doses. The combination of applied PRE, SP, followed by sequential application of PE and PO herbicides plus retention of 50% wheat straw mulch achieved the highest weed control efficacy. Furthermore, this practice produced the 21% higher yield and 62% higher profit relative to conventional tillage with three hand weedings without mulch.

Agronomic surveys of summer weed species are necessary to identify future research directions for optimal weed control, but usually focus on agricultural fields in a single season. To survey all species in the absence of weed control measures and determine species variability between seasons, a survey of 133 sites was conducted on roadsides adjoining agricultural fields throughout the Western Australian grainbelt in early 2015 and repeated in 2016 and 2017. The survey identified 144 species, but only 19 species were evident at more than 10% of sites. The most common species were weeping lovegrass [ Eragrostis curvula (Schrad.) Nees], fleabane ( Erigeron sp.), windmillgrass ( Chloris truncata R. Br.), and wild radish ( Raphanus raphanistrum L). The survey highlighted that weed species incidence varied between years. For example, C. truncata incidence was 30% in 2015 and 55% in 2016, while stinkgrass [ Eragrostis cilianensis (All.) Vignolo ex Janch.] ranged from 20% in 2015 to 50% of sites in 2017. Conversely, density of individual species on the roadside was usually low, and density remained consistent between years. The survey highlighted multiple weed species that will require further research to optimize management programs. Raphanus raphanistrum and wild oat ( Avena fatua L.) in particular are an issue for growers, as these species are highly detrimental winter weeds, and the survey demonstrates that they can also be common summer weeds. Control of these species with nonselective herbicides in summer as well as winter is likely to exacerbate the development of herbicide resistance.

Non-puddled transplanting is a promising establishment technique for rainy season rice. A study was carried out at Mymensingh, Bangladesh in transplanted rainy season rice to evaluate weed control efficiency of pyrazosulfuron-ethyl alone or in sequential application with post-emergence herbicide under non-puddled strip-tilled field condition. Residual effects of those herbicides were also examined on germination and growth of the subsequently grown crop in rice-wheat cropping pattern. Seven treatment combinations comprised of four herbicides, 1 pre-emergent (PEM): pyrazosulfuron-ethyl, 1 early post-emergent (EPOST): orthosulfamuron, and 2 late post-emergent (LPOST): butachlor plus propanil and 2,4-D amine, along with one weedy check and one weed-free check were tested. Grasses and sedges were the major weeds in non-puddled strip-tilled rice with Cynodon dactylon (L.) Pers. the most dominant species. Herbicide treatments provided a wide range of control (above 50–95%) on all types of weeds. Sequential application of PEM with EPOST or LPOST or both offered higher weed control than sole application of PEM by 27–65%. Pyrazosulfuron-ethyl (PEM) followed by (fb) orthosulfamuron (EPOST) fb butachlor plus propanil (LPOST) gave the most effective weed control as well as maximum rice grain yield. Moreover, bioassay study showed that tested herbicides had no adverse effect on germination and growth of the next season wheat crop. Therefore, the study suggests sequential application of pyrazosulfuron-ethyl with post-emergence herbicide(s) in any of the tested combinations to attain the optimum rice yield, however rotational use of herbicides along with maintaining appropriate rates and timing needs to be strictly followed to obtain maximum benefit.

In recent years, common sowthistle (Sonchus oleraceus) infestation has increased along the roadsides of Western Australia (WA) (Hashem et al 2016, Borger et al 2017). Common sowthistle, also known as milk thistle, is widespread across the grain-growing regions of Queensland and northern New South Wales (Widderick and Walker 2009). The increase in sowthistle is thought to be related to changes in Australian farming systems including a trend for growers to reduce the number of tillage operations and rely more on herbicides for weed control. The technique of ‘DoubleKnock’; glyphosate followed by paraquat is effective on sowthistle at various stages. However, sowthistle may survive and produce seed when treated with only a single application of herbicide(s). The ability of sowthistle to emerge and grow during both summer and winter is of great concern for winter grain crops in WA. In the eastern states of Australia, 23 populations of sowthistle have developed resistance to glyphosate (Preston 2018). Given the recent widespread occurrence of sowthistle along the roadside across the grain growing areas of WA, it is necessary to assess sowthistle populations for resistance to glyphosate and the potential to reduce seed production should the weed survive herbicide application.

Development of efficient farm machinery and availability of effective herbicides have resulted the higher profitability in conservation agriculture (CA) that in turn has been identified as an effective tool for sustainability of agriculture (Farooq et al., 2011). But weed species shifts and losses in crop yield caused from increased weed density have been cited as major hurdles of CA adoption (Dahal and Karki, 2014). Crop yields in CA can be similar to conventional systems if weeds are controlled (Chauhan et al., 2012). The availability of pre-plant, pre-emergence and post-emergence herbicides provides an opportunity to control weeds in CA. But weed control strategies adopted must reduce the development of herbicide resistance by weeds. The presence of crop residues on the soil surface may reduce weed infestation by affecting weed seed germination and emergence patterns. Considering the above facts, this on-farm experiment was conducted to examine the performance of strip tillage, residue mulching and weeding regimes on crop yield and weeds.

BACKGROUND: Sensitivity of crop cultivars may vary to commonly used herbicides resulting in potential yield loss and reduce farm profit. Transplanting of rice seedlings in strip-tilled non-puddled field is a new practice for which herbicide tolerant varieties need to select. Therefore, a study was executed at the Agronomy Field Laboratory of Bangladesh Agricultural University, Mymensingh during 2013 to evaluate the response of some popular transplanted aman rice varieties to different herbicides at their recommended rate and to select most tolerant aman rice variety or varieties for strip-tilled non-puddled transplanting. METHODOLOGY: Twelve aman rice varieties (BR11, BRRI dhan33, BRRI dhan39, BRRI dhan44, BRRI dhan46, BRRI dhan49, BRRI dhan51, BRRI dhan52, BRRI dhan56, BRRI dhan57, BRRI hybrid dhan-4 and BINA dhan7) were examined in the study against six herbicides (2 pre-emergence: pyrazosulfuron-ethyl and butachlor; 1 early post-emergence: orthosulfamuron and 3 late post-emergence: acetochlor + bensulfuron methyl, butachlor + propanil and 2,4-D amine) along with one untreated manually weed-free control. KEY FINDINGS: The study revealed that aman rice varieties responded differentially to different herbicides. All rice varieties performed better in pyrazosulfuron-ethyl treated plots relative to the other herbicide treated plots and even than the control plots. Pyrazosulfuron-ethyl increased grain yield of all aman rice varieties by 0.6-32.6% over control and butachlor + propanil provided increased grain yield in all rice varieties by 2.0-25.5% except BRRI hybrid dhan-4. The study also disclosed that BRRI dhan57 and BRRI hybrid dhan-4 gone through the yield loss by application of 2,4-D amine and BRRI dhan56 by application of butachlor and orthosulfamuron. Moreover, acetochlor + bensulfuron methyl produced shorter plants and caused yield loss by 7.8-27.1% in all aman rice varieties compared to the control and BRRI dhan39 was the most susceptible variety to this herbicide. CONCLUSION: Therefore, the study concluded that all transplanted aman rice varieties were tolerant to the recommended rate of pyrazosulfuron-ethyl. BRRI dhan33, BRRI dhan46, BRRI dhan51 and BINA dhan-7 were the tolerant aman rice varieties for strip-tilled non-puddled transplanting. All over, this study demands that breeder should undergo the herbicide sensitivity test before release of rice varieties. [Fundam Appl Agric 2017; 2(3.000): 303-310]