Application Of Bispyribac-sodium Research Articles

Evaluation of different weed management practices on growth and yield of transplanted rice (Oryza sativa L.) in Northeastern Zone of Tamil Nadu

Weeds cause a 57 per cent yield loss in transplanted rice and an 82 per cent yield loss in direct seeded rice, resulting in a $4.20 billion monetary loss per year. Weed infestation, species richness, density, dry matter accumulation and duration of association significantly affects rice grain production. Therefore, a field experiment was conducted in farmer’s field in Thiruvennainallur village, Villupuram District, Tamil Nadu, India during Navarai season of 2021, in order to evaluate the different weed management practices on growth and yield of rice under transplanted conditions. The experiment was laid out in a randomized block design, having fourteen treatment and replicated thrice. Treatment consists of hand weeding, butachlor, pretilachlor, pyrazosulfuron ethyl, bispyribac sodium, fenoxaprop-p-ethyl, Triafamone + ethoxy sulfuron, metsulfuron methyl + chlorimuron ethyl and penoxsulam + cyhalofop butyl were used as herbicides. Among the different herbicides tried out, pre emergence application of pyrazosulfuron ethyl 10% WP @ 0.15 g/ha fb post emergence application of bispyribac sodium 10% SC @ 0.25 l/ha recorded least weed density (15.55, 29.56 m-2), weed biomass (8.25, 16.02 g/m2) with weed index (2.18 %) and highest weed control index (89.22%, 85.18%), plant height (97.21 cm), dry matter production (12735 kg/ha), number of productive tillers/m2 (349.23), grain yield (6416 kg/ha) and straw yield (7839 kg/ha). Sequential application of pre-emergence followed by post emergence enhance the reduction of weed leads to higher productivity of transplanted rice.

Effect of different herbicide spray volumes on weed control efficiency of a battery-operated Unmanned aerial vehicle sprayer in transplanted rice (Oryza sativa L.)

The effect of spray volume on weed control in transplanted rice ecosystems using the Unmanned aerial vehicle (UAV) needs to be better understood for management in the advancements of UAV-based spraying technology. The present study aimed to find out the influence of varied spray volumes of 15 L/ha, 20 L/ha and 25 L/ha using the UAV and 500 L/ha using a Knapsack sprayer (KS) to compare the weed density, weed dry matter and weed control efficiency and yield in transplanted rice (Oryza sativa L.). Pre-emergence (PE) application of Pyrazosulfuron-ethyl at 25 g a.i./ha at three days after transplanting (DAT) and post-emergence (PoE) application of Bis-pyribac sodium at 25 g a.i./ha at 25 DAT were used as herbicide treatments. The results revealed that varied spray volumes significantly influenced the weed density, dry matter, and weed control efficiency of the UAV and KS. Application of herbicides using KS (500 L/ha) and UAV (25 L/ha) had better control on the weeds by reducing weed density and dry matter at 20, 40, and 60 DAT, with no significant difference. Higher grain yield and straw yield were recorded in KS (500 L/ha) and UAV (25 L/ha), with no significant difference. However, applying 25 L/ha had better weed control efficiency and higher yield, possibly due to optimum deposition. Considering the low volume application of UAV (25 L/ha) as compared with KS (500 L/ha), it is better to go for the optimal application of 25 L/ha, which is an energy-efficient and cost-effective, labour-saving approach compared to KS.

Weed management in direct-seeded rice (Oryza sativa) in central India

A field experiment was conducted in a split-plot design with 3 replications at Research Farm, College of Agriculture, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur (Madhya Pradesh), during the rainy (kharif) season of 2019, to evaluate the performance of different herbicides in direct-seeded rice (Oryza sativa L.). The experiment comprised of 2 main plots, viz. rainfed and irrigated, and 8 weed-control treatments, viz. bispyribac sodium at 25 g/ ha, fenoxaprop-p-ethyl at 60 g/ha, fenoxaprop-p-ethyl + penoxsulam at 60 + 26.7 g/ha, cyhalofop + penoxsulam at 135 + 26.7 g/ha, bispyribac sodium + metsulfuron-methyl + chlorimuron ethyl at 25 + 4 g/ha, triafamone + ethoxysulfuron at 40 + 20 g/ha, hand-weeding twice and weedy check, in subplots. The dominant weeds associated with direct-seeded rice experimental field were mainly comprised monocot, viz. jungle rice [Echinochloa colona (L.) Link] and Bermuda grass [Cynodon dactylon (L.) Pers.], sedge, viz. nutgrass [Cyperus iria (L.)], and dicot weed such as sissoo spinach [Alternanthera sessilis (L.) R. Br. ex DC.]. The results indicated that, post-emergence application of bispyribac sodium at 25 g/ha at 20 days after sowing (DAS) recorded the highest weed-control efficiency (87.75%), followed by fenoxaprop-p-ethyl + penoxsulam at 60 + 26.7 g/ha. Higher grain yield (3.09 t/ ha) was recorded with weed-free treatment which was at par with bispyribac sodium at 25 g/ha.

Influence of Weed Management Practices on Growth and Yield of Aerobic Rice

The present field experiment was conducted to evaluate the effects of different chemical and non-chemical weed management practices on aerobic rice. The experiment was carried out at the Wetlands Farm of the Department of Farm Management, Tamil Nadu Agricultural University, India. Pre emergence (PE) application of pendimethalin (1.0 kg ha-1), EPOE of bispyribac sodium (25 g ha-1) and EPOE of chlorimuron ethyl + metsulfuron methyl (4 g ha-1) were the chemical weed management practices. Daincha intercropping (1:1) fb spreading on 30DAS, Cowpea intercropping (1:1) fb spreading on 30DAS, Coir pith mulching (5 tons ha-1) on 3 DAS, Shredded coconut waste mulching (5 tons ha-1) on 3 DAS along with the combination of mechanical and hand weeding were the non chemical weed management practices. Pre emergence (PE) application of pendimethalin (1.0 kg ha-1) on 3 DAS fb Early post emergence (EPOE) application of bispyribac sodium (25 g ha-1) on 20 DAS recorded significantly higher growth and yield attributes. Sequential application of pendimethalin and bispyribac sodium recorded 4128 kg ha-1 grain yield which was nearly 60 per cent increased over the weedy check. Coir pith mulching @ 5 tons ha-1 on 3 DAS recorded significantly lower grain yield (1840 kg ha-1) over the rest of the treatments.

Effect of single and tank-mix of selected herbicides on weed control and yield of lowland Rice (Oryza sativa L.) in Lafia, Nasarawa State of Nigeria

Abstract. A field experiment was conducted in 2018 and 2019 in Lafia, Nigeria to determine the effects of single and tank-mix of seven selected herbicides (bispyribac-sodium; cyhalofop-butyl; penoxsulam; pendimenthalin; propanil; thiobencarb) and their mixtures in lowland rice (Oryza sativa L.). Rice grain yield following the single application of bispyribac-sodium post emergence (POST), cyhalofop-butyl POST and penoxsulam POST averaged 30% and 47% greater than the nontreated control in 2018 and 2019, respectively. The application of cyhalofop-butyl plus bispyribac-sodium or thiobencarb plus bispyribac-sodium POST reduced weed density over nontreated control, ranging 98 to 100% in 2018 compared to 88 – 91% reduction in weed density achieved with the application of cyhalofop-butyl alone and the sequential application of PRE pendimenthalin fb POST propanil. Bispyribac-sodium plus cyhalofop-butyl application resulted in the highest rice yield (5.13 and 5.60 t.ha−1) in 2018 and 2019, respectively. Mixtures of bispyribac–sodium with chyhalofop-butyl showed no injury on rice, whereas increased efficacy on weed control as compared with the single application of bispyribac–sodium. We recommend bispyribac-sodium and tank-mixed combination with cyhalofop-butyl to provide a broad spectrum of weed control in lowland rice system in Nigeria.

Herbicidal weed-management options for dry direct-seeded rice (Oryza sativa) in North-Eastern Plains of India

A field experiment was conducted during the rainy (kharif) seasons of 2017 and 2018 at Regional Station of the ICAR-Indian Agricultural Research Institute, Pusa, Samastipur, Bihar, to study the effect of herbicides in controlling mixed weed flora in direct-seeded rice (Oryza sativa L.). The experimental results revealed that, the alone and sequential application of herbicides significantly reduced the weed density and biomass of complex weed flora. The growth and yield attributes, viz. plant height at maturity, effective tillers/m2 , 1,000grain weight, grains/panicle and panicle length, were significantly influenced by application of herbicides. Weed-free condition resulted in significantly highest grain yield (4.49 t/ha). Among different herbicidal treatments, application of pendimethalin @ 1,000 ml/ha followed by (fb) tank-mix application of bispyribac sodium (25 g/ha) + pyrazosulfuron (15 g/ha) resulted in higher plant height (110.7 cm), higher number of effective tillers (320.0/m2 ), grains/panicle (132.2), ear length (29.8 cm), grain yield (4.49 t/ha), net returns (` 70,600/ha) and benefit : cost ratio (1.67), which was superior to rest of the treatments. Application of pendimethalin (1,000 ml/ha) fb tank-mix application of bispyribac sodium (25 g/ha) + pyrazosulfuron (15 g/ha) significantly reduced the weed density (56.8/m2 ) and weed biomass (26.6 g/m2 ).

Impact of Weed Management Practices on the Weed Dynamics, Nutrient Uptake Pattern of Weeds and Direct Seeded Rice

Herbicide based weed management is the emerging and effective method for controlling the weed flora of direct seeded rice. Weed growth often has an impact on crop development by interfering with plant nutrients. A two-year weed experiment with twelve treatments was set up at the University of Agricultural Sciences in Bangalore, Karnataka, India to know the effect of weed management practices on weed and nutrient dynamics in direct seeded rice. Significantly lower total weed density and biomass was observed with bispyribac sodium 10 SC 40 g a.i. ha-1 as post emergence which recorded statistically at par values with bensulfuron methyl + pretilachlor 6.6 GR 660 g a.i. ha-1 as pre-emergence during both the years of study. The allelochemicals used in the study performed well over unweeded control but it was far less when compared with chemical herbicides. Nutrient uptake by the direct seeded rice (82.17, 31.76 and 68.83 kg ha-1 NPK in 2020 and 89.38, 38.84 and 75.62 ha-1 NPK in 2021, respectively) and grain yield (4.98 t ha-1 in 2020 and 4.99 t ha-1 in 2021, respectively) was also reported to be higher with bispyribac sodium 10 SC 40 g a.i. ha-1 as post emergence which was on par with bensulfuron methyl + pretilachlor 6.6 GR 660 g a.i. ha-1 as pre-emergence. As the nutrient uptake by the crop and weeds are negatively correlated, the same treatments have recorded lower nutrient removal by the weeds. Higher weed biomass and rapid nutrient removal by weeds had resulted in poor soil nutritional status in unweeded control compared to all other treatments. Application of bispyribac sodium 10 SC 40 g a.i. ha-1 as post emergence or bensulfuron methyl + pretilachlor 6.6 GR 660 g a.i. ha-1 as pre-emergence were considered to be best management practices for weed management under direct seeded rice.

Response of transplanted finger millet to weed management practices under sodic soil condition

Weeds are the major biotic constraints in finger millet production and account for 41 to 63% yield loss. Weed management through herbicides plays a major role in increasing productivity. The field experiment was conducted at Anbil Dharmalingam Agricultural College and Research Institute, Tamil Nadu Agricultural University, Tiruchirapalli during Kharif, 2018, to evaluate the weed management practices on the growth and yield of transplanted finger millet under sodic soil conditions. The experiment was laid out in Randomized Block Design (RBD) with ten treatments and three replications. The treatment comprised weed management practices with different herbicides and their combinations. The results revealed that the highest plant height, total number of tillers/m2, dry matter production, leaf area index and crop growth rate were registered in PE application of bensulfuron methyl at 60 g/ha + pretilachlor at 600 g/ha fb EPOE application of bispyribac sodium at 25 g/ha. The highest grain and straw yield was also registered in PE application of bensulfuron methyl at 60 g/ha + pretilachlor at 600 g/ha fb EPOE application of bispyribac sodium at 25 g/ha, and it was on par with hand weeding at 15 and 30 DAT. Hence, in transplanted finger millet under sodic soil, the application of PE bensulfuron methyl at 60 g ha-1 + pretilachlor at 600 g ha-1 fb EPOE bispyribac sodium at 25 g ha-1 was found to be the most viable option for effective weed control besides increased productivity and profitability.

Effect of new generation herbicides on mixed weed flora and yield of direct seeded rice (Oryza sativa L.)

A field experiment was conducted during the “Navarai” season of 2019 and 2020 at Experimental Farm of the Department of Agronomy, Annamalai University, Annamalai Nagar, to find out the effect of new generation herbicides on direct seeded rice (Oryza sativa L.). The herbicide used were pre-emergence application of pyrazosulfuron-ethyl 10% WP at 200 g ha-1, pre-emergence application of metsulfuran-methyl 10% + chlorimuron-methyl 10% WP at 20g ha-1, pre-emergence application of pretilachlor 50% EC at 1250 ml ha-1, Early post-emergence application of pretilachlor 6% + pyrazosulfuran-ethyl 0.15% G at 615g ha-1, Early post-emergence application of bispyribac-sodium at 300 ml ha-1. The experimental result revealed that the new generation herbicide has a significant influence on weed flora and yield attributes and yield of direct seeding rice. The result indicated that application of Bispyribac-sodium 10% SC at 300 ml ha-1 at 15 DAS + one Hand weeding at 30 DAS recorded the lowest weed population, weed dry matter production and higher weed control index (WCI) and yield. Then twice hand weeding at 15, and 30 DAS was next in order. The lowest weed control index and yield were recorded with un-weeded control.

Efficacy of new generation herbicides on weeds in direct seeded rice (Oryza sativa L.)

A field study was conducted during Kuruvai season of 2020 to evaluate the efficacy of new generation herbicides at Pattathikadu village, Karambakudi Taluk, Pudukkottai district, Tamil Nadu. Eleven treatments were evaluated in RBD design and replicated thrice. Early post emergence application of bispyribac sodium 10 % SC @ 200 ml ha-1 on 15 DAS fb hand weeding on 40 DAS suppressed both weed population (20.16 m-2)andweed dry matter production (33.59 kg ha-1) and recorded highest weed control index (90.70 %) at 60 DAS over unweeded check. Growth and yield attributes of ricewere significantly improved with early post emergence application of bispyribac sodium 10 % SC @ 200 ml ha-1 on 15 DAS fb hand weeding on 40 DAS. Growth attributes viz., plant height (48.80, 78.56 cm at 30, 60 DAS and 94.54 cm at harvest respectively), leaf area index at flowering stage (6.89), number of panicle m-2 (434.14), number of tillers hill-1 (26.21), dry matter production (6,946, 11,917 and 13,646 kg ha-1 at 30, 60 DAS and harvest respectively) and yield attributes viz., number of filled grain panicle-1 (94.14)and grain (6540 kg ha-1) and straw (8522 kg ha-1) yieldswere recorded under early post emergence application of bispyribac sodium 10 % SC @ 200 ml ha-1 on 15 DAS fb hand weeding on 40 DAS hence appeared to be a viable strategy for weed control in direct seeded rice.

Efficacy of new generation herbicides on weeds in direct seeded rice (Oryza sativa L.)

A field study was conducted during Kuruvai season of 2020 to evaluate the efficacy of new generation herbicides at Pattathikadu village, Karambakudi Taluk, Pudukkottai district, Tamil Nadu. Eleven treatments were evaluated in RBD design and replicated thrice. Early post emergence application of bispyribac sodium 10 % SC @ 200 ml ha-1 on 15 DAS fb hand weeding on 40 DAS suppressed both weed population (20.16 m-2)andweed dry matter production (33.59 kg ha-1) and recorded highest weed control index (90.70 %) at 60 DAS over unweeded check. Growth and yield attributes of ricewere significantly improved with early post emergence application of bispyribac sodium 10 % SC @ 200 ml ha-1 on 15 DAS fb hand weeding on 40 DAS. Growth attributes viz., plant height (48.80, 78.56 cm at 30, 60 DAS and 94.54 cm at harvest respectively), leaf area index at flowering stage (6.89), number of panicle m-2 (434.14), number of tillers hill-1 (26.21), dry matter production (6,946, 11,917 and 13,646 kg ha-1 at 30, 60 DAS and harvest respectively) and yield attributes viz., number of filled grain panicle-1 (94.14)and grain (6540 kg ha-1) and straw (8522 kg ha-1) yieldswere recorded under early post emergence application of bispyribac sodium 10 % SC @ 200 ml ha-1 on 15 DAS fb hand weeding on 40 DAS hence appeared to be a viable strategy for weed control in direct seeded rice.

Response of herbicides in different rice varieties under wet direct-seeded ecosystem

The present study was conducted to evaluate the imazethapyr tolerant variety with different weed management methods. A field experiment was conducted in the experimental farm of the Department of Rice, TNAU, Coimbatore, Tamil Nadu during rabi season 2020 in split plot design with three replications. The treatments in main plot consisted of nine rice varieties viz HTM-N 22, N 22, Anna (R) 4, CO 53, CO 51, ADT 53, ADT 37, ADT 43 and ADT 45. In sub-plot weed management methods included early post-emergence herbicide application of imazethapyr @ 75 g ai/ha at 30 DAS, early post-emergence herbicide application of bispyribac sodium @ 25 g ai/ha at 15-20 DAS, pre-emergence herbicide application of pretilachlor @ 0.75 kg ai/ha at 8 DAS followed by early post-emergence herbicide application of bispyribac sodium @ 25 g ai/ha at 20-25 DAS, hand weeding twice at 20 and 40 DAS and un-weeded check. There were marked variations in the effect of various weed management practices in direct-seeded rice. In weed management methods, pre-emergence herbicide application of pretilachlor @ 0.75 kg ai/ha at 8 DAS followed by early post-emergence herbicide application of bispyribac sodium @ 25 g ai/ha at 20-25 DAS effectively controlled the weeds in wet direct-seeded rice ecosystem. Among the varieties tested, HTM-N 22 and N 22 only survived with the early post-emergence herbicide application of imazethapyr @ 75 g ai/ha at 30 DAS. The varieties HTM-N 22 and N 22 can be utilised for rice breeding programme for the development of herbicide tolerant varieties.

Influence of Post Emergence Application of Herbicides on Growth, Yield and Economics of Dry Direct Sown Rice

The field trial was conducted on sandy clay loam soils of agricultural research station Ragolu, A.P. India during two consecutive Kharif seasons of 2015 and 2016 .The trial was conducted in Randomized Block Design with three replications and nine treatments Viz., T1- post emergence application of Bis-pyribac sodium @ 25 g ai/ha at 20 DAS fb Amine salt of 2,4 D @ 0.58 kg ai/ha at 40 DAS; T2- post emergence application of Bis-pyribac sodium @ 25 g ai/ha at 20 DAS fb metsulfuron methyl + chlorimuron ethyl (Almix) 4 g ai/ha at 40 DAS; T3- post émergence application Bis-pyribac sodium @ 25 g ai/ha at 20 DAS fb Ethoxysulfuron @ 20 g ai/ha at 40DAS ; T4- post emergence application Bis-pyribac sodium @ 25 g ai/ha at 20 DAS fb postemergence application of Fenoxaprop P ethyl with safenor (Rice star) @ 625ml/ha at 40 DAS ; T5- post emergence application Bis-pyribac sodium @ 25 g ai/ha at 20 DAS fb postemergence application of Cyhalofopbutyl @100 g ai/ha + amine salt of 2,4, D @ 0.58 kg ai/ha at 40 DAS; T6- post emergence application Bis-pyribac sodium @ 25 g ai/ha at 20 DAS fb Ethoxysulfuron @ 20 g ai/ha+ Fenoxaprop PEthyl with safenor (Rice star) @ 625ml/ha at 40 DAS; T7- Post emergece application of Penoxulam@ 25g ai/ha at 20 DAS fb amine salt of 2,4, D @ 0.58 kg ai/ha at 40 DAS ;T8- Two hand weedings at 20 & 40 DAS and T9- Weedy Check. The study in dry direct sown rice on weed management by herbicides revealed that, uncontrolled weed growth in dry direct sown rice reduced the grain yield by 46 to 54 percent. Post emergence application of Bis-pyribac sodium @ 25 g ai/ha at 20 DAS followed by Ethoxysulfuron @ 20 g ai/ha+ Fenoxaprop P Ethyl with safenor (Rice star) @ 625 ml/ha at 40 DAS resulted into taller plants, maximum number of tillers/m2, The highest dry matter production at harvest, more number of panicles/m2 filled grains/panicle, 1000 grain wt, higher grain yield (82-108 %t over weedy check) Straw yield besides higher gross returns net returns and B:C ratio among different herbicide treatments.

Cross-talk between cold and bispyribac-sodium on rice seedlings

The shifting of rice planting date to early spring improved weed control, which is important to achieve high yield. However, early planting date exposes rice seedlings to cold stress, slowing crop establishment and affecting herbicide selectivity. The objective of this study was determine the effects of cold stress and bispyribac-sodium application on rice seedlings’ gene expression and physiological patterns. The experiment was performed in greenhouse in a factorial arrangement, and treatments included: factor A – two planting dates: late September and early November; factor B consisted in bispyribac-sodium application at rate of 50 g ai ha−1 and untreated check. Bispiribac-sodium caused greatest injury to rice seedlings at the early planting date. Lipid peroxidation and total phenol accumulation was stimulated by low temperature but, was not affected by bispyribac-sodium application. Gene expression of OsSOD, OsCAT, OsAPX, OsDREB1A, OsCDPK13, OsCYP72A2, OsGSTL2 and OsGSTU10 were responsive to low temperature and presented upregulation when exposed to the herbicide, providing evidence of an interaction between temperature and herbicide applications. Cold stress likely affects herbicide metabolism and effect rice seedling e oxidation mechanism response to herbicide.

New generation post-emergence herbicides and their impact on arbuscular mycorrhizae fungal association in rice

To prevent weed invasion in direct seeded rice cultivation, several new generation post emergence herbicides viz. bispyribac sodium, flucetosulfuron, ethoxysulfuron, fenoxaprop-p ethyl, penoxsulam, fenoxaprop-p-ethyl plus ethoxysulfuron and cyhalofop‑butyl plus penoxsulam are widely used in sub-tropical rice ecosystems of Eastern India. The main objective of this study was to know whether application of above listed post emergence herbicides at recommended (n1) and double recommended dose (n2) has any negative impact on arbuscular mycorrhizal fungal (AMF) association in rice plants. Further, the effects of herbicides on soil microbial properties viz. microbial biomass carbon (MBC), fluroscein diacetate (FDA), dehydrogenase (DHA), acid phosphatase (AcP) and alkaline phosphatase (AkP) activities were analyzed using unsupervised and supervised learning methods. Results indicated that among different herbicides evaluated only application of penoxsulam significantly (p<0.05) reduced the AMF root colonization (58.0%) at recommended dose (n1) compared to only AMF (70.3%) application. Whereas, application of bispyribac sodium (both n1 and n2 dose) enhanced AMF sporulation (1100 spores/100g) and root colonization (86.68%) compared to other herbicides application. Unsupervised learning approaches through PCA found that application of bispyribac sodium enhanced both above ground plant growth responses and soil microbial properties, but penoxsulam had negative impact. But, the combined application of penoxsulam and cyhalofop‑butyl did not show any negative impact on AMF association in rice plants. This study concluded that selection of right type of post-emergence herbicides are very important to minimize the harmful effect or enhance AMF association in rice plants.

Behaviour of bispyribac sodium in soil and its impact on biochemical constituents of rice

ABSTRACT The present study evaluates the dissipation behaviour of bispyribac sodium in acidic soils and its effect on biochemical constituents of rice. Dissipation kinetics followed first-order kinetics and >75% of applied bispyribac sodium dissipated within 7 days after application. Half life of bispyribac sodium ranged from 4.06 to 13.93 and 3.19 to 11.95 days in 2016 and 2017, respectively at studied application rates. The amount of bispyribac-sodium adsorbed increased with increase in concentration of herbicide and log KF of bispyribac-sodium was 1.528 µg1−1/n g−1 ml1/n in studied silty clay loam soil. Terminal residues in rice grain were below the maximum residue limit (<0.01). Acetolactate synthase activity and total carotenoids decreases significantly as compared to control up to 30 days after bispyribac sodium application and thereafter it recovered with the passage of time. Total chlorophyll and total sugar content in rice leaves increased significantly and maximum increase was observed when treated with bispyribac sodium at 20 g ha−1. Quality parameters, i.e. total protein and total sugars were not significantly influenced by application of bispyribac sodium. The use of bispyribac sodium at studied application rate in rice crop is safe both in terms of crop quality and food safety.

Effect of Weed Management Practices and Fertilizer Levels on Crop Nutrient Uptake and Weed Nutrient Removal in the Hybrid Rice

Aim: Comparative evaluation of weed management practices and fertilizer levels on crop nutrient uptake and weed nutrient removal in the hybrid rice.&#x0D; Study Design: The experiment was laid out in split-plot design with weed management in main-plot and fertilizer levels in sub-plot and was replicated thrice.&#x0D; Place and Duration of Study: Experiment was performed during the kharif period of 2017 at the Research Farm, TCA, Dholi, Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur (BIHAR).&#x0D; Methodology: The experiment was performed with twelve treatments in a split plot design. The main plot comprised four different weed management practices and under the sub-plot there were three fertilizer levels. Rice hybrid “ARIZE-6444” was taken as the test variety. Observations of the crop and weeds during the experimental duration were recorded at regular intervals, to assess the probable relationship between growth attributes and the final yield. The significance of the treatment impact was examined by the F test.&#x0D; Results: Among weed management practices, maximum uptake by rice with respect to nitrogen (152.85 Kg/ha), phosphorous (45.79 Kg/ha) and potassium (187.13 Kg/ha) and minimum removal by weed regarding nitrogen (1.30 Kg/ha), phosphorous (0.54 Kg/ha) and potassium (1.85 Kg/ha) was recorded in treatment hand weeding twice which was observed statistically at par with Bispyribac-sodium @ 25 g/ha + Pyrazosulfuron @ 25 g/ha at 25 DAT.&#x0D; Among fertilizer levels, application of 150 per cent RDF registered the highest portion of nitrogen (130.52 Kg/ha), phosphorous (40.40 Kg/ha) and potassium (164.49 Kg/ha) uptake by rice crop and nutrient removal through weeds is nitrogen (10.65 Kg/ha), phosphorous (4.84 Kg/ha) and potassium (15.59 Kg/ha) of, and respectively.&#x0D; Conclusion: Among different weed management practices combined application of Bispyribac-sodium @ 25 g/ha + Pyrazosulfuron @ 25 g/ha at @) DAT or hand weeding twice (20 and 40 DAT) was found effective in controlling weeds and increase in the quality and quantity of rice. Among fertilizer levels application of 125% RDF was found effective in increase in the yield, nutrient content of the crop and substantially reduction of nutrients removed by weed in rice field.

Crop Establishment and Weed Control Options for Sustaining Dry Direct Seeded Rice Production in Eastern India

Dry direct seeded rice (DSR) has emerged as an economically viable alternative to puddled transplanted rice to address emerging constraints of labor and water scarcity and the rising cost of cultivation. However, wide adoption of DSR is seriously constrained by weed management trade-off. Therefore, the availability of effective weed control options is critical for the success and wide-scale adoption of DSR. A field study was conducted at ICAR-National Rice Research Institute, Cuttack, India, in the dry seasons of 2015 and 2016 to evaluate the performance of three crop establishment methods and five weed control practices on weed management, productivity, profitability and energetics of dry DSR. The results demonstrated that weed density and weed dry weight was lower in drill seeding than broadcast seeding by 26–36% and manual line-seeding by 16–24%, respectively, at 30 and 60 days after crop emergence (DAE). Among herbicides, post-emergence application (17 DAE) of azimsulfuron was most effective in controlling weeds compared to early post application of bispyribac-sodium and bensulfuron-methyl+pretilachlor. Weed competition in the weedy check treatment resulted 58% reduction in rice yield. Among establishment methods, drill-seeding was most profitable with US $ 685 ha−1 higher net income than broadcast seeding primarily due to higher yield. Among weed control treatments, azimsulfuron was most profitable resulting in US $ 160 and 736 ha−1 higher net income than weed free and weedy check, respectively. The specific energy was lowest for drill seeding among establishment method and azimsulfuron among weed control practices, suggesting lowest energy consumed in producing per unit of grain yield.

Effect of weed control measures on yield and economics of rice (Oryza sativa)

An on farm trial was conducted during the rainy (kharif) season of 2014-15 at eight locations (farmers’ field) of the district, to validate, refine and popularize the technology developed at Directorate of weed science, Jabalpur for managing weeds in rice (Oryza Sativa L.). Effectiveness of post emergence application of bispyribac sodium @ 25g/ha and azimsulfuron @ 35g/ha over pre emergence application of butachlor @ 2kg/ha and weedy check (farmer’s practices) was studied on yield and profitability of rice. Highest grain yield (5188kg/ha) of rice was recorded with the post emergence application of bispyribac sodium @ 25/ha followed by post emergence application of azimsulfuron @ 35 g/ha (4991kg/ha), pre emergence application of butachlor @ 2 kg/ha (4331 kg/ha) and weedy check (3544kg/ha). However, the highest net return of Rs. 68071/ha was fetched with the application of bispyribac sodium as post emergence followed by azimsulfuron as post emergence (Rs. 64013/ha), butachlor as pre emergence (Rs. 50547/ha) and unwedded control (Rs. 33527/ha).

Weed control in transplanted rice with post-emergence herbicides and their effects on subsequent rapeseed in Eastern India

Effective broad-spectrum herbicides are needed to address the issues of herbicide resistance and weed shifts in common cropping systems. A field experiment was conducted in 2016 and 2017 in West Bengal, India to compare the performance of three post-emergence herbicides (bispyribac-sodium; fenoxaprop-p-ethyl; penoxsulam) in monsoon rice (Oryza sativa L.) and their residual effects on succeeding rapeseed (Brassica rapa L.). Rice yield loss due to competition with Echinochloa colona (L.) Link, Leersia hexandra Sw., Cyperus iria L., Ludwigia parviflora L., and Monochoria vaginalis (Burm f.) C. Presl. Ex Kunth was 64% compared with weed-free control. Bispyribac-sodium 10% SC applied at 30 g a.i. ha−1 20 days after transplanting reduced weed density over the weedy control, ranging from 37% (M. vaginalis) to 87% (L. hexandra). Fenoxaprop-p-ethyl and penoxsulam applied, respectively, at 86 and 20 g a.i. ha−1 were effective in controlling grasses, but less effective against sedges and broadleaves. Bispyribac-sodium application resulted in highest rice yield (5.45 t ha−1), net return (Indian Rupees 42,677 ha−1), and benefit cost ratio (1.72). Bispyribac-sodium had neither adverse effect on soil microbes nor phytotoxic effect on rice and subsequent rapeseed. We recommend bispyribac-sodium for weed control in transplanted rice under rice-rapeseed system in eastern India.