Post-emergence herbicides efficacy for weed managment in kharif maize

Not AvailableThe escalating labour prices have significantly increased the production cost of kharif maize in India. To addressthis, a field experiment was conducted (2017) to evaluate the efficacy of post-emergence herbicide in kharif maize(Zea mays L.) at ICAR-Indian Institute of Maize Research, Pusa Campus, New Delhi. The tank-mix post-emergenceherbicide application, viz. tembotrione (120 g/ha) or topramezone (25.2 g/ha) at 15 DAS with 75% atrazine (750 g/ha) or as a sequential application at 25 DAS after pre-emergence (PE) 75% atrazine gave significant weed control inkharif maize by reducing density and dry weight. Significantly higher weed-control efficiency, weed-control index,herbicide efficiency index and lower weed persistence index were found in weed-free check, which was at par withPE atrazine (1000 g/ha) followed by hand weeding at 25 DAS and the post-emergence herbicide application oftembotrione (120 g/ha) /topramezone (25.2 g/ha) as tank-mix with 75% atrazine dose as early post-emergence at 15DAS or as the sequential application of these combinations. Significantly lowest weed index was observed in thesequential application of tembotrione/topramezone at 25 DAS after 75% atrazine dose as PE while the highest weedindex (49.3) with alone halosulfuron application. It was concluded that the application of post-emergence herbicide,viz. tembotrione (120 g/ha) /topramezone (25.2 g/ha) as tank-mix at 15 DAS with 75% dose of atrazine (750 g/ha)or as a sequential application at 25 DAS after 75% atrazine as PE found promising for better weed control and grainyield in kharif maize.Not Availabl

Association of a novel mutation in the plasmodium falciparum chloroquine resistance transporter with decreased piperaquine sensitivity

Background. Amplified copy number in the plasmepsin II/III genes within Plasmodium falciparum has been associated with decreased sensitivity to piperaquine. To examine this association and test whether additional loci might also contribute, we performed a genome-wide association study of ex vivo P. falciparum susceptibility to piperaquine. Methods. Plasmodium falciparum DNA from 183 samples collected primarily from Cambodia was genotyped at 33 716 genomewide single nucleotide polymorphisms (SNPs). Linear mixed models and random forests were used to estimate associations between parasite genotypes and piperaquine susceptibility. Candidate polymorphisms were evaluated for their association with dihydroartemisinin- piperaquine treatment outcomes in an independent dataset. Results. Single nucleotide polymorphisms on multiple chromosomes were associated with piperaquine 90% inhibitory concentrations (IC90) in a genome-wide analysis. Fine-mapping of genomic regions implicated in genome-wide analyses identified multiple SNPs in linkage disequilibrium with each other that were significantly associated with piperaquine IC90, including a novel mutation within the gene encoding the P. falciparum chloroquine resistance transporter, PfCRT. This mutation (F145I) was associated with dihydroartemisinin-piperaquine treatment failure after adjusting for the presence of amplified plasmepsin II/III, which was also associated with decreased piperaquine sensitivity. Conclusions. Our data suggest that, in addition to plasmepsin II/III copy number, other loci, including pfcrt, may also be involved in piperaquine resistance

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Not AvailableTopramezone, halosulfuron and tembotrione are the selective, post-emergence herbicides that have been recently introduced for use in maize. These provide an easy option for herbicidal-based weed management in maize especially late in the season which is the critical period of crop-weed competition. The experiment was conducted to understand the effect of post-emergence herbicides on weed dynamics and crop growth of maize as well as the effect of post-emergence herbicide application on yield and economics of maize. The treatments were T1:Weedy check, T2: Weed free check, T3: Atrazine 1000 g/ha (PE) fb hand weeding at 25 DAS, T4: Topramezone 30 g/ha at 25 DAS, T5: Halosulfuron 75 g/ha at 25 DAS , T6: Tembotrione150 g/ha at 25 DAS, T7: Topramezone 25.2 g/ha + atrazine 750 g/ha at 15 DAS ,T8: Halosulfuron 67.5 g/ha + atrazine 750 g/ha at 15DAS, T9: Tembotrione 120 g/ha + atrazine 750 g/ha at 15 DAS, T10: Atrazine 750 g/ha (PE) fb topramezone 25.2 g/ha at 25 DAS, T11: Atrazine 750 g/ha (PE) fb halosulfuron 67.5 g/ha at 25 DAS, T12: Atrazine 750 g/ha (PE) fb tembotrione 120 g/ha at 25 DAS. It was concluded that the application of post emergence herbicide viz., tembotrione (120 g/ha)/topramezone (25.2 g/ha) as tank-mix as early post-emergence at 15 DAS with 75% recommended dose of the atrazine (750 g/ha) or as sequential application at 25 DAS after 75% atrazine as PE may be adopted for better weed control, higher yield and net return in kharif maize.Not Availabl

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Not AvailableGiven the increasing scarcity of production resources such as water, energy and labor compounded by growing climatic risks – maize based production systems in north - western India are potential alternatives to intensive rice - wheat (RW) rotation. Conservation agriculture (CA) based best - bet crop management practices may increase crop productivity, while conserving and sustaining natural resources. Such practices are also believed to provide mitigation co - benefits through reduced GHG emission and increased soil carbon sequestration. In a nine - year study of conservation agriculture experiment established in 2008, we have evaluated the performance of CA - based management practices [zero tilled permanent bed (PB) and zero tillage flat (ZT)] and conventional till flat (CT) in main plots for four intensified irrigated maize systems [maize - wheat - mungbean (MWMb), maize - chickpea - Sesbania green manure (MCS), maize - mustard - mungbean (MMuMb) and maize - maize - Sesbania (MMS)] in sub plots. The experimental design was split - plot with three replications. Significant (P<0.05) tillage and cropping system interactions were observed for cropping system productivity and carbon dynamics. Agronomic performance (yield attributes) of all the crops (except wheat) grown in sequence with maize was maximum with ZT. Wheat outperformed on PB over ZT and CT. In the initial two years, higher system productivity (maize equivalent yield) was recorded in PB (8.2 - 8.5 Mg ha - 1). The soil organic carbon (SOC) content and its fractions were greatly affected by tillage, and crop establishment methods and cropping systems. The ZT and PB based crop establishment methods increased more SOC stock (0−30 cm) than CT system compared to initial value.Not Availabl

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Not AvailableThe maize-wheat-mungbean (MWMb) cropping system is being advocated as an alternative to the traditional rice-based cropping systems of north-western Indo-Gangetic Plains (IGP) to address the issues of energy and nutritional scarcity, residue burning, decline in biomass productivity and water tables. In semi-arid regions, the climate-change-induced variability in rainfall and temperature may have an impact on phenological responses of cereals and pulses which in turn would affect biomass production, economic yield and energy and water-use efficiency (WUE) of the crops. Henceforth, quantification of bioequivalent yields, energy requirement, economics and WUE of MWMb system is essentially required owing to have better understanding of this cropping system. Following a 5-year study was conducted under different tillage, crop establishment methods and balanced nutrient management practices showed that MWMb system productivity was recorded highest in zero till permanent (PB) plots and lowest in conventional tilled (CT) plots. PB and ZT plots registered 18.3% and 22.3% higher 5-year pooled MEY compared to CT-Control, respectively. Similar to tillage effects the nutrient management effect on MEY of MWMb rotation was also significant (P< 0.05) for all the 5-years where significantly higher yield was obtained in site specific nutrient management (SSNM) plots compared to other nutrient management plots. Tillage and nutrient management practices also had significant (P<0.05) effect on MWMb system pooled average water use efficiency and economics in 5-years of study. The year-wise cost of cultivation for different crops in MWMb system was almost similar in PB and ZT but was lower than CT plots. PB and ZT plots registered maximum MWMb system pooled average WUE (1.019 -1.131 US$net returns/ha-mm), net returns (US$ 1819-1891/ha) and benefit cost ratio (1.68-1.73), respectively. Similar to tillage effects, the nutrient management also significantly (P<0.05) affected the MWMb system pooled average WUE and economics. Significant (P<0.05) increase in MWMb WUE and economics was recorded in SSNM and RDF for pooled average system WUE (30-35%), net returns (31-38%), and BC ratio (31- 32%), compared to FFP treatments, respectively. However, SSNM and RDF nutrient management treatments remained statistically at par with respect to system WUE, net returns and BC ratio. Thus, adoption of conservation tillage (ZT/PB) practices with improved balanced nutrient management (SSNM/RDF) could be a viable option for achieving higher biomass productivity, water and energy-use efficiency and profitability in MWMb system.Not Availabl

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Not AvailableA greater energy grant in diesel - fedmachinery driven farming substantiate the higher GHGs emission alongwith improper input (fertilizer, pesticide and irrigation) use and intensive soil management. Practicing conservation tillage, residue retention and diversified crop rotations were advocated because of their multiple benefits. Hence we explored the energy requirement and carbon footprint of conservation agriculture (CA) based maize production systems. CoatedNfertilizer [sulphur coated urea (SCU) and neemcoated urea (NCU)]were compared with unfertilized and uncoated prilled urea (PU) in the scenario ofwith andwithout residue retention on permanent beds (PB) under diversified maize systems [MMuMb, maize - mustard - mungbean and MWMb, maizewheat - mungbean] in search of a sustainable and energy efficient production systemwith lesser C - footprint. Results of the 4 - year study showed that crops planted on permanent bed with crop residue (PB+R) registered 11.7% increase in system productivity compared to PB without residue (PB−R). N management through Neem coated urea (NCU) recorded 2.3 and 10.9% higher system productivity compared with non - coated prilled urea plot under PB−R and PB+R, respectively. MMuMb was marginally superior than MWMb system in terms of cropping sequence yield, profitability, and energy and carbon use efficiency. Crop residue retention in zero tilled PB increased cost of cultivation by 125 and 147 USD/ha inMMuMb andMWMb systems, respectively. The quantified carbon footprint value was higher in MWMb system. In CA - based practices, crop residues management contributed the highest energy input (61.5–68.4%) followed by fertilizer application (17–20%). Among N management practices, neem coated urea (NCU) significantly improved system productivity and profitability in all the residue applied plots compared to un - fertilized and prilled urea (PU) applied plots. Similarly, higher energy outputwas also observed inNCU treated plots. However, carbon footprint valuewas higher in PU (268–285 CO2 - e kg/Mg) plots than NCU (259–264 CO2 - e kg/Mg) treated plots. Thus, the study supports and recommends that the CA - basedMMuMb system with efficient N management through NCU is an environmentally safe, clean and energy efficient one, hence can reduce carbon footprint, will ensure food security and will mitigate climate change.ICARNASF-ICA