The rice–wheat cropping system (RWCS) is the backbone of Indian farming, especially in the north-western region. But continuous adoption of the RWCS in northwest India has resulted in major challenges and stagnation in the productivity of this system. Additionally, the Indo-Gangetic Plains of Pakistan, Nepal, and Bangladesh are also facing similar challenges for sustainable production of the RWCS. Several emerging problems, such as the exhausting nutrient pool in soil, deteriorating soil health, groundwater depletion, escalating production cost, labor scarcity, environmental pollution due to crop residue burning and enhanced greenhouse gas emissions, climatic vulnerabilities, and herbicide resistance in weed species, are a few major threats to its sustainability. To address these challenges, a wide range of sustainable intensification technologies have been developed to reduce the irrigation and labor requirements, tillage intensity, and straw burning. Awareness and capacity building of the stakeholders and policy matching/advocacy need to be prioritized to adopt time- and need-based strategies at the ground level to combat these challenges. This review summarizes the current status and challenges of the RWCS in the northwest region of the country and also focuses on the precision management options for achieving high productivity, profitability, and sustainability.
Herbicide resistance in weeds is a global threat to sustaining food security. In India, herbicide-resistant Phalaris minor was the major problem in wheat for more than two decades, but the continuous use of metsulfuron-methyl (an ALS inhibitor) to control broadleaf weeds has resulted in the evolution of ALS inhibitor-resistant Rumex dentatus L. This review summarizes the current scenario of herbicide resistance in R. dentatus, along with its ecology and management perspectives. Studies have provided valuable insights on the emergence pattern of R. dentatus under different environments in relation to tillage, cropping systems, nutrients, and irrigation. Moreover, R. dentatus has exhibited higher emergence under zero tillage, with high infestation levels in rice-wheat compared to other wheat-based cropping systems (sorghum-wheat). Alternative herbicides for the management of resistant R. dentatus include pendimethalin, 2,4-D, carfentrazone, isoproturon, and metribuzin. Although the pre-emergence application of pendimethalin is highly successful in suppressing R. dentatus, but its efficiency is questionable under lower field soil moisture and heavy residue load conditions. Nevertheless, the biological data may be utilized to control R. dentatus. Therefore, herbicide rotation with suitable spray techniques, collecting weed seeds at differential heights from wheat, crop rotation, alternate tillage practices, and straw retention are recommended for addressing the resistance issue in R. dentatus in North India conditions. Overall, we discuss the current state of herbicide resistance in R. dentatus, the agronomic factors affecting its population, its proliferation in specific cropping systems (rice-wheat), and management strategies for containing an infestation of a resistant population.
Agriculture is an important part of the India’s economy. India ranks first in net cropland area in the world with 179.8 mha which is 9.6% of global net cropland area and India’s agriculture sector makes up 16% of the country’s economy, while accounting for 49% of employment (FAOSTAT, 2020). The rice-wheat cropping system (RWCS) is extensive in the subtropical areas of the Indo-Gangetic Plains of India while maize-wheat is widespread in tropical, sub-tropical and warm temperate regions. In north India, rice is grown in the summer season (June/July to September/October) whereas wheat is grown in the winter season (October/November to February/March). The area under wheat in India was 30.59 mha with an annual production of 99.78 mt and average productivity of 3.22 t ha-1 (Anonymous, 2019). The weeds are accounting as a major factor in yield reduction of wheat. The mechanical weed control is not so much effective in controlling weeds in wheat because of narrow inter row spacing. Further, the manual weeding is not much feasible because of mimicry weeds like Phalaris minor which are very much similar to wheat during initial stages. Therefore, the role of herbicides cannot be neglected. But the continuous application of herbicides with same mode of action year by year has resulted in evolution of herbicide resistance in weed species. The management of herbicide resistant weeds in crop production is a major challenge. This review mainly focuses on the current status of herbicide resistant weeds in India associated with wheat along with their management strategies.
Leucaena [Leucaena leucocephala (Lam.) de Wit] is a perennial weed in over 25 countries, including Australia. Knowledge regarding the seed biology of L. leucocephala could help in making weed management decisions. Experiments were conducted to study the effect of hot water (scarification), alternating temperatures, heat stress, salt stress, water stress, and burial depth on seed germination of two populations of L. leucocephala collected from Toowoomba and Gatton, Australia. The optimum duration of hot water treatment to break the hard seed coat dormancy was 2 minutes for both populations. The highest germination (92-98%) was recorded at 35/25 C for both populations and similar germination occurred at 30/20 C. Toowoomba population recorded greater germination at low temperature (15/5 C to 25/15 C) than the Gatton population. Additionally, the Gatton population had higher germination than the Toowoomba population after 5 minutes of exposure to temperatures of up to 100 C, suggesting that the Gatton population may be more tolerant to heat stress. Germination was completely inhibited at pretreatment (5 minutes) temperatures of 150 to 250 C. The Toowoomba population recorded 17% greater germination than Gatton at a high salt concentration (160 mM NaCl), indicating its greater salt tolerance. At low moisture stress (-0.1 and -0.2 MPa), higher germination was observed in the Toowoomba population than Gatton whereas germination was similar for both populations at higher water stress levels (-0.4 MPa or lower). Germination was similar for both populations at shallow depths (0 and 1 cm) but higher emergence was recorded for the Toowoomba population at 2-8 cm than the Gatton population. Differential germination behaviors of both populations suggest that they adapted differently in their respective local environment. Knowledge gained from this study will help in formulating integrated management practices for L. leucocephala.
Efficacy of some seed protectants against pulse beetle Callosobruchus chinensis (L.) in stored mungbean variety MH 421 was evaluated under laboratory conditions in the Department of Entomology, CCSHAU, Hisar during October-December 2018. The result revealed that the neem leaf powder (30g/ kg) and neem oil (10 ml/ kg) were found most effective with maximum adult mortality (100 and 98.33%, respectively), lowest grain damage and weight loss (1.06 and 1.20%) and (0.75 and 0.81%, respectively), followed by mentha oil (2.5 ml/ kg) and lemongrass oil (2.5 ml/ kg). Turmeric powder resulted in only less adult mortality (48.33%) with maximum infestation and weight loss (14.66 and 4.13%, respectively).
Evolution of herbicide resistance in weeds is a serious threat for sustainable crop production. There were reports of poor control of toothed dock (Rumex dentatus L.) with metsulfuron‐methyl herbicide, an acetolactate synthase (ALS) inhibitor used in wheat (Triticum aestivum L.) at farmers’ fields in Northwest India. Two‐year greenhouse and field studies were conducted to (a) determine the level of metsulfuron resistance in toothed dock biotypes collected from farmers’ fields and (b) find effective herbicides for its management. Metsulfuron‐resistant toothed dock biotypes were 6.8‐ to 23.0‐fold less sensitive relative to the susceptible biotype based on resistance index values. Metabolic herbicide resistance is less likely as there was no evidence of involvement of cytochrome P450s those inhibited by malathion. The resistant toothed dock biotypes had a Trp‐574‐Leu amino acid substitution in the ALS gene. Application of premixes such as metsulfuron methyl plus carfentrazone ethyl (5 + 20 g ha–1) and halauxifen plus fluroxypyr (7.3 + 233.3 g ha–1) resulted in effective control of metsulfuron‐resistant toothed dock biotypes in screenhouse and field studies. This first report elucidating the mechanism of resistance to metsulfuron methyl in toothed dock from India will help in devising sustainable weed management approaches.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.