ethoxy sulfuron, cyhalofop-butyl, chlorimuron, metsulfuron, bispyribac-sodium and penoxsulam controlled different types of weeds effectively in dry seeded rice [37, 106, 107]. ha1 suppressed various types of weeds which includes broad leaf weeds, grasses and sedges; hence enhanced the grain and straw yield of rice by up to 17.45 and 12.30%, respectively compared to the weedy check [101]. Apply any one of the pre-emergence herbicides like, Pretilachlor + safener 0.3kg per hectare, on 3rd or 4th day after sowing to control weeds in the lowland nursery. To access this article, please, Access everything in the JPASS collection, Download up to 10 article PDFs to save and keep, Download up to 120 article PDFs to save and keep. Weeds are one of the major biological threats to higher rice productivity worldwide. Various agronomic practices such as the use of tolerant cultivars, adjusting sowing time, tillage permutations and plant geometry may reduce the weed pressure in rice. Plow and harrow various times before planting. Both ecological and biological factors of a specific region affect weed composition, distribution and propagation as well as its diversification and occupancy in that region. Contact our London head office or media team here. In the tropics, it is largely grown on small family farms that are usually less than 4 ha, and in Asia. This chapter is distributed under the terms of the Creative Commons Attribution 3.0 License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. It may depend on rainfall or irrigation. Anaya [47] and Remington and Posner [43] reported that lack of weed control in fields shared about 12% of total waste production and suggested hand weeding, chemical or mechanical weeding or their combinations for better weed control. Adoption of 2010cm spacing and pre emergence application of anilofos 2, 4-D at 6 days after transplanted supplemented with 2, 4-D Na salt at 20 days after transplanted generally enhanced rice yield from 58.13 to 70.41%. Weeds being the most serious pests in agriculture have the ability to compete with the crop for nutrients through rapid growth and development. This review comprehends the role of planting geometry and herbicide application as a viable tool for weed management in rice. By manipulating diverse weed management strategies, the competitive ability of crop over weeds for the above and below ground resources can be enhanced. [38, 39] reported a reduction of 1298% in rice yield due to weed infestation. It is the most effective method of cultural control of weeds in rice. Lowland rice describes crops where the fields are inundated for at least part of the time between establishment and harvest. El-Nady etal. Avoid drainage of water as it will control germinating weeds. When the identity of a conventional cultivar is mistaken for a resistant cultivar in the field, the conventional cultivar is killed or severely injured by the herbicide that the resistant cultivar resists without adverse effects. Fields must be well levelled to ensure an even depth of water. Dense plant population may lead to intra-plant competition whereas low plant population provides the space for off-types to grow easily. The list of most common weeds infesting rice fields are presented in Table1. [13] suggested various herbicides packages like penoxsulam, bensulfuron, carfentrazone, molinate, bentazone, clomazone, pyrazosulfuron, fenoxaprop, propanil, bispyribac-sodium and cyhalofop-butyl control weeds in rice. Subscribe to our print & digital magazines now. Hand weeding is a cultural approach to control weeds but it is a very tedious, labor intensive and slow method [53]. [73]. For more information, visit http://journals.cambridge.org. *Address all correspondence to: umairashraf2056@gmail.com. [114] tested cyhalofop-butyl, quinclorac and propanil against 10 populations of Echinochloa crus-galliwhich were collected from rice field. Though generally, weeds can be controlled through herbicide. Time and method of butachlor application in wet-seeded rice (Oryza sativa) [Philippines], Two experiments were conducted to evaluate different techniques on the performance of butachlor. Echinochloa colonaL., known as a Jungle rice, grows vigorously in direct seeded rice whilst predominantly found in both direct-seeded and transplanted rice [13, 35, 36]. Hence, spatial arrangement of crop plants is the best cultural practice to reduce weed competition and raise rice yield. On the other hand, the study by Khaliq etal. Herbicides are chemicals that either kill or inhibit growth of plants. There are diverse weed communities and types in rice fields. The rice yield in closer spacing was 19.50% more than wider. Rice is considered as the most important food crop in developing countries and the crucial source of employment in rural areas. Lower grain yield could be due to intra specific competition in rice. [1] It is extensively used in India in the form of granules in rice as post emergence herbicide. [70] concluded that rice sown at the spacing of 2020cm and the application fertilizer (138kgNha1) gave maximum yield. *National Crop Protection Center Library (Philippines)", International Rice Research Inst., Los Banos, Laguna (Philippines) [Corporate Author]. Licensee IntechOpen. Herbicide resistance is the heritable capacity for plants to grow and reproduce after herbicide treatment that would have been fatal to all but one or a very few progenitors in an antecedent population. Weeds uptake available nutrients and compete with rice plants for water, light and space. Though, for successful flooding, water levels should be maintained. [18] reported that in too dense populated rice fields, inter- specific competition starts which may cause lodging and gradual shading and results in yield penalty. [59] studied three levels of plant spacings i.e., 1515, 2020, and 2525cm in interaction with number of seedlings per hill and found the highest grain yield from 1515cm. Many cultural, biological, physical and chemical practices affect the composition and intensity of weeds in rice fields. First weeding must be done between 15 and 21 days after germination. While using soil mix for nursery beds, you must make sure the soil is clean and free of weed seeds. [75] concluded that 2010cm spacing with the application of anilofos+2, 4-DEE (ready mix) 0.40+0.53kgha1 supplemented with 2, 4-D sodium salt 1kgha1 provided the maximum grain yield and minimum weed competition. Bispyribac-sodium reduced the density of Alternanthera philoxeroides, Ammaniasp.,Commelina diffusa, C. difformis, C. iria,and D. junceumwhile anilophos controlled Cyperus difformis, C. sanguinolentus,and C. iriaeffectively. Threshold levels of Cyperus iriaand Echinochloa crus-galliwere estimated about 30 and 20 plants m2 in transplanted rice [40, 41]. Furthermore, Jacob etal. Also, a level field helps retain a constant water level that controls weeds. [3] It is used as a selective pre-emergent herbicide. Weeds should be allowed to grow before the next cultivation. Bispyribac-sodium and penoxsulam at 25gha1 controlled weeds effectively in rice [107]. When the soil remained moist during the 2-week unflooded periods (1979 and 1981), weed emergence was slowed and no advantage with respect to enhanced weed control and increased rice yields could be demonstrated over that of the standard sequential propanil (3,4-dichloropropionanilide) application. Hussain etal. Under weed free conditions, yield was 29% higher in the plot with 10cm row spacing than 20cm whereas grain yield 8788% higher than uncontrolled weedy plots. However, high weed density led to significant reductions in tiller production and grain yield in rice [104]. Further, Pacanoski and Glatkova [89] reported that herbicides i.e., propanil + bentazon, mefenacet + bensulfuron-methyl, penoxsulam, and azimsulfuron + adjuvant controlled Cyperus rotundus, Echinochloa crus-gallieffectively in rice. Dear patron, thank you for being our reader. Rice is grown throughout the tropics in rainfed uplands, seasonally deep flooded areas, in rainfed and irrigated lowlands. Herbicides must be applied on 8 DAS with thin layer of water in the field. Regular monitoring and early detection of the evolution and mechanism of herbicide resistance and by adopting some suitable management strategies usefulness of herbicides may be enhanced otherwise weed control through herbicides might be at a high risk in future [116, 117]. Herbicides commonly used in rice mostly relate to acetyl co-enzyme A carboxylase (ACCase) inhibitors, acetolactate synthase (ALS), thiocarbamates, synthetic auxins and amides due to which herbicide resistance has become a serious problem in many regions [112]. There are about 50 weed species found in rice field causing severe losses in productivity all over the world [33]. An increase of 87188% was recorded in rice yield in herbicide treated plots than weedy check (control). Weed control is crucial to prevent losses in yield and production costs, and to preserve good grain quality. Early post emergence application of Bispyripac sodium 50 g a.i. Weeds being the most serious pests in agriculture have the ability to compete with the crop for available resources through rapid growth and development. Open Access is an initiative that aims to make scientific research freely available to all. Readers like you are an inspiration for us to move Agri Journalism forward. Weedicides can suppress weeds effectively and may provide a weed free environment if applied at proper stage and time [80]. Similarly higher grain yield was obtained in 50 hills m2 and the paddy yield record obtained due to high planting density over 16.7, 22.2, 25 and 33.3 hills m2 were 4.0, 9.5, 4.8 and 6.0%, respectively [68]. For terms and use, please refer to our Terms and Conditions Reduction in grain yield of direct seeded rice (DSR), wet seeded rice (WSR) and transplanted rice due to uncontrolled weeds was 75.8, 70.6 and 62.6% respectively [31]. With a personal account, you can read up to 100 articles each month for free. Chemical weed control has an edge over cultural weed control as it is quick, cost effective and saves labor, time and money. This premier institution of higher learning was established in 1908 and is now a university system composed of eight constituent universities and one autonomous college spread throughout 17 campuses in the archipelago. Integrated weed management is the best option to control weeds. [45] found weed control through herbicides as the best method followed by mechanical weeding without engine, three hand weeding and power mechanical weeding. Moreover, the total weed density was significantly reduced using bispyribac-sodium and cyhalofop butyl herbicides although the former caused a slight recoverable injury to the rice plant [98]. Weed control efficiency at reduced dose of herbicide tend to be lower than recommended doses, although in many cases it may be 60100% and acceptable commercially [82]. Weed Science publishes original research and scholarship focused on understanding "why" phenomena occur. Dense plant population may lead to intra-plant competition whereas lower plant population provides the space for off-types to grow easily [17]. Rahman etal. Rasool etal. Among all the weed control methods, chemical weed control is commonly used to overcome weed infestation which is easy, quick, time saving, cost effective and the most reliable method to control weeds. PE butachlor 0.75 kg per hectare + bensulfuron methyl 50 g ha-1 on 3 DAT must followed by mechanical weeding on 45 DAT is effective for broad spectrum weed control. Flooding to a depth of 10 cm prevents germination of most weed seeds and also kills the majority of weed seedlings. 20 and 25cm where the highest grain yield was recorded at 2515cm and the lowest at 202.5cm spacing. Brief introduction to this section that descibes Open Access especially from an IntechOpen perspective, Want to get in touch? Planting geometry-induced changes in weed density and yield of direct seeded and transplanted rice. Check Latest Updates, Commonwealth Games 2022: Achinta Sheuli Takes Home India's Third Gold Medal in Weightlifting. In wet seeded rice, sowing with drum seeder and cono weeding (manual / power weeder) must be done at 10, 20 and 30 DAS. Rice yield was 1115% higher and 0.19 more B:C ratio (net monetary return) than weedy control, All the herbicides reduced more than 80% weed density and 7487%. Weeds are the serious pest in rice production but these can be managed effectively by maintaining the critical periods of weed competition [11] as growth of the rice is greatly influenced by all the competition periods [49]. This weed infestation in rice disturbs the rice growth badly and may result in complete crop failure [30]. Zein etal. You choose the topics of your interest and we'll send you handpicked news and latest updates based on your choice. More than 200 active ingredients are registered as herbicides around the world, and this estimate does not include compounds that are used exclusively as crop growth regulators or crop desiccants. According to Awan etal. This item is part of a JSTOR Collection. Herbicides target different cellular strucures and functions and are very specific in their mechanism of action in plants. Both bispyribac-sodium and penoxsulam herbicides in suspension concentrate (SC) formulation were applied in combination with ethoxysulfuron as post emergence and found that bispyribac-sodium + ethoxysulfuron gave better weed control in rice [93]. The growth, development and the yield of rice as well as the intensity of weed infestation are greatly affected by plant spacing. Every contribution is valuable for our future. For instance, 1648% grain yield of transplanted rice is reduced due to the occurrence of weed flora in rice field [4]. Optimum plant density is necessary to obtain higher yields in rice [57]. Chauhan etal. Crop safety, weed control, and yield were not affected by application method when the herbicide was applied 3 days before seeding compared to 6 days after seeding. Penoxsulam (15g a.i. Throughout these smallholder systems, weeds are one of the major biological constraints to production. By making research easy to access, and puts the academic needs of the researchers before the business interests of publishers. Further, weed interference, its competitive ability and population dynamics changes with weed species composition which further affected by human efforts to control them. Singh etal. [103] evaluated the efficacy of different post emergence herbicides viz. Bispyribac-sodium is the most effective to the small and actively growing weeds especially against barnyard grass (alligator weed) when applied as an early post emergence herbicide applied at the 3-leaf stage of rice [92]. Further studies using four row spacings (1025, 1525, 2025, and 2525cm) resulted in significant improvements in rice yield and related components from 1525cm spacing with two seedlings per hill with four levels of seedlings per hill were assessed by Alam etal. Tari etal. [44] found some resistant populations of Echinochloa crus-gallito bispyribac-sodium and penoxsulam. Hence the use of a single herbicide cannot give satisfactory and cost-effective results of weed control [11]. [93] studied the efficacy of tank mixed pre- and post-emergence herbicides on weed control in rice. Here we will explain the role of planting geometry and herbicides as weed management strategies in rice and different methods to control weeds in rice. Weeds are one of the main factors which are responsible for low production of field crops [26, 27, 28]. Integrated approaches for weed management, emphasizing on the combination of management practices and scientific knowledge, may reduce the economic costs and improve weed control owing to the complexity of the weed community. Cambridge University Press is committed by its charter to disseminate knowledge as widely as possible across the globe. [108] reported that bispyribac-sodium and ethoxy sulfuron were efficient with 90 and 87% weed control efficiency, respectively in rice. So to minimize the weed density, various weed control strategies have been evaluated in rice crop to get maximum output [20, 30]. [16] studied four rice sowing methods and concluded that the highest grain yield (3.06tha1) was obtained from 2020cm spacing while the lowest of 2.52tha1 from direct seeding by broadcasting the seeds in the standing water. The University of the Philippines (UP) is the countrys national university.

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