<div>Background: Weeds are the major threat to direct seeded rice and a single strategy of weed control may not be effective for season-long weed control. Intending to accomplish the long-term and sustainable weed management of direct seeded rice, the integration approach of weed management strategies seems a better alternative. The current field study was aimed to evaluate the impact of integration of different weed control methods on direct seeded rice under irrigated ecosystem on weed growth and rice yield.</div>

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Methods: The experiment was laid out in randomized block design with three replications and twelve treatments during 2017 at G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India. The twelve treatments included the combination of cultural, mechanical, physical and chemical weed management methods.</div>

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Result: Combination of stale seedbed technique integrated with pre-emergence application of pendimethalin with mechanical weeding at 25 DAS followed by 1 hand weeding at 45 DAS, Sesbania (line sowing) fb application of pendimethalin (PE) fb 1 mechanical weeding at 25 DAS fb 1 hand weeding at 45 DAS, stale seedbed with application of pendimethalin (PE) with Sesbania brown manuring supplemented with mechanical weeding (25 DAS) fb hand weeding at 45 DAS, mulching with wheat straw mulch along with post-emergence application of penoxsulam (20 DAS) fb 1 hand weeding at 45 DAS and application of pendimethalin (PE) fb penoxsulum (PoE) at 20 DAS fb 1 hand weeding at 45 DAS with a row spacing of 25 cm found to be similar in the suppression of weed population and weed density at 40 and 60 DAS and crop yields (4.3, 4.1, 4.2, 4.0 and 4.2 t/ha, respectively) were on par with weed free plot i.e. 4.4t/ha. Application of pendimethalin (PE) fb penoxsulum (PoE) at 20 DAS fb 1 hand weeding at 45 DAS with row spacing of 25cm recorded 93.7%, 90.6% and 4.5% weed control efficiency, weed control index and weed index respectively, which was similar with above integrated weed management treatments. A negative correlation of the weed density and dry matter with the yield of rice was recorded.</div>

​Effect of Integrated Weed Management on Weed and Yield of Direct Seeded Rice

<div>Background: Weed populations reduce crop yields by influencing the pattern of crop growth and development throughout the season and by directly competing with the crop for limiting precious resources, like light, water or nutrients. A number of the factors that influence magnitude of crop yield losses from weed interference include the timing of weed emergence relative to the crop, weed density, pattern of weed growth and development. Weed management is one among the foremost critical factors influencing crop yield. By providing a window of weed-free growth early within the season, the size advantage that crop seedlings have over weeds can be utilized to reduce the intensity of direct competition for resources at the stages of crop development when yield is being determined. Weeds are identified as a significance drawback since they create biotic stress in realizing the genetic yield potential of this valuable crop. 
 
Methods: A field experiment was carried out during the rabi season of 2010-11 to 2014-15 at ICAR- National Research Centre on Seed Spices, Ajmer, Rajasthan to estimate the yield losses because of weed infestation and to work out the critical period for weed control (CPWC) in fenugreek (Trigonella foenum-graecum L.). There were 14 treatments comprising of initial weedy periods of 15, 30, 45, 60, 75, 90 days after sowing (DAS) and weed free period upto 15, 30, 45, 60, 75, 90 DAS along with weedy till harvest (un-weeded check) and weed free till harvest (weed free check). The treatments were replicated three times in a randomized block design. 
 
Result: Maximum pod length (cm), number of pods/plant, number of seed/pod, test weight (g), seed yield (kg/ha), straw yield (kg/ha) and harvesting index (%) to the tune of 9.47, 41.2, 16.67, 12.60, 2297, 4954 and 31.73 were recorded at weed free throughout growth period. Weed infestation up to 30, 45, 60, 75, 90 DAS and weedy throughout growth period reduced the seed yield significantly to the magnitude of 567.3, 801.7, 913.3, 1253.3, 1393.7 and 1736.3 kg/ha. Yield losses in fenugreek increase from 2.95 kg/ha/day at 15 days weed infestation to 12.31 kg/ha/day at 135 days weed infestation. Maximum gross return (`104248/ha), net return (`67018/ha) were obtained at weed free throughout growth period with the B:C ratio 2.80 among the weed free treatments. The employment of response curves with weed free or weed competition period showed that seed yield of fenugreek&nbsp;were&nbsp;the highest with the field&nbsp;free&nbsp;from weeds throughout the growth period and the critical period of weed/fenugreek competition was 32 days after sowing and lies between 30-45 days after sowing. In regression approach for fenugreek seed yield and weed free or weed competition period the quadratic function was fitted to estimate the expected yields which had the high significant with the data recorded and have the highest values of R2. If we predict the seed yield losses based on the quadratic model for weed free period model, it declined from 42.04 at 0 DAS to 0.0% at 135 days. Similarly, weed infestation period model predicted the seed yield losses increased from 0.00 at 0 days weed infestation to 73.42% at 135 days. Critical period for weed competition in fenugreek was found to be 32 days after sowing. The CPWC is helpful for making decisions on the necessity for and timing of weed control.</div>

<div>Yield Losses Due to Weeds, Critical Period for Weed-crop Competition in Fenugreek (Trigonella foenum-graecum L.)&nbsp;</div>

<div>Background: Weeds are widely reported as a key constraint in organic agriculture. Soybean-chickpea is important cropping sequence adopted in Maharashtra State under irrigated condition. Weed management is a serious problem in both the crop and it mostly controlled through chemical weed control. Today, widespread use of herbicides has resulted in purporated environmental and health problem as well as residual problems to succeeding crops. Now a days residue free food requirement is high. In organic farming cultural and mechanical methods are necessary to break the weed cycle. So, keeping this point in view present investigation was carried out to evaluate organic weed management practices on growth, yield and weed control in soybean-chickpea sequence under irrigated condition.&nbsp; 
 
Methods: A field experiment was conducted during Kharif and rabi seasons of 2017-18 and 2018-19. The present investigation consisted of ten weed management practices viz. two hand weeding at 20-25 and 45-50 DAS, one hoeing 20-25 DAS + one hand weeding at 45-50 DAS, soybean + sunhemp incorporation after 35-40 DAS in kharif season and chickpea + safflower (2:1) in rabi season,&nbsp;stale seed bed + reduced spacing + 2 tonne of wheat straw + one hand weeding at 25&nbsp;DAS, soil mulch at the time of sowing + one hand pulling at 25 DAS, incorporation of neem cake 1.5 tonne/ ha 15 days before sowing + one hand weeding at 25 DAS, soil solarization with 25 &mu; polythene mulch during summer + one hand weeding&nbsp;at 25 DAS, mulching with straw, weed free and weedy check. &nbsp;&nbsp; 
 
Result: The higher values of growth attributes was recorded by weed free treatment which was on par with two hand weeding at 20-25 and 45-50 DAS and soil solarization with 25 &mu; polythene mulch during summer + one hand weeding at 25 DAS and significantly superior over rest of the treatments during both the year study. Application of stale seed bed with reduced spacing and 2 tonne of wheat straw along with one hand weeding 25 DAS recorded higher soybean equivalent yield followed by soybean + sunhemp incorporation (35-45DAS) in kharif and chickpea + safflower (2:1) in rabi season during both the year. The lower weed density, dry weight and highest weed control efficiency at 40 days after sowing for both monocot and dicot weeds was recorded by weed free treatment followed by soil solarization with 25 &mu; polythene mulch during summer + one hand weeding at 25 DAS in soybean and chickpea during both the year.</div>

<div>Evaluation of Organic Weed Management Practices on Growth, Yield and Weed Control Efficiency in Soybean-chickpea Sequence under Irrigated Condition &nbsp;</div>

<div>Background: Weeds are prime factor that adversely effects on growth, quality and yield of mungbean during summer and rainy season. Being a short duration crop, it faces heavy weed competition right from the early growth stages to harvesting. The critical period of crop weed competition in mungbean was initial 25-30 days, yield may be reduce up to 50-90% if weeds not manage at this stage. Hence, there is a need to find out the successful weed management strategies to realize higher growth and yield. The progressive transformation of agriculture concerning intensive use of herbicides is gaining status in recent years due to easy, lower cost, timeliness and successful controlling weeds. Therefore, keeping above information in view, the present study was undertaken to assess the effect of different weed management practices in summer mungbean under zero tillage condition to find out the better weed management, higher productivity and profitability. 
 
Methods: In this field-laboratory investigation during summer season, 2019, different herbicides were applied to manage weeds in mungbean. Eight treatments were applied based on various application windows. In the field and laboratory, the collected samples were determined for crop weed competition, yield attributes, yields and net returns. &nbsp; 
 
Result: The results revealed that weed free treatment was recorded lowest weed population at 30 DAS and harvest (1.8 and 2.9), weed dry weight (1.1 and 1.9g) and highest weed control efficiency (96.3 and 94.9%) followed by Pendimethalin (PE) fb one HW and Shaked (Propaquizafop + Imezathyper) application. The similar results also observed in nutrients removed by weeds. Among yield attributes, weed free treatment recorded the longest pod length, no. of pods/plant, no. of seeds/pod and test weight (7.9, 21.0, 9.7 and 43.0g, respectively) which was at par with Pendimethalin (PE) fb one HW and Shaked (Propaquizafop + Imezathyper) application. The magnitude of seed yield was increased under weed free (10.1 q/ha) and Shaked (Propaquizafop + Imezathyper) (9.5 q/ha) treatments by 127.9 and 113.8%, respectively over weedy check. Application of Shaked (Propaquizafop + Imezathyper) recorded highest net returns (Rs 55,079/ha) and B: C (2.8) over rest of the treatments. It can concluded that application of Shaked (Propaquizafop + Imezathyper) @ 2 L/ha at 20 DAS recommended for better weed control, higher yield and net returns of summer mungbean under zero tillage condition.</div>

<div>Effect of Weed Management Practices on Weed Dynamics, Nutrient Depletion, Productivity and Profitability of Summer Mungbean (Vigna radiata) under Zero Tillage Condition</div>

<div>Background: Balancing productivity, profitability and environmental health is a key challenge for maintaining agricultural sustainability. The use of locally available agro-inputs in agriculture by avoiding or minimizing the use of synthetically compounded agro-chemicals appears to be one of the probable options to sustain the agricultural productivity. Widespread use of herbicides has resulted in purported environmental and health problems as well as residual toxicity issues in succeeding crops. At present, the awareness on safe food is increasing. So, keeping this point in view the present investigation was carried out to evaluate the influence of organic sources of nutrients and weed management on growth, yield and weed flora of Frenchbean.&nbsp; 
 
Methods:&nbsp;A field experiment was conducted during summer season of 2016 and 2017. The present investigation was laid out in split plot design with six sources of nutrients in main plot and four weed management treatments in sub plots.&nbsp; 
 
Result: Application of treatment T5 recorded significantly higher growth parameters, yield attributes, fresh pod yield, net returns and B:C ratio of French bean which was statistically at par with T3 and T2. Amongst the weed management treatments, treatment W1 resulted in significantly lowest species wise and total weed density and biomass, highest weed control efficiency, lowest weed index, highest growth, yield attributes and fresh pod yield of French bean which was statistically at par with W2 and W0. However, the highest net returns and B:C ratio were obtained in weed free plots.</div>

Weed Dynamics and Productivity of French Bean (Phaseolus vulgaris L.) as Influenced by Organic Sources of Nutrients and Weed Management

<div>Background: Soybean being a rainy season crops, is heavily infested with weeds thus ultimately affect the crop yield and economic return. 
 
Methods: Field experiment was conducted at Birsa Agricultural University, Ranchi during rainy season of 2019 and 2020 under randomized block design replicated thrice with eight different weed control methods viz., imazathapyr 75 g/ha at 20 days after sowing (DAS), imazathapyr 35% + imazamox 35% ready mix (RM) 75 g/ha at 20 DAS, quizalofop ethyl 50 g/ha at 20 DAS, sodium acifluorfen 16.5% + clodinafop propargyl 8% (RM) 125 g/ha at 20 DAS, imazathapyr 2% + pendimethalin 30% (RM) 1 kg/ha at 20 DAS, hand weeding at 20 and 40 DAS, weed free (three hand weeding at 20, 40 and 60 DAS) and weedy check.&nbsp; 
 
Result: Among herbicides, application of quizalofop ethyl 50 g/ha recorded higher growth and yield attributes of soybean due to reduced weed density and weed dry matter which resulted in higher weed control efficiency, weed management index, agronomic management index, thereby recorded maximum soybean yield (2065 kg/ha), net return (₹ 54,743/ha) and B:C ratio (2.50). The soybean yield was negatively correlated with weed dry matter particularly with grassy as well as total weed dry matter while plant dry matter accumulation was strongly correlated with soybean yield.</div>

Weed Dynamics, Growth, Yield and Correlation Study as Affected by Weed Control Methods in Soybean [Glycine max (L.) Merril.]

<div>Background: Weeds are the major biotic constraint to reduce the rice productivity in direct wet seeded rice. Weed infestation and competition are severe in direct wet seeded rice as compared to transplanted rice, because of the simultaneous growth of both crops and weeds. The yield loss due to weeds varies from 40 to 100 per cent in direct seeded rice. Use of herbicides either singly or in combination with manual or mechanical weeding in puddled direct seeded rice has been highlighted by several workers. Use of alternative herbicides with wide spectrum control of the weeds in direct seeded puddled rice is the need of the present time. The present study aimed to evaluate different weed management practices in direct wet seeded rice under sodic soil. 
 
Methods: A field experiment was conducted during Samba season (Rabi) 2016-17. to evaluate the weed management practices in direct wet seeded rice under sodic soil. The treatments comprised of different combination of weed management practices viz., pre emergence, early post emergence herbicides, mechanical weeding and hand weeding twice were tested. Total weed density and weed dry weight, weed control efficiency, yield parameters and yield of rice were recorded.&nbsp; 
 
Result: Among the different weed management practices, the lowest total weed density, total weed dry weight and higher WCE, yield attributes, grain and straw yields were registered under application of PE pyrazosulfuron ethyl 25 g/ha fb EPOE bispyribac sodium 25 g/ha. This was followed by application of PE pretilachlor 0.75 kg/ha fb EPOE bispyribac sodium 25 g/ha.&nbsp;</div>

<div>Weed Dynamics and Productivity of Direct Wet Seeded Rice under Different Weed Management Practices</div>

<div style="text-align: justify;">An experiment was carried out to find out suitable method of planting and weed management in green gram grown during the kharif season of 2014 and 2015. The density of E. colona and C. rotundus was significantly reduced in raised bed planting method. Significant reduction in total dry weight of weeds was obtained in raised bed planting method as compared to conventional and zero till planting method. Maximum weed control efficiency was found in raised bed planting method. Significantly more number of seeds pod-1 were observed in raised bed planting method as compared to conventional and zero till planting method. Seed yield and straw yield were found maximum in raised bed planting method during both years of study and were statistically at par in conventional and zero till planting method. Harvest index was not influenced by planting methods. Phytotoxicity on crop due to different herbicides was similar under different planting methods. Among different weed management treatments, HW at 15 and 30 DAS was found most effective in reducing density and dry weight of weeds during crop growing period except at 15 DAS (where weeding was done after taking observation). Maximum weed control efficiency was observed in HW (15 &amp; 30 DAS). Weedy check treatment resulted in minimum while weed free treatment resulted in maximum number of seeds pod-1. Among the treatments having herbicide application, post emergence application of Imazethapyr @ 100 g ha-1 resulted in maximum seed and stover yield.&nbsp;</div>

Effect of planting methods and weed management practices on yield of green gram {Vigna radiata (L.) R. Wilczek}, weed dynamics vis a vis phytotoxicity in green gram

Background: Maize is the third most important cereal in India after rice and wheat which contributes nearly 9% in national food basket. Weed infestation is a major problem in maize, primarily at initial growth stages and due to wider spacing, hence weed control is essential to reduce the competition with maize crop. In maize row to row spacing is more so maximum number of weeds appears and compete with main crop. 
 
Methods: A field experiment was conducted in the University Agricultural Farm under the Department of Agronomy in kharif 2019. The soil of the experimental field was sandy loam in texture having pH 6.87 and electrical conductivity 0.32 mmhos/cm. The experiment was comprised of eight treatments and laid out in randomized block design with three replications T0 (Control), T1 (Hand weeding at 20 DAS, 40 DAS), T2 (Atrazine 1 kg/ha after 3 days of sowing), T3 (Metribuzin 1 kg/ha after 3 days of sowing), T4 (Alachlor 1.5 kg/ha after 3 days of sowing), T5 (Atrazine + hand weeding 1 kg/ha (after 3 days and 30 days after sowing), T6 (Metribuzin + hand weeding 1 kg/ha (after 3 days and 30 days after sowing), T7 (Alachlor + hand weeding 1.5 kg/ha (after 3 days and 30 days after sowing). The texture of the experimental field soil was sandy loam having pH-6.87, EC-0.32 mmhos/cm.&nbsp; 
 
Result:&nbsp;The weed species recorded at the experimental site were mainly comprised with grasses, sedges and broadleaf weeds. The dominant weed species infested in the experimental field were: Cynodon dactylon (doob grass), Cyperus rotundus, Amaranthus viridis, Anagallis arvensis, Argemone mexicana, Chenopodium album, Parthenium hysterophorus and Trianthema prolacastrum. Significant reduction in the weed density was recorded in manual weeding. The highest plant height, stem girth, number of leaves, flag leaf length, chlorophyll content, leaf area index, grain yield and stover yield was recorded highest with hand weeding which was followed by T7 (Alachlor + hand weeding 1.5 kg/ha (after 3 days and 30 days after sowing).

Effect of Integrated Weed Management Practices on Weed Dynamics and Performance of Maize Crop

<div>Background: Maize (Zea mays L.) is the most versatile and emerging food crop of global importance. Weeds are ubiquitous but their presence in wide spaced and initially slow growing crop like maize acts as an obstacle for plentiful harvest. Nutrient uptake by weeds during the first thirty days of maize growth was 59 kg N, 10 kg P2O5 and 59 kg K2O per ha, which was 7-10 times higher than the nutrient uptake by maize. 
 
Methods: The present field experiment was conducted during Rabi, 2018-19 under irrigated conditions at wetland farm of S.V. Agricultural College, Tirupati andhra Pradesh, with ten treatments and three replications in a randomized block design. 
 
Result: Lower density and dry weight of weeds with higher weed control efficiency, lower nutrient uptake by weeds and higher nutrient up take by maize at 80 DAS, kernel and stover yield was recorded with hand weeding twice at 15 and 30 DAS, which was statistically at par with atrazine 1.0 kg ha-1 as PE fb topramezone 30 g ha-1 or tembotrione 120 g ha-1 as PoE or atrazine 1.0 kg ha-1 as PE fb HW at 30 DAS, while these were lowest with weedy check. Higher benefit cost ratio of maize was noticed with both atrazine 1.0 kg ha-1 as PE fb topramezone 30 g ha-1 as PoE (T3), which was in parity with atrazine 1.0 kg ha-1 as PE fb tembotrione 120 g ha-1 as PoE (T2) and hand weeding twice at 15 and 30 DAS (T9). From the present study it may be concluded that atrazine 1.0 kg ha-1 as PE fb topramezone 30 g ha-1 or tembotrione 120 g ha-1 as PoE were considered to be the most effective and economic weed management practices to increase the productivity of Rabi maize at times of labour scarcity.</div>