<div>Background:&nbsp;Weeds are the major biological constraint in okra due to its slow initial growth and wider row spacing. Due to severe crop weed competition, weeds removed considerable amount of nutrients from the soil. Competition exists between the crop and weed for nutrients results in nutrient deficiencies in crop. Hence the present experiment is formulated to assess the effect of stale seedbed, mulching and mechanical weeding on nutrient availability, nutrient uptake by crop and weed in okra. 
 
Methods: Experiment was conducted at Coconut Research Station, Balaramapuram, Thiruvananthapuram, Kerala during Rabi 2020-21. Design adopted for the study was RBD with two factors. The first factor was seedbed preparation (S) and the second factor was weed management (W). Stale seedbed (S1) and normal seedbed (S2) were the two different seedbed preparation methods and dried banana leaf mulch @10 t ha-1 alone (W1), dried banana leaf mulch @10 t ha-1 fb wheel hoe weeding at 30 and 45 DAS (W2), dried banana leaf mulch @10 t ha-1 fb hand weeding at 30 and 45 DAS (W3), wheel hoe weeding at 15, 30 and 45 DAS (W4), hand weeding at 15, 30 and 45 DAS (W5) and weedy check (W6) were the six different weed management options tried. Soil samples were collected after the harvest of the crop to determine the nutrient availability. Weed samples at 30 and 60 DAS and plant samples at harvest were analyzed to determine the NPK content and respective uptake of nutrients were calculated by multiplying the nutrient content with DMP. 
 
Result: Stale seedbed significantly enhanced the dry matter production and nutrient uptake by okra at harvest and lowered the nutrient removal by weeds at 30 and 60 DAS. Compared to non-stale, stale seedbed recorded significantly higher fruit yield. Among the weed management, wheel hoe weeding at 15, 30 and 45 DAS, recorded the lowest total weed dry weight at 30 and 60 DAS and resulted in the highest NPK uptake by crop and fruit yield. Uncontrolled weed growth resulted in a loss of 81.33, 18.16 and 50.84 kg N:P:K ha-1&nbsp;at 30 DAS and 102.09, 57.90 and 55.31 kg N:P:K ha-1 at 60 DAS, respectively. Nutrient removal by weeds was the lowest in wheel hoe weeding at 15, 30 and 45 DAS and the highest in weedy check. It could be concluded that, wheel hoe weeding at 15, 30 and 45 DAS was the best option for the management of weeds, higher nutrient availability and uptake and yield in okra.</div>

Nutrient Availability and Nutrient Uptake by Crop and Weed as Influenced by Stale Seedbed, Mulching and Mechanical Weeding in Okra

Background: Clusterbean is one of the most important crop of arid and semi-arid region of India. It is mainly grown for vegetable, manure, fodder and seed purpose. Seeds of clusterbean contain galactomann (stored in endosperm) which has industrial uses, thus making it the major cash earner crop. Various biotic and abiotic stresses affects the crop during its growth stages. Among biotic stresses, weeds are the major one affecting the crop growth and yield. Due to initial slow growth of the clusterbean intense crop-weed competition takes place upto 20-30 DAS and if weeds are not managed properly there will be a severe yield reduction. Under Haryana conditions only manual weeding is recommended which is time consuming and expensive hence there is need to exploit other methods of weed control. Therefore, present study was conducted to study the effect of mechanical methods of weed management on growth, yield and economics of clusterbean. 
 
Methods: A field experiment was conducted during kharif season 2018 to study the effect of mechanized weed management practices on growth, yield and economics of clusterbean at Regional Research Station, Bawal (Rewari), CCS Haryana Agricultural University, Hisar. Experiment was performed in randomized block design with ten treatments and three replication. 
 
Result: It was found that among various weed management practices, two mechanized weeding with power weeder at 20 DAS and 35 DAS under 60 cm row spacing resulted in significantly higher plant height, leaf area index, dry matter accumulation, seed yield and its attributes in comparison to other treatments and it was statistically at par with mechanized weeding at 20 DAS and 35 DAS with tractor drawn cultivator. The weeding with tractor drawn cultivator was found to be most economical with maximum net returns (Rs. 36076 ha-1) and B:C (2.37) in comparison to other treatments followed by weeding with power weeder that fetched net return of Rs. 35868 ha-1 with B:C of 2.25. Therefore, two times interculture with power weeder or tractor drawn cultivator found beneficial and economical for farmers.

Growth, Yield and Economics of Rainfed Clusterbean (Cyamopsis tetragonoloba) as Influenced by Various Mechanized Weed Management Practices

<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>

<div> 
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>

<div> 
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: 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>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>

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>

<div>Weed Dynamics and Nutrient Uptake of Maize as Influenced by Different Weed Management Practices</div>

<div>The present study was conducted in kharif seasons of 2015, 2016 and 2017 at experimental farm of Rajasthan Agricultural Research Institute, Durgapura, Jaipur (Rajasthan) to study efficacy of different weed management practices in clusterbean. Three years result shows that compared to weedy check (6.82 m-2) application of Pendimethalin @ 0.75 kg a.i. ha-1 as PE fb one hand weeding recorded lowest weed density (3.58 m-2). Among herbicidal treatments, Pendimethalin @ 0.75kg a.i/ha as PE fb one hand weeding at 25 DAS (83.7%) and Pendimethalin @ 0.75 kg a.i./ha as PE+ Imazathapyr+ Imazamox @ 40g a.i./ha PoE (74.0%) recorded highest weed control efficiency. Likewise, application of Pendimethalin @ 0.75kg a.i/ha as PE fb one hand weeding at 25 DAS and Pendimethalin 0.75kg/ha at PE fb Imazathapyr + Imazamox @ 40g a.i. ha-1 recorded significantly higher seed (1136 kg ha-1 and 1009 kg ha-1), haulm (3304 kg ha-1 and 2943 kg ha-1) and biological yield (4440 kg ha-1 and 3953 kg ha-1), respectively over other herbicidal treatments. Economic evaluation indicated that application of Pendimethalin @ 0.75kg a.i/ha as PE fb one hand weeding at 25 and which was followed by with Pendimethalin @ 0.75 kg a.i./ha as PE+ Imazathapyr+ Imazamox@ 40g a.i./ha recorded, gross return (INR 55352 ha-1 and INR 49189 ha-1) net returns (INR 38852 ha-1 and INR 34289 ha-1) and B:C ratio (2.35 and 2.20), respectively. Whereas, minimum cost of cultivation (INR 10000 ha-1) and gross returns (INR 25632 ha-1), net returns (INR 15632 ha-1) and B:C ratio (1.56) were recorded under weed check. So looking to the laborious pressure of hand weeding, cost effectiveness ease of application of chemical herbicides, application of Pendimethalin 0.75 kg ha-1 fb one hand weeding can be an effective weed control option in cluster bean crop with higher seed and haulm yield under Semi-arid and Arid regions of Rajasthan.</div>

<div>Effect of Different Weed Management Practices on Weed Dynamics, Productivity and Farm Profitability of Cluster Bean</div>

<div>Background:&nbsp;Onion is a widely accepted as vegetable as well as spice crop, sharing a 14.31 lakh ha area with 267.3 lakh MT production in 2020. Improved management structure and healthy seedling are important factors in overcoming the cause and even developing effective transplanter. The information of morphological properties is essential before designing modern farming equipment. 
 
Methods: Present study focuses on the properties and age of seedlings for automated transplanting, five majorly cultivated varieties of onion Light red gavran, N-53 Nasik red, AFDR, KSP-117 and Nafed were selected. The morphological (height, weight, diameter) and mechanical (compressive strength and static coefficient of friction) properties were measured under 10 days intervals to compare 30-70 days seedling. 
 
Result: Bulb and stem diameter were in the range from 2.82 to 3.82 mm and 0.86 to 2.12 mm, respectively. The model was found significantly different with concerning days. Plywood and aluminium had less influence on the seedling&rsquo;s outer surface moisture content. The morphological parameters and compressive strength increased while a static coefficient of friction reduced with an increase in the age of the seedling. Regression and ANN (using FFBP method) models were developed for the prediction of compressive strength of seedling stem as well as a bulb with respect to the age and diameter. The ANN model was found best with the coefficient of determination of 0.76. It is concluded that 60 and 70 days, seedling is best suited for mechanical or automated transplanting.</div>

Morphological and Mechanical Characteristics of Onion Seedlings Insight to Mechanized Transplantation

The experiment was laid out in randomized block design with three replications and eight weed control treatments viz., weedy check, polythene mulching as pre emergence (PE), pendimethalin30EC (PE), chlorimuron ethyl 9g ha-1as post emergence (POE), quizalofop ethyl 50g ha-1 (POE), imazethapyr 100g ha-1 as early post emergence (EPOE), one hand weeding at 40 days after sowing (DAS) and two hand weeding at 20 and 40 DAS. The results showed that polythene mulching had the lowest weed dry matter due to effectively suppression of weed emergence. It was followed by twice hand weeding at 20 and 40 days after sowing. Weed index was found to be the highest with weedy check (42.10%) followed by the pre-emergence application of pendimethalin (19.09%). The effect of herbicide applied as pre-emergence was subdued at this belated stage, which may possibly be on account of longer period after application and restricted effective residual period. Plant height, number of pods per plant and grain yield of soybean was found to be highest in the treatments twice hand weeding at 20 and 40 DAS as well as polythene mulching. However, the net return and B:C ratio was lower in comparison to imazethapyr and quizalofop ethyl due to higher cost of labour and polythene material respectively. On an average, the application of imazethapyr as early post emergence (3.17) and quizalofop ethyl (3.02) gave significantly highest B:C ratio than the other treatments for soybean.