WEED MANAGEMENT IN AEROBIC RICE: ROLE OF ESTABLISHMENT METHODS AND HERBICIDES

2017 ◽  
Vol 55 (1) ◽  
pp. 88-104
Author(s):  
SUSHMITA MUNDA ◽  
SANJOY SAHA ◽  
TOTAN ADAK ◽  
NITIPRASAD JAMBHULKAR

SUMMARYWeed management in rice depends on establishment method and proper selection of herbicide. A field experiment was conducted during dry seasons of 2013 and 2014 to develop a robust strategy for effective weed management in aerobic rice system for tropical rice belts. The efficacy of post-emergent herbicides bispyribac-sodium, azimsulfuron and flucetosulfuron were evaluated under different rice establishment methods (row sowing, spot seeding and broadcasting). Grass weed species constituted 58–68% of the total weed density across the establishment methods in the weedy check treatment. The total weed density and weed biomass were lowest in spot seeding with azimsulfuron (35 g active ingredient (a.i.) ha−1) 30 and 60 days after sowing. Among herbicides, use of azimsulfuron caused the highest grain yield (5.2 Mg ha−1), realizing 72% increase in grain yield over the weedy check. Yields in row sowing and spot seeding were similar and the same was verified when comparing yields in plots treated with bispyribac-sodium and azimsulfuron. Based on our findings and considering both weed presence and grain yield, azimsulfuron in spot seeding can be recommended in aerobic rice.

2020 ◽  
Vol 5 (3) ◽  
pp. 320-327
Author(s):  
Md. Abdus Salam ◽  
Jannatul Ferdus ◽  
Afroza Sultana ◽  
Abu Salek

The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during the period from December 2017 through May 2018 to study the effect of rice residue on weed suppression and yield of boro rice. The experiment consisted of four different rice residue treatments such as no rice residue, 2.5, 5 and 7.5t ha-1rice residue, and five different herbicidal treatments such as no herbicide (H0), 25% of the recommended dose (RD), 50% RD, 75% RD and 100% of RD. The experiment was laid out in a randomized complete block design with three replications. Seven weed species belonging to five families infested the experimental plots. Weed density and weed dry weight were significantly affected by incorporation of rice residue and herbicidal treatment. The maximum weed growth was noticed with no rice residue incorporation and application of no herbicide. The minimum weed density and dry weight were found in incorporation of 5 t rice residue ha-1 and application of 100% of RD of herbicide treatment. Rice residue exerted significant effect on yield and yield contributing characters like plant height, number of total tillers hill-1, number of effective tillers hill-1 and grain yield. The highest grain yield (4.89 t ha-1) was recorded with the incorporation of 2.5 t ha-1 rice residue which was statistically identical with5 and 7.5 t ha-1 rice residues. The grain yield (5.70 t ha-1) produced by 75% of RD of herbicide was the highest among the other herbicidal treatments. The highest number of effective tillers hill-1 (12.80), 1000-grain weight (21.07), grain yield (5.87 t ha-1) and straw yield (7.21 t ha-1) were observed with the incorporation of 5 t rice residue ha-1 and 75% of the RD of herbicide treatment. Results of this study indicate that rice residue showed potentiality to inhibit the growth of weed and exerted significant effect on the yield of boro rice. Rice residue @ 5 t ha-1 with application of herbicide of 75% RD might be suggested to use for effective weed management and better grain yield of boro rice.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Alexandra M. Knight ◽  
Wesley J. Everman ◽  
David L. Jordan ◽  
Ronnie W. Heiniger ◽  
T. Jot Smyth

Adequate fertility combined with effective weed management is important in maximizing corn (Zea mays L.) grain yield. Corn uptake of nitrogen (N) is dependent upon many factors including weed species and density and the rate and formulation of applied N fertilizer. Understanding interactions among corn, applied N, and weeds is important in developing management strategies. Field studies were conducted in North Carolina to compare corn and weed responses to urea ammonium nitrate (UAN), sulfur-coated urea (SCU), and composted poultry litter (CPL) when a mixture of Palmer amaranth (Amaranthus palmeri S. Wats.) and large crabgrass (Digitaria sanguinalis L.) was removed with herbicides at heights of 8 or 16 cm. These respective removal timings corresponded with 22 and 28 days after corn planting or V2 and V3 stages of growth, respectively. Differences in N content in above-ground biomass of corn were noted early in the season due to weed interference but did not translate into differences in corn grain yield. Interactions of N source and N rate were noted for corn grain yield but these factors did not interact with timing of weed control. These results underscore that timely implementation of control tactics regardless of N fertility management is important to protect corn grain yield.


2020 ◽  
pp. 7-30
Author(s):  
Md. Golam Mostafa ◽  
Syed Arvin Hassan ◽  
Md. Ehsanul Haq ◽  
Md. Ahasan Habib ◽  
Kaniz Fatema ◽  
...  

A field experiment was conducted in medium fertile soil at Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during November 2017 to April 2018 in Rabi season with a view to evaluate the performance of wheat varieties under different weed control methods. The experiment was carried out with three varieties i.e. BARI Gom-28, BARI Gom-29 and BARI Gom-30 in the main plot and five weed management methods viz. control (no weeding), two hand weeding at 20 and 40 DAS, Panida 33EC (Pendimethalin) @ 2000 ml ha-1 at 5 DAS pre-emergence, Afinity 50.75WP (Isoproturon) 1500 g ha-1 at 25 DAS as post-emergence herbicide and Panida 33EC (Pendimethalin) @ 2000 ml ha-1 at 5 DAS + Afinity 50.75WP (Isoproturon)1500 g ha-1 at 25 DAS in the sub plot in split plot design. Nine different major weed species were found in the field such as Cynodon dactylon, Cyperus rotundus, Echinochloa colonum, Eleusine indica, Chenopodium album, Alternanthera philoxeroides, Brassica kaber, Leliotropium indicum, Vicia sativa. Results reveled that BARI Gom-30 contributed the highest grain yield 3.01 tha-1. Pre-emergence application of Panida 33EC controlled weeds significantly which showed highest growth followed by yield achieved in wheat. BARI Gom-30 in combination with Panida 33EC produced the highest grain yield 3.52 tha-1 while the lowest grain yield 2.09 t ha-1 was obtained from BARI Gom-28 with no weeding treatment. Results reveled that Panida 33EC (pre-emergence) was found more effective to controlling weeds in wheat. Results of the study finally reveled that Panida 33EC might be considered as a feasible option for combating weed and ensuring higher yield in wheat cultivation.


2020 ◽  
Vol 34 (6) ◽  
pp. 876-881
Author(s):  
Jed B. Colquhoun ◽  
Richard A. Rittmeyer ◽  
Daniel J. Heider

AbstractWeed management in carrot is challenging, given slow and inconsistent crop emergence and early-season growth and the lack of practical season-long management tools such as herbicides. We investigated holistic carrot production systems with a focus on minimizing inputs while optimizing resource use. In an overall sense, results of this work were consistent between years, and stark. The choice of carrot variety had a moderate influence on carrot foliar canopy development and, subsequently, weed density. For example, ‘Cupar’ carrot formed a complete crop canopy sooner than the other dicer-type ‘Canada’ variety. Likely as a result, density of weed species such as spotted ladysthumb and common lambsquarters was less where ‘Cupar’ was grown compared with where ‘Canada’ was grown. Gibberellic acid as a foliar application was not successful in these studies and, in a few cases, may have even increased weed-seed germination and establishment. Adding two carrot rows to the current regional industry-standard three-row bed system not only enhanced competitiveness with weeds but also improved carrot yield without additional fertilizer, water, or pest management inputs. By far, though, the most successful strategy to reduce weed density while maintaining or improving carrot yield was to delay seeding by 17 to 19 d. We anticipate more holistic production system research that integrates low-input alternatives in other crops as herbicide-resistant weeds proliferate while few new herbicides are developed. As was demonstrated in this research, such novel approaches can be successful without adding significant economic burden to the farmer or increasing risk of crop failure.


2017 ◽  
Vol 15 (2) ◽  
pp. 133-139
Author(s):  
MN Hossain ◽  
MR Uddin ◽  
UK Sarker ◽  
S Ferdousi ◽  
MJ Uddin

Crop allelopathy may be useful to minimize serious problems in the present agricultural production such as environmental pollution, unsafe production, human health concerns, depletion of crop diversity, soil sickness and reduction of crop productivity. In this phenomenon an experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh to evaluate the effect of crop residues of mustard on weed management and crop performance of T. aman rice. The experiment consisted of three cultivars of T. aman rice viz., BR11, BR23 and BRRI dhan49 and five different level of mustard crop residues such as no crop residues, mustard crop residues @ 0.5, 1.0, 1.5 and 2.0 t ha–1. The experiment was laid out in a randomized complete block design with three replications. Five weed species belonging to three families infested the experimental plots. Weed population, weed dry weight and percent inhibition of weed were significantly influenced by mustard crop residues and cultivar. The maximum weed growth was noticed with the cultivar BR23 and the minimum was found in the cultivar BR11. The grain yield as well as the other yield contributing characters produced by BR11 was the highest among the studied varieties. The highest percent inhibition of 71.17, 69.19, 80.88, 70.48 and 86.97 was in Shama (Echinochlo acrusgalli), Panishapla (Nymphaea nouchali), Panichaise (Scirpus juncoides), Panikachu (Monochoria vaginalis) and Susnishak (Marsilea quadrifolia), respectively which was caused by the application of mustard crop residues @ 2 t ha–1. The highest loss of grain yield was obtained where no crop residues were incorporated. The highest numbers of tillers hill-1, numbers of grains panicle–1, 1000-grain weight, grain yield, straw yield were observed where mustard crop residues were incorporated @ 2.0 t ha–1. BR11 cultivar with all treatments produced the highest grain and straw yield among the treatment combination. The results of this study indicate that different amount of mustard crop residues showed potential activity to suppress weed growth.J. Bangladesh Agril. Univ. 15(2): 133-139, December 2017


2019 ◽  
Vol 34 (3) ◽  
pp. 408-415
Author(s):  
Gatlin Bunton ◽  
Zachary Trower ◽  
Kevin W. Bradley

AbstractDuring the 2015, 2016, and 2017 growing seasons, a survey of 63 pastures in Missouri was conducted to determine the effects of selected soil and forage parameters on the density of common annual, biennial, and perennial weed species. Permanent sampling areas were established in each pasture at a frequency of one representative 20-m2 area per 4 ha of pasture, and weed species and density in each area were determined at 14-d intervals for a period from mid-April until late September. The parameters evaluated included soil pH, phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), sulfur (S), zinc (Zn), manganese (Mn), and copper (Cu) concentrations, as well as tall fescue density, forage groundcover density, and stocking rate. An increase of 1 unit in soil pH was associated with 146 fewer weeds per hectare, the largest reduction in weed density in response to any soil parameter. Increased soil pH was associated with the greatest reduction in perennial grass weed density, along with an average reduction of 1,410 brush weeds per hectare for each 1-unit increase in soil pH. Common ragweed, a widespread weed of pastures, could be reduced by 3,056 weeds ha−1 when soil pH was 1 unit greater. A 1-ppm increase in soil P was correlated with a decrease of 206 biennial broadleaf weeds per hectare. Perennial broadleaf weed density was reduced in soils with greater concentrations of P, K, and Ca. Additionally, for every 1% increase of tall fescue and forage groundcover, there was a decrease of 18 and 38 perennial broadleaf weeds per hectare. The results from this research indicate that the density of many common weed species can be reduced with higher soil pH and adjustments to soil macro- and micronutrient concentrations, especially P.


Weed Science ◽  
1996 ◽  
Vol 44 (1) ◽  
pp. 126-132 ◽  
Author(s):  
Anita Dieleman ◽  
Allan S. Hamill ◽  
Glenn C. Fox ◽  
Clarence J. Swanton

Weed control decision rules were derived for the application of postemergence herbicides to control pigweed species in soybean. Field experiments were conducted at two locations in 1992 and 1993 to evaluate soybean-pigweed interference. A damage function was determined that related yield loss to time of pigweed emergence, density, and soybean weed-free yield. A control function described pigweed species response to variable doses of imazethapyr and thifensulfuron. The integration of these two functions formed the basis of an economic model used to derive two weed control decision rules, the biologist's “threshold weed density” and the economist's “optimal dose.” Time of weed emergence had a more significant role than weed density in the economic model. Later-emerging pigweed caused less yield loss and therefore, decision rules lead to overuse of herbicides if emergence time is not considered. The selected herbicide dose influenced the outcome of the control function. Depending on the desired level of weed control, a herbicide could be chosen to either eradicate the escaped weed species (label or biologically-effective doses) or reduce the growth of the weed species and thereby offset interference (optimal dose). The development of a biologically-effective dose by weed species matrix was recommended. Decision rules should not be utilized as an exclusive weed management strategy but rather as a component of an integrated weed management program.


Author(s):  
Melih Yilar Omer Sozen ◽  
Ufuk Karadavut

This study was conducted to determine the effects of weed density and different weed control treatments on chickpea yield and yield components. The experiment was carried out in split plot design with 3 replications in experimental fields of Kirsehir Ahi Evran University during 2016 and 2017 crop seasons. Total nine treatments (no weed control, permanent weed control, one-time hoeing, two-time hoeing, three-time hoeing, herbicide application after emergence, one-time hoeing with herbicide application, two-time hoeing with herbicide application and three-time hoeing with herbicide application) were compared to know the most effective weed control method. Vaccaria pyramidata Medik., Sinapis arvensis L., Acroptilon repens L. weed species were found to be the most intense in the experimental area. All weed control applications had significant effect on chickpea yield and yield components compared to weedy plots. Three-time hoeing with herbicide application increased the yield by 361.55-478.50% compared to weedy plots. Likewise, three-time hoeing application even increased the yield by 348.50-357.09% compared to weedy plots. The results revealed that three-time hoeing with herbicide and three-time hoeing applications stood out in weed management to obtain a good yield in chickpea cultivation at Kirsehir province.


2014 ◽  
Vol 28 (4) ◽  
pp. 729-733 ◽  
Author(s):  
Héctor Roberto Huarte ◽  
Antonio Jesús Ruiz Carmona ◽  
María Luz Zapiola

Understanding seed biology and onset of germination requirements is a key point for designing effective weed management programs. Gibberellins (GAs) are known to play a role in onset of germination of several species. Onset of germination often requires an increase in de novo GA content or an increase in sensitivity to GAs. Reduced germination of seeds incubated in solutions containing compounds that inhibit GA synthesis provide evidence that GAs are required to trigger germination. Trinexapac-ethyl (TE), a GA synthesis inhibitor, is frequently used as a plant growth regulator in crop production. However, to the best of our knowledge, TE has not been used to study the requirement of GAs in onset of germination. Germination studies were conducted using seeds of artichoke thistle and common teasel under a range of TE concentrations (0 to 500 μM TE), a combined solution of 125 μM TE + 100 μM GA3for artichoke, and 250 μM TE + 100 μM GA3for common teasel. Germination tests were conducted at 20/10 C (12-h thermoperiod) in darkness for artichoke and at constant 15 C with 12 h of light for common teasel. Germination of artichoke in 125 μM TE was reduced to 47% when compared with the check (95%), but the combined TE + GA3solution maintained germination at 84%. Germination of common teasel in 250 μM TE was reduced to 10% when compared with the check (91%), and the combined TE + GA3solution increased germination to 63%. These results demonstrate the utility of TE to study the role of GAs in onset of germination. This novel use of TE is a valuable option to study germination requirements of weed species, and therefore contributes to the design of weed management programs.


2017 ◽  
Vol 5 (3) ◽  
pp. 387-395
Author(s):  
Raj Kumar Nagar ◽  
Dinesh Kumar Jain

A field experiment was conducted to analyze the types of flora, intensity, cover and effects on yields of coriander. Pooled analysis of data indicated that Goose foot (Chenopodium murale L.), Corn spurry (Spergula arvensis L.) among dicots and Purple nutsedge (Cyperus rotundus L.) among monocots were found most dominant weeds at all stages of crop growth. Of the total eight weed species reported dicot weeds were found most dominating weed species and comprises 78-80 percent of total weed density throughout crop cycle. All weed management practices significantly reduced the density of monocot and dicot weeds and improved the yield (seed and biological yield) of crop as compared to control. Two hand weeding at 30 and 45 DAS resulted in maximum reduction in total weed density and gave the highest seed (15.84 q/ha) and biological yield (41.11 q/ha) of coriander. However, seed and biological yields was obtained at par by pendimethalin 1.0 kg/ha + one hand weeding at 45 DAS. This treatment also resulted in favorably lowest weed competition index as compared to rest of other practices. Balanced fertilization with N+P+K+S also improved monocot and dicot weed density but the effect was not significant over N+P and N+P+K fertilization. N+P+K+S fertilization significantly enhanced crop seed and biological yields over N+P (1.86 q/ha and 4.36 q/ha, respectively) and N+P+K application (0.94 q/ha and 2.20 q/ha, respectively). Weed management and balanced fertilization practices also found to have significant interaction effect on seed and biological yield of coriander.


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