Weed Yield Research Articles

Tillage and nitrogen management effects on weed seedbank and yield of fingermillet

Field and pot culture studies were conducted at Bengaluru to study the influence of three tillage practices, viz. conventional tillage (3 ploughings + 3 inter cultivations), reduced tillage (2 ploughings + 2 inter cultivations) and minimum tillage (1 ploughing + 1 inter cultivation) and three nitrogen management practices, viz. 100% N through Urea, 100% N through integrated supply (50% N through urea+ 25% N through FYM+ 25% N through Glyricidia) and 100% N through organic source (50% N through FYM+ 50% N through Glyricidia) on live weed seedbank and yield of fingermillet (Eleusine coracana L.) under rainfed pigeonpea-fingermillet system in Alfisols. The results showed that conventional tillage reduced the infestation of Borreria articularis, Cynodon dactylon and Cyperus rotundus compared to other tillage practices. However nitrogen management practices didn't influence live weed seed bank significantly. Among tillage practices, conventional tillage recorded significantly higher fingermillet yield (3.03 t/ha) compared to other tillage practices and among nutrient management practices integrated supply of N recorded higher yield of 2.67 t/ha compared to other nutrient management practices. More live weed seeds were distributed in upper 10 cm soil depth in minimum tillage whereas in conventional tillage live weed seed distribution was more or less uniform in the soil profile studied.

Tillage effects on weed biomass and yield of direct-seeded rice

Field experiments were conducted during the rainy seasons of 2011 and 2012 in Odisha, India to evaluate the efficiency of different tillage practices at beausaning on weed flora and yield of direct-seeded rice (Oryza sativa L.). Two passes of ploughing at 5 cm depth and 15 cm spacing with country plough at ‘beausaning’ showed the highest yield of grain (4.06 t/ha) and straw (4.66 t/ha), which was associated with higher weed control efficiency, effective tillers/hill, panicle length, number of filled grains/panicle, 1000-grain weight and with lower number of non-bearing tillers/hill and sterile spikelet/panicle. The lowest value of all parameters was found in 1 and 2 passes with tractor. Two passes by power tiller was as good as 2 passes by country plough in controlling weeds and achieving higher yield. Though 1 and 2 passes with country plough and power-tiller showed statistically identical result, but the B: C ratio (2.25) was more in later treatment than the former (2.10).

Performance of Herbicides in Black Gram(Vigna MungoL.) and Associated Weed Flora

A field experiment was conducted during 2014 and 2015. To evaluate the effect of weed management practices on weed flora, weed dry weight, yield attributes and yield of blackgram (Vigna mungo L.). All the weed species were controlled effectively by the application of herbicides. Among the herbicides with the application of Pendimethalin 900 g ha-1 as pre - emergence + one hand weeding recorded minimum total dry weight in weeds and maximum grain yield of blackgram. The reduction in total dry weight (25.4 g m-2) and maximum yield was found in hand weeding at 20 and 40 DAS. However Pendimethalin 900 g ha-1 Pre-emergence+ one hand weeding and Imazethapy + Pendimethalin (Pre-emergence) was found at par with two hand weeding.

Effect of herbicides on weed infestation and yield in boro rice

A field experiment was conducted at the agronomy field of the Bangladesh Institute of Nuclear Agriculture (BINA), Mymensingh, Bangladesh, under wet land condition during December 2014 to May 2015. The aim was to see the effects of the weed control treatments on crop growth and yield in boro rice. Five selected herbicides (Metsulfuron-methyl 20 WG at 50 g/ha, pretilachlor 500 EC at 988 ml/ha, bensulfuran methyl 4%+acetachor 14% 18 WP at 800 g/ha, pyrazosulfuron-ethyl 10 WP at 125 g/ha and butachlor 5G at 25 kg/ha) were tested along with two hand weedings. Population density, fresh and dry weight of weed were taken. Eight weed species belonging to five families, namely, Echinochloa colonum, Paspalums crobiculatum, Monochoria vaginalis, Leersia hexandra L., Scirpus mucronatus L., Digitaria sanguinalis, Cyperus rotundus and Eclipta alba Hassk were found to grow in the experimental plots. Among the weed control treatments highest grain yield (5.73 t/ha) was produced with the treatment pyrazosulfuron-ethyl 10 WP at 125 g/ha followed by two hand weedings (5.50 t/ha). The increased yield due to application of herbicide contributed mainly from increasing the number of total tillers per plant, effective tillers per plant, filled grains per panicle and 1000-seed weight (g). Maximum benefit: cost ratio with pyrazosulfuron-ethyl 10 WP at 125 g/ha suggested that this herbicidal treatment could be used as an alternative when labour was a limiting factor in producing transplant boro rice.

Management of mixed weed flora in transplanted rice using herbicide combinations

A field experiment was conducted to study the bio-efficacy of herbicide combinations on mixed weed flora and productivity in puddled transplanted rice. Twelve treatments including bispyribac-Na 25 g/ha, penoxsulam 22.5 g/ha, bispyribac-Na 25 g + ethoxysulfuron 18.75 g/ha, tank-mix of bispyribac-Na 20 g + pre-mix of chlorimuron + metsulfuron 4 g/ha, pretilachlor 750 g followed by (fb) ethoxysulfuron 18.75 g/ha, pretilachlor 750 g fb pre-mix of chlorimuron+metsulfuron 4 g/ha, pyrazosulfuron 20 g fb pre-mix of chlorimuron + metsulfuron 4 g/ha, pre-mix of penoxsulam + cyhalofop 135 g/ha, pre-mix of triafamone + ethoxysulfuron 60 g/ha and pendimethalin 750 g at fb bispyribac-Na 25 g/ha along with hand weedings and weedy check were tested. Different herbicides recorded effective weed control and yield increase of 52–66% compared with weedy check. Unchecked weed growth depleted the soil of 234.2 kg N/ha, 17.6 kg P/ha and 292.7 kg K/ha. Sequential application of pyrazosulfuron and chlorimuron + metsulfuron (pre-mix) could not control grasses and yielded poorly compared with other herbicide combinations. Post-emergence, tank-mix application of bispyribac-Na with either ethoxysulfuron or chlorimuron + metsulfuron (pre-mix) recorded comparable yield to as obtained with sequential application of pendimethalin and bispyribac-Na or pretilachlor with either ethoxysulfuron or chlorimuron + metsulfuron (pre-mix).

Benefit of Adding Ammonium Sulfate or Additional Glyphosate to Glyphosate in Corn and Soybean

Nine field trials (4 in corn and 5 in soybean) were conducted over 2 years (2014 and 2015) to determine if there is greater benefit of adding ammonium sulfate (AMS) (2.5 L·haˉ1) or an equal dollar value of glyphosate (406 g·ae·haˉ1) to glyphosate applied at 450, 675 or 900 g·ae·haˉ1 for weed control in corn and soybean. Glyphosate applied at 450 g·ae·haˉ1 controlled velvetleaf 90% to 98%, common ragweed 80% - 97%, common lambsquarters 91% - 99%, Eastern black nightshade 83% - 100% and barnyardgrass 73% - 97% in corn and common ragweed 37% - 89%, common lambsquarters 39% - 98%, barnyardgrass 90% - 98% and green foxtail 91% - 98% in soybean. The addition of AMS to glyphosate applied at 450, 675 or 900 g·ae·haˉ1 provided little to no added benefit for the control of velvetleaf, common ragweed, common lambsquarters, Eastern black nightshade, barnyardgrass and green foxtail in corn and soybean. There was a greater benefit in weed control efficacy by simply adding and equal dollar value of glyphosate (406 g·ae·haˉ1) than AMS (2.5 L·haˉ1) to glyphosate. There was no difference in corn or soybean yield among the herbicide treatments evaluated. Based on these results, addition of AMS to glyphosate at rates evaluated had little benefit on weed control efficacy or yield of corn and soybean.

Effect of nitrogen and weed management on weed control efficiency and yield of fodder turnip

A field experiment was conducted at Forage Research and Management Centre, NDRI, Karnal during <italic>rabi</italic> season in 2013-14 to study the effect of nitrogen application and weed management on growth and yield of fodder turnip (<italic>Brassica compestris</italic> var. rapa) with four levels of nitrogen (0, 50, 100, and 150 kg N/ha) and four weed management practices (pendimethalin @ 1.0 kg a.i./ha, hand weeding, isoproturon @ 0.75 kg a.i./ha and weedy check) in split plot design. Among the nitrogen treatments 150 kg nitrogen/ha gave the highest growth, yield and better quality of fodder turnip. Application of pendimethalin @1.0 kg a.i. proved better in terms of growth and yield of turnip. Weed control efficiency was 65% with 150 kg N/ha and 83.23% with pendimethalin 1.0 kg a.i./ha.

Productivity and energy efficiency of three tillage systems for maize (Zea mayz L.) production

The amount of inputs and dry matter yields of grain, stover and weeds were quantified in six sites located in the districts of Zaachila and Etla, in the Central Valleys of Oaxaca Region, Mexico. The tillage systems evaluated, which are the most widely used for corn production in this region, were full animal traction (FAT), mixed traction (MXT) and mechanical traction (MT). The higher productivity was achieved in the MT system, followed by the MxT system . According to the energy balance, the largest energy efficiency (EE) was achieved in the FAT system with a value of 34.4 and the least one with the MT system. The lowest EE of the MT system was associated to a higher use of machinery operations and the use of petrol derivate products . N o significant differences in EE were found between the FAT and MxT systems; when weed`s dry matter production was considered, EE in this last system was increased 14 %, while in the FAT system an 8 % increase was observed. Therefore, besides the FAT system MxT is also recommended because in the region it is common to have plots smaller than 1 ha and mechanical plowing is more efficient for primary tillage operations while animal power can be used as a renewable source of energy for tasks such as weeding and transport.

Differences between organically grown varieties of spring wheat, in response to weed competition and yield

AbstractWhen growing wheat, one of the non-chemical methods of weed regulation is to choose wheat varieties which have a high ability to compete with weeds. The first aim of the research was the estimation of the relationships between the morphological features and canopy parameters of six spring wheat varieties. The second aim was the estimation of the varieties’ competitive ability against weeds. The third aim was the estimation of the grain yield of the six varieties. The experiment was carried out in the 2011–2013 time period, on fields which had been organically managed since 1994. Different features affected the weed infestation levels of the spring wheat varieties. For Bombona, negative correlations between the number of weeds and the height, dry matter of wheat, and wheat density, were proved. For Brawura, Hewilla, and Żura, the height, number of tillers, and dry matter of wheat were the main factors influencing weed abundance. A strong negative correlation between the number of weeds and the dry matter of wheat was found for Parabola. Cluster analysis indicated that Bombona and Brawura were the most competitive against weeds, while Monsun and Parabola were characterized as being the least competitive against weeds. Weed number significantly affected the grain yield of spring wheat (r= −0.418). The grain yield was positively correlated with the number of tillers (r= 0.459) and ears (r= 0.355), and the height (r= 0.534) and wheat dry matter (r= 0.411). Bombona and Brawura were the lowest yielding varieties (3.03 and 3.20 t · ha−1, respectively), whereas the highest yield was achieved by Żura (3.82 t · ha−1, on average).

Effect of nitrogen and wheat residue on cotton (Gossypium hirsutum L.) yield and weed control

Wheat (Triticum aestivum L.) residues and nitrogen (N) management are the major problems in the southern part of Iran where irrigated wheat–cotton (Gossypium hirsutum L.)–wheat rotation is a common practice. A 2-year (2009–2011) field experiment was conducted as a split plot design with four replications at a cotton field (Darab), Fars Province, Iran, to determine the influence of different rates of wheat residue (0%, 25%, 50%, and 75%) incorporation and N rates (150, 200, 300, and 400 kg ha−1) on weed suppression, yield, and yield components of cotton. Results showed that a higher residue incorporation and a lower N rate improved weed suppression in both years. For treatments receiving 150 kg N ha−1 and 75% of wheat residues (2250 kg ha−1), weed biomass and density were significantly lower compared to treatments receiving 400 kg N ha−1. The highest cotton lint yield (about 2400–2700 kg ha−1) was obtained by 300 kg N ha−1 in the absence of residue application, in both years. Incorporation of 25% of wheat residue (750 kg ha−1) and application of 300 kg N ha−1 are recommended to guarantee an optimum level of cotton lint yield and weed suppression in a wheat–cotton–wheat rotation in this region.

Effect of nitrogen scheduling and weed management on weed density, growth and yield of direct-seeded rice (Oryza sativaL.)

A field experiment was conducted during rainy (kharif) seasons of 2012 and 2013 to study the effect of nitrogen scheduling and weed management in direct-seeded rice (Oryza sativa L.) under irrigated condition. Nitrogen scheduling significantly reduced the total weed density and dry weight and increased the yield-attributing charactersand yield of crop. The results indicated that the minimum total weed density and dry weight, and maximum crop growth and yield attributing characters were recorded under four nitrogen splits: ¼ 2 WS+¼ 4 WS+¼ 6 WS+¼ 8 WS followed by 1/3 2 WS+1/3 4 WS+1/3 6 WS. Application of nitrogen scheduling at ¼ basal+¾ 4 WS and ¼ basal+½ 4 WS+¼ 6 WS recorded higher weed density and dry weightat all stages of observation during both the years. The various weed management treatments significantly decreased the density and dry weight of weed and increased the weed control efficiency, growth and yield attributing characters compared with the weedy check. Application of pendimethalin 1.0 kg/hafb bispyribac+carfentrazone (25 + 20 g)/ha and pendimethalin 1.0 kg/ha fb bispyribac+ethoxysulfuron (25+18 g)/ha recorded minimum weed density and dry weight of weed and increased the weed control efficiency, growth and yield attributing characters comparable to other treatments.

Effect of different weed management practices on weed population, yield potential and nutrient status of peach cv. July Elberta

The investigation was carried out in the experimental farm of Department of Fruit Science, Dr. Y. S. Parmar University of Horticulture and Forestry, Nauni, Solan (H. P.) to see the effect of different weed management practices on weed population and yield potential of peach cv. July Elberta during the years 2012 and 2013. The experiment was laid out with 13 treatments in randomized block design and replicated thrice. The peach trees of cv. July Elberta were treated with different treatment combinations viz., T1: Pendimethalin (1.0 kg/ha), T2: Pendimethalin (1.5 kg/ha), T3: Pendimethalin (2.0 kg/ha), T4: Glyphosate (0.8 kg/ha), T5: Glyphosate (1.6 kg/ha), T6: Glyphosate (2.4 kg/ha), T7: Pendimethalin (1.0 kg/ha) followed by glyphosate (0.8 kg/ha), T8: Pendimethalin (1.5 kg/ha) followed by glyphosate (0.8 kg/ha), T9: Pendimethalin (2.0 kg/ha) followed by glyphosate (0.8 kg/ha), T10: Pendimethalin (2.0 kg/ha) followed by grass mulch, T11: Grass mulch followed by glyphosate (0.8 kg/ha), T12: Hand weeding at 30 days interval and T13: Control. The results revealed that the treatment combination of grass mulch followed by two applications of glyphosate 0.8 kg/ha (first week of April and second mid-July) was found to be the best treatment for most of the characters among all the treatments and maximum weed control efficiency was registered in T9. Finally, the treatment T11: Grass mulch followed by two sprays of glyphosate 0.8 kg/ha was found to be the most economical (B: C ratio 4.31: 1) for fruit grower's point of view.

The impact of no-tillage cultivation and white mustard as a cover crop on weed infestation and yield of carrot and red beet

In a two-year field experiment, no-tillage cultivation using white mustard (<em>Sinapis alba</em> L. ‘Bardena’), 30 kg ha<sup>−1</sup>, as a cover crop did not influence emergence of red beet (<em>Beta vulgaris</em> L. ‘Czerwona Kula REW’) and had a favorable effect on emergence of carrot (<em>Daucus carota</em> L. ‘Berlikumer 2 – Perfekcja REW’). However, further growth of both vegetables was significantly slower under no-tillage cultivation. Both vegetables produced a higher yield of roots and the diameter of these roots was bigger under conventional cultivation. The effect of cultivation method on the content of total nitrogen, phosphorus, potassium, calcium and magnesium in carrot and red beet leaves varied, while the content of dry matter, monosaccharides and total sugars was significantly higher in the roots of both vegetables harvested under no-tillage cultivation. The number of weeds growing on no-tilled plots covered with mustard mulch 4 weeks after seed sowing was lower by about 75%, but their fresh weight was higher more than 6 times in comparison to that under conventional cultivation. This was caused by the emergence of wintering and winter hardy weeds in places not covered by mustard plants in the autumn of the year preceding the cultivation of vegetables. Next year, they started to grow in the early spring and some of them produced a considerable amount of fresh weight and attained the flowering stage in the middle of April.

Influence of tank mixtures of pre-emergence herbicides on growing leeks (Allium porrum L.)

The effect of mixtures of pre-emergence herbicides on weed infestation and yield of leek was evaluated. Three tank mixtures were applied: s-metolachlor (Dual Gold 960 EC at a dose of 80 ml/da) + oxyfluorfen (Goal 2 E at a dose of 100 ml/da); s-metolachlor (Dual Gold 960 EC at a dose of 60 ml/da) + oxyfluorfen (Goal 2 E at a dose of 75 ml/da); and s-metolachlor (Dual Gold 960 EC at a dose of 40 ml/da) + oxyfluorfen (Goal 2 E at a dose of 50 ml/da). The number of weeds was recorded following the application of the tank mixture. It was found that treatment with a tank mixture of herbicides Dual Gold 960 EC and Goal 2 E caused a reduction in weed infestation at all three application rates as compared to the control. The lowest weed infestation was established after treatment with the highest doses of herbicides. It was suggested that the applied herbicide mixture could be used effectively at the leeks growth stage.

Chemical, mechanical and integrated weed management under two phosphorous fertilizer application methods in rapeseed

A two-year field experiment was conducted in 2011 and 2012 at the College of Agriculture and Natural Resources, Shiraz University, Iran to determine the effect of the herbicide trifluralin, mechanical and integrated weed control under different application methods of P fertilizer (midrow banded and surface broadcast) on weed biomass and yield of rapeseed, cultivar Talayeh. Plants grown in unweeded plots at midrow banded and surface broadcast P fertilization methods produced the greatest rapeseed yield (3217 and 1034 kg ha−1, respectively). The increasing effect of P fertilizer on rapeseed yield was less consistent when rapeseed was competing with weeds. It showed that weeds were able to prevent rapeseed from capturing the full benefit of P fertilizer. Trifluralin at 1400 g ha−1 + rotary cultivator + sweep cultivator consistently provided the highest rapeseed grain (2953.5 and 2912 kg ha−1, respectively) and oil yield (1363 and 1320 kg ha−1, respectively). Additionally, trifluralin alone did not provide acceptable full season weed control in rapeseed. Since mechanical weed control implements such as rotary and sweep cultivators are available and inexpensive to Iranian farmers, trifluralin at 1400 g ha−1 + rotary cultivator + sweep cultivator is recommended to improve weed control in rapeseed.

Weed dynamics, yield, quality and root growth of capsicum under drip irrigation and mulching

A field experiment was conducted during 2006-07 and 2007-08 at Precision Farming Development Centre, Horticulture Farm, Indira Gandhi Agricultural University, Raipur, Chhattisgarh, India to evaluate the weed dynamics, yield, quality, organoleptic parameters and root growth of Capsicum as influenced by drip irrigation and mulches. The black polythene mulch being at par with paddy straw mulch gave the least weed population, dry weight and highest weed control efficiency over other mulches. Drip irrigation at 0.6 Epan obtained the least value of weed growth and highest weed control efficiency. Drip irrigation at 1.0 Epan showed highest fruit yield (32.02 t ha-1), total soluble solid (5.72), ascorbic acid (120.25 mg 100g-1) and organoleptic parameters but root growth registered maximum in flood irrigation at 1.0 IW/CPE. Black polythene followed by paddy straw mulch showed maximum fruit yield and other parameters. Pungent test scored maximum with flood irrigation at 1.0 IW/CPE and no mulch. Drip irrigation at 1.0 Epan along with black polythene as well as paddy straw mulch restrict weed growth, harvested quality fruit with higher fruit yield of capsicum. DOI: http://dx.doi.org/10.3329/sja.v10i2.18325 SAARC J. Agri., 10(2): 71-82 (2012)

Companion Crops for Organic Alfalfa Establishment

In organic cropping systems, companion crops are used for establishment of forage legumes, but a comparison of alternative companion crops for alfalfa (Medicago sativa L.) has not been conducted. We determined the yield of spring‐seeded companion crops and their effect on alfalfa forage yield, weed yield, and net return in five environments. Crops were managed using organic practices. Barley (Hordeum vulgare L.) was among the highest yielding small grains, while annual ryegrass (Lolium multiflorium Lam.) was among the highest yielding forage companion crops. Companion crop effects on alfalfa yields were inconsistent among environments. In the establishment year, in two environments, alfalfa yields were similar for all establishment treatments. In three environments, rapid cycling brassica (Brassica rapa L.), annual ryegrass, and winter wheat (Triticum aestivum L.) companion crop treatments often resulted in alfalfa yields that were greater than those following field pea (Pisum sativum L.), flax (Linum usitatissimum L.), barley, oat (Avena sativa L.), and wheat. In the year following seeding, alfalfa yields in three environments were similar for all treatments, while in two environments, all treatments except field pea had yields equal to a weedy control. Spring‐seeded wheat, barley, and oat companion crops provided greater net returns than the control, field pea, flax, or forage (non‐vernalized winter wheat, annual ryegrass, and rapid‐cycling brassica) companion crop treatments. Small grain companion crops provide high and consistent net returns without adversely affecting alfalfa yields, and should be used for alfalfa establishment in organic crop production systems.

Diversity of weed flora, selected biometric characteristics and yielding of Miscanthus spp. cultivated on light and heavy soil

<p>An important issue related to the cultivation of plants for energy purposes and poorly recognized so far is their impact on the environment, including biodiversity. The aim of the work was to assess weed flora diversity, canopy structure and yield of miscanthus<em> </em>cultivated on two types of soil: light and heavy.</p><p>The study was carried out in the Experimental Station of the Institute of Soil Science and Plant Cultivation – State Research Institute at Osiny, Poland (N:51<sup>o</sup>28, E:22<sup>o</sup>4), on two fields of miscanthus (<em>Miscanthus saccharflorus Robustus × M. sinensis</em>– M-115) established in 2004, on light loamy sand and heavy loam. The analysis of weed flora was carried out in 2010 and 2011, in mid-June and mid-August, using two methods: the frame method and phytosociological relevés. Moreover, an analysis of green and dry matter yield of miscanthus, some biometric features and leaf area index (LAI) was carried out.</p><p>The results showed that weed species diversity in a miscanthus crop was dependent on soil type. A larger number of weed species was found in miscanthus cultivated on heavy soil – 37 – in comparison with miscanthus cultivated on light soil – 33. Sorensen’s indicators showed low similarity between weed communities in miscanthus on light and heavy soil. Weed abundance and percentage of weed cover were lower in miscanthus cultivated on light soil. Weed density decreased during the vegetation season as a result of increasing competitiveness of the miscanthus canopy against weeds. Miscanthus yields were more dependent on weather conditions than the type of soil. Plant height and shoot diameter as well as leaf area index (LAI) were higher in miscanthus grown on heavy soil.</p>

Effects of post emergence herbicides on weed control and yields of field pea and their residual effect on succeeding sorghum and mungbean crop.

A field experiment was conducted during 2008-09 and 2009-10 to evaluate different post emergence herbicides applied against weeds in field pea and their residual effect on succeeding sorghum and mungbean crop. Pendimethalin herbicide applied 1.5 kg ha-1 as pre-emergence gave effective control against all the weeds whereas, among post emergence herbicides imazethapyr was found effective against broadleaf weeds and quizalofop-ethyl was effective only against grassy weeds. During both the years, application of imazethapyr 50 g ha-1 at 30 days after sowing gave effective control of weeds and resulted minimum density and dry biomass of weeds compared to all the post emergence herbicide treatments. During second year, residual effect of imazethapyr was observed only on sorghum crop.

Evaluation of Winter Wheat Genotypes for Weed Competitiveness and Yield under Organic Production Management

Evaluation of Winter Wheat Genotypes for Weed Competitiveness and Yield under Organic Production Management