Influence of Weed Competition on Cotton

Weed Science ◽  
1970 ◽  
Vol 18 (1) ◽  
pp. 149-154 ◽  
Author(s):  
Gale A. Buchanan ◽  
Earl R. Burns
Keyword(s):  
Gossypium Hirsutum ◽  
Plant Height ◽  
Weed Control ◽  
Stem Diameter ◽  
Control Measures ◽  
The Other ◽  
Weed Competition ◽  
Cotton Yield ◽  
Critical Periods ◽  
Annual Weeds

Cotton (Gossypium hirsutumL.) grown at two locations in Alabama from 1966 to 1968 produced maximum yields when kept free of annual weeds for approximately 8 weeks after emergence. Weed control for longer periods failed to increase yields. When initial weed control measures were delayed until 6 to 7 weeks after emergence at one location and 4 to 5 weeks at the other location, cotton was not injured. Prolonged weed competition past the critical periods usually resulted in drastic cotton yield reductions. Plant height and stem diameter of cotton were reduced by some of the weed competition treatments.

The Concept and Application of Early Economic Period Threshold: The Case of DCPA in Onions (Allium Cepa)

Weed Science ◽  
1995 ◽  
Vol 43 (4) ◽  
pp. 634-639 ◽  
Author(s):  
Claudio M. Dunan ◽  
Philip Westra ◽  
Edward E. Schweizer ◽  
Donald W. Lybecker ◽  
Frank D. Moore
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Crop Yields ◽  
Economic Feasibility ◽  
Control Measures ◽  
Economic Losses ◽  
Weed Competition ◽  
Critical Periods ◽  
Control Efficacy ◽  
The Impact

The question of when to control weeds traditionally has been approached with the calculation of critical periods (CP) based on crop yields. The concept of economic critical period (ECP) and early (EEPT) and late (LEFT) economic period thresholds are presented as a comprehensive approach to answer the same question based on economic losses and costs of control. ECP is defined as the period when the benefit of controlling weeds is greater than its cost. EEPT and LEFT are the limits of the ECP and can be used to determine when first and last weed control measures should be performed. Calculation of EEPT accounts for the economic losses due to weed competition that occur between planting and postemergence weed control. In this way it is possible to better evaluate the economic feasibility of using preplant or preemergence control tactics. The EEPT for DCPA application is analyzed in the context of onion production in Colorado. The EEPT for DCPA application was calculated from an empirical regression model that assessed the impact of weed load and time of weed removal on onion yields. The EEPT was affected by control efficacy, weed-free yield, DCPA cost, and onion price. DCPA application was economically advisable in only one of 20 fields analyzed because of the tow DCPA efficacy (60%).

Rates of Herbicides in Irrigated Cotton

Weed Science ◽  
1975 ◽  
Vol 23 (3) ◽  
pp. 179-181
Author(s):  
H. F. Arle ◽  
K. C. Hamilton
Keyword(s):  
Gossypium Hirsutum ◽  
Weed Control ◽  
Crop Yield ◽  
Weed Competition ◽  
Fiber Fineness ◽  
Herbicide Treatments ◽  
Boll Weight ◽  
Annual Weeds

Rates of trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) applied preplanting were combined with rates of diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] applied postemergence in cotton (Gossypium hirsutumL. ‘Deltapine 16’). In another experiment, two levels of these herbicides were applied in three populations of cotton. All herbicide combinations improved weed control, compared to that of cultivated checks. Applications of 0.28, 0.42, and 0.56 kg/ha of trifluralin combined with 0.56 kg/ha of diuron controlled annual weeds and produced the highest cotton yields. Herbicide treatments had more influence than crop spacing on weed control and crop yield. Weed competition on cultivated checks affected boll weight, seed per boll, and fiber fineness.

Effects of Simulated MSMA Drift on Rice (Oryza sativa) Growth and Yield

Weed Science ◽  
1981 ◽  
Vol 29 (3) ◽  
pp. 303-308 ◽  
Author(s):  
E. P. Richard ◽  
H. R. Hurst ◽  
R. D. Wauchope
Keyword(s):  
Oryza Sativa ◽  
Gossypium Hirsutum ◽  
Plant Height ◽  
Weed Control ◽  
Developmental Stages ◽  
Growth And Yield ◽  
Stages Of Development ◽  
Early Season ◽  
Application Timing ◽  
Over The Top

Levels of MSMA (monosodium methanearsonate) that simulated drift (0.2, 0.39, and 0.78 kg/ha) were applied over-the-top to rice (Oryza sativaL. ‘Vista’, ‘Starbonnet’, or ‘Labelle’) after flooding at four developmental stages between early tillering and late jointing. The MSMA rates used were equivalent to, or lower than, the 0.78-kg/ha rate that would be applied as an over-the-top application to cotton (Gossypium hirsutumL.) for early season weed control. Over-the-top applications of MSMA did not affect heading and maturity dates of filled grains regardless of the rate or application timing. Reductions occurred, however, in plant height, number of panicles, and yield. In addition, the percentage of erect panicles showing typical “straighthead” symptoms increased. Rice sensitivity to MSMA depended on MSMA rate and stage of growth with injury being most severe as rice approached the reproductive stages of development. Because aerial applications of MSMA to cotton are normally made before rice reaches the reproductive stage, injury resulting from MSMA drift should be minimal.

Weed and Disease Responses to Herbicides in Single- and Double-Row Cotton (Gossypium hirsutum)

Weed Science ◽  
1979 ◽  
Vol 27 (4) ◽  
pp. 444-449 ◽  
Author(s):  
J. H. Miller ◽  
C. H. Carter ◽  
R. H. Garber ◽  
J. E. DeVay
Keyword(s):  
Gossypium Hirsutum ◽  
Weed Control ◽  
Pythium Ultimum ◽  
Thielaviopsis Basicola ◽  
Annual Grass ◽  
Double Row ◽  
Planting Pattern ◽  
Single Row ◽  
Cotton Plants ◽  
Annual Weeds

For 3 yr, herbicide treatments of preplant trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), postemergence diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea], both herbicides, or none were superimposed on cotton (Gossypium hirsutumL. ‘Acala SJ-2′) grown on beds centered at 102 cm using a single row or two rows spaced 28 cm apart. Cotton stand, after thinning, was 5.1 plants/m in each cotton row. Herbicides controlled annual weeds regardless of planting pattern. Cultivation, without herbicides, controlled annual grass weeds much better in cotton grown in single rows than in double rows. Preplant applications of trifluralin did not influence populations of cotton plants, regardless of row pattern. Single- and double-row plots treated with trifluralin always yielded more than untreated double rows. In two of three seasons, however, single-row plots without herbicides yielded as much as those treated with trifluralin. The lower yields in the double-row cotton were associated with reduced annual grass control especially in plots not treated with trifluralin. Weed control treatments or planting patterns did not influence the occurrence ofPythium ultimumTrow orRhizoctonia solaniKühn on cotton seedlings. The presence ofThielaviopsis basicola(Berk & Br.) Ferr. on cotton seedlings was not influenced by planting pattern but was increased by trifluralin in the third year of the study. Percentage of cotton plants with symptoms of verticillium wilt (Verticillium dahliaeKleb.) was not influenced by weed control treatments, but the percentage of diseased plants was higher in single-row than in double-row planting patterns. We attribute this response to fewer plants per hectare in single rows compared to double rows.

scholarly journals Effect of Glyphosat and Paraquat Herbicides on Weed Control and Productivity of Cotton

2017 ◽  
Vol 50 (2) ◽  
pp. 51-56
Author(s):  
R.A. Hameed ◽  
S. Ajum ◽  
M.N. Afzal
Keyword(s):  
Plant Height ◽  
Weed Control ◽  
Untreated Control ◽  
Growth And Yield ◽  
Cotton Yield ◽  
Contributing Factors ◽  
Control Cost ◽  
Cotton Crop ◽  
Weed Biomass ◽  
Boll Weight

AbstractWeed control management has a vital role in increasing cotton yield and yield components. In cotton crop weed, infestation may harm significant growth and yield loses. To control the weeds under field conditions in cotton crop, different herbicides were selected with different dose levels. Response of various post emergence herbicides at different levels, i.e. Round up 490 G/L at the rate of 4.7 L ha−1, 2.7 L ha−1and 1.5 L ha−1(Glyphosate), Gramoxone 20EC (Paraquat) at the rate of 2.5 L ha−1and untreated (Control) were field experimented against cotton cultivar CIM-473 under field condition at Agronomic Research Area of Central Cotton Research Institute (CCRI) Multan, Pakistan. Significant control of weeds, i.e. number of weeds m−2, fresh weed biomass in g m−2, dry weed biomass in g m−2and increase in yield and yield contributing factors, like number of bolls plant−1, cotton boll weight (g), final cotton plant height (cm) and seed cotton yield (kg ha−1) were observed. The field data for weed control in term of numbers, fresh and dry weight was observed after 10, 20 and 30 days of sowing. It was indicated that the highest significant yield, total number of bolls per plant, fresh weed biomass, dry weed biomass, plant height and weed control were obtained by using herbicide Round up (Glyphosate) at the rate of 4.7 L ha−1, as compared to the other treatments with different application rates including untreated (control). Average boll weight was not significant among treatments, but significant against control. Cost benefit analysis showed that the highest net profit was obtained by the Round up 490 G/L, when treated @ 4.7 L ha−1than all other treatments.

scholarly journals CARACTERÍSTICAS AGRONÔMICAS DE SOJA EM FUNÇÃO DE ESPAÇAMENTOS ENTRE LINHAS DE SEMEADURA

2018 ◽  
Vol 14 (3) ◽  
pp. 187-193
Author(s):  
Maycon Wilhann Pereira ◽  
Leandro Meert ◽  
Antônio Mendes de Oliveira Neto ◽  
Naiara Guerra ◽  
Antonio Krenski ◽  
...  
Keyword(s):  
Plant Height ◽  
Stem Diameter ◽  
The Other ◽  
Row Spacing ◽  
Soybean Yield ◽  
Positive Correlation ◽  
Soybean Crop ◽  
High Yields ◽  
Response Variables

To obtain high yields in the soybean crop, it is necessary to have the minimum of competition among the plants.The objective of this work was to evaluate the influence of different spacing on productivity components and soybean yield. The design adopted was randomized blocks with 4 treatments (22, 44, 66 and 88 cm between rows) and six replicates. The cultivar used was 5909 with a population of 204 thousand plants per hectare. The response variables evaluated were plant height and first pod insertion, stem diameter, number of pods per plant, number of grains per pod, mass of one thousand grains and productivity. The height of plants and the diameter of the stem behaved in a quadratic manner, where the measure with which one increased the other reduced. The highest number of pods per plant (92) was obtained with the spacing of 64 cm between rows. The number of grainsper pod reduced linearly with increasing row spacing. The mass of 1000 grains and the productivity presented a quadratic behavior for the spacing, where the highest productivity 4772.60 kg ha-1was obtained with the spacing of 60 cm. The stem diameter showed a positive correlation with the number of pods per plant and with productivity. The height of insertion of the first pod showed a positive correlation with the mass of a thousand grains. The number of pods per plant was the variable that presented the highest correlation with productivity (0.84).

Competition of Prickly Sida with Cotton

Weed Science ◽  
1977 ◽  
Vol 25 (2) ◽  
pp. 106-110 ◽  
Author(s):  
G.A. Buchanan ◽  
R.H. Crowley ◽  
R.D. McLaughlin
Keyword(s):  
Gossypium Hirsutum ◽  
Plant Height ◽  
Cotton Plant ◽  
Total Yield ◽  
Growing Season ◽  
Weed Competition ◽  
Seed Cotton ◽  
Weed Density ◽  
Sida Spinosa ◽  
Prickly Sida

Seed cotton (Gossypium hirsutumL.) yields were not reduced when competing with prickly sida (Sida spinosaL.) for 7 weeks or less after cotton emergence and maintained weed-free for the remainder of the season. Cotton yields were not affected when pure prickly sida stands were controlled for 5 to 6 weeks after cotton emergence and then allowed to grow uncontrolled for the remainder of the season. In the more severe weed competition treatments, cotton plant height and main stem diameter were reduced; however, yield of seed cotton was the most sensitive indicator of prickly sida competition. Maturity of cotton, as measured by percent of total yield obtained at first picking, indicated a delay in maturity in 1 of 3 yr in treatments where competing prickly sida was present for 8 weeks or more. In density studies, where prickly sida emerged with cotton and was allowed to compete for the full growing season, 45 prickly sida plants/15 m of row caused reductions in yield of seed cotton in two of five experiments. In another series of three experiments as few as 32 prickly sida plants/15 m of row significantly reduced seed cotton yields in two of the three experiments. Trash content of machine-harvested cotton was increased at densities of 64 and 128 prickly sida plants/15 m of row in one experiment. Staple length and grade of cotton were not affected by any weed density studied. Micronaire measurements of cotton were reduced at prickly sida densities of 64 and 128 weeds/15 m of row during 1972.

scholarly journals Effect of phosphorus and potassium on yield and on agronomical characteristics of cotton

1999 ◽  
Vol 34 (10) ◽  
pp. 1839-1843 ◽  
Author(s):  
Luiz Alberto Staut ◽  
Manoel Luiz Ferreira Athayde
Keyword(s):  
Gossypium Hirsutum ◽  
Plant Height ◽  
Significant Influence ◽  
Cotton Yield ◽  
Triple Superphosphate ◽  
Seed Cotton ◽  
Gossypium Hirsutum L ◽  
Seed Cotton Yield ◽  
Technological Characteristics ◽  
Phosphorus And Potassium

With the objective of studying the effect of increasing phosphorus and potassium doses on the agronomical and technological characteristics of the cotton (Gossypium hirsutum L.), cultivar IAC 20, an experiment was carried out during 1994/95 on a Red-Dark Latossol at the Embrapa-Centro de Pesquisa Agropecuária do Oeste (CPAO) in Ponta Porã, MS, Brazil. A randomized bloch design was used in a 3 x 5 factorial arrangement with four replications. The doses were 30, 60 and 90 kg ha-1 of P2O5, applied as triple superphosphate, and 0, 30, 60, 90 and 120 kg ha-1 of K2O as KCl. The K2O doses used had a significant influence on the seed cotton yield, plant height and weight of 100 seeds and of bolls.

Silverleaf Nightshade (Solanum elaeagnifolium) Control in Cotton (Gossypium hirsutum) with Glyphosate

1994 ◽  
Vol 8 (4) ◽  
pp. 720-727 ◽  
Author(s):  
R. Brent Westerman ◽  
Don S. Murray
Keyword(s):  
Gossypium Hirsutum ◽  
Weed Control ◽  
Cotton Yield ◽  
Cotton Lint ◽  
Herbicide Treatment ◽  
Silverleaf Nightshade ◽  
Solanum Elaeagnifolium ◽  
Multiple Spot

Glyphosate, alone and in combination with other herbicides or additives, was evaluated as a spot or shielded treatment for the control of silverleaf nightshade in cotton in three experiments over four years. Glyphosate used at 10.8 g ae/L in 1985 on dryland cotton controlled 81 to 98% of the silverleaf nightshade, but cotton lint yields were reduced by all treatments compared to the weed-free check. Glyphosate used at 7.2 g ae/L in 1986 on irrigated cotton controlled 6 to 83% of the silverleaf nightshade, and lint yields were reduced only when multiple spot applications were made. Spot applications of glyphosate were effective for silverleaf nightshade control when applied 7 wk after crop emergence in 1988. Weed control and cotton injury were lower with shielded applications than spot applications. In 1989, retreatments during a season or the next year resulted in 95% or greater silverleaf nightshade control. Cotton yield increases from herbicide treatment were not observed in 1988; however, yield increases were observed in 1989 when spot treatments were applied to the more successful 1988 plots.

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