scholarly journals Glyphosate-resistant hairy fleabane competition in RR® soybean

Bragantia ◽  
2014 ◽  
Vol 73 (4) ◽  
pp. 451-457 ◽  
Author(s):  
Diecson Ruy Orsolin da Silva ◽  
Leandro Vargas ◽  
Dirceu Agostinetto ◽  
Franciele Mariani
Keyword(s):  
Field Experiment ◽  
Competitive Ability ◽  
Growing Season ◽  
Weed Competition ◽  
Soybean Yield ◽  
Soybean Crop ◽  
Weed Interference ◽  
Growth Development ◽  
Positive Correlations ◽  
Hairy Fleabane

Weed competition in the soybean causes changes in morphological and physiological characteristics that reduce the competitive ability of the crop. The objective of this study was to determine the control periods and coexistence of glyphosate-resistant hairy fleabane and its interference in morphological and photosynthetic variables and RR soybean yield. A field experiment was conducted during the 2011/2012 growing season, the treatments consisted of weed interference and weed free periods of the glyphosate-resistant hairy fleabane with soybean (BRS Estância RR). The periods were 0, 7, 14, 21, 28, 35, 42 and 154 days after the soybean emergence. The results sugested no differences between the control periods for the variables evaluated. The increase interference period of the weed reduced growth, development and the photosynthetic variables in the soybean. There are positive correlations between morphological and photosynthetic variables of soybean during the weed interference. The period before the glyphosate-resistant hairy fleabane interference in the soybean crop is 24 days for plants established before the crop sowing.

scholarly journals Weed Interference Affects Dry Bean Yield and Growth

2012 ◽  
Vol 4 (3) ◽  
pp. 70-75 ◽  
Author(s):  
Hossein GHAMARI ◽  
Goudarz AHMADVAND
Keyword(s):  
Chenopodium Album ◽  
Growing Season ◽  
Amaranthus Retroflexus ◽  
Growth And Yield ◽  
Weed Competition ◽  
Weed Species ◽  
Dry Bean ◽  
Logistic Equations ◽  
Weed Interference ◽  
Minimum Number

Dry bean is one of the most important pulse crops in Iran. Field study was conducted in 2011 to evaluate effects of weed competition from a natural flora on growth and yield of dry bean (Phaseolus vulgaris L.). The treatments consisted of weed infestation and weed removal periods (10, 20, 30, 40 and 50 days) after crop emergence. Control plots kept weed-infested and weed-free throughout growing season. To assess the weed competition effect on crop characteristics, Richards, Gompertz and logistic equations were fitted to the data. The most abundant weed species were Chenopodium album and Amaranthus retroflexus. Increase in duration of weed interference decreased the stem height of dry bean. At the end of the growing season, dry bean was 20 cm taller in season-long weed-free treatment compared to the season-long weed-infested treatment. As the number of days of weed interference increased, a declining trend of LAI and number of pods was observed. The minimum number of pods was obtained in season-long weed-infested treatment (5.01 pods/plant). Weed interference during the whole growing season, caused a 60% reduction in yield. Considering 5% and 10% acceptable yield lost, the critical period of weed competition was determined from 20 to 68 and 23 to 55 days after planting (DAE), respectively.

scholarly journals Growth Analysis of Dry Bean (Phaseolus vulgaris L.) in Different Weed Interference Situations

2013 ◽  
Vol 5 (3) ◽  
pp. 394-399 ◽  
Author(s):  
Hossein GHAMARI ◽  
Goudarz AHMADVAND
Keyword(s):  
Dry Matter ◽  
Growth Analysis ◽  
Yield Loss ◽  
Growing Season ◽  
Crop Growth ◽  
Weed Competition ◽  
Dry Matter Accumulation ◽  
Dry Bean ◽  
Weed Interference ◽  
Crop Biomass

In production agriculture, weed plants play an important role in yield reduction. Analysis of crop growth can reveal underlying processes of yield loss under weed interference conditions. Therefore, an experiment was conducted in 2011 in order to assess the effect of weed competition on different aspects of dry bean growth. The experiment was a randomized complete block design with 3 replications. Treatments included weed-infested and weed-free periods until 0, 10, 20, 30, 40 and 50 days after crop emergence. Aboveground dry matter and leaf area were measured every two weeks. The functional approach to growth analysis was used to examine temporal patterns in crop growth in weed interference conditions. A negative relationship between weed biomass and dry bean growth indexes was observed. In all treatments, crop biomass had a similar trend and progressively increased over the crop cycle, then after reaching the maximum amount, gradually decreased. The lowest crop biomass (676.60 g m-2) was observed in season-long weed-infested treatment, while the maximum one (1238.82 g m-2) was recorded in season-long weed-free treatment. Relative growth rate (RGR) and net assimilation rate (NAR) had a declining trend during the growing season. Increase in weed-infested periods intensified decrease of them. Effect of weed competition on crop growth was trifle at the early of growing season. Since NAR and RGR represent photosynthesis potential and dry matter accumulation of the crop, their reduction can be the main cause of yield loss.

scholarly journals WEED COMPETITION WITH SOYBEAN IN NO-TILLAGE AGROFORESTRY AND SOLE-CROP SYSTEMS IN SUBTROPICAL BRAZIL

2017 ◽  
Vol 35 (0) ◽  
Author(s):  
L. DEISS ◽  
A. MORAES ◽  
A. PELISSARI ◽  
A.J. FRANZLUEBBERS ◽  
F.S. NETO ◽  
...  
Keyword(s):  
Grain Yield ◽  
Yield Components ◽  
Growing Season ◽  
Agroforestry System ◽  
Growth And Yield ◽  
Weed Competition ◽  
Soybean Yield ◽  
Sole Crop ◽  
Yield And Yield Components ◽  
Sole Cropping

ABSTRACT Weed competition on soybean (Glycine max) growth and yield was expected to be different when managed in an agroforestry system as compared with sole-cropping without trees. Therefore agronomic practices to control weeds might need to be modified in agroforestry systems. We analyzed weed competition effects on soybean growth, grain yield, and yield components at different distances from 4year-old eucalyptus (Eucalyptus benthamii) in an alley cropping system, as well as in a sole-crop system in southern Brazil. Above-ground soybean biomass was collected throughout the growing season and a logistic function was used to model crop growth. Weed above-ground biomass sampled during the soybean cycle, and grain yield and yield components at the end of the growing season were evaluated using regression analysis across positions between tree lines, and results compared to those without influence of trees. Soybean yield components were mostly reduced between tree lines compared with sole-cropping without trees. Soybean growth and yield within the eucalyptus agroforestry system was not affected by weed competition. However, weeds reduced soybean growth and yield in sole-cropping without trees. Reduction in soybean yield in the agroforestry system was rather caused by competition from trees. Therefore, tree interference may limit both weed and soybean growth potential.

Interference of Wild Poinsettia (Euphorbia heterophylla) with Soybean (Glycine max)

1994 ◽  
Vol 8 (4) ◽  
pp. 679-683 ◽  
Author(s):  
Teresa S. Willard ◽  
James L. Griffin ◽  
Daniel B. Reynolds ◽  
Arnold M. Saxton
Keyword(s):  
Glycine Max ◽  
Dry Weight ◽  
Growing Season ◽  
Field Studies ◽  
Yield Reduction ◽  
Soybean Yield ◽  
Weed Interference ◽  
Soybean Canopy ◽  
Area Of Influence

Field-studies were conducted over two years to determine the area of influence and duration of interference of wild poinsettia in soybean. Soybean canopy width averaged across years was reduced approximately 10% beginning at 6 wk of interference for both the 0- to 10-and 10-to 20-cm distances from the weed. Soybean dry weights decreased from 14 to 38% within 20 cm of the weed for 12 through 18 wk of interference. In 1990, soybean yield within 10 cm of wild poinsettia was similar to distances of 10 to 20 and 20 to 40 cm, but was less than that for distances greater than 40 cm from the weed. Weed interference resulted in a 9.5% yield reduction in the 0- to 10-cm distance when compared with the 80-to 100-cm distance. In contrast, yield of soybean in 1991 growing within 10 cm of the weed was less than at greater distances, corresponding to an 18% yield reduction when compared with 80 to 100 cm. Differences in wild poinsettia dry weights when growing alone and when growing within the soybean row occurred after 6 and 8 wk of interference in 1990 and 1991, respectively. In 1991 when rainfall during the growing season was twice that of the previous year, canopy width and dry weight of wild poinsettia growing within the soybean row were reduced an average of 57 and 82%, respectively, compared with weeds growing alone.

scholarly journals Periods of Weed Interference on Orange Tree Crops

2018 ◽  
Vol 36 (0) ◽  
Author(s):  
G.S. GONÇALVES ◽  
J.E.B. CARVALHO ◽  
M.V.B. GARCIA ◽  
L.A. GAMA ◽  
C.L.L.L. AZEVEDO ◽  
...  
Keyword(s):  
Weed Management ◽  
Growing Season ◽  
Control Treatment ◽  
Weed Interference ◽  
Orange Tree ◽  
Cultivation Practices ◽  
Fruit Productivity ◽  
Orange Trees ◽  
Production Problems ◽  
Unripe Fruits

ABSTRACT: Current orange tree cultivation practices in the Brazilian State of Amazonas present several production problems, being the inadequate weed management the most important one, and significantly affecting fruit productivity. However, if weeds are managed properly, their coexistence with orange cultivars does not affect the fruit yield of orange trees. Thus, the objective of this research was to identify the period of longer weed interference in orange production. The treatments were conducted during the 2013 and 2014 harvests as follows: one control treatment with no coexistence of weeds and crop throughout the growing season; and six periods of coexistence (October to January, February to May, June to September, October to May, October to January, June to September, and February to September). The coexistence of weeds from October to May with orange trees increased the fall of unripe fruits and reduced the yield and the number of oranges per plant. Therefore, this period was considered as the most critical one for the control of weeds in orange trees.

Influence of fertilizers and of the autumn tillage method on potato yield and phytopathologiс characteristics of tubers

2021 ◽  
Vol 22 (3) ◽  
pp. 393-400
Author(s):  
V. I. Titova ◽  
E. T. Akopdzhanyan
Keyword(s):  
Field Experiment ◽  
Ammonium Nitrate ◽  
Nitrogen Fertilizer ◽  
Growing Season ◽  
Potato Yield ◽  
Loamy Soil ◽  
Pest Damage ◽  
Tillage Method ◽  
Nizhny Novgorod Region ◽  
Production Conditions

The field experiment on identifying differences in the effect of the herbicide and foliar feeding of plants with liquid nitrogen fertilizer (UAN-32) against the background of autumn tillage with a cultivator or plow on potato yield and phytopathologic characteristics of tubers during storage was carried out in 2019-2020 in the Nizhny Novgorod region. The experiment was laid on sod-podzolic sandy loamy soil in production conditions on two varieties of potato ‒ the super-early Сolomba variety and the medium-early Innovator variety grown for seeds. The variants under study were surface application of the soil herbicide Gezagard in a tank mixture with UAN-32 and foliar feeding of plants with UAN-32 (N42) during the growing season against the background of N42P42K169 (calcium chloride in autumn + ammonium nitrate phosphate in spring). The results indicate that the background fertilization provides the yield of Colombа variety potato of 20.7-29.0 t/ha, the Innovator variety – 17.4-23.1 t/ha. The use of the herbicide is more effective during autumn tillage with a cultivator, providing an increase in yield of 28-37 % on both potato varieties, feeding of plants with UAN-32 contributes to an increase in yield (8-10 %) only on the Сolomba variety. Plowing the soil for potatoes helps to avoid the pest damage of tubers and to reduce their susceptibility to rhizoctonia by 6-27 %, to wet rot ‒ up to 55 %. In general, it has been established that due to autumn plowing with fertilization at a dose of N42P42K169, it is possible to obtain an increase in potato yield exceeding the increase provided both by herbicides and the use of foliar feeding of potatoes.

Growth and Development of Giant Burreed (Sparganium eurycarpum)

1990 ◽  
Vol 4 (4) ◽  
pp. 849-854 ◽  
Author(s):  
John W. Leif ◽  
Ervin A. Oelke
Keyword(s):  
Wild Rice ◽  
Growth And Development ◽  
Vegetative Reproduction ◽  
Growing Season ◽  
Maximum Height ◽  
Cumulative Length ◽  
Growth Development ◽  
Rhizome Bud ◽  
Sparganium Eurycarpum ◽  
Outdoor Experiments

Outdoor experiments were conducted at two locations in Minnesota to characterize the growth, development, and vegetative reproduction potential of giant burreed grown with and without wild rice. Giant burreed growth was influenced by environment more than the presence of wild rice. Shoots emerged from corms 2 to 3 wk after planting (WAP), and continued throughout the growing season. Giant burreed attained a maximum height of 135 cm with an average 36 shoots/plant. Rhizome production started 4 to 6 WAP, and continued throughout the growing season. Corm formation at the base of shoots started 8 WAP and continued throughout the growing season. Rhizomes grew to a maximum cumulative length of 2500 cm/plant spreading in all directions and produced up to 250 buds/plant. Corm and rhizome bud viability was 15 and 10%, respectively. These data suggest that giant burreed grown in wild rice should be controlled by 2 to 3 wk after emergence to prevent vegetative reproduction.

Growth and Development of Organic Arsenical-Susceptible and -Resistant Common Cocklebur (Xanthium strumarium) Biotypes Under Noncompetitive Conditions

1994 ◽  
Vol 8 (1) ◽  
pp. 154-158 ◽  
Author(s):  
William E. Haigler ◽  
Billy J. Gossett ◽  
James R. Harris ◽  
Joe E. Toler
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Plant Height ◽  
Growth And Development ◽  
Reproductive Potential ◽  
Dry Weight ◽  
Growing Season ◽  
Xanthium Strumarium ◽  
Relative Growth ◽  
Growth Development

The growth, development, and reproductive potential of several populations of organic arsenical-susceptible (S) and -resistant (R) common cocklebur biotypes were compared under noncompetitive field conditions. Plant height, leaf area, aboveground dry weights, and relative growth rate (RGR) were measured periodically during the growing season. Days to flowering, bur dry weight, and number of burs per plant were also recorded. Arsenical S- and R-biotypes were similar in all measured parameters of growth, development, and reproductive potential. Populations within each biotype varied occasionally in plant height, leaf area, aboveground dry weights, and reproductive potential.

scholarly journals Dry Bean Morpho-Physiological Responses to Gradual Weed Biomass Accumulation

2013 ◽  
Vol 5 (1) ◽  
pp. 74-78
Author(s):  
Hossein GHAMARI ◽  
Goudarz AHMADVAND
Keyword(s):  
Biomass Accumulation ◽  
Physiological Traits ◽  
Weed Competition ◽  
Dry Matter Accumulation ◽  
Dry Bean ◽  
Weed Biomass ◽  
Weed Interference ◽  
Free Treatment ◽  
Crop Cycle ◽  
Number Of Branches

Field study was carried out in 2011 in west of Iran to assess responses of dry bean (Phaseolus vulgaris L.) morpho-physiological traits to gradual weed biomass accumulation. The treatments consisted of two different periods of weed interference, which weeds either infested the plots or removed for an increasing duration of time (0, 10, 20, 30, 40, 50 days) after crop emergence. Relative dominance and relative importance of weed species fluctuated over the crop cycle. As the duration of weed interference was increased, a declining trend of crop growth rate (CGR) was observed. When weeds were allowed to compete with crop throughout the crop cycle, maximum value of CGR was decreased from 25.57 g m-2 days in full season weed free treatment to 16.78 g m-2 days in full season weed infested treatment. Effect of treatments on leaf area index (LAI) was significant. Weed removal increased LAI but it could not significantly affect this trait, at the early of growing season. Weed interference caused a significant reduction on number of branches. The minimum number of branches was registered in full season weed infested treatment (2.58 branches per plant), while the maximum one was observed in the full season weed free treatment (4.25 branches per plant). Weed competition severely reduced crop yield. At 10 and 20 days after crop emergence, weed infestation could not significantly affect the yield. A negative relationship between weeds’ dry matter accumulation and LAI as well as number of branches was observed which signify the vulnerability of these morpho-physiological traits to weed competition.

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