Seasonal Emergence and Growth ofSorghum almum

1988 ◽  
Vol 2 (3) ◽  
pp. 275-281
Author(s):  
Charlotte V. Eberlein ◽  
Timothy L. Miller ◽  
Edith L. Lurvey
Keyword(s):  
Seed Production ◽  
Dry Weight ◽  
Field Studies ◽  
Planting Date ◽  
Corn Yield ◽  
Seed Plant ◽  
Planting Dates ◽  
Shoot Dry Weight ◽  
Two Peaks ◽  
Growth And Reproduction

Field studies on time of emergence, influence of planting date on growth and reproduction, and winter survival of rhizomes were conducted on sorghum-almum grown in corn and crop-free environments. In 1985, peak emergence of sorghum-almum occurred during early May in crop-free plots and mid-May in corn. In 1986, two peaks of emergence, one in early June and one in late June, were noted in both crop-free and corn plots. Emergence after mid-July was 4% or less of the total emerged in 1985, and no sorghum-almum emerged after mid-July in 1986. In planting date studies, sorghum-almum was seeded alone or in corn at 2-week intervals. Corn competition reduced sorghum-almum shoot, rhizome, and root growth at all planting dates. Maximum sorghum-almum seed production was 43 110 seed/plant when grown without competition but only 1050 seed/plant when grown with corn competition. When grown with corn competition, no seed developed on sorghum-almum seeded 6 or more weeks (mid-June or later) after corn planting. Shoot dry weight of sorghum-almum grown with corn competition was 3 g/plant or less for plants seeded 4 or more weeks (early June or later) after corn planting. Therefore, controlling sorghum-almum in corn through mid-June should prevent seed production and corn yield losses due to sorghum-almum competition. Rhizomes produced by sorghum-almum grown alone or with corn competition did not survive the winter; therefore, in Minnesota, sorghum-almum survival from one growing season to the next depends on seed production.

Dog mustard (Erucastrum gallicum) response to crop competition

Weed Science ◽  
1997 ◽  
Vol 45 (3) ◽  
pp. 397-403
Author(s):  
David A. Wall
Keyword(s):  
Interspecific Competition ◽  
Leaf Area ◽  
Seed Production ◽  
Growth And Development ◽  
Dry Weight ◽  
Field Studies ◽  
Limiting Factor ◽  
Shoot Dry Weight ◽  
Summer Fallow ◽  
Crop Competition

Greenhouse studies suggested that dog mustard was less competitive than wheat, but of similar competitiveness to flax. In field studies, dog mustard growth and development were markedly affected by crop competition. Competition from flax and wheat reduced dog mustard leaf area, shoot dry weight, plant height, and seed production compared with the weed grown on summer-fallow. Dog mustard was a prolific seed producer when grown in the absence of interspecific competition. On summer-fallow, dog mustard produced as many as 79,100 seeds plant−1when moisture was not a limiting factor. However, average seed production was 19,400 and 8000 seeds plant−1in 1994 and 1995, respectively.

scholarly journals Growth Analysis of Two Pea Cultivars as Influenced by Planting Date

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 785E-785
Author(s):  
Abdullah A. Alsadon
Keyword(s):  
Leaf Area ◽  
Growth Analysis ◽  
Correlation Coefficients ◽  
Dry Weight ◽  
Analysis Data ◽  
Planting Date ◽  
Planting Dates ◽  
Growing Seasons ◽  
Shoot Dry Weight ◽  
Growth Attributes

`Lincoln' and `Rondo' pea cultivars (Pisum sativum L. subsp. hortense) were planted at early, midseason, and late dates during 1989–90 and 1990–91 growing seasons. Plant growth analysis data were collected via weekly harvests throughout the growing season. Plant height, leaf area, and shoot dry weight were measured, and LAI, SLA, and SLW were also determined. Derived growth quantities such as RGR, NAR, and CGR were calculated. `Rondo' plants were taller, larger in leaf area, had more vegetative and dry weight, and were earlier in flowering than `Lincoln' plants. Leaf area was not significantly affected by planting date. Optimum LAI was obtained between harvests 7 and 9, which coincides with the time of highest values of NAR and CGR. Significant correlation coefficients were obtained between growth attributes in both seasons, and, in most cases, for all planting dates.

Response of Common Lambsquarters (Chenopodium album) to Glyphosate Application Timing and Rate in Glyphosate-Resistant Corn

2004 ◽  
Vol 18 (4) ◽  
pp. 908-916 ◽  
Author(s):  
Peter H. Sikkema ◽  
Christy Shropshire ◽  
Allan S. Hamill ◽  
Susan E. Weaver ◽  
Paul B. Cavers
Keyword(s):  
Seed Production ◽  
Weed Management ◽  
Crop Yields ◽  
Dry Weight ◽  
Field Studies ◽  
Corn Yield ◽  
Soil Cores ◽  
Herbicide Application ◽  
Common Lambsquarters ◽  
Time Of Application

Field studies were conducted over 3 yr at two locations to evaluate the effect of glyphosate rate and time of application on common lambsquarters control, density, dry weight, seed production, and the number of seedlings emerging from soil cores taken the year after herbicide application in glyphosate-resistant corn. Glyphosate was applied at 0, 112, 225, 450, 675, or 900 g ai/ha when common lambsquarters were at the two-, four-, or six-leaf stage of growth. Nicosulfuron was applied to all experimental areas to control annual grasses. Visual estimates of percent control increased, whereas density, dry weight, seed production, and seedlings emerging the year after treatment decreased as the rate of glyphosate was increased from 0 to 450 g/ha. Increasing the glyphosate rate above 450 g/ha had little effect on these parameters. Corn yield declined only at glyphosate rates below 450 g/ha. Time of application had no effect on common lambsquarters control and corn yield because little emergence occurred after the first glyphosate application. There was no interaction between glyphosate rate and time of application for any of the parameters evaluated. In these studies, the application of glyphosate at half the manufacturer's registered rate provided control of common lambsquarters equivalent to the full-registered rate with no measured increase in weed seed production and no increase in weed seedlings emerging from soil cores the year after herbicide application. The results suggest that in some cases the use of reduced herbicide rates can provide excellent weed control and maintain crop yields, while reducing the cost of production and the environmental impact of herbicides. The use of extremely low rates (112 or 225 g/ha), however, resulted in reduced corn yields, increased common lambsquarters seed production and seedlings emerging the year after application, and possibly increased weed management costs in subsequent years.

Effect of planting date and density on calendula and peppermint herbs

2014 ◽  
Vol 1 (1) ◽  
pp. 25-29
Author(s):  
Rahim Mohammadian ◽  
Behnam Tahmasebpour ◽  
Peyvand Samimifar
Keyword(s):  
Mutual Effect ◽  
Dry Weight ◽  
Planting Date ◽  
Mass Reduction ◽  
Flower Number ◽  
Planting Dates ◽  
Randomized Design ◽  
Significant Difference ◽  
Completely Randomized Design ◽  
Total Maximum

A factorial experiment was conducted with a completely randomized design to evaluate the effects of planting date and density on calendula herbs and peppermint. It had 3 replicates and was done in Khosroshahr research farm, Tabriz in 2006. Under studied factors were: 3 planting dates (10 May, 25 May and 10 June) in 4 densities (25, 35, 45, 55) of the plant in square meters. The results of variance a nalysis showed that there was 1% probability significant difference between the effects of planting date and bush density on the leave number, bush height and the bush dry weight. But the mutual effect of the plant date in mentioned traits density was insignificant. Regarding the traits mean comparison, the total maximum dry weight was about the 55 bush density in mm. Also, the bush high density in mm causes the bush growth and its mass reduction. When there is the density grain, the flower number will increase due to bush grain in surface unit. Overall, we can conclude that 10 June planting and 45 bush density in mm is the most suitable items and results in favored production with high essence for these crops.

Spring Wheat (Triticum aestivum)Cultivar Responses to Trifluralin and Postemergence Herbicides

1995 ◽  
Vol 9 (2) ◽  
pp. 352-355 ◽  
Author(s):  
Sharon A. Clay ◽  
Jim F. Gaffney ◽  
Leon J. Wrage
Keyword(s):  
Spring Wheat ◽  
Plant Stress ◽  
Dry Weight ◽  
Field Studies ◽  
Growth And Yield ◽  
Hard Red Spring Wheat ◽  
Wheat Field ◽  
Shoot Dry Weight ◽  
Cultivar Responses ◽  
Postemergence Herbicides

Trifluralin is used for weed control in wheat but may reduce vegetative growth and yield. Postemergence (POST) herbicides may cause additional plant stress to trifluralin-stressed wheat. Field studies at Groton, SD in 1991 and 1992 and at Highmore, SD in 1992 evaluated the effects of 2,4-D-amine, difenzoquat, metsulfuron, and a combination of fenoxaprop-ethyl + 2,4-D-ester + MCPA-ester on hard red spring wheat cultivars ‘2375,’ ‘Prospect,’ and ‘Butte 86’ seeded in areas treated with preplant incorporated trifluralin either in the spring before seeding (0.56 kg ai/ha) or the previous year (1.12 or 2.24 kg ai/ha). Trifluralin applied alone in the spring, and followed by some POST herbicides, reduced shoot dry weight and grain yield. Trifluralin reduced the yield of Prospect the most and the yield of 2375 the least. Yields of trifluralin-treated wheat were reduced 23% by metsulfuron and 14% by fenoxaprop-ethyl + 2,4-D + MCPA compared to yields of wheat treated with only the respective POST herbicide. Yields were not reduced with any trifluralin-POST herbicide combination when trifluralin was applied a year prior to seeding wheat.

Control of common cocklebur (Xanthium strumarium L.) in corn

2010 ◽  
Vol 90 (6) ◽  
pp. 933-938 ◽  
Author(s):  
N. Soltani ◽  
C. Shropshire ◽  
P.H. Sikkema
Keyword(s):  
Environmental Conditions ◽  
Dry Weight ◽  
Field Trials ◽  
Xanthium Strumarium ◽  
Corn Yield ◽  
Shoot Dry Weight ◽  
Herbicide Treatments ◽  
Excellent Control

Nine field trials (five with PRE and four with POST herbicides) were conducted in 2006 to 2009 on various Ontario farms with heavy common cocklebur infestations to determine the effectiveness of PRE and POST herbicides for the control of common cocklebur in corn. There was no commercially significant corn injury from the PRE herbicides evaluated. Saflufenacil, saflufenacil/dimethenamid-p, isoxaflutole + atrazine, mesotrione + atrazine and dicamba/atrazine, applied PRE provided 85, 85, 76, 73 and 67% control of common cocklebur in corn 8 wk after emergence (WAE), respectively. Common cocklebur shoot dry weight was reduced 84, 80, 79, 75 and 68% with saflufenacil/dimethenamid-p, isoxaflutole + atrazine, mesotrione + atrazine, saflufenacil and dicamba/atrazine, respectively. There was no effect on corn yield compared with the weedy control with the PRE herbicides evaluated. The application of 2,4-D/atrazine POST resulted in unacceptable injury (28%) in corn. Dicamba/atrazine, dicamba/diflufenzopyr, dicamba and mesotrione + atrazine provided up to 98, 95, 90 and 90% control of common cocklebur 8 wk after application (WAA), respectively. All POST herbicide treatments increased corn yield compared with the non-treated control. Saflufenacil and saflufenacil/dimethenamid-p applied PRE and dicamba, dicamba/diflufenzopyr, dicamba/atrazine or mesotrione + atrazine applied POST have potential to provide good to excellent control of common cocklebur in corn under Ontario environmental conditions.

Modelling the demography of crenate broomrape (Orobanche crenata) as affected by broad bean (Vicia faba) cropping frequency and planting date

Weed Science ◽  
1997 ◽  
Vol 45 (2) ◽  
pp. 261-268 ◽  
Author(s):  
Francisca López-Granados ◽  
Luis García-Torres
Keyword(s):  
Broad Bean ◽  
Management Strategies ◽  
Field Studies ◽  
Planting Date ◽  
Planting Dates ◽  
Cropping Frequency ◽  
Seed Loss ◽  
Model Predictions ◽  
Reported Data

A mathematical model of crenate broomrape populations in broad bean as affected by cropping frequency and planting dates in the absence of crenate broomrape control practices was constructed using previously reported data. In consecutive broad bean cropping, broomrape populations reached a maximum infection severity (D) of 62, 47, and 30 emerged broomrape m−2for early (mid-October), intermediate (mid-November), and late (mid-December) planting dates, respectively. The maximumDvalues were reached earlier as planting dates were brought forward, taking from 4 to 6 yr, starting from very low initial infections (D ≤0.2 emerged broomrape m−2). If broad bean was cropped every 3 yr, 15, 21, and 27 yr were needed, respectively, according to the model, to reach the maximumDfor the three planting dates considered. A sensitivity analysis was conducted to determine the effect of changing the values of the main demographic parameters in broomrape life cycle (germination, attachment, and seed loss) on the output of the model under different management strategies (planting dates and cropping frequency). Generally, an increase in seed attachment and a decrease in seed loss affected broomrape population dynamics. Between the two processes evaluated, the time taken to reach the maximum infection severity (D) was less sensitive than the maximum broomrape population values. Model predictions were validated using results from long-term field studies at the late planting date sown every year. Simulated values generated good predictions (R2= 0.82).

Texas Panicum (Panicum texanum) Growth as Affected by Irrigation Management and Planting Date

Weed Science ◽  
1990 ◽  
Vol 38 (4-5) ◽  
pp. 374-378 ◽  
Author(s):  
Jill Schroeder ◽  
Clyde C. Dowler ◽  
James R. Stansell
Keyword(s):  
Seed Production ◽  
Irrigation Management ◽  
Dry Weight ◽  
Planting Date ◽  
Soil Matric Potential ◽  
Seed Number ◽  
Matric Potential ◽  
Total Seed

The effect of soil matric potential from −0.02 to <–1.5 MPa on Texas panicum growth in drainage lysimeters covered by an automatic rainfall shelter was measured in 1984, 1985, and 1986. Rate of tiller production was faster for plants established in April than June in 1984 and 1985, but not 1986. In 1985 and 1986, dry weight was greater, but total seed production was less for plants established in April than June. Irrigation when the soil matric potential was −0.02, −0.075, or −1.5 MPa did not affect rate of tiller production in 1984. Irrigation when the soil matric potential was −1.5 MPa decreased dry weight of plants but increased seed number per panicle compared to irrigation when the soil matric potential was −0.02 MPa in 1985 and 1986. Plants grown in lysimeters irrigated at soil matric potential <–1.5 MPa in 1985 and 1986 did not wilt at 8:00 a.m.; therefore, they were not watered after establishment. These nonirrigated plants averaged 0.9 and 0.4 kg dry weight and produced 92 200 and 16 100 seeds in 1985 and 1986, respectively.

Effects of Barnyardgrass (Echinochloa crus-galli) on Growth, Yield, and Nutrient Status of Transplanted Tomato (Lycopersicon esculentum)

Weed Science ◽  
1988 ◽  
Vol 36 (6) ◽  
pp. 775-778 ◽  
Author(s):  
Prasanta C. Bhowmik ◽  
Krishna N. Reddy
Keyword(s):  
Unit Area ◽  
Tomato Fruit ◽  
Growth Yield ◽  
Dry Weight ◽  
Nutrient Status ◽  
Field Studies ◽  
Fruit Weight ◽  
Fresh Weight ◽  
Shoot Dry Weight ◽  
Marketable Fruit

Field studies were conducted to determine the effects of various barnyardgrass populations on growth, yield, and nutrient concentration of transplanted “Jetstar’ tomato. Barnyardgrass densities at 16, 32, and 64 plants/m tomato row were tested in 1982 and 1983. Barnyardgrass shoot fresh weights/unit area increased as density increased. Fresh weight of barnyardgrass shoots ranged from 17 100 kg/ha at 16 plants/m of row to 35 500 kg/ha at 64 plants/m of row. At the vegetative stage, tomato shoot dry weight was unaffected by barnyardgrass. As crop growth progressed, tomato shoot dry weight decreased at all barnyardgrass densities. Season-long interference of barnyardgrass reduced marketable tomato fruit number and fruit weight at all densities compared to weed-free plots. Reductions in marketable fruit weight ranged from 26% to 16 plants/m row to 84% at 64 plants/m row. In 1982, concentrations of N, P, K, Ca, and Mg in tomato shoots were unaffected by season-long interference of barnyardgrass at all densities. However, in 1983, concentrations of N and K decreased and concentration of P increased in tomato leaves as the density of barnyardgrass increased. Concentrations of Ca and Mg in tomato leaves were unaltered by barnyardgrass density.

Within-Season Changes in the Residual Weed Community and Crop Tolerance to Interference over the Long Planting Season of Sweet Corn

Weed Science ◽  
2009 ◽  
Vol 57 (3) ◽  
pp. 319-325 ◽  
Author(s):  
Martin M. Williams
Keyword(s):  
Sweet Corn ◽  
Growth Period ◽  
Field Studies ◽  
Planting Date ◽  
Growth And Yield ◽  
Planting Dates ◽  
Crop Tolerance ◽  
Weed Interference ◽  
Control Failure ◽  
Planting Season

Sweet corn is planted over a long season to temporally extend the perishable supply of ears for fresh and processing markets. Most growers' fields have weeds persisting to harvest (hereafter called residual weeds), and evidence suggests the crop's ability to endure competitive stress from residual weeds (i.e., crop tolerance) is not constant over the planting season. Field studies were conducted to characterize changes in the residual weed community over the long planting season and determine the extent to which planting date influences crop tolerance to weed interference in growth and yield traits. Total weed density at harvest was similar across five planting dates from mid-April to early-July; however, some changes in composition of species common to the midwestern United States were observed. Production of viable weed seed within the relatively short growth period of individual sweet corn plantings showed weed seedbank additions are influenced by species and planting date. Crop tolerances in growth and yield were variable in the mid-April and both May plantings, and the crop was least affected by weed interference in the mid-June and early-July planting dates. As the planting season progressed from late-May to early-July, sweet corn accounted for a great proportion of the total crop–weed biomass. Based on results from Illinois, a risk management perspective to weeds should recognize the significance of planting date on sweet corn competitive ability. This work suggests risk of yield loss from weed control failure is lower in late-season sweet corn plantings (June and July) than earlier plantings (April and May).

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