Relationships Among Green Foxtail (Setaria viridis) Seedling Development, Growing Degree Days, and Time of Nicosulfuron Application

1996 ◽  
Vol 10 (1) ◽  
pp. 60-67 ◽  
Author(s):  
Frank Forcella ◽  
Kevin R. Banken
Keyword(s):  
Seedling Growth ◽  
Weed Management ◽  
Corn Yield ◽  
Growing Degree Days ◽  
Yield Losses ◽  
Degree Days ◽  
Predictive Tool ◽  
Application Timing ◽  
Green Foxtail ◽  
The Relationship

Success of postemergence weed management often depends upon application timing and weed seedling size. To develop a predictive tool for estimating green foxtail development and optimizing timing of management operations, seedling growth was monitored in fields for two years, as well as in a single greenhouse experiment, and compared with elapsed thermal time (growing degree days, GDD, base 10 C). The relationship between seedling height (mm) and GDD was similar both years and could be described by the following equation: Height = (-0.27 + 0.033 * GDD)2. A comparable equation described seedling growth in a greenhouse. Leaf number was linearly related to GDD. Green foxtail in corn was controlled with nicosulfuron applied at seven intervals between 100 and 450 GDD after corn planting in 1993 and 1994. In 1993 corn yield losses due to green foxtail interference were least when nicosulfuron was applied 200 to 300 GDD after planting, at which time green foxtail height was 50 to 100 mm. In 1994 corn yield losses were minimized if nicosulfuron was applied any time before 300 GDD.

Changing of Vegetative to Reproductive Ratio as a Response to Different Sowing Dates in Sunflower

Helia ◽  
2018 ◽  
Vol 41 (69) ◽  
pp. 253-266
Author(s):  
Ali Asghar Aliloo
Keyword(s):  
Edible Oils ◽  
Sowing Date ◽  
Biodiesel Production ◽  
Growing Degree Days ◽  
Comprehensive Model ◽  
Yield Losses ◽  
Degree Days ◽  
North West ◽  
Long Period ◽  
Sowing Dates

AbstractSunflower is an important source for edible oils and biodiesel production. Its productivity is limited by many agronomical practices one of which is the sowing date. In this study, the effects of different sowing dates from early April to late June on phenology and yield of sunflower cultivars were investigated. The results showed that sunflower has a relatively long period of possible sowing dates, stretching from early April to late June in North West of Iran. However, delayed sowing dates significantly decreased the number of days needed for phenophases. For every day of delay, the model predicted (R2=0.97) a losing rate in achene yield by 22.2 kg h−1 from the first sowing date. For relationships between growing degree days (GDD) and yield, almost the same results were obtained. About 22 kg h−1 reduction (R2=0.79) in yield per day was estimated by GDD index when the average GDDs per day was 14.2. However, helio-thermal units (HTU) did not predict this reduction accurately. A suggested comprehensive model, that used the percent of yield losses and changes in vegetative to reproductive ratio, found a significant and positive relationship between the indices and yield losses. For all indices, an increase in vegetative to reproductive ratio resulted in increased grain yield losses.

Relationships among growing degree-days, tenderness, other harvest attributes and market value of processing pea (Pisum sativum L.) cultivars grown in Quebec

2006 ◽  
Vol 86 (2) ◽  
pp. 525-537 ◽  
Author(s):  
Edith Fallon, Nicolas Tremblay ◽  
Yves Desjardins
Keyword(s):  
Moisture Content ◽  
Size Distribution ◽  
Seed Size ◽  
Growing Degree Days ◽  
Harvest Time ◽  
Degree Days ◽  
Fresh Matter ◽  
Yield And Quality ◽  
Grain Moisture ◽  
The Relationship

In Quebec, grower income from processing peas is a function of yield and tenderometer reading. If peas are harvested early, the yield is poor, but the overall quality is superior, as indicated by lower tenderometer readings. Later harvests result in g reater yields but reduced quality (higher tenderometer readings). A better understanding of the relationship between harvest time, yield and quality is needed. In this study, the relationships between yield, tenderometer readings, size distribution and grain moisture content were examined as a function of growing degree-days (GDD) and production year for pea cultivars of different seed size categories. Yield and harvest attributes (tenderometer readings, seed size distribution and moisture content) were highly season dependent and their rates of change over the course of the harvest period also varied with the cultivar and year. Quality declined rapidly once the crop reached optimal maturity, while yield increased in a less predictable manner. Consequently, it was difficult to identify a harvest time that would consistently maximize grower returns. The highest income was generally not obtained at the optimal tenderometer readings presently used by the industry. Key words: Maturity, harvest date, climate, fresh matter yield, tenderometer, pea size

Influence of application timing and herbicide rate on the efficacy of tolpyralate plus atrazine

2019 ◽  
Vol 33 (03) ◽  
pp. 448-458 ◽  
Author(s):  
Brendan A. Metzger ◽  
Nader Soltani ◽  
Alan J. Raeder ◽  
David C. Hooker ◽  
Darren E. Robinson ◽  
...  
Keyword(s):  
Weed Management ◽  
Field Experiments ◽  
Integrated Weed Management ◽  
Herbicide Application ◽  
Weed Species ◽  
Common Ragweed ◽  
Application Timing ◽  
Common Lambsquarters ◽  
Green Foxtail ◽  
Equivalent Control

AbstractEffective POST herbicides and herbicide mixtures are key components of integrated weed management in corn; however, herbicides vary in their efficacy based on application timing. Six field experiments were conducted over 2 yr (2017–2018) in southwestern Ontario, Canada, to determine the effects of herbicide application timing and rate on the efficacy of tolpyralate, a new 4-hydroxyphenyl pyruvate dioxygenase inhibitor. Tolpyralate at 15, 30, or 40 g ai ha−1 in combination with atrazine at 500 or 1,000 g ai ha−1 was applied PRE, early POST, mid-POST, or late POST. Tolpyralate + atrazine at rates ≥30 + 1,000 g ha−1 provided equivalent control of common lambsquarters and Powell amaranth applied PRE or POST, whereas no rate applied PRE controlled common ragweed, velvetleaf, barnyardgrass, or green foxtail. Common ragweed, common lambsquarters, velvetleaf, and Powell amaranth were controlled equally regardless of POST timing. In contrast, control of barnyardgrass and green foxtail declined when herbicide application was delayed to the late-POST timing, irrespective of herbicide rate. Similarly, corn grain yield declined within each tolpyralate + atrazine rate when herbicide applications were delayed to late-POST timing. Overall, the results of this study indicate that several monocot and dicot weed species can be controlled with tolpyralate + atrazine with an early to mid-POST herbicide application timing, before weeds reach 30 cm in height, and Powell amaranth and common lambsquarters can also be controlled PRE. Additionally, this study provides further evidence highlighting the importance of effective, early-season weed control in corn.

YIELD LOSSES IN WHEAT DUE TO WEED COMMUNITIES DOMINATED BY GREEN FOXTAIL [Setaria viridis (L.) BEAUV.]: A MULTISPECIES APPROACH

1989 ◽  
Vol 69 (2) ◽  
pp. 521-529 ◽  
Author(s):  
L. HUME
Keyword(s):  
Yield Loss ◽  
Triticum Aestivum L ◽  
Crop Loss ◽  
Setaria Viridis ◽  
Yield Losses ◽  
Degree Days ◽  
Relative Time ◽  
Weed Communities ◽  
Green Foxtail ◽  
Multispecies Competition

A model was developed to predict wheat (Triticum aestivum L.) loss due to interference by multi-species weed communities dominated by green foxtail [Setaria viridis (L.) Beauv.], 3–4 wk after seeding. Results indicated that green foxtail-dominated weed communities averaging 427 plants m−2 over 4 yr reduced yield by about 7.8%. When plots were kept free of green foxtail, different species became important components of a second model developed to predict the yield loss. The combined effect of precipitation and growing degree days was an important component of both models. It is postulated that these environmental variables reflected the relative time of emergence of the weeds and the crop. Advantages of models based upon multispecies tests over those determined from one-weed one-crop tests are discussed as they relate to crop loss in multispecies situations.Key words: Setaria viridis, green foxtail, crop loss, multispecies competition, weed communities, modeling

Green Foxtail (Setaria viridis) and Pale Smartweed (Polygonum lapathifolium) Interference in Field Crops

1994 ◽  
Vol 8 (2) ◽  
pp. 311-316 ◽  
Author(s):  
John T. O'Donovan
Keyword(s):  
Crop Yield ◽  
Field Experiments ◽  
Dry Weight ◽  
Limiting Factor ◽  
Yield Losses ◽  
Weed Density ◽  
Green Foxtail ◽  
Polygonum Lapathifolium ◽  
And Control ◽  
The Relationship

Field experiments were conducted at Vegreville, Alberta in 1984, 1985, 1986, and 1988 to determine the effects of green foxtail and pale smartweed on yield of wheat, barley, and canola. There was considerable variation among years in the response of crop yield to both weeds and in the relationship between weed dry weight and weed density. Mostly relationships between crop yield and either weed density or dry weight were poor, suggesting that the weeds competed weakly with the crops. Thus density or dry weight may be poor predictors of crop yield losses due to green foxtail or pale smartweed. Where the crops emerged ahead of these weeds, and where soil moisture was not a limiting factor, crop yield losses were minimal and control with herbicides probably uneconomical. In some instances, growth and development of the weeds was suppressed by the crops to the extent that little or no weed dry matter was present at crop maturity. This was most evident with barley, and where the crops emerged ahead of the weeds.

Silage corn yield is reduced by burcucumber competition and drought in New York State

2021 ◽  
pp. 1-25
Author(s):  
Kristine M. Averill ◽  
Anna S. Westbrook ◽  
Scott H. Morris ◽  
Emma Kubinski ◽  
Antonio DiTommaso
Keyword(s):  
Climate Change ◽  
New York ◽  
Weed Management ◽  
New York State ◽  
Planting Density ◽  
Corn Yield ◽  
Yield Losses ◽  
Drought Treatment ◽  
York State ◽  
Effects Of Drought

Abstract Drought stress and weed competition are two of the most important threats to corn production in the northeastern United States. Both pressures have the potential to worsen under climate change. In a two-year field study in Ithaca, NY, USA, we tested the effects of drought and burcucumber, an increasingly problematic annual vine, on silage corn. Burcucumber seedlings were transplanted into corn rows at densities of 0, 0.5, 2, and 3 plants m−2 and the drought treatment was later imposed with rainout shelters constructed from steel frames and high-clarity plastic. Available soil moisture was lower in drought plots (47% ± 1% in 2018 and 52% ± 2% in 2019) than no-drought plots (69% ± 1% in 2018 and 68% ± 1% in 2019). Burcucumber planting density (P=0.008) reduced fresh silage yield. Drought also reduced fresh silage yield (P<0.001) with a drought-by-year interaction (P=0.007): drought reduced fresh weight by 29% in 2018 (48,000 ± 2,000 kg ha−1 to 34,000 ± 3,000 kg ha−1) and 9% in 2019 (38,000 ± 3,000 kg ha−1 to 34,000 ± 3,000 kg ha−1). Burcucumber planting density and drought did not interact. Overall, our findings indicate that drought and competition from burcucumber may have additive effects on silage corn in New York State. Regardless of water availability, active weed management is required to prevent yield losses due to burcucumber. Yield losses may be similar or greater in grain corn and might increase under climate change.

Microtopography, Microenvironments, and Weed Populations in Ridge-Tilled Soybean

2006 ◽  
Vol 20 (3) ◽  
pp. 593-604
Author(s):  
Thomas W. Jurik
Keyword(s):  
Seedling Emergence ◽  
Growing Season ◽  
Growing Degree Days ◽  
Degree Days ◽  
Weed Species ◽  
Redroot Pigweed ◽  
Giant Foxtail ◽  
Green Foxtail ◽  
Weed Emergence

The effects of microtopographic position on soil microenvironment and weed populations in ridge-tilled soybean were evaluated on three farms in Iowa in 1989 and 1990. In both years, over all weed species (primarily giant foxtail, green foxtail, yellow foxtail, redroot pigweed, and Pennsylvania smartweed), seedling emergence was highest in late May and early June, with few seedlings emerging after mid-June. Weed populations were highest in May and early June, after which rotary hoeing and cultivation reduced weed numbers in all plots. Microtopographic position (row, shoulder, and furrow) had a large effect on soil microenvironment and weed populations. Furrows were the wettest position through most of the growing season. Rows were the warmest position early in the season and the coolest position late in the season. Cumulative weed emergence early in the season was closely related to growing degree days, which accumulated faster in the row position than the furrow position. Following rotary hoeing and cultivation, the row position had significantly more total weeds than the shoulder and furrow positions on all farms in August of both years.

Volunteer Potato Density Influences Critical Time of Weed Removal in Bulb Onion

2007 ◽  
Vol 21 (1) ◽  
pp. 136-140 ◽  
Author(s):  
Martin M. Williams ◽  
Corey V. Ransom ◽  
W. Mack Thompson
Keyword(s):  
Yield Loss ◽  
Critical Time ◽  
Field Trials ◽  
Growing Degree Days ◽  
Crop Loss ◽  
Yield Losses ◽  
Degree Days ◽  
Potato Plants ◽  
Volunteer Potato ◽  
Weed Removal

Volunteer potato is highly competitive with onion and few control tactics are effective for removing this weed from an onion crop. Both volunteer potato density and duration of interference reduce onion yield, but the interaction of these factors is unknown. Field trials were conducted in 2003 in Idaho, Oregon, and Washington to determine the influence of volunteer potato density on the critical time of weed removal (CTWR) in onion. Yield losses of 2.5, 5.0, and 10% were estimated to occur at 534, 654, and 830 growing degree days (GDD) after onion emergence, respectively, with a volunteer potato density of 0.5 plants/m2. At 2.0 volunteer potato plants/m2, yield losses of 2.5, 5.0, and 10% were estimated to occur at 388, 481, and 598 GDD after onion emergence, respectively. Volunteer potato at 2.0 plants/m2had to be removed at least one onion leaf stage sooner, compared to a weed density of 0.5 plants/m2, to avoid yield loss. Yield loss due to volunteer potato density or duration of interference was greatest among jumbo, colossal, and supercolossal market grades (P ≤ 0.1). Lowering potato tuber density in crops preceding onion will extend the critical time for weed removal and reduce the risk of crop loss.

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