Emergence Pattern and Periodicity of Palmer Amaranth (Amaranthus palmeri) Populations from Southcentral Great Plains

2021 ◽  
pp. 1-21
Author(s):  
Rui Liu ◽  
Vipan Kumar ◽  
Prashant Jha ◽  
Phillip W. Stahlman
Keyword(s):  
Great Plains ◽  
Prediction Models ◽  
Agricultural Research ◽  
Control Strategies ◽  
Growing Season ◽  
Palmer Amaranth ◽  
Effective Control ◽  
Emergence Period ◽  
Emergence Pattern ◽  
Growing Seasons

Evolution of multiple herbicide-resistant Palmer amaranth warrants the development of integrated strategies for its control in the Southcentral Great Plains (SGP). In order to develop effective control strategies, an improved understanding of the emergence biology of Palmer amaranth populations from the SGP region is needed. A common garden study was conducted in a no-till (NT) fallow field at Kansas State University Agricultural Research Center near Hays, KS, during 2018 and 2019 growing seasons, to determine the emergence pattern and periodicity of Palmer amaranth populations collected from the SGP region. Nine Palmer amaranth populations collected from five states in the SGP region: Colorado (CO1, CO2), Oklahoma (OK), Kansas (KS1, KS2), Texas (TX), and Nebraska (NE1, NE2, NE3) were included. During the 2018 growing season, the CO1 and KS1 populations displayed more rapid emergence rates, with greater parameter b values (−5.4, and −5.3, respectively), whereas the TX and NE3 populations had the highest emergence rates (b = −12.2) in the 2019 growing season. The cumulative growing degree days (cGDD) required to achieve 10%, 50%, and 90% cumulative emergence ranged from 125 to 144, 190 to 254, and 285 to 445 in 2018 and 54 to 74, 88 to 160, and 105 to 420 in the 2019 growing season across all tested populations, respectively. The OK population exhibited the longest emergence duration (301 and 359 cGDD) in both growing seasons. All tested Palmer amaranth populations had peak emergence period between May 11 and June 8 in 2018, and April 30 and June 1 in the 2019 growing season. Altogether, these results indicate the existence of differential emergence pattern and peak emergence periods of geographically-distant Palmer amaranth populations from the SGP region. This information will help in developing prediction models for decision-making tools to manage Palmer amaranth in the region.

Palmer Amaranth (Amaranthus palmeri) Control in Postharvest Wheat Stubble in the Central Great Plains

2021 ◽  
pp. 1-17
Author(s):  
Vipan Kumar ◽  
Rui Liu ◽  
Amit J. Jhala ◽  
Prashant Jha ◽  
Misha Manuchehri
Keyword(s):  
Seed Production ◽  
Great Plains ◽  
Field Experiments ◽  
Agricultural Research ◽  
Palmer Amaranth ◽  
Shoot Biomass ◽  
Late Season ◽  
Growing Seasons ◽  
Wheat Stubble ◽  
Kansas State University

Abstract Late-season control of Palmer amaranth in postharvest wheat stubble is important for reducing the seedbank. Our objectives were to evaluate the efficacy of late-season POST herbicides for Palmer amaranth control, shoot dry biomass and seed production in postharvest wheat stubble. Field experiments were conducted at Kansas State University Agricultural Research Center near Hays, KS during 2019 and 2020 growing seasons. The study site had a natural seedbank of Palmer amaranth. Herbicide treatments were applied 3 wk after wheat harvest when Palmer amaranth plants had reached inflorescence initiation stage. Palmer amaranth was controlled 96 to 98% 8 weeks after treatment and shoot biomass as well as seed production was prevented when paraquat was applied alone or when mixed with atrazine, metribuzin, flumioxazin, 2,4-D, sulfentrazone, pyroxasulfone + sulfentrazone, or flumioxazin + metribuzin, and with glyphosate + dicamba, glyphosate + 2,4-D, saflufenacil + 2,4-D, glufosinate + dicamba + glyphosate, and glufosinate + 2,4-D + glyphosate. Palmer amaranth was controlled 89 to 93% with application of glyphosate, glufosinate, dicamba + 2,4-D, saflufenacil + atrazine, and saflufenacil + metribuzin resulting in Palmer amaranth shoot biomass of 15 to 56 g m -2 and production of 1,080 to 7,040 seeds m−2. Palmer amaranth control was less than 86% with application of dicamba, 2,4-D, dicamba + atrazine, and saflufenacil resulting in Palmer amaranth shoot biomass of 38 to 47 g m−2 and production of 3,110 to 6,190 seeds m−2. Palmer amaranth was controlled 63 and 72%, shoot biomass was 178 and 161 g m−2 and seed production was 35,180 and 39,510 seeds m−2, respectively, with application of 2,4-D + bromoxynil + fluroxypyr, and bromoxynil + pyrasulfotole + atrazine. Growers should utilize these effective POST herbicide mixes for Palmer amaranth control to prevent seed prevention postharvest in wheat stubble.

Emergence Pattern of Five Weeds in the Central Great Plains

1996 ◽  
Vol 10 (4) ◽  
pp. 744-749 ◽  
Author(s):  
R. L. Anderson ◽  
D. C. Nielsen
Keyword(s):  
Great Plains ◽  
Seedling Emergence ◽  
Growing Season ◽  
Crop Canopy ◽  
Emergence Pattern ◽  
Proso Millet ◽  
Annual Crops ◽  
No Till ◽  
Green Foxtail ◽  
Wheat Stubble

Seedling emergence was characterized for five weeds that infest summer annual crops in the central Great Plains as affected by crop canopy or tillage. The study was established in winter wheat stubble between 1987 and 1990, with seedling emergence recorded weekly between April 1 and November 1. Kochia emerged primarily from early April to late June, whereas green foxtail, wild-proso millet, and redroot pigweed began emerging in late May and continued until August. Volunteer wheat emerged throughout the growing season. Tillage did not affect the emergence pattern of any species, but the numbers of kochia, volunteer wheat, and green foxtail seedlings were increased in no-till. Conversely, wild-proso millet emergence was greater with tillage. Only volunteer wheat's emergence was affected by crop canopy, as fall emergence of volunteer wheat was more than three times greater in corn than in proso millet.

scholarly journals Infection Courts and Timing of Infection of Apple Fruit by Phacidiopycnis washingtonensis in the Orchard in Relation to Speck Rot During Storage

Plant Disease ◽  
2014 ◽  
Vol 98 (11) ◽  
pp. 1467-1475 ◽  
Author(s):  
P. Sikdar ◽  
M. Mazzola ◽  
C. L. Xiao
Keyword(s):  
Control Strategies ◽  
Growing Season ◽  
Apple Fruit ◽  
Fruit Rot ◽  
Effective Control ◽  
Micro Cracks ◽  
Fuji Apple ◽  
Phacidiopycnis Washingtonensis ◽  
Inoculation Time ◽  
Rot Disease

Phacidiopycnis washingtonensis is the cause of speck rot, a recently reported postharvest fruit rot disease of apple. The pathogen is believed to incite infections in the field, and disease symptoms become evident only during storage. To determine the timing of apple fruit infection in relation to development of speck rot in storage, ‘Red Delicious’ and ‘Fuji’ apple fruit were inoculated in the orchard with P. washingtonensis at different times during the growing season, harvested, and monitored for decay development during storage at 0°C. Fruit inoculated in both field and laboratory also were used to identify the infection courts and mode of apple fruit penetration by P. washingtonensis. In all 3 years, stem-end speck rot and calyx-end speck rot developed during cold storage on fruit inoculated during the growing season, regardless of inoculation time; and the incidence of total speck rot in storage increased as the fruit inoculation time approached harvest. On fruit floral parts, the pathogen colonized sepals at higher rates than stamens. Availability of naturally occurring necrotic tissues favored the colonization of the fungus on sepals. Histological studies indicated that infection occurred through micro-cracks on the surfaces of pedicels and sepals of the fruit, and invasion of these tissues was restricted between the cuticle and epidermis. Findings of this study will assist in the development of effective control strategies for speck rot.

Emergence Dynamics of Kochia (Kochia scoparia) Populations from the U.S. Great Plains: A Multi-Site-Year Study

Weed Science ◽  
2017 ◽  
Vol 66 (1) ◽  
pp. 25-35 ◽  
Author(s):  
Vipan Kumar ◽  
Prashant Jha ◽  
J. Anita Dille ◽  
Phillip W. Stahlman
Keyword(s):  
New Mexico ◽  
Great Plains ◽  
Field Experiments ◽  
Emergence Period ◽  
Emergence Pattern ◽  
The North ◽  
Rate Of Emergence ◽  
Sites Of Action ◽  
Rapid Emergence ◽  
The U.S

Evolution of kochia biotypes resistant to multiple herbicide sites of action is an increasing concern for growers across the U.S. Great Plains. This necessitates the development of integrated strategies for kochia control in this region based on improved forecasting of periodicity and patterns of kochia emergence in the field. Field experiments were conducted near Huntley, MT, in 2013 and 2014, and in Manhattan and Hays, KS, in 2013 to characterize the timing and pattern of emergence of several kochia populations collected from the U.S. Great Plains’ states. The more rapid accumulation of growing degree days (GDD) resulted in a shorter emergence duration (E90–E10) in 2014 compared with 2013 in Montana. Kochia populations exhibited an extended emergence period (early April through mid-July). Among all kochia populations, in 2013, Kansas-Garden City (KS-GC), Kansas-Manhattan (KS-MN), Oklahoma (OK), and Montana (MT) populations began to emerge earlier, with a minimum of 151 cumulative GDD to achieve 10% cumulative emergence (E10values) in Montana. The New Mexico-Los Lunas (NM-LL) population exhibited a delayed onset but a rapid emergence rate, while the North Dakota (ND) and Kansas-Colby (KS-CB) populations emerged over a longer duration (E90–E10of 556 and 547 GDD, respectively) in 2013 in Montana. In 2013 at the two locations in Kansas, kochia populations exhibited a similar emergence pattern, with no differences in the time to initiate germination (E10), rate of emergence (parameterb), or duration of emergence (E90–E10). At Hays, KS, the GDD for E50and E90were less for ND compared with KS-MN and KS-GC local populations. In 2014 the KS-MN kochia population exhibited an early (ED10value of 215 GDD) but a more gradual emergence pattern (E90–E10=526 GDD) in Montana. In contrast, OK and New Mexico-Las Cruces (NM-LC) populations had an early and a more rapid emergence pattern (E90–E10=153 and 154 GDD, respectively). Kochia in Montana exhibited two to four emergence peaks. This differential emergence pattern of kochia populations reflects the occurrence of different emergence “biotypes” and emphasizes the need to adopt more location-specific and diversified weed control tactics to manage kochia seedbanks.

Rotational Cropping Systems to Reduce Cheat (Bromus secalinus) Densities

2006 ◽  
Vol 20 (2) ◽  
pp. 445-452 ◽  
Author(s):  
Jon C. Stone ◽  
Thomas F. Peeper ◽  
Amanda E. Stone
Keyword(s):  
Winter Wheat ◽  
Great Plains ◽  
Cropping Systems ◽  
Control Strategies ◽  
Growing Season ◽  
Grain Sorghum ◽  
Economic Returns ◽  
Southern Great Plains ◽  
Net Returns ◽  
Bromus Secalinus

In the Southern Great Plains, producers of hard red winter wheat seek sustainable methods for controlling cheat and improving economic returns. Experiments were conducted at two sites in north-central Oklahoma to determine the effect of cheat management programs, with various weed control strategies, on cheat densities and total net returns. The cheat management programs, initiated following harvest of winter wheat, included conventionally tilled, double-crop grain sorghum (Sorghum bicolorL.) followed by soybean (Glycine maxL.); and continuous winter wheat. Rotating out of winter wheat for one growing season increased yield of succedent wheat up to 32% and 42% at Billings and Ponca City, respectively. Dockage due to cheat in the succedent wheat was reduced up to 78% and 87% by rotating out of winter wheat for one growing season at Billings and Ponca City, respectively. Cheat management programs including a crop rotation with herbicides applied to the grain sorghum, except for an application of atrazine + metolachlor at Ponca City, improved total net returns over the nontreated continuous wheat option. Cheat panicles in the succedent wheat were reduced up to 87% by rotation out of winter wheat for one growing season.

scholarly journals Using an “Index of Merit” to Evaluate Winterhardy Pea Lines

2016 ◽  
Vol 8 (10) ◽  
pp. 45
Author(s):  
Azize Homer ◽  
Robin W. Groose
Keyword(s):  
Great Plains ◽  
Seed Yield ◽  
Production Systems ◽  
Growing Season ◽  
Complete Replacement ◽  
Growing Seasons ◽  
Trade Offs ◽  
Standardized Index ◽  
Summer Fallow ◽  
Growing Season Precipitation

<p>Winter feed pea (<em>Pisum sativum</em> ssp. arvense) might serve as a partial or complete replacement for fallow in the winter wheat-summer fallow (WW-SF) system with potential to integrate cereal and livestock production in the Central Great Plains (CGP). The objective of this study was to evaluate advanced winter pea lines bred in the Wyoming environment in comparison with existing winter feed pea cultivars that were bred elsewhere. Six elite lines, one a blend of two lines, and three check cultivars were compared for overall merit, based on yield for forage and seed, and in two different production systems, dryland and irrigated, and at two locations (Lingle WY and Laramie WY) during the 2010-2011 and 2011-2012 growing seasons. Indices of merit, calculated in two ways: a mean-adjusted index and a standardized index, were used to simultaneously evaluate lines/cultivars for forage and seed yield. Based on the results from both indices, five Wyoming-bred elite lines (one a blend of two lines) ranked in the top five lines of 10 lines/cultivars tested. Importantly, three Wyoming-bred lines (Wyo#11, Wyo#11 +Wyo#13, and Wyo#13) all ranked significantly higher for overall merit than any existing winter feed pea cultivar tested in this study: ‘Common’, ‘Specter’ and ‘Windham’. Because four measures of merit in the both indices are positively correlated no serious compromises or “trade-offs” are manifested among these four traits. This research shows that winter pea has potential value for forage and seed yield, mostly depending on growing season precipitation in the CGP.</p>

Herbicide programs to manage glyphosate/dicamba-resistant kochia (Bassia scoparia) in glyphosate/dicamba-resistant soybean

2020 ◽  
Vol 34 (4) ◽  
pp. 568-574
Author(s):  
Ramawatar Yadav ◽  
Vipan Kumar ◽  
Prashant Jha
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Great Plains ◽  
Field Experiments ◽  
Control Strategies ◽  
Effective Control ◽  
The Us ◽  
Herbicide Programs ◽  
Us Great Plains

AbstractEvolution of kochia resistance to glyphosate and dicamba is a concern for growers in the US Great Plains. An increasing use of glyphosate and dicamba with the widespread adoption of glyphosate/dicamba-resistant (GDR) soybean in recent years may warrant greater attention. Long-term stewardship of this new stacked-trait technology will require the implementation of diverse weed control strategies, such as the use of soil-residual herbicides (PRE) aimed at effective control of GDR kochia. Field experiments were conducted in Huntley, MT, in 2017 and 2018, and Hays, KS, in 2018 to determine the effectiveness of various PRE herbicides applied alone or followed by (fb) a POST treatment of glyphosate plus dicamba for controlling GDR kochia in GDR soybean. Among PRE herbicides tested, sulfentrazone provided complete (100%), season-long control of GDR kochia at both sites. In addition, PRE fb POST programs tested in this study brought 71% to 100% control of GDR kochia throughout the season at both sites. Pyroxasulfone applied PRE resulted in 57% to 70% control across sites at 9 to 10 wk after PRE (WAPRE). However, mixing dicamba with pyroxasulfone improved control up to 25% at both sites. Kochia plants surviving pyroxasulfone applied PRE alone produced 2,530 seeds m−2 compared with pyroxasulfone + dicamba (230 seeds m−2) at the Montana site. No differences in soybean grain yields were observed with PRE alone or PRE fb POST treatments at the Montana site; however, dicamba, pyroxasulfone, and pendimethalin + dimethenamid-P applied PRE brought lower grain yield (1,150 kg ha−1) compared to all other tested programs at the Kansas site. In conclusion, effective PRE or PRE fb POST (two-pass) programs tested in this research should be proactively utilized by the growers to manage GDR kochia in GDR soybean.

Herbicide Treatment and Application Method Influence Root Sprouting in Chinese Tallowtree (Triadica sebifera)

2015 ◽  
Vol 8 (2) ◽  
pp. 160-168 ◽  
Author(s):  
Stephen F. Enloe ◽  
Nancy J. Loewenstein ◽  
Douglas Streett ◽  
Dwight K. Lauer
Keyword(s):  
Control Strategies ◽  
Lateral Roots ◽  
Effective Control ◽  
Individual Plant ◽  
Negative Effects ◽  
Growing Seasons ◽  
Herbicide Treatments ◽  
Cut Stump ◽  
Root Collar ◽  
Better Than

Chinese tallowtree is an invasive tree found throughout the southeastern United States and in California. Its negative effects can be seen in numerous natural and managed ecosystems, including bottomland hardwood forests, pastures, pine plantations, and along lakes, ponds, streams, and rivers. Despite its troublesome presence for many decades, relatively few effective control strategies are available. Root sprouting following management efforts is a major impediment to successful control. Studies were conducted in Alabama and Louisiana at three locations to test several herbicides for cut stump, basal bark, and foliar individual plant treatment (IPT) methods. Herbicide treatments included triclopyr amine and ester formulations, imazamox, aminopyralid, aminocyclopyrachlor, and fluroxypyr. Data were collected just before leaf senescence at one and two growing seasons after treatment and included Chinese tallowtree foliar cover, number of stump or root collar sprouts, and number of sprouts originating from lateral roots within a 1-m radius of each tree. For the cut stump and basal bark studies, most herbicide treatments prevented sprouting from the stump or root collar region better than they did from the lateral roots. Aminopyralid reduced total sprouting better than all other treatments in the cut stump study. The high rates of aminocyclopyrachlor and fluroxypyr resulted in the highest mortality in the basal bark study. Aminocyclopyrachlor reduced total sprouting better than all other herbicides in the foliar treatment study. Triclopyr amine and ester formulations, which are commercial standards, did not consistently control Chinese tallowtree across these IPT studies. These studies provide some promising treatments to increase the number of effective tools that can be used to manage Chinese tallowtree. Additional research is needed to address the prolific nature of lateral root sprouting following any of these treatment methods.

scholarly journals Amaranthus palmeri--Palmer Amaranth

EDIS ◽  
2020 ◽  
Vol 2020 (2) ◽  
Author(s):  
Pratap Devkota ◽  
Ramon Leon
Keyword(s):  
Control Strategies ◽  
Palmer Amaranth ◽  
Effective Control ◽  
Amaranthus Palmeri ◽  
Accurate Identification ◽  
Development Of Resistance ◽  
Southeastern Us ◽  
Management And Development ◽  
Vigorous Growth ◽  
Resistance To Herbicides

Palmer amaranth has become one of the most troublesome weeds in the southeastern US due to its vigorous growth rate, high seed production, and development of resistance to herbicides from multiple modes of action. This 4-page publication illustrates characteristics of this weed to assist in accurate identification, proper management, and development of effective control strategies. Written by Sergio Morichetti, Jason Ferrell, and Pratap Devkota, and published by the UF/IFAS Agronomy Department, revised April 2020.

scholarly journals Improving Wheat Yield Prediction Using Secondary Traits and High-Density Phenotyping Under Heat-Stressed Environments

2021 ◽  
Vol 12 ◽  
Author(s):  
Mohammad Mokhlesur Rahman ◽  
Jared Crain ◽  
Atena Haghighattalab ◽  
Ravi P. Singh ◽  
Jesse Poland
Keyword(s):  
Grain Yield ◽  
Prediction Models ◽  
Agricultural Research ◽  
Wheat Yield ◽  
High Density ◽  
Research Station ◽  
Multivariate Models ◽  
Proximal Sensing ◽  
Growing Seasons ◽  
Secondary Traits

A primary selection target for wheat (Triticum aestivum) improvement is grain yield. However, the selection for yield is limited by the extent of field trials, fluctuating environments, and the time needed to obtain multiyear assessments. Secondary traits such as spectral reflectance and canopy temperature (CT), which can be rapidly measured many times throughout the growing season, are frequently correlated with grain yield and could be used for indirect selection in large populations particularly in earlier generations in the breeding cycle prior to replicated yield testing. While proximal sensing data collection is increasingly implemented with high-throughput platforms that provide powerful and affordable information, efficient and effective use of these data is challenging. The objective of this study was to monitor wheat growth and predict grain yield in wheat breeding trials using high-density proximal sensing measurements under extreme terminal heat stress that is common in Bangladesh. Over five growing seasons, we analyzed normalized difference vegetation index (NDVI) and CT measurements collected in elite breeding lines from the International Maize and Wheat Improvement Center at the Regional Agricultural Research Station, Jamalpur, Bangladesh. We explored several variable reduction and regularization techniques followed by using the combined secondary traits to predict grain yield. Across years, grain yield heritability ranged from 0.30 to 0.72, with variable secondary trait heritability (0.0–0.6), while the correlation between grain yield and secondary traits ranged from −0.5 to 0.5. The prediction accuracy was calculated by a cross-fold validation approach as the correlation between observed and predicted grain yield using univariate and multivariate models. We found that the multivariate models resulted in higher prediction accuracies for grain yield than the univariate models. Stepwise regression performed equal to, or better than, other models in predicting grain yield. When incorporating all secondary traits into the models, we obtained high prediction accuracies (0.58–0.68) across the five growing seasons. Our results show that the optimized phenotypic prediction models can leverage secondary traits to deliver accurate predictions of wheat grain yield, allowing breeding programs to make more robust and rapid selections.

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