Winter wheat competition against jointed goatgrass (Aegilops cylindrica) as influenced by wheat plant height, seeding rate, and seed size

Weed Science ◽  
2004 ◽  
Vol 52 (6) ◽  
pp. 996-1001 ◽  
Author(s):  
Joseph P. Yenish ◽  
Frank L. Young

Jointed goatgrass is a troublesome weed in winter wheat with selective control only possible with a herbicide-resistant crop. Even with herbicide-resistant wheat, cultural control is still an important part of jointed goatgrass management. A study was conducted in 1998 and 2000 to determine whether using larger sized seed of a tall wheat variety at an increased seeding rate would reduce the effect of jointed goatgrass on winter wheat. Wheat seed size, seeding rate, and variety height had no effect on jointed goatgrass plant density. Tall (∼130 cm) wheat reduced mature jointed goatgrass biomass 46 and 16% compared with short (∼100 cm) wheat in years 1 and 2 of the experiment, respectively. Spikelet biomass was also reduced approximately 70 and 30% in the same respective years. One thousand–spikelet weight of jointed goatgrass was reduced 37 and 7% in years 1 and 2, respectively, when grown in competition with taller compared with shorter wheat. Moreover, dockage was 80 and 30% less in years 1 and 2, respectively, when grown in competition with taller than shorter wheat. Mature jointed goatgrass height was similar regardless of the competitive wheat height. However, jointed goatgrass was as much as 18% taller than the short wheat and 15% shorter than the tall wheat. Seeding rate had the most consistent effect on wheat yield. Wheat seed yield was about 10% greater with 60 than 40 seed m−1of row when competing with jointed goatgrass. Results of this study indicate that growers could use a tall winter wheat variety to improve crop competition against jointed goatgrass. Results also indicate that plant breeders should consider plant height because herbicide-resistant varieties are developed for the integrated management of jointed goatgrass.

1999 ◽  
Vol 13 (1) ◽  
pp. 77-82 ◽  
Author(s):  
Daniel A. Ball ◽  
Frank L. Young ◽  
Alex G. Ogg

Jointed goatgrass (Aegilops cylindrica) is a serious problem for winter wheat producers throughout the western U.S. Interference from this weed can severely reduce grain yield and contaminate harvested grain, resulting in dockage losses. There are currently no selective herbicides registered for controlling jointed goatgrass in wheat. Imazamox, an imidazolinone herbicide, was applied to an imidazolinone herbicide-resistant (IMI) wheat mutant of the winter wheat cultivar ‘Fidel.’ Jointed goatgrass control from spring postemergence application of imazamox ranged from 61 to 97% when applied at 36 g/ha. Negligible crop injury from imazamox treatment was observed at 36 g/ha at several locations under dryland environments in the U.S. Pacific Northwest. Wheat yield was increased 19 to 41% by imazamox treatment in three of four experiments. Percent dockage resulting from jointed goatgrass spikelet contamination of harvested wheat grain was eliminated by imazamox treatment. Introduction of the IMI trait into commercial wheat cultivars could provide an effective method for selective control of jointed goatgrass in winter wheat.


Weed Science ◽  
2005 ◽  
Vol 53 (5) ◽  
pp. 594-599 ◽  
Author(s):  
Lynn Fandrich ◽  
Carol Mallory-Smith

A better understanding of the persistence of jointed goatgrass seed in soil and its dormancy will lead to the development of more effective weed-management strategies. Three populations of jointed goatgrass were collected from winter wheat fields in Oregon, and grown together with the winter wheat variety ‘Madsen’ in nurseries at Moro and Pendleton, OR. Germination responses of jointed goatgrass and wheat seed were recorded over 14 d at 5/5, 15/10, 15/15, 25/15, 25/25, and 30/20 C day/night temperatures and a 12-h photoperiod. Because jointed goatgrass spikelets often contain two seed, primary and secondary seed germination values were recorded. Secondary seed germination was defined as 3-mm radicle protrusion, and primary seed germination was defined as 5-mm emergence of the second coleoptile. Jointed goatgrass secondary seed germinated when exposed to all temperature regimes. Jointed goatgrass secondary seed germination occurred 3 d earlier in temperature regimes involving 15 C compared to germination at 5/5, 25/25, and 30/20 C. Final germination values for jointed goatgrass secondary seed were greatest when seed were incubated at 25/15 C. Wheat seed germinated at all temperature regimes, although the onset of germination occurred 1 to 1.5 d later at 5/5 C compared to other temperature regimes. Jointed goatgrass primary seed germinated only at 15/10, 15/15, and 25/15 C, and maximum germination occurred at 25/15 C. Dormancy in jointed goatgrass might prevent germination of seed within freshly shattered spikelets until autumn when temperatures are low and moisture is available. Because final germination percentages in jointed goatgrass primary and secondary seed were less than 100%, additional research on factors regulating dormancy is needed.


1991 ◽  
Vol 5 (4) ◽  
pp. 707-712 ◽  
Author(s):  
Jeffrey A. Koscelny ◽  
Thomas F. Peeper ◽  
John B. Solie ◽  
Stanley G. Solomon

Field experiments were conducted in Oklahoma to determine the effects of winter wheat seeding date and cheat infestation level on cultural cheat control obtained by increasing winter wheat seeding rates and decreasing row spacing. Seeding rate and row spacing interactions influenced cheat density, biomass, or seed in harvested wheat (dockage) at two of three locations. Suppressive effects on cheat of increasing wheat seeding rates and reduced row spacings were greater in wheat seeded in September than later. At two other locations, increasing seeding rate from 67 to 101 kg ha–1or reducing row spacings from 22.5 to 15 cm increased winter wheat yield over a range of cheat infestation levels.


2002 ◽  
Vol 139 (4) ◽  
pp. 385-395 ◽  
Author(s):  
A. M. BLAIR ◽  
P. A. JONES ◽  
R. H. INGLE ◽  
N. D. TILLETT ◽  
T. HAGUE

Two systems for integrated weed control in winter wheat based around the combination of herbicides with cultural control have been investigated and compared with conventional practice in experiments between 1993 and 2001. These systems were (a) an overall spray of a reduced herbicide dose followed by spring tine harrow weeding and (b) the combination of herbicide applied over the crop row with a novel vision guided inter-row hoe. The latter required wheat to be established with a wider (22 cm) inter-row spacing than standard (12·5 cm). Experiments over 10 sites/seasons indicated that this increased spacing could be achieved without yield loss. Trials to measure the accuracy of hoe blade lateral positioning using the vision guidance system indicated that error was normally distributed with standard deviation of 12 mm and a bias that could be set to within 1 cm. This performance could be maintained through the normal hoeing period and the crop row location and tracking techniques were robust to moderate weed infestation. In the absence of weeds neither overall harrowing nor inter-row hoeing affected winter wheat yield, 1000-seed weight or specific weight in 12·5 or 22 cm rows. When combined with inter-row hoeing, manually targeted banded applications of fluazolate, pendimethalin or isoproturon reduced grass weed levels and increased yields over untreated controls, though better results were obtained using overall herbicides. However, improvements would be possible with more accurately targeted herbicide applications and more effective inter-row grass weed control. The implications and costs of using such an integrated system are discussed and requirements for future developments identified.


1999 ◽  
Vol 13 (2) ◽  
pp. 374-377 ◽  
Author(s):  
Abdel O. Mesbah ◽  
Stephen D. Miller

A 3-yr study was conducted in eastern Wyoming from 1995 to 1997 to evaluate the effect of fertilizer placement on jointed goatgrass competitiveness with winter wheat. Fertilizer placement methods consisted of applying 45 kg/ha of nitrogen (50% as urea and 50% as ammonium nitrate) in a deep band 5 cm below and 2.5 cm to the side of the wheat row, broadcasting on the soil surface, or injecting fertilizer by spoke wheel 10 cm deep and 5 cm to the side of the wheat row. Neither fertilizer placement nor jointed goatgrass presence affected winter wheat stand. Wheat yield reductions from jointed goatgrass competition were 7 and 10% higher with the broadcast than deep-band or spoke-wheel injection methods, respectively. Wheat spikes/plant, seeds/spike, 200-seed weight, and plant height were not influenced by fertilizer placement; however, the presence of 35 jointed goatgrass plants/m2reduced spikes/plant 21%, seeds/spike 12%, and 200-seed weight 6%. Jointed goatgrass populations were not influenced by fertilizer placement method; however, the number of spikes/plant was reduced 8 and 10%, joints/spike 3%, and biomass 15 and 21% by deep band or spoke wheel fertilizer placement.


Weed Science ◽  
1998 ◽  
Vol 46 (6) ◽  
pp. 632-634 ◽  
Author(s):  
Steven S. Seefeldt ◽  
Robert Zemetra ◽  
Frank L. Young ◽  
Stephen S. Jones

Imazamox-resistant hybrids resulted from a cross between jointed goatgrass and an imazamox-resistant wheat (cv. FS-4 IR wheat). Two imazamox-resistant hybrids were discovered in a research plot where FS-4 IR wheat seed had been replanted from the harvest of an imazamox efficacy study conducted the year before at a different location. These hybrid plants survived imazamox applied at 0.053 and 0.069 kg ai ha−1in the field and produced seven viable seeds (BC1). This seed germinated, and chromosomes were counted from the roots (2N number ranged from 39 to 54). In the greenhouse, six of the seven plants survived an application of 0.072 kg ai ha−1imazamox, which confirmed that the resistance trait had been passed to these progeny. A large amount of phenotypic variation was observed in the mature BC1plants. A genetic description of the movement of the resistant gene is proposed based on the case of the gene being located on the D and the A or B genomes. Management strategies to reduce the occurrence of herbicide-resistant hybrids are presented.


1998 ◽  
Vol 12 (3) ◽  
pp. 478-483 ◽  
Author(s):  
R. L. Anderson

Producers rely on cultural practices to manage downy brome, jointed goatgrass, and feral rye in winter wheat because there are no effective herbicides for in-crop control. This study characterized seedling emergence, growth, and development of these winter annual grasses, with the goal of suggesting or improving cultural control strategies. Feral rye seedlings emerged within 4 wk, whereas downy brome and jointed goatgrass seedlings emerged over a 10-wk period. Emergence patterns of these grasses suggest that delay of winter wheat planting may be effective in reducing feral rye densities, but this strategy most likely will be ineffective with downy brome or jointed goatgrass. Downy brome began anthesis 1 to 2 wk earlier than the other two grasses and winter wheat. Both downy brome and jointed goatgrass were shorter than winter wheat during the growing season, whereas feral rye was at least as tall as wheat. Producers mow infested wheat to prevent weed seed production, but this practice may not be effective with jointed goatgrass and downy brome because of their short stature and downy brome's earlier development. Conversely, mowing has potential in preventing feral rye seed production. The grasses produced between 340 and 770 seeds/ plant.


Agriculture ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 127 ◽  
Author(s):  
Gniewko Niedbała ◽  
Danuta Kurasiak-Popowska ◽  
Kinga Stuper-Szablewska ◽  
Jerzy Nawracała

Biotic stress, which includes infection by pathogenic fungi, causes losses of wheat yield in terms of quantity and quality. Ear Fusarium is caused by strains of F. graminearum and F. culmorum, which can produce mycotoxins—deoxynivalenol (DON) and nivalenol (NIV). One of the wheat’s defense mechanisms against stressors is the activation of biosynthesis pathways of antioxidant compounds, including ferulic acid. The aim of the study was to conduct pilot studies on the basis of which neural models were created that would examine the impact of the variety and weather conditions on the concentration of ferulic acid, and link its content with the concentration of deoxynivalenol and nivalenol. The plant material was 23 winter wheat genotypes with different Fusarium resistance. The field experiment was conducted in 2011–2013 in Poland in three experimental combinations, namely: with full chemical protection; without chemical protection, but infested with natural disease (control); and in the absence of fungicidal protection, with artificial inoculation by genus Fusarium fungi. As a result of the pilot studies, three neural models—FERUANN analytical models (ferulic acid content), DONANN (deoxynivalenol content) and NIVANN (nivalenol content)—were produced. Each model was based on 14 independent features, 12 of which were in the form of quantitative data, and the other two were presented as qualitative data. The structure of the created models was based on an artificial neural network (ANN) of the multilayer perceptron (MLP) with two hidden layers. The sensitivity analysis of the neural network showed the two most important features determining the concentration of ferulic acid, deoxynivalenol, and nivalenol in winter wheat seeds. These are the experiment variant (VAR) and winter wheat variety (VOW).


1999 ◽  
Vol 13 (1) ◽  
pp. 183-190 ◽  
Author(s):  
Frank L. Young ◽  
Steven S. Seefeldt ◽  
Gwen F. Barnes

A 1984–1985 and 1988–1989 field study near Pullman, WA, evaluated the effect of two winter wheat planting geometries on the growth of wheat and competition against jointed goatgrass. Treatments included paired and constant row planting geometries of wheat and locations of jointed goatgrass within each geometry. No planting geometry by weed location interactions occurred at any harvest date for plant height, shoot number, leaf area, plant dry weight, or N uptake for either wheat or jointed goatgrass. During the 1984–1985 growing season, N uptake data indicated that by heading, jointed goatgrass had taken up N that had been deep-banded between wheat rows located 25 cm from the weed. Winter wheat yields were not different in the paired-row and the constant row spacing geometry in a weed-free environment. Within years, for both planting geometries, winter wheat yield reduction from weed competition was similar for the jointed goatgrass locations. In contrast, based on jointed goatgrass spikelets produced, wheat grown in paired-rows was more competitive against jointed goatgrass compared to constant row spacing.


2013 ◽  
Vol 27 (4) ◽  
pp. 768-777 ◽  
Author(s):  
Alexander Menegat ◽  
Ortrud Jäck ◽  
Jinwei Zhang ◽  
Kathrin Kleinknecht ◽  
Bettina U. Müller ◽  
...  

Japanese bindweed was found to be one of the most abundant and most difficult-to-control weed species during a 2-yr weed survey in more than 100 winter wheat fields in the North China Plain region. Multivariate data analysis showed that Japanese bindweed is most abundant at sites with comparative low nitrogen (N) fertilization intensities and low crop densities. To gain deeper insights into the biology of Japanese bindweed under various N fertilization intensities, winter wheat seeding rates, herbicide treatments, and their interactions, a 2-yr field experiment was performed. In nonfertilized plots, a herbicide efficacy (based on density reduction) of 22% for 2,4-D, and of 25% for tribenuron-methyl was found. The maximum herbicide efficacy in Nmin-fertilized plots (target N value based on expected crop yield minus soil mineral nitrogen content,) was 32% for 2,4-D and 34% for tribenuron-methyl. In plots fertilized according to the farmer's practices, a maximum herbicide efficacy of 72% for 2,4-D and of 64% for tribenuron-methyl could be observed. Furthermore, medium and high seeding rates improved the herbicide efficacy by at least 39% for tribenuron-methyl and 44% for 2,4-D compared to the low seeding rate. Winter wheat yield was not significantly affected by seeding rate itself, whereas at low and medium seeding rates, Nminfertilization was decreasing winter wheat yield significantly compared to the farmer's usual fertilization practice. At the highest seeding rate, Nminfertilization resulted in equal yields compared to the farmer's practices of fertilization.


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