Scentless chamomile (Matricaria perforata Mérat) interference in winter wheat

1992 ◽  
Vol 72 (4) ◽  
pp. 1383-1387 ◽  
Author(s):  
D. W. Douglas ◽  
A. G. Thomas ◽  
D. P. Peschken ◽  
G. G. Bowes ◽  
D. A. Derksen

The effect of summer and winter annual scentless chamomile (Matricaria perforata Mérat) on the grain yield of winter wheat was investigated for 3 yr in experimental plots. Summer annuals only affected yield in a year with much greater than normal precipitation. Under near-normal weather conditions, winter annuals reduced yield. Yield reductions due to interference from either summer annual or winter annual scentless chamomile were not detected in a year marked by hot and dry conditions.Key words: Scentless chamomile, Matricaria perforata, winter wheat, weed interference, yield loss

1991 ◽  
Vol 71 (3) ◽  
pp. 841-850 ◽  
Author(s):  
D. W. Douglas ◽  
A. G. Thomas ◽  
D. P. Peschken ◽  
G. G. Bowes ◽  
D. A. Derksen

The influence of summer and winter annual scentless chamomile (Matricaria perforata Mérat) on the yield of spring wheat in Saskatchewan was determined. In experimental plots, spring wheat was seeded into barley stubble where summer and winter annual scentless chamomile had been established. A rectangular hyperbolic model was used to describe the relationship between wheat yield and the density of flowering scentless chamomile plants. Winter annuals caused more yield reduction than did summer annuals. Weather conditions appeared to have an influence on the effect of scentless chamomile on spring wheat yield. The same model was fitted to sample data from farmers' fields and showed yield losses similar to those on the experimental plots. The rectangular hyperbolic model fitted the data best when high weed densities occurred. At densities more typical of those found in farm fields, the asymptotic yield loss parameter of the model was poorly estimated. Key words: Scentless chamomile, Matricaria perforata, yield loss, weed competition, rectangular hyperbola, spring wheat


Author(s):  
Jindřiška Kučerová

The results of three-year trials (1999 to 2001) conducted with six winter wheat varieties in which was studied the grain yield and parameters of technological quality. Varieties of wheat come from four different localities of the Czech Republic. The most favourable weather conditions, a lot of precipitation and high temperature in the course of ripening from three years were proved in the year 2000. The best grain yield were in 2001 (average of sites 8.84 t/ha) and variety Semper, worst quality, had the highest grain yield of 9.17 t/ha, the least grain yield had Sulamit, best quality (7.94 t/ha). The laboratory analysis revealed negative correlation between grain yield and baking quality. The number of statistically highly significant correlations among bread-making quality parameters too.The negative correlation was of grain yield and grain volume mass (P < 0.05), Zeleny test and protein content taken as a whole for three years (P < 0.01). The correlation of loaf volume, which is the traits of baking quality and Zeleny test (r = 0.6016**), protein content (r = 0.5932**), dough stability (r = 0.2898**) and flour water absorption (r = 0.3632**) was positive (P < 0.01).


2010 ◽  
Vol 24 (4) ◽  
pp. 416-424 ◽  
Author(s):  
John C. Frihauf ◽  
Phillip W. Stahlman ◽  
Patrick W. Geier ◽  
Dallas E. Peterson

Field experiments in winter wheat were initiated at two locations in the fall of 2006 and 2007 to evaluate winter annual broadleaf weeds and winter wheat response to POST applications of two saflufenacil formulations applied alone and in combination with 2,4-D amine. Emulsifiable concentrate (EC) and water-dispersible granule (WG) formulations of saflufenacil at 13, 25, and 50 g ai ha−1were applied with 1.0% (v/v) crop oil concentrate (COC) and mixed with 2,4-D amine at 533 g ae ha−1without adjuvant. Regardless of rate or formulation, saflufenacil plus COC and saflufenacil plus 2,4-D amine controlled blue mustard ≥ 91% at 17 to 20 d after treatment (DAT) compared with ≤ 50% control with 2,4-D amine alone. At least 25 g ha−1of saflufenacil EC was necessary to control flixweed > 90%. Excluding COC from saflufenacil plus 2,4-D amine reduced flixweed control from the saflufenacil WG formulation more than the EC formulation. Most saflufenacil treatments did not control henbit satisfactorily (≤ 80%). Wheat foliar necrosis increased with increasing saflufenacil rate to as high as 30% at 3 to 6 DAT, but declined to < 15% at 10 to 20 DAT and was not evident at 30 DAT. Saflufenacil rate, formulation, and mixing with 2,4-D amine also influenced wheat stunting, but to a lesser extent than foliar necrosis. Saflufenacil EC consistently caused greater foliar necrosis and stunting on wheat than saflufenacil WG. Leaf necrosis and stunting were reduced by tank-mixing saflufenacil formulations with 2,4-D amine without COC. Grain yields of most saflufenacil treatments were similar to 2,4-D amine under weedy conditions and herbicide treatments had no effect on grain yield in weed-free experiments. Saflufenacil formulations at 25 to 50 g ha−1with 2,4-D amine and saflufenacil WG at 25 to 50 g ha−1with COC can control winter annual broadleaf weeds with minimal injury (< 15%) and no grain yield reductions. The addition of saflufenacil as a POST-applied herbicide would give wheat growers another useful tool to control annual broadleaf weeds, including herbicide-resistant weed species.


2016 ◽  
Vol 1 (1) ◽  
pp. 57-60
Author(s):  
Лысиков ◽  
Pavel Lysikov

The purpose of the study is to reduce yield loss of winter wheat crops infested with stem borer. The studies were conducted in the forest of the Samara region in the vicinity of st. Ust-Kinelsky in 2011, 2012 and 2014. in the fields of the Povolzsje Science Research Institute of selection and seeds production of P. N. Konstantinov with the meso form of the relief at the landscape profile length of about 8 m to 4 varieties of soft winter wheat: Povolgskaya 86, Kinelskay 8, Kinelskay 4 and Konstantinovskaya (Erythrospermum). The damage of productive stalks of wheat sawfly larvae was 0.5-1.2%, peaking at an average of weather conditions in 2012, the minimum – in a relatively arid 2014 and depended on the plant population, sawflies favored more sparse crops with a correlation coefficient In 2011, 2012 –0,472- –0.480, –0.734 – in 2014. Under the influence of the sawfly larvae damaged ear stem length was reduced by no more than 5.2, the number of grains per ear – 14.4, the weight of grain in the ear – 14.4, weight of 1000 seeds – 15,2%. The largest decrease in the length of the spike observed in average weather conditions for 2012, the number and grains weight per ear – in a wet 2011, the mass of 1000 grains – in the dry 2014 from wet to dry years, the harmfulness of the sawfly increased from an average to the bottom of the slope. The smallest decrease in all indicators of productivity observed in the upper part of the slope. The number of adults cephus pygmaeus in all parts of the slopes were almost equally low (0.2-0.4 ind./100 net sweeps). The cephus pygmaeus loss of of wheat grain productivity were minor and were 3-35 kg/h.


2016 ◽  
Vol 69 (3) ◽  
Author(s):  
Elżbieta Harasim ◽  
Marian Wesołowski ◽  
Cezary Kwiatkowski ◽  
Paweł Harasim ◽  
Mariola Staniak ◽  
...  

<p>The aim of the present study was to determine the effect of different growth regulator rates and nitrogen fertilization levels on yield components and to evaluate their influence on winter wheat productivity. A field experiment with winter wheat ‘Muza’ was conducted at the Czesławice Experimental Farm, belonging to the University of Life Sciences in Lublin, Poland over the period 2004–2007. In this experiment, the effect of the studied factors on yield and its components was primarily dependent on weather conditions during the study period.</p><p>An increase in nitrogen rate from 100 to 150 kg ha<sup>−1</sup> in 2005 and 2007 had a significant effect on the increase in grain yield per unit area. In 2005, the grain yield rose through increased spike density (by 6.3%) and a higher number of grains per spike (by 1.6%). The 1000-grain weight decreased the grain yield per unit area (by 0.04 t ha<sup>−1</sup>). In 2007, the higher yield of wheat fertilized with nitrogen at a rate of 150 kg N ha<sup>−1</sup> was positively affected by all the three yield components. The statistical analysis of the results showed that the winter wheat grain yields were also significantly affected by the retardant rates applied depending on the year.</p>


2015 ◽  
Vol 105 (5) ◽  
pp. 621-627 ◽  
Author(s):  
Gautam P. Pradhan ◽  
Qingwu Xue ◽  
Kirk E. Jessup ◽  
Baozhen Hao ◽  
Jacob A. Price ◽  
...  

Wheat streak mosaic virus (WSMV) causes significant yield loss in hard red winter wheat in the U.S. Southern High Plains. Despite the prevalence of this pathogen, little is known about the physiological response of wheat to WSMV infection. A 2-year study was initiated to (i) investigate the effect of WSMV, inoculated at different development stages, on shoot and root growth, water use, water use efficiency (WUE), and photosynthesis and (ii) understand the relationships between yield and photosynthetic parameters during WSMV infection. Two greenhouse experiments were conducted with two wheat cultivars mechanically inoculated with WSMV at different developmental stages, from three-leaf to booting. WSMV inoculated early, at three- to five-leaf stage, resulted in a significant reduction in shoot biomass, root dry weight, and yield compared with wheat infected at the jointing and booting stages. However, even when inoculated as late as jointing, WSMV still reduced grain yield by at least 53%. Reduced tillers, shoot biomass, root dry weight, water use, and WUE contributed to yield loss under WSMV infection. However, infection by WSMV did not affect rooting depth and the number of seminal roots but reduced the number of nodal roots. Leaf photosynthetic parameters (chlorophyll [SPAD], net photosynthetic rate [Pn], stomatal conductance [Gs], intercellular CO2 concentration [Ci], and transpiration rate [Tr]) were reduced when infected by WSMV, and early infection reduced parameters more than late infection. Photosynthetic parameters had a linear relationship with grain yield and shoot biomass. The reduced Pn under WSMV infection was mainly in response to decreased Gs, Ci, and SPAD. The results of this study indicated that leaf chlorophyll and gas exchange parameters can be used to quantify WSMV effects on biomass and grain yield in wheat.


Plant Disease ◽  
1999 ◽  
Vol 83 (7) ◽  
pp. 609-614 ◽  
Author(s):  
B. L. Tillman ◽  
W. S. Kursell ◽  
S. A. Harrison ◽  
J. S. Russin

The relationship between severity of bacterial streak and yield in winter wheat was studied in field plots and using a single-tiller method. Regression analysis from single-tiller studies showed that the grain weight per spike decreased as bacterial streak severity increased in cvs. Florida 304 and Savannah. The number of kernels per spike decreased as bacterial streak severity increased in Savannah but not in Florida 304. There was no difference in slope of the regression line between different years, locations, or cultivars for grain weight per spike. However, grain weight per spike at 0% bacterial streak (intercept) was different for different years, locations, and cultivars. The average reduction in grain weight per spike was 0.012 g for every 1% increase in bacterial streak severity. Using this relationship for cv. Savannah, average bacterial streak severity of 10% would result in about a 9% reduction in the grain weight per spike. In Florida 304, bacterial streak severity of 10% would result in about a 7% reduction in the grain weight per spike. During 1993-94, the largest difference in bacterial streak severity between inoculated and noninoculated plots was 4% in cv. Pioneer 2548, and the smallest difference was less than 1% in cvs. Terral 101 and Florida 304. There were no yield differences between inoculated and noninoculated treatments for any genotype. In field plot studies at two locations during 1989-90, bacterial streak severity did not differ between inoculated and noninoculated plots in Alexandria, Louisiana; but in Winnsboro, Louisiana, bacterial streak severity was 18 to 40% in inoculated plots and less than 5% in noninoculated plots. Differences in yield between inoculated and noninoculated plots ranged from 1,370 kg/ha (24% loss) to -121 kg/ha in Winns-boro. During the three seasons in which these studies were conducted, bacterial streak severity averaged about 10% or less in susceptible cultivars in all experiments except one. Based on the relationships derived from single-tiller studies, this suggests that yield loss is likely to be low most years. As indicated by the experiment in Winnsboro, however, more severe yield reductions could occur in a susceptible cultivar if weather conditions are favorable for disease development.


2018 ◽  
Vol 23 ◽  
pp. 291-296
Author(s):  
O. V. Zborivska ◽  
G. O. Priadkina ◽  
O. G. Sokolovska-Sergienko ◽  
N. M. Makharinska

Aim. Estimation of the mass of dry matter of the stem of the main shoots of different varieties of winter wheat in the phases of flowering and full ripeness as a criterion for the grain productivity of its ear in years with different meteorological conditions. Methods. Field, morphometric, mathematical and statistical. Results. The mass of dry matter of the stem of the main shoots of winter wheat varieties was studied in years that differed significantly in weather conditions in the flowering phase and at full grain maturity. It was established that the mass of dry matter of the stem of the main shoot at the flowering and the full grain maturity varied significantly, respectively 0.6–1.2 g and 0.5–1.0 g in 2014, and 1.0–2.0 g and 0.8–1.5 g in 2016 depending on the variety, and under different growing conditions. Limits of variation of grain yield of the ear in 2014, ranged from 0.9 to 2.2 g and from 1.5 to 2.5 g in 2016. It was established that at the flowering, the correlation between the mass of grain from the head and the mass of the dry substance of the stem was significant at 99 % probability under growing conditions (r = 0.8–0.9). Conclusions. It is shown that grain productivity of main shoot in winter wheat is related to the ability of its stem to store assimilates during the vegetative period. It was established that the mass of the dry matter of the stem of the main shoots in the flowering phase can serve as a criterion for assessing its grain productivity. Keywords: Triticum aestivum L., mass of stem, grain yield.


Weed Science ◽  
1993 ◽  
Vol 41 (3) ◽  
pp. 388-393 ◽  
Author(s):  
R. L. Anderson

Jointed goatgrass is a serious weed in winter wheat, and presently no herbicides are available for its selective control. This study examined the effect of time of emergence and removal on jointed goatgrass interference in winter wheat, as well as its rate of development and soil water extraction. The goal of this study was to suggest cultural practices that minimize jointed goatgrass interference in winter wheat. Jointed goatgrass development was identical to ‘Vona’ winter wheat in two crop seasons, even though precipitation differed drastically between seasons. Depth of soil water extraction of both species was also similar. Jointed goatgrass at 18 plants m−2reduced grain yield 27 and 17% when emerging 0 and 42 d after Vona, respectively. The relationship between time of jointed goatgrass emergence after winter wheat and grain yield loss was Y = 30.6–0.29X (X = days, r = 0.72), indicating that plants emerging in late fall still caused yield loss. Removing jointed goatgrass by early March prevented winter wheat grain yield loss. The interference data suggests that producers assess infestation levels and plan control measures in early March.


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