The effect of light on development of the rosette growth habit of winter wheat

1984 ◽  
Vol 62 (4) ◽  
pp. 818-822 ◽  
Author(s):  
D. W. A. Roberts

Young plants of the cold-hardy winter wheat (Triticum aestivum L. emend. Thell.) Kharkov 22 MC did not develop atypical prostrate or rosette growth habit unless light supply exceeded 350 klux∙h∙day−1. Prostrate habit developed under both short (10-h) and long (16-h or 24-h) photoperiods. Under a given photoperiod, expression of this trait intensified as light intensities increased. This finding was demonstrated in both field and growth-cabinet experiments. The degree of development of the rosette growth habit may be assessed by plotting plant height against plant age. Plants that develop typical rosettes decline in height when the rosettes develop whereas plants that remain erect show a continuous increase in height.

1988 ◽  
Vol 68 (3) ◽  
pp. 527-535 ◽  
Author(s):  
W. W. WILHELM ◽  
L. N. MIELKE

Dense soil tillage pans can develop from the improper use of tillage tools. The influence of compacted layers or pans on plant growth and development, although much studied, is not clearly understood. This greenhouse experiment evaluated the influence of uniformly compacted soil and thin layers of compacted soil placed at various depths on early growth of winter wheat (Triticum aestivum L.). Artificially compacted soil [Alliance silt loam, Aridic Argiustoll (Eluviated Brown Chernozem); A horizon] profiles were constructed in polyvinyl chloride tubes of 150-mm diameter by 350 mm long. Treatments were: (1) uniformly noncompacted (bulk density 1.30 Mg m−3) soil; (2) uniformly compacted (bulk density 1.80 Mg m−3) soil; (3) a compacted (bulk density 1.80 Mg m−3) soil layer at 100- to 120-mm depth with the remaining soil noncompacted (bulk density 1.30 Mg m−3); or (4) a compacted (bulk density 1.80 Mg m−3) soil layer at 180- to 200-mm depth with the remaining soil noncompacted (bulk density 1.30 Mg m−3). Generally, winter wheat grown in cores that were uniformly compacted or compacted in the upper layer responded similarly. Plant height, at the end of the experiment (32 d after planting), for the uniformly compacted and upper compacted layer treatments was 280 mm, compared to 323 mm for the control (uniformly noncompacted). Leaf area development was similar to the response indicated for plant height throughout the growth period. Root mass and length tended to be less in layered or compacted soil than in noncompacted soil. Roots accumulated within or immediately above compacted soil layers. Higher bulk density or a shallow compacted layer produced winter wheat with reduced height, leaf area, and dry matter compared with soil of normal density or with a deeper compacted layer. Key words: Bulk density, Triticum aestivum L., tillage pan, wheat (winter)


2018 ◽  
Vol 23 ◽  
pp. 63-67 ◽  
Author(s):  
O. I. Zhuk

Aim. The goal of research was to study the effects of soil drought on the productivity of winter wheat plants (Triticum aestivum L.). Methods. Wheat plants of the cultivars of Zolotocolosa and Astarta were grown under optimal nutrition and moisture to the earing-flowering phase. After the beginning of it the experimental plants were transferred to drought conditions for 8 days, after that the optimal water supply was restored to the end of the vegetation. The yield structure was analyzed in mature plants. Results. It is established that the effect of drought in the critical phase of ontogenesis led to a decrease in plant height, ear size, mass and number of grains in it. At the same time, the number of grains in ears of plants decreased more significantly in the cultivar Zolotocolosa compared to the Astarta, especially in the tillers. The loss of grains mass from the ear was lower in cultivar Zolotocolosa than to the Astarta. Conclusions. Water deficit in the soil in the critical phase of ear-flowering led to a decrease in the productivity of wheat plants due to the inhibition of growth, the laying and the formation elements of the ear and grains, that depended on the specificity of the cultivar. Keywords: Triticum aestivum L., stem, ear, productivity, drought.


1983 ◽  
Vol 63 (4) ◽  
pp. 879-888 ◽  
Author(s):  
W. G. LEGGE ◽  
D. B. FOWLER ◽  
L. V. GUSTA

The cold hardiness of tillers separated from the plant immediately before freezing (CTM) or left intact on the crown (ICM) was determined by artificial freeze tests on two sampling dates for four winter wheat (Triticum aestivum L.) cultivars acclimated in the field. Plants with 9 and 13 tillers excluding coleoptile tillers were selected in mid-October and at the end of October, respectively. No differences in lethal dose temperature (LT50) were detected among CTM or ICM tillers sampled in mid-October. The three youngest CTM tillers sampled at the end of October were less cold hardy than older tillers. However, younger CTM tillers did not survive the unfrozen control treatment as well as older tillers. ICM tillers sampled at the end of October had the same LT50 except for one of the older tillers. No correlation was found between either the moisture content or dry weight and the LT50 of tillers. Winter survival of tillers was evaluated for two cultivars in the spring. Tillers of intermediate age and two of the youngest tillers had the highest survival rates. Tiller regeneration from axillary buds rather than the apical meristem occurred following cold stress and was negatively correlated to tiller emergence date. It was concluded that differences in cold hardiness among tillers must be taken into consideration if tillers are utilized to estimate the LT50 of a plant.Key words: Cold hardiness, tillers, winter wheat, Triticum aestivum L., developmental stage, moisture content


PLoS ONE ◽  
2014 ◽  
Vol 9 (11) ◽  
pp. e113287 ◽  
Author(s):  
Christine D. Zanke ◽  
Jie Ling ◽  
Jörg Plieske ◽  
Sonja Kollers ◽  
Erhard Ebmeyer ◽  
...  

1990 ◽  
Vol 70 (4) ◽  
pp. 1033-1041 ◽  
Author(s):  
J. B. THOMAS ◽  
R. A. BUTTS

Russian wheat aphid (RWA) (Diruaphis noxia (Mordvilko)) is a new and cold-hardy pest of temperate cereals in western Canada. In view of the risk of fall infestation of winter wheat (Triticum aestivum L. em. Thell.), this study was made to establish whether feeding by RWA can interfere with cold hardening and plant survival of overwintering winter wheat. Feeding by RWA significantly increased the LT50 of field-hardened Norstar winter wheat by + 2 to + 4 °C. Application of 400 g (a.i.) ha−1 of the insecticide chlorpyrifos in mid-October to control severe RWA infestations in two different fields of Norstar winter wheat significantly improved winter survival of the crop. The pattern of winterkill within the two fields suggested that this protective effect of chlorpyrifos was greatest in areas where microtopography resulted in the least accumulations of snow and cold stress was most intense. It was concluded that heavy RWA infestation in the fall significantly reduced freezing tolerance of winter wheat and increased the likelihood of winterkilling of the crop by severe cold.Key words: Winter survival, cold hardening, Diuraphis noxia, insecticide, chlorpyrifos, Triticum aestivum, crop damage


2015 ◽  
Vol 95 (2) ◽  
pp. 325-333 ◽  
Author(s):  
Melody A. Robinson ◽  
Jocelyne Letarte ◽  
Michael J. Cowbrough ◽  
Peter H. Sikkema ◽  
François J. Tardif

Robinson, M. A., Letarte, J., Cowbrough, M. J., Sikkema, P. H. and Tardif, F. J. 2015. Winter wheat (Triticum aestivum L.) response to herbicides as affected by application timing and temperature. Can. J. Plant Sci. 95: 325–333. Field studies were conducted to determine the effects of cold temperatures and physiological growth stage at the time of application on the tolerance of winter wheat (Triticum aestivum L.) to 10 herbicides used in Ontario, Canada. Herbicides were applied: early during a frost event (when forecasted temperatures ≤ 0°C); at a normal timing (Zadoks 21–29); and a late timing (Zadoks 39). Visible injury, yield, plant height at maturity, test weight and 1000-kernel weight were measured to determine if environmental conditions or growth stage at the time of herbicide application influenced wheat tolerance. Cold temperatures at the time of herbicide application resulted in injury with three treatments: 2,4-D, dicamba/MCPA/mecoprop and dichlorprop/2,4-D. Visible injury was greatest at 14 d after treatment (DAT); it was, however, transient and yield, plant height, test weight and 1000-kernel weight were not affected. The herbicides 2,4-D, dichlorprop/2,4-D, and fenoxaprop-p-ethyl caused visible injury 14 DAT when applied at the normal timing, while 2,4-D at this timing, also caused injury 7 DAT. Dicamba/MCPA/mecoprop was the most injurious herbicide, causing 4% injury at the normal timing and 11% injury at the late application timing (42 DAT). Dicamba/MCPA/mecoprop caused yield reductions of 11 to 24% at two locations in 2010 when applied at the normal timing. Dicamba/MCPA/mecoprop reduced yield at 6 of the 8 site-years when applied late, and also reduced plant height. Cold temperatures at the time of application did not affect tolerance of winter wheat; however, visible injury was more likely to occur when herbicides were applied at later growth stages. In most cases, herbicide injury was transient and no impact on yield was observed. Dicamba/MCPA/mecoprop was the most injurious herbicide, causing prolonged injury at all application timings and reducing yields when applied at the normal timing. In addition, yield and plant height were affected negatively when this herbicide was applied late.


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