Short communication. Trends in estimated optimum seeding date for winter wheat in the Atlantic Provinces

2011 ◽  
Vol 91 (6) ◽  
pp. 1101-1103
Author(s):  
A. Bootsma

Bootsma, A. 2011.Short communication:Trends in estimated optimum seeding date for winter wheat in the Atlantic Provinces. Can. J. Plant Sci. 91: 1101–1103. Seeding date is an important management factor affecting the performance of winter wheat (Triticum aestivum L.) in the Atlantic region of Canada. In this study, decadal trends in estimated optimum seeding dates were estimated from air temperature in September and October at nine locations in the Atlantic region of Canada from as early as 1899. The optimum seeding period averaged over all locations was delayed by 8 d for the past 10 yr compared with earlier decadal periods. If the warming trend continues, producers will be able to seed winter wheat successfully at dates later than previously recommended.

1993 ◽  
Vol 73 (2) ◽  
pp. 389-396 ◽  
Author(s):  
A. Bootsma ◽  
C. J. Andrews ◽  
W. L. Seaman ◽  
G. J. Hoekstra ◽  
A. E. Smid

Winter wheat (Triticum aestivum L.) must be seeded during an optimum period in the fall to achieve maximum yields. Present recommendations for fall seeding based on corn heat unit zones for Ontario have not been satisfactory in all areas. Results from seeding-date trials at five locations across Ontario confirmed the concept of a 2-wk optimum seeding period (OSP) for winter wheat. A highly significant non-linear regression relationship (R2 = 0.997) was established between the average optimum seeding date (OSD) for six locations in Ontario (taken as the mid-point of the OSP) and the average daily mean air temperature for the period 1 Sept. – 31 Oct. This relationship estimated OSDs more accurately for Ontario than a previously developed relationship based on data from across Canada. Climatic normals (1951–1980) data for more than 350 locations were used to construct 13 OSD zones for Ontario. Estimated OSD ranged from as late as 15 Oct. for the Windsor area to before 21 Aug. in the north around Kapuskasing. Average losses in yield from seeding after the OSP ranged from 75 kg ha−1 day−1 in southwestern Ontario to 40–65 kg ha−1 day−1 in eastern Ontario. Key words: Triticum aestivum L., optimum seeding date zones, climatic normals


1986 ◽  
Vol 66 (3) ◽  
pp. 553-557 ◽  
Author(s):  
D. B. FOWLER

Winter wheat (Triticum aestivum L.) and rye (Secale cereale L.) were seeded into stubble the first week of September and October on four different years at a total of 11 sites in the central, eastern and northern part of the agricultural region of Saskatchewan. The average response to delayed seeding was a reduction in yield and hectolitre weight for both species. In contrast, date of seeding did not have a large influence on kernel size. A significant environmental effect was observed for all characters measured. Productivity of both wheat and rye was high when moisture conditions were adequate. Average yield of rye was higher and 1000-kernel and hectolitre weight lower than for wheat. Significant first and second order interactions demonstrated that the effects of seeding date, species and environment were not independent. These interactions were of sufficient magnitude to introduce a risk factor which should be taken into consideration when conclusions are drawn on the influence of seeding date on yield and other agronomic characters of stubble-seeded winter cereals.Key words: Triticum aestivum L., Secale cereale L., yield, hectolitre weight, kernel size, seeding date


1986 ◽  
Vol 66 (3) ◽  
pp. 789-793 ◽  
Author(s):  
A. BOOTSMA ◽  
MICHIO SUZUKI

Seeding date is an important management factor affecting the performance of winter wheat (Triticum aestivum L.). In this study, optimum seeding date was closely related to air temperatures in autumn in various regions of Canada (R = 0.998). This relationship was used to estimate optimum seeding period (SP) and construct a zonation map for the Maritime Provinces. Seeding period ranged from 15–28 Aug. in northern New Brunswick to 10–25 Sept. in the Annapolis Valley region of Nova Scotia.Key words: Wheat (winter), climate, winter survival, zonation map


2021 ◽  
Vol 22 (6) ◽  
pp. 2855
Author(s):  
Anna Janeczko ◽  
Jana Oklestkova ◽  
Danuše Tarkowská ◽  
Barbara Drygaś

Ecdysteroids (ECs) are steroid hormones originally found in the animal kingdom where they function as insect molting hormones. Interestingly, a relatively high number of these substances can also be formed in plant cells. Moreover, ECs have certain regulatory effects on plant physiology, but their role in plants still requires further study. One of the main aims of the present study was to verify a hypothesis that fenarimol, an inhibitor of the biosynthesis of ECs in the animal kingdom, also affects the content of endogenous ECs in plants using winter wheat Triticum aestivum L. as a model plant. The levels of endogenous ECs in winter wheat, including the estimation of their changes during a course of different temperature treatments, have been determined using a sensitive analytical method based on UHPLC-MS/MS. Under our experimental conditions, four substances of EC character were detected in the tissue of interest in amounts ranging from less than 1 to over 200 pg·g−1 FW: 20-hydroxyecdysone, polypodine B, turkesterone, and isovitexirone. Among them, turkesterone was observed to be the most abundant EC and accumulated mainly in the crowns and leaves of wheat. Importantly, the level of ECs was observed to be dependent on the age of the plants, as well as on growth conditions (especially temperature). Fenarimol, an inhibitor of a cytochrome P450 monooxygenase, was shown to significantly decrease the level of naturally occurring ECs in experimental plants, which may indicate its potential use in studies related to the biosynthesis and physiological function of these substances in plants.


Weed Research ◽  
1991 ◽  
Vol 31 (6) ◽  
pp. 409-415 ◽  
Author(s):  
B. R. MCLENNAN ◽  
R. ASHFORD ◽  
M. D. DEVINE

Sign in / Sign up

Export Citation Format

Share Document