Estimated optimum seeding dates for winter wheat in Ontario

1993 ◽  
Vol 73 (2) ◽  
pp. 389-396 ◽  
Author(s):  
A. Bootsma ◽  
C. J. Andrews ◽  
W. L. Seaman ◽  
G. J. Hoekstra ◽  
A. E. Smid
Keyword(s):  
Triticum Aestivum ◽  
Linear Regression ◽  
Winter Wheat ◽  
Air Temperature ◽  
Triticum Aestivum L ◽  
Heat Unit ◽  
The North ◽  
Seeding Date ◽  
Regression Relationship ◽  
Optimum Period

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

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
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Air Temperature ◽  
Short Communication ◽  
Triticum Aestivum L ◽  
Warming Trend ◽  
Atlantic Region ◽  
The Past ◽  
Seeding Date

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.

INFLUENCE OF DATE OF SEEDING ON YIELD AND OTHER AGRONOMIC CHARACTERS OF WINTER WHEAT AND RYE GROWN IN SASKATCHEWAN

1983 ◽  
Vol 63 (1) ◽  
pp. 109-113 ◽  
Author(s):  
D. B. FOWLER
Keyword(s):  
Winter Wheat ◽  
Kernel Weight ◽  
Yield Reduction ◽  
Winter Rye ◽  
Significant Trial ◽  
North Central ◽  
The North ◽  
Seeding Date ◽  
Reduced Height ◽  
Optimum Period

Four wheat and two rye cultivars were seeded at 2-wk intervals between 1 Aug. and 15 Oct. in five summer-fallow and two stubble-seeded trials at three locations in the north-central part of the agricultural area of Saskatchewan. Averaged over 3 yr, the optimum dates for planting both winter wheat and rye were between 15 Aug. and 1 Sept. Seeding earlier than this usually resulted in reduced yield and lower 1000-kernel weight. Later seeding usually resulted in a yield reduction, delayed heading, later maturity and reduced hectoliter weight. Reduced height in rye and reduced 1000-kernel weight in wheat were also associated with delayed seeding dates. However, exceptions to these generalizations did occur with the result that a significant trial by date of seeding interaction was recorded for all characters measured. For the optimum period for seeding, rye cultivars were higher yielding, earlier heading and maturing, taller and had lower 1000-kernel and hectoliter weight than winter wheat cultivars.Key words: Winter wheat, winter rye, yield, seeding date, maturity

INFLUENCE OF DELAYED SEEDING ON YIELD, HECTOLITRE WEIGHT AND SEED SIZE OF STUBBLE-SEEDED WINTER WHEAT AND RYE GROWN IN SASKATCHEWAN

1986 ◽  
Vol 66 (3) ◽  
pp. 553-557 ◽  
Author(s):  
D. B. FOWLER
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Secale Cereale ◽  
Triticum Aestivum L ◽  
Agronomic Characters ◽  
Kernel Size ◽  
Seeding Date ◽  
Secale Cereale L ◽  
Sufficient Magnitude ◽  
Moisture Conditions

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

The development of winter wheat in the field. 2. The control of primordium initiation rate by temperature and photoperiod

1983 ◽  
Vol 101 (2) ◽  
pp. 337-344 ◽  
Author(s):  
C. K. Baker ◽  
J. N. Gallagher
Keyword(s):  
Triticum Aestivum ◽  
Linear Regression ◽  
Winter Wheat ◽  
Air Temperature ◽  
Initiation Rate ◽  
Field Crops

SUMMARYA scheme was developed to describe how the rate at which apical primordia are initiated in cereals depends on temperature and photoperiod. It was used to analyse initiation in field crops of winter wheat (Triticum aestivum L., cv. Maris Huntsman).For the initiation of leaves and spikelets, a straightforward linear regression of initiation rate R against mean air temperature (Ta) gave base temperatures (Tb) close to 0 °C for leaves and for spikelets. However, initiation rate was also correlated with mean photoperiod (P) and base photoperiods (Pb) of –0·5 h and 4h were established for leaf and spikelet initiation. When R was correlated with the index (T – Tb) (P – Pb), r2 was 0·62 for both leaves and spikelets.

ZONATION OF OPTIMUM SEEDING PERIOD OF WINTER WHEAT BASED ON AUTUMN TEMPERATURES

1986 ◽  
Vol 66 (3) ◽  
pp. 789-793 ◽  
Author(s):  
A. BOOTSMA ◽  
MICHIO SUZUKI
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
New Brunswick ◽  
Triticum Aestivum L ◽  
Maritime Provinces ◽  
Winter Climate ◽  
Zonation Map ◽  
Air Temperatures ◽  
Seeding Date ◽  
Annapolis Valley

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

scholarly journals Naturally Occurring Ecdysteroids in Triticum aestivum L. and Evaluation of Fenarimol as a Potential Inhibitor of Their Biosynthesis in Plants

2021 ◽  
Vol 22 (6) ◽  
pp. 2855
Author(s):  
Anna Janeczko ◽  
Jana Oklestkova ◽  
Danuše Tarkowská ◽  
Barbara Drygaś
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Triticum Aestivum L ◽  
Growth Conditions ◽  
Animal Kingdom ◽  
Experimental Conditions ◽  
P450 Monooxygenase ◽  
Naturally Occurring ◽  
Regulatory Effects ◽  
Potential Use

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.

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