CDC Covert

Wheat

Variety Description

Varieties used for comparison: 'AAC Cabri', 'CDC Credence', 'CDC Precision' and 'Strongfield'

Summary: At the 4 leaf stage, the intensity of anthocyanin colouration on the coleoptile of 'CDC Covert' is absent to very weak whereas it is weak on 'AAC Cabri' and 'Strongfield'. At booting, the frequency of plants with recurved flag leaves is very high for 'CDC Covert' whereas it is absent or very low for 'AAC Cabri', 'CDC Credence' and 'CDC Precision' and low for 'Strongfield'. The flag leaf of 'CDC Covert' is shorter than that of 'Strongfield' and wider than those of 'AAC Cabri', 'CDC Credence' and 'CDC Precision'. The anthocyanin colouration of the auricles on the flag leaf of 'CDC Covert' is absent or very weak whereas it is weak for that of 'CDC Credence'. At maturity, the plants of 'CDC Covert' are shorter than that of 'CDC Credence'. In cross-section, the straw pith of 'CDC Covert' is of medium thickness whereas it is thick for 'AAC Cabri'. The glaucosity on the culm of 'CDC Covert' is medium to strong whereas the glaucosity is weak on the culm of 'CDC Credence'. 'CDC Covert' has a longer spike than that of 'CDC Credence' and 'CDC Precision'. At maturity, the awns of 'CDC Covert' are white whereas they are black for 'CDC Credence'.

Description:

PLANT: durum spring type, erect growth habit at the 5 to 9 tiller stage, very high frequency of plants with recurved flag leaves, heads emerge mid-season, matures early to mid-season

SEEDLING (4 LEAF STAGE): absent or very weak intensity of anthocyanin colouration of coleoptile, glabrous sheath and blade of lower leaves

FLAG LEAF: absent or very weak intensity of anthocyanin colouration of the auricles, strong glaucosity of sheath, glabrous blade and sheath

CULM: medium to strong glaucosity, curved neck
STRAW: medium thickness of pith in cross-section, no anthocyanin colouration at maturity

SPIKE: strong glaucosity at heading, parallel-sided shape in profile, dense, yellow at maturity, erect attitude, medium density of hairiness of convex surface of apical rachis segment
AWNS: longer than spike, white at maturity
LOWER GLUME: long, medium width, glabrous, sparse extent of internal hairs
LOWER GLUME SHOULDER: narrow to medium width, strongly elevated with second point present
LOWER GLUME BEAK: medium length, moderately curved
LOWEST LEMMA: straight to slightly curved beak

KERNEL: amber, large, long, medium width, elliptical shape, angular cheek shape, short to medium brush hairs, medium to wide crease, medium to deep crease
GERM: medium size, broad elliptical to elliptical shape

PASTA QUALITY: good

DISEASE REACTIONS: resistant to Common bunt (Tilletia laevis Kühn in Rabenh.,T. tritici Bjerk.), Leaf rust (Puccina recondita), Stem rust (Puccinia graminis f. sp. tritici) and Stripe rust (Puccina striiformis); moderately resistant to Loose smut (Ustilago tritici) and moderately susceptible to Fusarium head blight (Fusarium graminearum, Fusarium species)

Origin & Breeding History: 'CDC Covert' (experimental designations D09.46.101 and 'DT1003') originated from the cross between 'DT558', as the female parent, and 'AAC Current', as the male parent, conducted in the summer of 2009 at the Crop Development Centre of the University of Saskatchewan in Saskatoon, Saskatchewan. The F1 generation was increased at a contra-season nursery near Christchurch, New Zealand. The F2 and F3 generations were increased in bulk in Saskatoon and near Christchurch in 2010. In 2011, the F4 generation was planted in a nursery in Saskatoon with another 600 single spikes selected and grown as F5 head rows at Saskatoon in 2012. From these head rows, a line designated, as D09.46.101, was selected based on plant height, maturity and straw strength. In 2013, D09.46.101 was evaluated in un-replicated F6 yield trials in Saskatoon. In 2013, the resistance to Fusarium head blight and to leaf, stem and stripe rusts were evaluated in inoculated nurseries in Carmen, Manitoba. D09.46.101 was further evaluated in 2014 and 2015 at various locations in Saskatchewan and Alberta in the Western Durum Wheat B-test. From 2016 to 2018, 'DT1003' was evaluated in the Durum Wheat co-operative tests. Selection criteria were yield, plant maturity, plant height, straw strength, test weight, thousand kernel weight, and quality traits such as yellow pigment, protein and gluten content, and milling properties such as semolina milling yield and semolina ash content.

Tests & Trials: The comparative tests and trials of 'CDC Covert' were conducted during the 2018 and 2019 growing seasons at the Crop Science Field Laboratory, University of Saskatchewan, Saskatoon, Saskatchewan. There were three replications arranged in a RCB Design. Plots consisted of 5 rows spaced 20 cm apart. The plot size was 4.0 square metres with a minimum density of 300 plants per square metre. Observations and measured characteristics are based on 20 measurements per variety per year. Mean differences are significant at the 5% probability level based on a paired Student's T-test. Disease ratings for 'CDC Covert' were provided through the Disease Evaluation team of the Prairie Recommending Committee for Wheat, Rye and Triticale and the Prairie Grain Development Committee from the Durum Wheat Co-operative Registration Trials conducted from 2016 to 2018.

Comparison tables for 'CDC Covert' with reference varieties 'AAC Cabri', 'CDC Credence', 'CDC Precision' and 'Strongfield'

Flag leaf length (cm)

Flag leaf width (cm)

Plant height at maturity (including awns) (cm)

Spike length (excluding awns) (cm)

Click on image for larger view

Wheat: 'CDC Covert' (left) with reference varieties 'Strongfield' (centre left), 'CDC Precision' (centre), 'CDC Credence' (right centre) and 'AAC Cabri' (right)