Koa

Soybean

Variety Description

Varieties used for comparison: 'Asahi' and 'Maya'

Summary: The intensity of anthocyanin colouration on the hypocotyl of 'Koa' is strong to very strong whereas it is of medium to strong intensity for 'Maya'. When 50% of the flowers are open, the branching attitude of 'Koa' is semi-erect to horizontal whereas it is erect to semi-erect for the reference varieties. The lateral leaflet of 'Koa' is small while that of 'Maya' is medium sized. The intensity of green colour on the leaf of 'Koa' is light to medium whereas it is medium to dark for 'Asahi' and dark for 'Maya'. The intensity of brown colour on the pod of 'Koa' is light to medium whereas it is medium to dark for 'Asahi' and dark for 'Maya'. The plants of 'Koa' mature earlier than those of the reference varieties.

Description:

PLANT: oilseed type, indeterminate growth type, semi-erect to horizontal branch attitude, tawny pubescence on middle third of main stem, begins flowering early to mid-season, matures very early to early in the season

HYPOCOTYL: strong to very strong intensity of anthocyanin colouration

LEAF: small triangular to pointed ovate lateral leaflet, light to medium green

FLOWER: violet

POD: light to medium brown

SEED: small to medium sized, spherical flattened, yellow ground colour of testa
HILUM: yellow

Origin & Breeding History: 'Koa' (experimental designations PR130989Z-26 and SYN13098926) originated from a cross between 'S04192.53' and 'OAC Wallace' conducted in 2013 in Saint-Césaire, Quebec. A modified single seed descent method was used to develop the variety from the F1 to F3 generation in Argentina and Canada from 2013 to 2014. In 2015, 'Koa' was identified as a single plant at the F4 generation in Saint-Césaire, Quebec. In 2020, the final selections were made in the F8 and F9 generations. The selection criteria were based on a visual assessment of resistance to lodging, maturity date, yield and disease resistance.

Tests & Trials: The comparative trials for 'Koa' were conducted at Semences Prograin Inc. in Saint-Cesaire, Quebec in 2022 and 2023. The 7.2 square metre plot trials were planted in a RCB design with 2 replicates per variety and each row measuring 5 metres long. Each plot consisted of a row spacing of 0.76 metres. The seeding density was such that it resulted in a total of approximately 350 plants per variety. For each variety, the plant height was based on 20 measurements per year. Mean differences were significant at the 5% probability level based on a Students t-test.

Comparison table for 'Koa' with reference varieties 'Asahi' and 'Maya'

Time of maturity (number of days from planting to maturity)

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Soybean: 'Koa' (center) with reference varieties 'Asahi' (left) and 'Maya' (right)

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Soybean: 'Koa' (left) with reference varieties 'Asahi' (center) and 'Maya' (right)

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Soybean: 'Koa' (center) with reference varieties 'Asahi' (top) and 'Maya' (bottom)