Roko

Potato

Variety Description

Varieties used for comparison: 'Desiree' and 'Sangre'

Summary: 'Roko' has a narrowly ovate terminal leaflet while 'Desiree' and 'Sangre' have a medium ovate terminal leaflet. The terminal and lateral leaflets of 'Roko' have absent or very low coalescence whereas 'Sangre' has a medium to high frequency of coalescence. The terminal and lateral leaflets of 'Roko' have stronger waviness than the reference varieties. The colour at the base of the tuber eye is white for 'Roko' while it is red for the reference varieties. The tip of the light sprout of 'Roko' is larger than the base, whereas it is equal in size in 'Desiree', and smaller in 'Sangre'. The tip of the light sprout of 'Roko' has weak anthocynanin, whereas 'Desiree' has none and 'Sangre' has strong anthocyanin. Pubescence on the tip of the light sprout of 'Roko' is moderate, whereas it is absent or very sparse in 'Sangre'.

Description:

PLANT: semi-upright growth habit, intermediate to leaf type foliage structure

STEM: moderate anthocyanin evenly distributed, main stem medium in thickness, swelling of nodes absent or very low

LEAF: light to medium green, intermediate silhouette, anthocyanin in rachis and petiole moderate
TERMINAL LEAFLET: narrowly ovate, acute to acuminate tip, obtuse base, absent or very low frequency of coalescence of terminal and lateral leaflets
LATERAL LEAFLETS: small to medium size, narrowly ovate, acuminate to acute tip, obtuse to cordate base, moderately deep veins, strong waviness of margins, medium glossiness, no pubescence on blade (at apical rosette), moderate presence of secondary leaflets

INFLORESCENCE: medium size, moderate flowering profusion, persistent buds, moderate anthocyanin in buds
COROLLA: medium to large size, red-violet colour, medium anthocyanin on inner surface, prominent star
PEDUNCLE: moderate anthocyanin

TUBER: oval, eyes shallow and predominantly apical, eyebrows not prominent, cream coloured flesh with no secondary colour
SKIN: red, white at base of eye, strong anthocyanin when exposed to light, smooth to rough texture

LIGHT SPROUT: medium in size, spherical, few root tips, short lateral roots
BASE: strong anthocyanin, moderate proportion of blue, sparse pubescence
TIP: larger than base, intermediate habit, weak anthocyanin, medium pubescence.

Origin & Breeding History: 'Roko' was selected from the F1 progeny of the crossing of 'Alwawa' and 'MA81-536' made in 1988 in Meires, Austria. The selection process was based on negative agronomic traits.

Tests & Trials: Trials for 'Roko' were conducted in Drummond, New Brunswick in 2005. A block design was used with four replicates per variety. All entries were planted in single-row plots and each entry had one replicate per block. Plots consisted of rows 5.5 metres long and between row spacing of 91 cm. Measured characteristics were based on 10 measurements. Colour determinations were made using the 1986 RHS colour chart.

Comparison tables for 'Roko' with reference varieties 'Desiree' and 'Sangre'

Leaf length (cm)

Leaf width (cm)

Colour of corolla (RHS)

Click on image for larger view

Potato: 'Roko' (center) with reference varieties 'Sangre' (left) and 'Desiree' (right)