SJM188

Apple

Variety Description

Varieties used for comparison: 'M.26' and 'M.9'

Summary: 'SJM188' is an apple rootstock variety which has a higher suckering tendency than variety 'M.26'. The one-year-old shoots of 'SJM188' have less pubescence on their upper half than the references, and the bark is more shiny than that of 'M.26' and less shiny than that of 'M.9'. The internodes of dormant one-year-old shoots of 'SJM188' are shorter than those of 'M.9'. The leaves of 'SJM188' have less pubescence on the lower side than those of 'M.26' and more than those of 'M.9'. The petioles of 'SJM188' are longer than those of the reference varieties. The petals of 'SJM188' are white on the upper side and purple red on the lower side whereas those of 'M.26' are purple on the upper and lower side. The fruit of 'SJM188' is smaller than that of 'M.26'.

Description:

TREE: end use as clonal rootstock, intermediate vigour, moderate number of basal shoots, wavy growth of basal shoot, moderate tendency to produce suckers, poor root anchorage, dwarfing effect

DORMANT ONE-YEAR OLD SHOOT: sparse pubescence on upper half, moderate shine of bark, weak to moderate flexibility, moderate number to many mid-size lenticels, predominantly reddish brown on sunny side
LATERAL BUD: small to medium in size, pointed tip, adpressed to slightly held out position relative to axis of shoot, small to medium size support
GROWING TIP: white

SHOOT TIP LEAVES: straight in cross section, moderate to dense pubescence on upper side, reddish-green on lower side, secondary colour on leaf blade
LEAF: no lobes, medium in size, upwards to outwards, length/width ratio of 1.5, cuspidate apex, serrate margin, weak glossiness on upper side, moderate pubescence on lower side, weak anthocyanin colouration of veins, medium green upper side with absent or very weak anthocyanin colouration, medium to large stipule

FLOWER BUD: early burst, mainly white with pink along the margin fading towards the centre (RHS 54A) at full balloon stage
FLOWER: single type, green pedicel
PETAL: broad ovate, overlapping margins, white on upper side, blush (RHS 54A) on lower side

FRUIT: very small, flat to globose in shape, mainly symmetric in side view, strong ribbing, weak to moderate crowning at distal end, medium eye mainly closed, persistent calyx in mature fruit, long sepals overlapping at base, absent to shallow and narrow eye basin, thin and long stalk, narrow and shallow stalk cavity
FRUIT SURFACE: smooth, moderate bloom when present, yellow ground colour, high amount (60-80%) of pinkish-red over colour, solid, washed out and streaked over colour, absent or very low amount of russet positioned around the eye basin, not prominent to very slightly prominent small lenticels
FRUIT IN CROSS-SECTION: yellowish flesh, weak to moderate core line, closed locules

SEED: normal in shape

Origin & Breeding History: 'SJM188' originated from a cross between Malus baccata 'Nertchinsk' and variety M.26 ('M.16' × 'M.9') performed at the Agriculture and Agri-Food Canada station in Morden. It is a new dwarfing clonal apple rootstock developed at the Agriculture and Agri-Food Canada Research Station in St-Jean-sur-Richelieu, Quebec. 'SJM188' was budded with 'McIntosh VC309' in 1971, and planted in 1974 at Frelighsburg were it was evaluated until 1984 for hardiness, tree size and efficiency. It was selected in 1984 and planted in 1997 in replicated trials in several plots at the Frelighsburg substation and at two grower sites.

Tests & Trials: Trials for variety 'SJM188' were conducted at the Agriculture and Agri-Food Canada substation of Frelighsburg and L'Acadie, Quebec. Trees were planted in a randomized block design, with four replicates in 3 metre rows with trees 40 cm apart. All colour characteristics were determined using the 2001 Royal Horticultural Society (RHS) colour chart and measured characteristics were based on ten measurements.

Comparison tables for 'SJM188' with reference varieties 'M.26' and 'M.9'

Length of internode (cm)

Length of petiole (cm)

Click on image for larger view

Apple: 'SJM188' (bottom) with reference varieties 'M.26' (top) and 'M.9' (centre)