SJM189

Apple

Variety Description

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

Summary: 'SJM189' is an apple rootstock variety which produces more basal shoots in stool beds than reference varieties 'M.26' and 'M.9', and that has a higher suckering tendency than 'M.26'. The one-year-old shoots of 'SJM189' have less pubescence on their upper half than the references, and a less shiny bark than that of 'M.9'. The leaves of 'SJM189' are longer than those of the reference varieties. The pubescence on the lower side of leaves of 'SJM189' is more sparse than in 'M.26' and more dense than in 'M.9'. The petioles of 'SJM189' are longer than those of the reference varieties. The colour of the unopened buds of 'SJM189' is darker than in 'M.26'. The fruit of 'SJM189' is smaller and has more pronounced ribbing than that of 'M.26'.

Description:

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

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

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

FLOWER BUD: mainly white with pink (RHS 54A) along the margin fading towards the centre at full balloon stage
FLOWER: single type, green pedicel
PETAL: broad ovate to oblong with wavy margins, overlapping margins, white on upper side and 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 with mainly open aperture, persistent calyx in mature fruit, long sepals mainly touching at base, 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 (RHS 53A) over colour, solid, washed out and streaked over colour, absent or very low amount of russet positioned around stalk cavity, small lenticels, not prominent to slightly prominent lenticels
FRUIT IN CROSS-SECTION: yellowish flesh, weak to moderate core line, closed locules

SEED: normal in shape

Origin & Breeding History: 'SJM189' originated from a cross between Malus baccata 'Nertchinsk' and variety 'M.26' ('M.16' × 'M.9') performed at Agriculture and Agri-Food Canada, in 1960. It is a new dwarfing clonal apple rootstock developed at the Agriculture Canada Research Station, St-Jean-sur-Richelieu, Quebec. 'SJM-189' was budded with 'McIntosh VC309' in 1971, and planted in 1974 at Frelighsburg were it was evaluated until 1984 for hardiness, tree size and yield 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 'SJM189' were conducted at the Agriculture and Agri-Food Canada substations 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 'SJM189' with reference varieties 'M.26' and 'M.9'

Length of leaf (cm)

Length of petiole (cm)

Click on image for larger view

Apple: 'SJM189' (bottom) with reference varieties 'M.26' (top) and 'M.9' (centre)