DELAYED HARVEST EFFECTS ON YIELD, FRUIT SIZE AND STARCH CYCLING IN AVOCADO (PERSEA-AMERICANA MILL) IN SUBTROPICAL ENVIRONMENTS .2. THE LATE-MATURING CV HASS
Aw. Whiley et al., DELAYED HARVEST EFFECTS ON YIELD, FRUIT SIZE AND STARCH CYCLING IN AVOCADO (PERSEA-AMERICANA MILL) IN SUBTROPICAL ENVIRONMENTS .2. THE LATE-MATURING CV HASS, Scientia horticulturae, 66(1-2), 1996, pp. 35-49
Effects of early and delayed harvest were investigated in 'Hass' avoca
do, at Childers, a warm subtropical site (over 4 years), and at Maleny
, a cool, mesic subtropical site (over 3 years) in S.E. Queensland. Ea
rly harvesting at 25 to 30% flesh dry matter (DM) sustained high produ
ctivity (especially at the cooler site), but a delayed harvest up to 4
months later at 35% flesh DM eventually depressed yield (at Childers)
and precipitated alternate bearing. Split harvests (early and late) w
ere less detrimental to sustainability of high yields (> 20 t ha(-1)).
Where alternate bearing was already entrenched at the start of the ex
periment at the cooler site (Maleny), early harvest was insufficient t
o break this pattern. Starch cycling in trunk wood and new shoots foll
owed predictable seasonal patterns, and peak concentrations were reduc
ed by heavy fruiting, Pre-flowering starch concentrations in shoots (C
hilders) or trunks (Maleny) were directly correlated to the following
seasons' yield.