New Zealand Journal of Crop and Horticultural Science abstracts
Some factors influencing fruit set in `Sundrop' apricot
G. F. McLAREN
J. A. FRASER
The Horticulture and Food Research
Institute of New Zealand
Clyde Research Centre
R.D.1, Alexandra
New Zealand
J. E. GRANT
New Zealand Institute for Crop and Food
Research Limited
Private Bag 4704
Christchurch, New Zealand
Abstract Two apricot (Prunus armeniaca L.) cultivars,
`Sundrop' and `Moorpark' were found to be cross-compatible with pollen of 32
genetically diverse cultivars. The flowers of `Valleygold', `CluthaGold', and
`Moorpark' remained receptive to pollination for up to 8 days after
emasculation at the balloon stage. Floral receptivity declined in `Moorpark',
`Sundrop', and `CluthaGold' (but not `Valleygold') over the 8 days. `Sundrop'
had the lowest receptivity and `Moorpark' the highest. Percentage set of
`Sundrop' flowers varied between properties and years in Central Otago, New
Zealand, with significantly lower sets being recorded in 1992 and 1993 than in
1991. In these three seasons, a 2 ha block of `Sundrop', with no pollenisers
within it, showed a decrease in fruit set as the distance from the nearest
polleniser on the edge of the block increased; fruit set was unacceptably low
beyond the first four or five rows. Bee density did not decline across the
block in the same manner. The fruit were smaller on trees adjacent to the
polleniser but were generally of similar storage quality to those from 10 rows
away. The addition of extra beehives in 1992 and 1993 increased the bee numbers
per tree throughout the block, but not fruit set. In comparison, another 1.7 ha
block of `Sundrop' on the same property with just 3% of the trees planted at
random in the cultivar `Trevatt', produced a better set in each of the 3 years.
Over 8 years, correlations were found between percentage fruit set and the mean
temperature between 5 and 90% bloom; the number of days when the maximum
temperature exceeded 18deg.C between 5 and 90% bloom; and the mean temperature
over the 3 weeks from 90% bloom. The roles of in-hive pollen exchange and
self-pollination in `Sundrop' are discussed. Planting of pollenisers within the
block remains the most reliable method of increasing fruit set in large blocks
of `Sundrop'.
Keywords pollination; bees; temperature; pollenisers
New Zealand Journal of Crop and Horticultural Science, 1996, Vol. 24:
55-63
0114-0671/96/2401-0055 $2.50/0 (c) The Royal Society of New Zealand
1996
PDF file of entire paper: medium quality (621K); (scanned from paper original: notes about this process)
This year's abstracts |
Journal home page |
All abstracts |
Publishing home page
