Agriculture Reference
In-Depth Information
◦
C, with
consequent improvements in red coloration and sometimes improvements in
size, shape and incidence of bitter pit and cork spot.
In a cooler climate Goode
et al.
(
Unrath (
a, b) found that apple fruits could be cooled by
-
) found that over-tree misting increased
leaf
ψ
w
. It led to an increase in fruit bud production,
number of fruits and yield per tree but did not affect fruit size.
Uses of over-tree irrigation to prevent de-chilling, delay blossoming and
prevent frost damage have been discussed earlier (pp.
ψ
w
and
ψ
p
and also fruit
,
-
).
Droughting
Inthetropicsdroughtingmaybeusedtoinduceleaffallandstimulatebudbreak
under conditions of inadequate winter chilling.
Effects of flooding
Flooding affects apple and pear trees by reducing availability of oxygen around
their roots. It has little adverse effect when the trees are leafless and dormant
but can have lethal effects after leafing out. These appear to be largely due
to increases in root resistance, leading to water-stress and wilting of leaves
(Lakso,
).
Rootstocks differ in their sensitivity to flooding. This was discussed in
Chapter
.
References
Allen, R.G., Smith, M., Pereira, L.S. and Pruitt, W.O. (
). Proposed revision
to the FAO procedure for estimating crop water requirements.
Acta
Horticulturae
.
Alleyne, V., Larsen, F.E. and Higgins, S.S. (
,
-
). Water relations of
container-grown, virus-tested and common apple (
Malus domestica
Borkh).
Scientia Horticulturae
.
Anon, ().
Irrigation Reference Book .
London: Her Majesty's Stationery
Office.
Atkinson, C.J., Else, M.A., Taylor, L. and Webster, A.D. (). The rootstock
graft union: a contribution to the hydraulics of the worked fruit tree.
Acta
Horticulturae
, -.
Atkinson, C.J., Policarpo, M., Webster, A.D. and Kingswell, G. (). Drought
tolerance of clonal
Malus
determined from measurements of stomatal
conductance and leaf water potential.
Tree Physiology
, - .
Atkinson, D. (). The distribution and effectiveness of the roots of tree crops.
Horticultural Reviews
, -.
,
-
