|Authors: ||I. Goodwin, R. Bruce|
|Keywords: ||fruit disorders, fruit set, fruit size, midday leaf water potential, water stress|
Drought has substantially reduced irrigation allocation to Australian peach growers in the past 4 years.
Water saving is a high priority and many growers have cut-off irrigation during the post harvest period to reduce costs with varying results the following season.
The objective of this study was to investigate the effects of post harvest water deficits on subsequent yield and fruit quality disorders in a clingstone peach (Prunus persica (L.) Batsch ‘T204’) used predominantly for canning.
A field experiment was established immediately after harvest in a commercial orchard in the Goulburn Valley region of Victoria in 2008. Irrigation treatments were 50, 80, 100, 150 and 190% of grower irrigation practice.
Preliminary results from the first year of a 3-year study are presented.
The total amount of irrigation applied during the post harvest period to the 50, 80, 100, 150 and 190% treatments was 88, 140, 173, 262 and 328 mm, respectively.
Rainfall during the post harvest period (early February to the end of April) was negligible with one effective rainfall event (14.8 mm) 49 days after harvest (DAH). ETo during the post harvest period was 341 mm.
Average leaf water potential for the period from harvest to DAH = 78 was -2.08, -2.05, -1.86, -1.79 and -1.74 MPa for the 50, 80, 100, 150 and 190% treatments, respectively.
Flower number per lateral tended to be less and the duration of flowering was greater in the deficit treatments in the subsequent season.
There was no difference in flower bud dry weight.
Fruit number per lateral prior to fruit thinning was substantially less and even after commercial thinning there was a significant difference in fruit number per tree at harvest in the deficit treatments.
There was no effect of the deficit treatments on the number of defective fruit (split stones, twins or deep sutures). Canning yield was above 90% in the deficit treatments whereas the 100 and 190% treatments failed to meet canning size requirement suggesting these treatments were over-cropped.
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