The timing of pruning affects flushing, flowering and yield of macadamia
J. D. Wilkie A B D , M. Sedgley A and T. Olesen CA Faculty of Arts and Sciences, The University of New England, Armidale, NSW 2351, Australia.
B Present address: Agri-science Queensland, Department of Employment, Economic Development and Innovation, Applethorpe Research Station, PO Box 501, Stanthorpe, Qld 4380, Australia.
C Centre for Tropical Horticulture, New South Wales Department of Primary Industries, Alstonville, NSW 2477, Australia.
D Corresponding author. Email: john.wilkie@deedi.qld.gov.au
Crop and Pasture Science 61(7) 588-600 https://doi.org/10.1071/CP09167
Submitted: 10 June 2009 Accepted: 13 May 2010 Published: 6 July 2010
Abstract
Macadamia (Macadamia integrifolia, M. integrifolia × M. tetraphylla) trees were pruned at different times at sites near Alstonville, northern New South Wales, Australia, to examine the effects on vegetative flushing, subsequent flower raceme production and yield. Pruning of cv. 849 and cv. A268 modified the cycle of flush development. Pruning times that resulted in immature flushes on the canopy in late autumn or early winter inhibited raceme production. In contrast, pruning in late May and early June did not generally reduce raceme production relative to production on unpruned trees. The times of pruning that reduced raceme production also reduced yield. The yields of trees pruned in late May were also reduced, presumably because of decreased light interception. In the season after treatment the trees pruned in early April had greater numbers of racemes per unit of tree canopy volume than the trees pruned in late May. The trees of the lighter flowering cv. 849 pruned in early April had higher yield efficiencies than the trees pruned in late May, whereas there was no effect on yield efficiency in the prolifically flowering cv. A268. The differences in raceme production in the season after pruning may have been due to a combination of an alternate bearing response, characteristics of the stems produced after pruning, or maturity of the flushes. In a separate experiment, uniconazole sprays immediately after pruning reduced the length of the new stems, slowed canopy expansion, and increased kernel recovery compared with untreated hedged trees, but did not affect flowering or yield. In another experiment, hedging in early June had no effect on raceme production in cv. 849 trees in consecutive seasons, and no effect on canopy volume or yield in the first season. In contrast, canopy volume and yield were reduced in the second season. Finally, pruning of young, yet-to-flower cv. 849 trees from late winter to spring staggered flush development, with the earliest pruned trees producing more racemes and setting more fruit than the later pruned trees.
Additional keywords: bud release, canopy management, floral initiation, uniconazole.
Acknowledgments
The work was funded by The Primary Industries Innovation Centre (a joint venture between the University of New England and the NSW Department of Primary Industries), The Australian Macadamia Society, and Horticulture Australia Limited. We thank Newrybar Farm Partnership for access to their orchard; Sumitomo Chemicals Australia Pty Ltd for the ‘Sunny’; Sumitomo Chemicals Australia Pty Ltd and Agrimac Macadamias International for support with macadamia quality assessment; Stephen Morris for statistical support; and Lauren Baker, Alistair Janetzki, Lloyd Morgan, Steven Muldoon, Russell Priddle, David Robertson and Glenn Smith for technical assistance.
Batten DJ, McConchie CA
(1995) Floral induction in growing buds of lychee (Litchi chinensis) and mango (Mangifera indica). Australian Journal of Plant Physiology 22, 783–791.
| Crossref | GoogleScholarGoogle Scholar |
(accessed 8 June 2010)
Rademacher W
(1995) Growth retardants: biochemical features and applications in horticulture. Acta Horticulturae 394, 57–73.
|
CAS |
Sukhvibul N,
Whiley AW,
Smith MK,
Hetherington SE, Vithanage V
(1999) Effect of temperature on inflorescence and floral development in four mango (Mangifera indica L.) cultivars. Scientia Horticulturae 82, 67–84.
| Crossref | GoogleScholarGoogle Scholar |
Trueman SJ,
McConchie CA, Turnbull CGN
(2002) Ethephon promotion of crop abscission for unshaken and mechanically shaken macadamia. Australian Journal of Experimental Agriculture 42, 1001–1008.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
Trueman SJ, Turnbull CGN
(1994) Fruit set, abscission and dry matter accumulation on girdled branches of macadamia. Annals of Botany 74, 667–674.
| Crossref | GoogleScholarGoogle Scholar |
Wilkie JD,
Sedgley M,
Morris S,
Muldoon S, Olesen T
(2009a) Raceme position in macadamia. The Journal of Horticultural Science & Biotechnology 84, 387–392.
Wilkie JD,
Sedgley M, Olesen T
(2008) Regulation of floral initiation in horticultural trees. Journal of Experimental Botany 59, 3215–3228.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
PubMed |
Wilkie JD,
Sedgley M, Olesen T
(2009b) A model of vegetative flush development and its potential use managing macadamia tree canopies. Crop & Pasture Science 60, 420–426.
| Crossref | GoogleScholarGoogle Scholar |
Winston EC
(1992) Evaluation of paclobutrazol on growth, flowering and yield of mango cv. Kensington Pride. Australian Journal of Experimental Agriculture 32, 97–104.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
