Stone fruit :
Site selection
Bruce Topp, Department of Primary Industries and Fisheries.
Stone fruit can be grown in many parts of Queensland, but the
success of an orchard depend largely on the suitability of the planting site.
There are several factors to be considered when selecting a site for the growing
of stone fruit. The main considerations are climate, soil and aspect.
Climate
Chilling
Stone fruit require a period of winter cold to break dormancy, and this is of particular significance in coastal areas. The number of hours below 7 C that is needed to condition the tree to break dormancy and resume normal growth is called the chilling requirement. The chilling requirement varies depending on the type of stone fruit and the variety. It can be as low as 50 hours for some peaches and as high as 1 200 hours for some European plums. It is important to choose varieties with the correct chilling requirement for your area. Techniques are available for assessing chilling units.
Inadequate chilling occurs when varieties with a high chilling requirement are grown in warm areas. It results in death of flower buds, bud shed, erratic flowering, poor fruit set and poor fruit size. Leaf development is also delayed and erratic. In very severe cases the shoots may remain dormant and die back.
Excess chilling occurs when low chilling varieties are grown in very cold areas. The result can be early flowering and frost damage.
Frost
Frost damage to flowers and fruitlets in spring can severely reduce yields. Stone fruit at the small green fruit stage are more susceptible to frost damage than are the blossoms. Peaches and nectarines are marginally more tolerant to frost than apricots and plums. High sites with good air drainage are used to avoid spring frost damage.
Rainfall
It is important to avoid moisture stress in growing high quality stone fruit. Low rainfall is not a problem provided it is supplemented by irrigation. Diseases are more prevalent in areas with high rainfall during the growing season. Rain during the harvest period can result in fruit splitting of some varieties.
Soil
Type
Stone fruit can be grown on a wide range of soil types but generally do best on open textured soils. Most stone fruit in Queensland are grown on loams, sandy loams and sands.
Slope
Stone fruit can be planted on fairly steep slopes However, where the slope exceeds 3%, rows should a be planted along the contour to reduce erosion.
Drainage
This is the most important factor in determining soil suitability. Stone fruit trees will not tolerate standing for any length of time in soils with free water. Soils must be open and well drained throughout the soil profile. When selecting a site the soil needs to be checked for hardpans and wet spots.
Poor drainage leads to reduced vigour, poor drought resistance, root disease, water logging and death. To remove wet spots and obtain good drainage, it is necessary to prevent external water moving on to the land and/or install underground pipes.
Depth
Stone fruit prefer deep soils. Where soil depth is limited it can be improved by hilling the soil along the rows before planting.
Fertility
The natural fertility of a soil is of fairly minor importance as this can be modified by application of nutrients.
Disease
Stone fruit are susceptible to a number of root diseases which can be present in old orchard land, old vegetable land and natural bush. These diseases include Armillaria, Phytophthora cinnamomi and Verticillium. After clearing the bush or old orchards, all roots should be removed and the land fallowed or cropped for at least 12 months before planting trees.
Stone fruit roots are damaged by root knot and root lesion nematodes. Where nematodes are present, soil treatment should be practised or resistant rootstocks used.
Aspect
Air drainage
Good air drainage is necessary in the colder regions of the State to ensure freedom from damage from spring frosts. Obstacles to air drainage on the lower side should be removed, and low lying sites avoided.
In warmer parts of the State the best sites may h be those with poor air drainage to ensure that the trees receive sufficient chilling during winter.
Wind protection
Protection from wind is not essential but it is desirable to prevent damage to trees and fruit. Wind can cause fruit marking, break limbs, blow trees over, increase moisture loss and make spraying difficult. Provision should be made for the protection of trees against prevailing winds when choosing an orchard site.
Sunlight
A north to north-easterly aspect will maximise sunlight and the warming effect of the sun during spring. This reduces frost incidence and can also result in earlier maturing fruit.
A north-south row orientation is most efficient for sunlight interception.
Information contained in this publication is provided as general advice only. For application to specific circumstances, professional advice should be sought. The Department of Primary Industries and Fisheries, Queensland has taken all reasonable steps to ensure the information in this publication is accurate at the time of publication. Readers should ensure that they make appropriate inquiries to determine whether new information is available on the particular subject matter.
Last updated 04 February 2004
