Kiwifruit Site Selection
Vine growth and fruiting habit of both fuzzy and hardy kiwifruit are similar. The following information on vineyard establishment applies to all the aforementioned species unless differences are noted.
Proper site selection, soil preparation, irrigation system design, planting design, and training are essential to developing a productive kiwifruit vineyard.
The single most limiting factor for fuzzy kiwifruit production is temperature. A. deliciosa Hayward can withstand temperatures as low as 10oF (-12oC). Although the buds of Hayward have a high chilling requirement (700 to 800 hours), the vines are very prone to frost injury during the growing season. In Oregon, cold injury to Hayward has occurred in some winters..
Dormant A. arguta vines are much more cold hardy than the fuzzy types (to -10 to -25oF or -23 to -32oC). However, young vines of this species also can suffer winter injury, particularly to the trunk, if temperatures fluctuate from warm to cold in late winter. A. arguta vines also are sensitive to spring frost damage to young shoots.
Male vines are less hardy than female vines (documented in Oregon).
There are several ways to help prevent freeze and frost injury:
- Do not plant in low areas or cool sites.
- Remove barriers (e.g., trees) to cold air drainage.
- Keep in mind that clean, cultivated sites are warmer during frost periods than sites with permanent cover crops.
- Do not cultivate immediately prior to a projected frost, because this reduces heat transfer from soil to air at night.
- Use overhead irrigation systems in areas susceptible to late spring frosts. (see Irrigation Systems for Kiwifruit).
Chemicals that reduce vine transpiration (i.e., anti-dessicants) have not been shown to reduce frost injury in kiwifruit.
Kiwi vines do best in deep, well-drained soils. They are very sensitive to standing water, especially after bud break in spring. Research in New Zealand has shown that if roots are waterlogged for 3 days or more, the root system and vine growth are severely damaged.
In California, it is recommended that kiwifruit be planted on 3 feet of well-drained soil. However, Hayward vines have grown well on soils with an effective rooting depth of 2 feet, provided the water table is lower than this.
Another option is to plant vines on raised beds (at least 1′ high). This is advisable in heavy soils, since it also may protect against phytophthora root rots.
Install well-designed drain tiles to improve drainage if necessary. Ripping the soil below the row before planting also can benefit growth.
The optimum pH for Hayward is between 5.5 and 6.0. Vines show poor growth at a pH above 7.2. It is not known if other species differ in pH requirements.
Previous cropping history
Kiwifruit are susceptible to verticillium wilt. Avoid planting in soils with a history of strawberry, black raspberry, potatoes, or other solanaceous crops.
Plants also are sensitive to phytophthora and root knot nematodes (Meloidogyne spp.). Although the literature relates to Hayward, it’s best to assume that arguta is similarly sensitive. Kiwifruit also are susceptible to Armillaria oak root fungus, which may be present on sites previously planted to oak trees.
A pre-plant soil test for nematodes is recommended. If nematodes or oak root fungus are present, use a preplant fumigation.
Young kiwifruit vines compete poorly with weeds, so eliminate as many perennial weeds as possible before planting. A permanent cover crop or a natural weed strip may be maintained between rows.
A plentiful supply of good quality water is required for kiwifruit production. Plants need 40-48 acre-inches of water a year. Table 1 shows irrigation guidelines that are considered safe in California.
|Table 1. Irrigation water guidelines|
|electrical conductivity, EC x 10||<0.75|
Long shoots in spring and summer are very susceptible to wind damage or breakage. Not only can wind cause fruit loss, but it also may reduce economic yields by rubbing the fruit. When rubbed, fuzzy kiwi first lose their “fuzz” and then develop callus, whereas the hardy kiwi types develop a callused or scabbed area.
In windy areas, wind breaks such as poplars help reduce economic losses. Plant wind breaks to provide 200 to 250 feet of protection downwind. Make sure wind breaks are not planted close enough to the vineyard rows to reduce yield of the kiwifruit.
Bernadine C. Strik, Extension Berry Crops Specialist, Oregon State University.
This fact sheet is adapted from Oregon State University Extension Publication EC1464, Growing Kiwifruit, which can be purchased from the Department of Extension & Experiment Station Communications. How to Order