Buying Winegrape Plants
Additional Fact Sheets on Phylloxera:
- Phylloxera: What is it?
- Reducing the Risk of Phylloxera Infestation
- Sampling Vines to Confirm the Presence of Phylloxera
- How to Monitor Rate of Spread of Phylloxera in Your Vineyard
- Managing a Phylloxera-infested Vineyard
- Replanting Options for Establishing Phylloxera-resistant Vineyards
- Buying Winegrape Plants
- Tips for Producing Phylloxera-resistant Grafted Vines
Contributing List of Authors: Ed Hellman. Oregon State University. This fact sheet and others on grape phylloxera were produced as a set by a phylloxera task force at Oregon State University: Bernadine Strik, Extension Berry Crops Specialist; M. Carmo Candolfi-Vasconcelos, Extension Viticulture Specialist; Glenn Fisher, Extension Entomologist; Edward Hellman, Extension Horticulture Agent; Steven Price, Post-doctoral Research Associate, viticulture; Anne Connelly, Master’s student, horticulture; and Paula Stonerod, Research Aide, horticulture. The authors of this fact sheet acknowledge the help and guidance of others on this task force.
Patty Skinkis, Ph.D. and Bernadine Strik, Ph.D. Oregon State University
Selecting good plant material is a critical step in establishing a profitable vineyard. Sanitation procedures to reduce risk of phylloxera infestation (see Reducing the Risk of Phylloxera Infestation) are not 100% effective. Use of winegrapes grafted onto a resistant rootstock is the only method of “control” against phylloxera. Considering vineyard establishment costs and potential longevity, it is important to start with “clean” plant material. Choosing a good nursery source is an important step in procuring good quality, true-to-type plants. When you’ve made decisions on what cultivars/clones to plant, you still need to choose plant type (green or dormant; self-rooted or grafted) and plant disease status (certified; hot-water dipped for pest control). All of these things must be considered when ordering your plants.
Nurseries offer dormant field-grown and greenhouse (“green”) potted plants for sale. Green plants need to be properly hardened off before planting and may need more careful attention with regard to irrigation after planting. Check with nurseries for availability and recommendations.
Dormant, field-grown plants are available in two grades based mainly on plant size. You should check with nurseries for availability and costs of grades for the cultivars/clones you’re interested in.
Self-rooted or grafted?
Although self-rooted (non-grafted) plants are less expensive (about 1/6 the cost) than grafted vines, the Oregon State University Extension Service does not recommend planting self-rooted vineyards in Oregon due to the presence of phylloxera (see Phylloxera: What is it?). Self-rooted European winegrapes are not resistant to grape phylloxera and will die after they become infested. Vines grafted onto a resistant rootstock are the best insurance and the only control measure against phylloxera. There are many types of rootstocks to choose from. Choose a resistant stock that best suits your site and desired viticultural traits (see Phylloxera-resistant Rootstocks for Grapevines).In a grafted plant, the resistant rootstock is called the “stock” or “rootstock” and the cultivar/clone grafted onto it is called the “scion”. The most popular rootstock/scion combinations are in great demand. Order your plants well in advance of your desired planting date.
Plant Disease Status:
The Oregon Department of Agriculture has an established plant quarantine against fanleaf and leafroll viruses and grape phylloxera. If you wish to purchase plants from nurseries in California or other states, you must follow these regulations. It is against quarantine regulations to import grape plant material that is NOT certified to be free of fanleaf and leafroll viruses and phylloxera. Also, the only rooted grape plants that may be imported are those that have been grown in soilless, sterile media. For more information, contact the Oregon Department of Agriculture.
Treatment of nursery plants
Plants purchased from Oregon grapevine nurseries are commonly field-grown. Although nurseries in Oregon are inspected annually for presence of phylloxera, it is very difficult to find this insect pest (see Phylloxera: What is it?). Nursery inspectors check plants for presence of phylloxera or symptoms of infestation in the winter when plants are dug. However, this and other certification or inspection methods for phylloxera are not foolproof. Certified grapevine nurseries in Oregon are also inspected once during the growing season for presence of leaf symptoms of viral infestation. Approximately every five years, nurseries are sampled during the growing season for the plant parasitic nematodes that vector the two viruses.
As added insurance against phylloxera infestation, some nurseries will treat their plants in a hot water dip or with insecticide to kill any phylloxera that may be present. This may increase the cost of plants.For an effective hot water dip, plants must be dipped for 5 minutes at 110 F (to warm the roots) and 5 minutes at 125F to kill any phylloxera life stages present. We have shown this treatment to work at eradicating phylloxera without harming self-rooted or grafted plants that are dormant when dipped.As an alternative to hot water dipping, there is an insecticide (Malathion 5EC) presently registered for use as a nursery plant treatment for insect control. Nurseries or growers using this product should check the label carefully prior to use.
Keep in mind that phylloxera can live on the roots of resistant rootstocks. The resistant rootstock does not die as a result of phylloxera feeding, but can serve as a source of phylloxera for infesting nearby vineyards. This is an important fact to keep in mind, especially if you’re planting near an established European, self-rooted vineyard block.