Phylloxera Strategiesis for Management in Oregon's Vineyards Information

EC 1463 • November 1995 $2.50 DATE. OF OUTPhylloxera StrategiesIS for management in Oregon's vineyards information: PUBLICATIONcurrent most THIS For http://extension.oregonstate.edu/catalog OREGON STATE UNIVERSITY EXTENSION SERVICE Contents Chapter 1. Phylloxera: What is it? 1 Chapter 2. Reducing the risk of phylloxera infestation 3 Chapter 3. Sampling vines to confirm the presence of phylloxera 4 Chapter 4. How to monitor the rate of spread of phylloxera in your vineyard 5 Chapter 5. Managing a phylloxera-infested vineyard DATE. 7 Chapter 6. Replanting options for establishing phylloxera-resistant vineyards 9 Chapter 7. Phylloxera-resistant rootstocks for grapevines 12 Chapter 8. Buying winegrape plants OF 19 Chapter 9. Tips for producing phylloxera-resistant grafted vines 20 OUT IS Authors This publication was prepared by a phylloxera task force at Oregon State University. Members are Bemadine Strik, Extensioninformation: berry crops specialist; M. Carmo Candolfi-Vasconcelos, Extension viticulture specialist; Glenn Fisher, Extension entomologist; Edward Hellman, Extension agent, North Willamette Research and Extension Center; Barney Watson, Extension enologist: Steven Price, postdoctoral research associate, viticulture; Anne Connelly, master's program student, horticulture; and Paula Stonerod, research aide, horticulture.PUBLICATION current most THIS For http://extension.oregonstate.edu/catalog Chapter 1 Phylloxera: What is It? B. Strik, A. Connelly, and G. Fisher History green, or light brown; on weakened distances. In Oregon, above-ground roots they are brown or orange. Mature nymphs have been detected on trunk The grape phylloxera, Daktulosphaira adults become brown or purplish- wraps in July and August. vitifoliae (Fitch), is an aphidlike insect brown, no matter on what kind of root that feeds on grape roots. Phylloxera they have fed. In summer,DATE. possibly due to environ- are native to the eastern and southern mental or population conditions, some United States. The pest was inadvert- Each female can lay as many as 400 nymphs may develop wing pads and ently introduced to France from North eggs. Newly deposited eggs are lemon emergeOF from the ground as winged America in 1860, and by the end of the yellow, oval, 0.5 to adult females century had destroyed two-thirds of the 0.7 mm long, and (alates). The vineyards in Europe, all self-rooted about half as wide. rhylloxera now are in every females usually Vitis vinifera. Since then, phylloxera fly to an upright The pest's rate of have invaded most grape-growing major grape-producing surface such as development areas of the world; for example. New regionOUT in Oregon. the vine's trunk. depends on the Zealand, Australia, and South Africa. They lay male grape root and IS and female eggs, They were introduced into Cahfomia vine phenology as well as on numerous which hatch into male and female in the 1850s from the eastern United environmental factors, including soil phylloxera that have no mouth parts— States. Phylloxera were identified in and air temperature and humidity. and thus do not directly damage the the Penticton area of British Columbia grape-vines—but can and do mate. in 1961 and, in 1988, in eight sites in Phylloxera overwinter on roots as Washington state, one of which was a small, dark nymphs (hibemants). In the The female lays a large egg that V. vinifera vineyard. spring, when soil information:temperatures exceed overwinters probably in crevices on the a critical level (from our research, that trunk. This egg hatches into a female 0 Phylloxera also were discovered in can be between about 45 and 65 F) and who feeds on the leaves of susceptible Oregon about 20 years ago. However, vine sap starts to flow, the nymphs grape varieties, creating a leaf gall. She it was not until 1990 that this pest was begin feeding and then molt to adult- lays eggs that produce a population of discovered for the first time in modem hood. The mature forms deposit eggs nymphs, which can reinfest the root commercial vineyards. Phylloxera now by asexual reproduction. In Oregon system or other leaves. are in every major grape-producing vineyards, two to three generations a region in Oregon. In 1995, 13 infested currentyear have been seen, the first eggs in At the end of September, nymphs vineyards were identified;PUBLICATION probably June. begin to hibernate, and by mid- many more are infested in the state. December all forms are hibemants. Phylloxera are most numerous in late summer to early fall. Thus, they are The winged, or sexual, stage of phyl- most easiest to detect then by digging up loxera has been found in Oregon, DescriptionTHIS grape roots—and the risk of spreading caught on sticky trunk wraps in July and life cycle the insect also is the greatest then (see and August. It is not known whether Chapter 2, "Reducing the risk of winged phylloxera can complete their All adults are Forfemale. They are very phylloxera infestation"). life cycle on European wine grapes. If difficult to detect because they are they can, the pest's rate of spread will extremely small—0.7 to 1 millimeter Newly hatched nymphs usually leave increase dramatically. However, we do (Vso to Vas inch) long andhttp://extension.oregonstate.edu/catalog 0.4 to the roots where they were hatched only know that the winged form can com- 0.6 millimeter wide (see Chapter 3, if a high phylloxera population has plete its life cycle on the foliage of "Sampling vines to confirm the created feeding competition or when a American grapes such as 'Concord' or presence of phylloxera"). vine is near death. These "crawlers" a rootstock or on the foliage of French- travel on the soil surface or in cracks in American hybrids such as 'Marechal Color of the adults varies with the food the soil, or they can climb the vine and Foch.' supply. On fresh vigorous roots, they be blown by the wind for considerable are pale green, yellowish-green, olive Injury Injury to the above-ground portion of clay, generally are more favorable to the vine is an indirect result of root infestation than light sandy soils, Phylloxera damage Vinifera grapevines damage. Thus, the symptoms are which appear to be almost immune to mainly by inhabiting and feeding on similar to those of other pest problems phylloxera. Heavier soils contract and roots. It is believed that, when feeding, such as Armillaria (oak root fungus), crack when drying, and these openings phylloxera inject poisonous saliva that gopher damage, or nematodes (which allow the insect to crawl to and infest causes roots to swell. Feeding gener- also may cause similar root symptoms) root systems. ally is on the tips of the rootlets, and to symptoms of environmental causing yellowish-brown, hook-shaped problems such as severe water stress Rate of spread in Oregon has ranged swellings or galls (nodosities) to form. and winter injury. from nearly 2x (the infestation's These may curve and bulge around the doubling in size annually) to 1 Ox on a insect's body. In most cases, the The severity of the infestation may site where the pest came in on infested swelling stops differ because of the plant material. Managing an infested rootlet growth, and variety of grape, the vineyard, therefore, is a challenge (see the infested portion I here is no way to vine's age and Chapter 5, "Managing a phylloxera- eventually dies. vigor, soil condi- infestedDATE. vineyard"). Feeding on larger eradicate phylloxera in tion, and drainage. roots causes an infested, susceptible There is no way to eradicate phyllox- rounded swellings vineyard. Vigorous vines era in an infested, susceptible vineyard. (tuberosities), resist phylloxera OFThe only method of control is to plant which give the root attack better than do vines grafted to a resistant rootstock a warty appearance. The tuberosities weak ones. Differences in vine vigor (see Chapter 7, "Phylloxera-resistant also may decay, further weakening the can be due to site differences, but also rootstocks for grapevines"). vine. to varietal differences. OUT Root injuries impair the absorption of Infested vines live longer in fertile, nutrients and water, causing a decline deep, well-drained soil than in shallow in vine vigor and productivity. Second- soil or soil with ISpoor drainage. Vines ary fungal infection and the feeding of growing in heavy, shallow soils appear other insects and mites also hastens to succumb to the infestation most decomposition of roots. rapidly. Fine-textured soils, such as information: PUBLICATIONcurrent most THIS For http://extension.oregonstate.edu/catalog Chapter 2 Reducing the risk of phyiloxera infestation E. Hellman and B. Watson Phylloxera can be spread from vine- Prevention is one of the few weapons can support populations of phylloxera yard to vineyard on soil or root pieces for combating phylloxera. and serve asDATE. a source of new infesta- carried by workers' boots, picking tions. A phylloxera infestation usually Prevention primarily means restricting totes, vehicle tires, and other means. is not diagnosed until several years movement of people, equipment, and Infested soil also could be exchanged after its introduction into the vineyard. materials among vineyards and among vineyards at the winery via Therefore,OF controlled access and thoroughly cleaning all items that picking bins during the hectic activities sanitation procedures are important for come in contact with vineyard soil. of harvest dehvery and crush. There- all vineyards and wineries. We fore, both vineyards and wineries All vineyards should be considered recommend vineyards and wineries should take precautions against the potentially phylloxerated. Even follow these procedures to reduce the movement of potentially infested soil. grafted vines on resistant rootstocksOUT risk of spreading phylloxera. IS In the vineyard At the winery Make every effort to restrict the When that is not feasible, be especially Restricted movement movement of people and equipment in thorough with your sanitation prac- • Restrict all vehicles to paved areas.

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