54663 853 Road
Pierce NE 68767
402-329-6774
Hours:
January-April
Friday, Saturday and Sunday 1:00 pm-5:00 pm
May-December
Wednesday-Saturday
11:00 am-6:00 pm,
Sunday 1:00 pm-6:00 pm
Closed Easter Sunday, Thanksgiving Day, Christmas Eve Day, Christmas Day, New Year's Eve Day, New Year's Day, Super Bowl Sunday
Common diseases found in Nebraska Vineyards
Downy Mildew Powdery Mildew Phomopsis cane and leaf spot
Black Rot Anthracnose Botrytis Eutypa dieback
Canopy Management
Canopy management is critical in the management of diseases. When a canopy is too dense, sprays are unable to penetrate into the inner most parts, and fruit is oftentimes missed. Shoot positioning with all types of training systems as well as summer pruning and hedging should be practiced when needed. Also leaf pulling can open up fruit clusters to spray penetration. All of these practices increase air flow through the canopy and through the whole vineyard giving vines the ability to cool on hot days and to dry properly after rain and fog periods.
Sanitation and vineyard floor management
Removing cuttings, trunks and cordons removed at pruning time can be a very effective way of controlling any over wintering diseases on your vineyard floor. When conditions are right rain can splash new spores from old wood and start things all over again. This is extremely important in older vineyards that have vines that have shown signs of Eutypa dieback. When these vines are pruned back to find good wood, the old wod must be taken away and burned and the pruning shears or loppers disinfected before using on another vine. Benomyl is effective in treating the pruning wound from such vines as well as the tools.
Another method of treating dormant wood is by spraying with liquid lime sulfur at least 2 weeks before bud swell. This will help control over wintering anthracnose and powdery mildew. Chopping cuttings and working them into the soil is also an option, although less effective than removing and burning.
Leaving grass in row middles can cause humidity to be higher and thus increase the risk of many diseases, but this is probably a compromise area here because of the high risk of erosion in most parts of Nebraska during the growing season. If grassed middles are employed you should keep them trimmed close when possible at least until after harvest.
"Grape Insect Pests", a Virginia Tech Site with info on just about all
insects that attack grapes:
"Grape Insect Pests of Ontario", includes color photos of all the common
grape insect pests:
University of California's publication, "Grape Pest Management":
Michigan State's Publication, "Common Diseases of the Grapevine in
Michigan",
Michigan State's "2002 Fruit Spraying Calendar", updated yearly with the
latest info on pesticides, etc.:
Chemical Sprays
Sprays can be divided in groups by their mode of action, or by whether they are only protective and preventative or also curative in their action. Formulations that are curative are most always also systemic in some form. It is important not to spray a particular product more than 2 times consecutively without switching to a product with a different mode of action for a particular disease problem. If this is not done, the possibility of a disease building up resistance to a particular product is quite high. This has been observed many times with powdery mildew.
The timing of sprays are critical and for black rot, phomopsis and downy mildew they should start when the shoots are only about 1/2" in length. If you have just applied only protective and preventative sprays you must spray again as soon as possible if the chemical is washed off by rain.
Only use the recommended rates on the package, some products may be phyto toxic at higher rates.
Methods of Disease Management
Sprays - Protective and preventative
- These types of chemicals will protect from infection and prevent new infections from occurring for a specified period of time as long as the spray remains on the surface of the plant and is not washed off.Sulfur - used for powdery mildew, this is a very inexpensive preventative but is phyto toxic to many cultivars and has not been tested on most Swenson cultivars.
Captan - is quite effective on downy mildew and phomopsis, it has a 96 hour re-entry restriction.
Dithane DF - this product is highly effective on black rot and downy mildew and moderately so on phomopsis. Care must be taken not to use Dithane DF or other Mancozeb products too late in the season because there is a 66 day restriction before harvest.
Copper Formulations - we have no experience with copper fungicides at Cuthills. Many cultivars are phyto toxic to copper formulations, and again most Swenson hybrids have not been properly tested (refer to the MN Grape Growers Association for more information on this). Also because copper tends to remain in the soil without breaking down, countries that have been using it for many years now have toxic levels in their soil.
Baking Soda - Sodium Bicarbonate - this household chemical apparently had good control of downy mildew.
Protective, preventative and curative
Rovral - effective against botrytis
Elevate - effective against botrytis (Elevate and Rovral can be used to alternate because they have different modes of actions.)
Nova - effective against powdery mildew and black rot. Nova's mode of action is a sterol inhibitor, it can be used opposite, sulfur and the strobulurins such as Abound and Flint but not with Bayleton.
Bayleton - effective against powdery mildew and black rot.
Abound - effective against powdery mildew, black rot, downy mildew and phomopsis. Phyto toxicity has shown on days when sprays were applied with temperatures over 90°F. Some growers question Abounds effectiveness on powdery mildew. Abound is a strobilurin.
Flint - effective against powdery mildew and somewhat effective against phomopsis and downy mildew. Flint is phyto toxic to concord vines.
Sovran - effective against powdery mildew, black rot, downy mildew and phomopsis.
NOTE: Abound, Flint and Sovran are strobulurins, they should not be used together in a spray schedule for the same control, because of resistance build up.
This is not an extensive list of chemicals. There are others available, but with less or no use in Nebraska. Remember to always follow label directions for each product.
2-4-D and Banvil are the worst. Because they are very volatile, although anything else that's carried during windy situations as far as herbicides go, will cause damage. If anyone is using insecticides near you and they drift onto the grapes, make sure that they are registered for grapes otherwise you won't be able to use them. If they are registered for grapes you must make sure that you know the days to harvest restrictions on those chemicals.