Lynn E. Long Horticulture Extension Agent Oregon State University Wasco County Extension

Sweet Cherry Pickings

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April 2001 Newsletter

		A new publication entitled Cherry Training Systems: Selection and Development is now available from Extension offices in Wasco and Hood River counties. This is an illustrated publication that I wrote last year while on sabbatical. The publication covers Steep Leader, Vogel Central Leader, and Spanish Bush training and how to choose the right one for you. Drop by the Extension office to pick up a copy at $3.00 each.
		Here is a helpful planting tip from Mel Omeg. When planting a tree, partially refill the hole, paint the trunk with a white exterior latex paint, wait 30 minutes, then finish backfilling. This will keep the paint mitt from getting covered with dirt. Alternatively, take a tip from Dave Cooper who paints his trees before planting.
		Another growing season is upon us and the status of Success® insecticide for export markets is still questionable. In the past few days I have visited with both Dr. Mike Willet of the Northwest Hort Council and Herb Steffen from Dow AgroSciences about using Success on potential export cherries. I am told that there is no problem for its use on fruit exported to Japan or Taiwan, but as yet, there are still no tolerances established for Canada or the European Union.
		Dr. Willet commented that export tolerance problems are likely to increase as the EPA fast tracks safer alternative pesticides, especially when the alternative can be used as a substitute to organophosphates. The problem is that other countries do not similarly fast track registration of these same chemicals, so the U.S. may be several years ahead of these countries in their registration process. This means that chemicals like Success may be greatly limited in their use until tolerances can be set in foreign countries. Willet believes that these issues will become more, rather than less, common in the future.
		We recently received word that the EPA was officially denying our request for a Section 18 on Procure. Dr. Gary Grove, WSU, and myself pursued this Section 18 for Washington and Oregon, respectively. It was hoped that Procure would give growers another alternative for controlling powdery mildew. Obtaining additional control options was of significant concern to Washington growers where powdery mildew resistance had been established. In denying the request, the EPA stated that they were not convinced of an economic emergency.

Maintaining an IFP Orchard

As we increase our exports to Europe and other countries, maintaining an IFP orchard is becoming more and more important. Be sure that you review this checklist and perform these simple procedures.

Although orchards have been relatively free of OBLR problems over the last few years it would be premature for us to assume that we can relax our control efforts. Leafrollers have not gone away, however summer generation maturation seems to have been delayed so harvests have been larvae free over the last few years.

By experience we have learned that populations can explode in unsprayed orchards. In addition, larvae will feed on surrounding vegetation such as oak, blackberry, and wild rose with larvae ballooning into and adults laying eggs in nearby orchards.

How to remain diligent
·   If larval populations were high the previous year plan on applying a petal fall spray.
·   All growers in The Dalles area should trap during the adult flight.
·   Scout the orchard if trapped moths exceed 20 per flight.
·   Spray with Bt or spinosad if scouting reveals a pest problem.

How to spray
·   Make sure sprayer is properly calibrated
·   Adjust tractor speed to 2 mph or less
·   Good coverage is essential, do not spray in windy conditions
·   Direct nozzles to hit rootsuckers and tree centers

What to spray
·  Bt

	>	Apply anytime after petal fall when daytime temperatures are above 60° F to 70° F and no rain is expected for several days.
	>	Most effective when larvae are small, use spinosad on larger larvae
	>	Re-scout orchard 14 days after application to assure effectiveness
	>	Zero day pre-harvest interval

·  Spinosad (Success ®)

	>	Apply anytime after petal fall
	>	Use with ¼ % oil for added effectiveness
	>	Can be mixed with oil when spraying for powdery mildew
	>	Spinosad is pH sensitive, consult with your fieldman before tank mixing.
	>	Can help to reduce late season leafminer populations
	>	Seven day pre-harvest interval
	>	Check with your packing house before using this product as export tolerances have not been established for some markets.

For more information refer to Monitoring Obliquebanded Leafroller in Sweet Cherry Orchards (rev. May, 2000), published by the Wasco County Extension Office.

The weather stations project has made considerable progress in the last year. The Fruit and Produce League in cooperation with Wy'East Resource Conservation and Development have been successful in obtaining grants from state, federal and local sources. Ken Bailey and John Carter, head up the project management and have requested proposals for weather station equipment from several weather station vendors. We plan to have some of the stations up and running by the end of summer and the entire network on line for next year.

The weather station data will provide orchard managers with the ability to manage orchards for maximum benefit of Integrated Fruit Production practices with special attention to pest management. This network's solar powered weather stations will use radio's to transmit all weather data to a central computer server. The server will post onto an internet web site the current weather conditions at all stations along with pest and disease models. Data collected from each weather station includes temperature, rainfall, hours of leaf wetness, humidity, wind speed and direction and dew point. The pest management model and weather data will be available on the web to all growers, packing house field staff, crop consultants, chemical company field staff, OSU extension agents, and the general public.

Monitoring moisture in the soil is even more critical this year than usual. Even in this drought year you still don't want to over-irrigate. There is currently moisture in the soil and trees are not under stress at this time. However, waiting too long to apply the first irrigation can stress the trees. Adequate moisture needs to be present in the top 24 inches of soil where cherry feeder roots are located.

There are several ways to determine when to irrigate, but one of the simplest procedures is the "look and feel" method. Use a soil auger to take a sample down to 12 inches. Squeeze the soil in your hand until it forms a ball. Evaluate the soil moisture capacity using the soil cards reproduced on this page.

For The Dalles and upper Mosier Valley use the "Sandy clay loam and loam" card, for Dallesport and near the river in Mosier use the "Sandy loam and fine sandy loam" card. Take a second sample at the 12 to 24 inch depth and repeat the above procedure. If the plant available water is 50% or less, especially at the 12-24 inch depth, it is time to irrigate. For more information see EM 8716, Simple Irrigation Scheduling publication, available at the Wasco and Hood River county Extension offices.

Minimum Spray Guide for Royal Ann

At the Wasco County Fruit and Produce League meeting Mike Omeg and Diana Bailey presented a minimum spray guide for a Royal Ann block. Mike and Diana mad the premise that the block was to be removed in a year, therefore a nutrient program was not given. Both Drs. Helmut Riedl and Bob Spotts reviewed the guide before it was presented to growers in February. It is reproduced here only as a suggested guide.

Irrigation Workshop Scheduled

Wasco County Extension will be hosting an Irrigation Management Workshop on April 24, from 8:30 to 12:30 at the Columbia Gorge Community College Cafeteria Training Center (Building 1). The workshop will focus on irrigation in cherries, small grains, hay and pasture.

Pre-registration is requested by calling the Extension office at 296-5494.

Topics are as follows:

1. Irrigation Management: an economic perspective
   --The costs of under-irrigation and poor irrigation timing
   --The high costs of over-irrigation (lost yields, leaching of fertilizers, etc.)

2. Determining when and how much to irrigate
   --Soil moisture measurement techniques
   --Methods for estimating Evapotranspiration in Oregon
   --Commercial Scheduling Services
   --Using the AgriMet program, published guidelines, expert systems

3. Optimizing irrigation system performance
   --Estimating and controlling spray losses
   --Estimating and controlling irrigation application efficiency
   --System test and maintenance procedures for best performance

Winegrape Disease Management Workshop

On May 2, 2001, OSU Extension will sponsor a workshop on winegrape disease management to be held at the Pine Grove Grange. Topics to be covered will include management of powdery mildew, botrytis bunch rot, and eutypa dieback in winegrape vineyards. Vineyard canopy management for winegrape disease management will also be addressed. Coffee and donuts will be available starting at 8:30 a.m. The program will run from 9 to 11:30 a.m.

ODA and WSDA pesticide recertification credits have been applied for.

For more information call the OSU Extension office in Hood River at (541) 396-3343.

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