WEATHER

Very warm weather occurred this past week causing very rapid crop development. Generally, little rainfall has occurred in NW Michigan, though localized thunderstorms resulted in spotty precipitation on 5/7 and 5/8. Rainfall at the NWMHRS totaled 0.63 inches (all on 5/7). Evaporation increased to 1.85" last week, from 1.29" the previous week, or an average of about 0.26" per day.

GROWING DEGREE DAY ACCUMULATIONS as of May 8th at the NWMHRS

Year       2000    1999     1998     1997
GDD42   437       412       423       202
GDD50   214       193       196        70

GROWTH STAGES:
Apricot: Harcot -- fruit set
Plum: Stanley -- fruit set
Pear: Bartlet -- petal fall
Apple: Red Delicious -- full bloom
Sweet Cherry: Napoleon -- early fruit set
Tart Cherry: Montmorency -- petal fall
Grapes: Chardonnay -- 1" - 3" shoots

COMMODITY REPORTS

Sweet cherries at the NWMHRS were in full bloom on 5/3 for mid-season blooming varieties. Many varieties and/or locations in the warmer areas of NW Michigan had a poor looking bloom. Tarts came into full bloom at the NWMHRS on 5/5. These are the same full bloom dates as in 1999 for both sweets and tarts. Sunday's rain resulted in a light infection period for cherry leaf spot and no infection for apple scab. Green fruitworm are 1/4" long, and the adults are still flying. Climbing cutworms are still a threat in new plantings. Lesser peachtree borer flight is expected to start this week, and LPTB pheromone disruption ties should be put out as soon as possible. Plum curculio are active in the orchards but are a very minor threat until shuck split.

In Red Delicious and Golden Delicious apples it is common to find weak or non-existent king blooms. Thinning will be a challenge where the king bloom is missing. European red mites are hatching. Codling moth traps should be hung as soon as possible, as flight is expected this week. Pheromone disruption ties should be put out as soon as possible for codling moth. The spotted tentiform leafminer trap catches remained high for the week, with the average catch being 797 per trap at the NWMHRS. If Provado is going to be used for control at petal fall, the application should not be delayed this year. Late sprays cannot control the tissue feeding stage. Rosy apple aphids can be found in the clusters.

FAX BACK SYSTEM
By Gary Thornton

An important component of the Code-A-Phone (PestNet hotline) is the fax back system. To access this, press "5" at the main menu. A listing of the available documents, based on the weather from the various weather stations, is listed in the "2000 Catalog of Fax-Back Document Numbers" in this FruitNet (except the web version). The following documents will be faxed back to you upon request:

• 21 day summary (previous 21 days and prediction for the next 7 days' scab spore maturity, wetting events and rainfall).
• Codling moth (Chart to time sprays for egg hatch, You will need biofix date -- date when 5 moths per trap are caught).
• Plum curculio (Chart to use if postponing insecticide use in tart cherry; you will need biofix date of full bloom).
• Fireblight (Chart to use to determine and predict "Epiphytic Infection Potential" (EIP). You will need a biofix date, the date bloom opened in your apples or pears).

NEW CODE-A-PHONE SYSTEM -- PESTNET HOTLINE
By Gary Thornton

Many growers are still not aware of all the changes in the code a phone (PestNet Hotline) this year. The following information is now available to all growers with a touch tone phone:

Stone fruit message
Pome fruit message
Grape message
Disease prediction (wetting events) from 12 weather stations
Fax Back system

Please send any comments or suggestions regarding this site to: 
Bill Klein, kleinw@pilot.msu.edu

Last Revised:5-9-00