Northern Michigan FruitNet 2002
Weekly Update
James E. Nugent      Gary E. Thornton       William M. Klein
NW Michigan Horticultural Research Station
Michigan State University

May 28, 2002

WEATHER
Cool temperatures are finally giving way to more seasonal levels. A long wetting event occurred on 5/26-5/28. This spring conditions have generally been favorable for the development of bacterial canker.

GROWTH STAGES
Apple: Red Delicious—50% bloom
Pear: Bartlett – petal fall
Sweet Cherry: Napoleon – shuck split
Tart Cherry: Montmorency – late petal fall
Plum: European type – petal fall
Grapes: Chardonnay – bud burst

COMMODITY REPORTS

Apples: The latest infection period for apple scab was classified as high throughout NW Michigan. If growers didn't have protection on their apples going into the rain, they should apply either an SI or a strobilurin fungicide which has back action. These should be applied as soon as possible after the foliage dries. Fireblight may be a threat if we have rain on Thursday or later this week. Insect activity remains very light. No codling moth flight reported. Growers should hang traps if they are planning on scouting for codling moth.

Cherries: The latest cherry leaf spot infection was heavy. Brown rot has not been reported so far. The freeze on 5/19 that significantly shortened the sweet cherry crop also caused damage to spur and terminal growth tissues. It appears that this cold injury has allowed the subsequent invasion of the pathogens that cause bacterial canker into the tissues. Beginning on Monday, 5/27, we began seeing the first symptoms of the collapse of spurs, which we think is the result of this bacterial canker invasion of spur tissue.

Climbing cutworms are a threat to newly planted orchards. 

GIBBERELLIC ACID ON CHERRIES
By James E. Nugent
District Horticulturist, MSUE

Gibberellic acid (GA) is used in young tart and sweet cherries to reduce flowering and fruiting, which maximizes growth and minimizes pollen transmitted virus infection. GA is used in mature tart cherries to increase the fruiting capacity by stimulating the development of lateral shoots and spurs.

With the very small tart cherry crop in many orchards in 2002, the question being asked is what is the best strategy for GA use this year? GA functions by shifting a portion of the buds that would produce next year's fruit into vegetative buds. The very light fruit crop this year will likely result in strong vegetative growth, and hence, heavy fruit bud production. This could result in a large crop in 2003. Dr. John Bukovac and I discussed this situation for bearing tarts and reached the following conclusions:

Apply when high temperatures are expected to be above 70 ° F for a couple of days, if possible. Applications made when high temps are expected to be below 60 ° F have given poor results. 

Addition of a surfactant may influence the tree's response to GA. Results with different surfactants vary from no effect to over-response and phytotoxicity. Therefore, a surfactant is not recommended with GA unless a grower has enough experience with a particular surfactant to have confidence in the response. Never use a silicon-based surfactant, because of potential phytotoxicity.

Non-bearing tart and sweet cherries -- With a handgun, apply either 100 ppm (40 fl. oz. of product containing 4%GA / 100 gals of water) in a single application 3-4 weeks after full bloom, or 50 ppm (20 fl.oz./100 gal) about 3 weeks after full bloom plus a second application at 50 ppm 3 weeks later. Two applications at 50 ppm are generally more effective than a single application at 100 ppm. Do not apply to trees the year of planting.

To bring young trees into bearing following treatment with high rates during non-bearing years, it is very important to not discontinue GA all at once. This results in oversetting of fruit and stunting of trees. We suggest weaning trees off GA over two or three years. The year prior to desired first fruiting, apply 30 to 40 ppm dilute (12-16 fl oz /100 gal), or about 20-24 fl. oz./acre if applied concentrate. This rate per acre for concentrate spraying already takes into account the average tree size of this age tree; i.e., do not reduce the rate further based on tree row volume. The next year, decrease this rate to 15 to 20 ppm applied dilute (6-8 fl oz./100 gal) or 10-12 fl oz./acre applied concentrate. The following year, 10 ppm is optional but often not required. In orchards where growth is weaker, it may be desirable to continue annual GA applications at 10-15 ppm, rather than discontinue at this time.

Mature tart cherries – Use 10-20 ppm of GA, which is equivalent to 6-12 fl. oz./acre on mature trees. Lower rates are typically used on more vigorous orchards or where GA was used successfully last year; higher rates are used on low vigor orchards. Rates of about 15 ppm are most common.

GA may also be applied later in the season on sweet cherries to increase fruit firmness and delay harvest. Results in Michigan have not been very consistent and may lead to increased cracking. See label for details.

PROPOSED WELL PERMITS FOR MICHIGAN
By Jim Nugent

I thought our fruit growers and processors might want to be aware of some newly proposed legislation that is currently working its way through the state legislature. I pulled the following information from the Senate's web at : 

http://www.michiganlegislature.org/documents/2001-2002/billintroduced/senate/htm/2002-SIB-1197.htm and 
http://www.michiganlegislature.org/documents/2001-2002/billintroduced/senate/pdf/2002-SIB-1198.pdf on 5/21. This is only proposed legislation, not a new law at this time, but now is the time to communicate your thoughts to state legislators. The proposed legislation could significantly impact our ability in the future to irrigate orchards, cool cherries or process fruit.

Legislation has been introduced into the Michigan Senate that would require a permit for withdrawal of groundwater that exceeds "100,000 gallons per day averaged over 30 consecutive days". In other words, a permit would be required if a well or combination of wells, will pump 70 gallons per minute or more for 30 days. It appears that existing wells do not need permits, but the addition of any increased pumping capacity (adding an additional well or increasing the capacity of an existing well) would trigger the requirement if exceeding the above water usage.

To be issued a permit the applicant must meet all of the following standards:

1. Demonstrate need for proposed withdrawal
2. Withdrawal and use will prevent or minimize water loss from the watershed through return flow and implementation of environmentally sound and economically feasible water conservation measures
3. The withdrawal will result in no significant adverse individual or cumulative impacts to the quantity and quality of the waters of the Great Lakes basin and water dependent natural resources of the Great Lakes basin
4. The withdrawal will not adversely affect other users of the same aquifer
5. The withdrawal is consistent with the future water use needs identified in any master land use or zoning plan adopted by the local unit of government in which the withdrawal is proposed.

To obtain a permit the following information would need to be submitted by the applicant to the DEQ:

1. Purpose of the withdrawal
2. Location of proposed well site
3. Current ecosystem status of the water source
4. Maximum use rates per day, month or year
5. Estimation of amount, time of year, and place that water returns to the ecosystem
6. Condition of water drawn and returned
7. Frequency, duration and months of proposed withdrawal
8. Recharge rate and estimated area and depth of the cone of depression of any affected aquifer
9. Means for monitoring and documenting return flow
10. Ecosystem status of the waters that will receive the return flow, and expected impact of return flow on that status.
11. Need for water and alternatives to withdrawal
12. Measures that will be taken to do both of the following:

a. Implement environmentally sound and economically feasible waterconservation measures
b. Improve the waters of the Great Lakes basin

Upon receipt of the permit, the DEQ will: 

1. Notify local units of government and Indian Tribes (if applicable). (Proposed legislation does not state whether or not their approval is required).
2. Hold a public comment period of at least 30 days.

The DEQ is to collect annual permit fees to offset the cost of administering the program. Users must reapply every 10 years to renew their permit.

Some of the issues that may concern to agriculture are:

1. A very high burden of proof lies with the applicant. To accomplish the permit application will require a lot of time and hydrological and ecological expertise, and costs to hire necessary consultants may exceed the resources of most family farmers. 

2. Proving "no effect" can be technically extremely difficult. For example, how does one prove that water flowing through cherry tanks has no adverse impact on water quality? What if the neighbor claims during the public comment period, or to the local unit of government, that the cherries on the cooling pad warm the water (which they do). Can we prove this has no adverse impact on any water-dependent natural resources of the Great Lakes basin?

3. How do we prove that pumping ground water for agricultural production or processing will "improve the waters of the Great Lakes basin and the water-dependent natural resources of the Great Lakes basin"?

Please send any comments or suggestions regarding this site to: 

Bill Klein, kleinw@pilot.msu.edu
Last Revised: 5-28-02