Potential Impact of Global Warming on Michigan’s Fruit Industry

1. Potential Impact of Global Warming on Michigan’s Fruit Industry Jim Nugent District Horticulturist

2. Michigan Fruit Plums, pears, strawberries, raspberries, cranberries, nectarines

3. Michigan Fruit Regions

5. Influence of Lake Michigan • Reduces winter injury • Delays spring bud development • Reduces risk of late spring frost • Cools in summer • Reduces risk of early fall frost

6. Effect of Warming on Winter Injury • Warmer late fall temps will delay onset of winter acclimation • Warmer temps will reduce cold hardiness • Question: Will cold events in early and mid winter continue? • Most prone to winter injury: wine grapes, peaches & sweet cherries

7. Effect of Warmer Springs on Fruit Buds • Fruit buds will become susceptible to cold injury earlier in the spring • Question: Will the probability of late spring frosts be reduced at a rate equal to the advance in fruit crop development? • Most prone to spring flower bud injury: tart and sweet cherries, apricots

8. Effect of Warmer Summers • Transpiration increases increased water needs • Possible scenarios: • Increased summer rainfall • May offset increased transpiration loss • Would hurt sweet cherries (cracking) • Would increase disease pressure

9. Effect of Warmer Summers – Scenarios, cont. • Equal or decreased summer rainfall increased drought stress: • Increased need for irrigation • Equal or decreased disease pressure • Equal or decreased sweet cherry cracking

10. ProbableOutcomes • Most probable winner: Wine grapes • Most probable loser: Tart cherries