West Central Michigan fruit update
This spring is about four weeks behind last season and two weeks behind “normal.”
Weather and crop development
Sunday was the day that we finally declared spring! This past winter was long and, at times, it seemed like it would never end. Compared to last year this season is well behind: about four weeks or so. In comparison to the “normal” year, this season is two weeks behind. With the exception of Sunday’s summer-like temperature of 78°°F for high, this past week had slightly cooler temperatures than what would be seasonable for this area. Over the weekend the whole west side of the state was in the “box” indicating possible tornados. Fortunately, except for some light rain (less than 0.1”) and some wind, nothing major happened.
Trees are just starting to show signs of life. Sweet cherries are at swollen bud to very early side green. Tarts are at swollen bud as well as plums, peaches and pears. Apples are at silver tip. Block with southern exposure in the southern part of Oceana County are a bit further ahead with buds starting to pull apart scales and the green tissue, though still not visible, just about to show. If we get two to three seasonably warm days, Idareds will show some green.
West Central Michigan growing degree day totals since March 1, 2011
As of Sunday, April 10:
There are no signs of any insect activity as of yet.
Apple scab. There was very good snow coverage in the orchards all winter and until just about a week ago. It covered all the leaves “preserving” the scab lesions. So we might have higher than normal presence of inoculum. That is likely to translate into “enhanced” potential for infections.
At this time, there is still no green tissue out. The most recent wetting events did not produce any spore discharge.
Bacterial canker. Just a reminder that this is an opportunistic disease of a cool season that will multiply reaching its peak at just about bud break. Bacteria overwinters in the buds near the cankers or near the effected spurs as well as in the vascular tissue. It will invade the trees through the wounds resulted from winter freeze-injury or from pruning in spring. It is recommended that the growers assess the damage and the amount of inoculum in their blocks (mainly sweet cherries, peaches, plums, apricots) and plan their management strategy. Blocks that have had excellent, vigorous growth last season and had extended seasonal growth are particularly at high risk of sustaining winter injury. There has been a significant cold event in Oceana County in January when the temperature dropped to almost 13°F below zero followed by another cold snap in March that might have been even more damaging. In March we had a 10-day period with temperatures from high 40’s to high 50’s. That was enough to provoke some sap flow. Then, the cold front came dropping temperatures to 8-9°F where it stayed for 4 days. These weather conditions paired up with low-laying terrain and frost pockets were enough to cause significant tree losses in young orchards like the two-year-old cherry orchard I was in yesterday. Use of copper sprays for epiphytic bacteria reduction is strongly recommended.