West Michigan tree fruit regional report – April 7, 2015
Tree fruit development is slightly delayed in west Michigan, but growers should be ready.
A bit similar to 2014, spring is slow to arrive in 2015. Fruit growers tend to be pleased with a slow start to spring as it increases the odds of getting through bloom with fewer frost events. Growing degree day (GDD) totals for the general west Michigan area continue to run behind normal by roughly two to three weeks and totals are very similar to this same time in 2014 when first green on apples was April 20. However, if the much warmer weather predicted in the forecast holds true, we will move along quickly in GDD accumulation and could see first green on early apple cultivars in the next few days.
Historically, first green in McIntosh occurs around 125 GDD42. Using forecasted temperatures, that total will be reached by the end of the day Monday, April 13, 2015, which is only a few days behind the average date of April 10.
Slight bud swelling and some silver tip is being reported in apples; sweet cherry and peach buds are swelling slightly, but no green tissue in any tree fruits yet.
Tree fruit diseases
Copper applications on sweet cherries and other stone fruits can be applied at any time. Make sure there is no green tissue showing if you are using full rates to help with bacterial canker. Copper in apples for fire blight management is best timed for delayed dormant or silver tip and it has activity against apple scab as well.
Peach leaf curl sprays should definitely be considered this spring, even if you applied them last fall. If you applied last fall, any residue will be gone due to all the precipitation we’ve had over the winter. If this pattern of a cool, drawn out spring continues, it is perfect environmental conditions for the peach leaf curl fungus to get a foothold in early developing buds.
We are at first bud swell in sweet cherries in the general Grand Rapids, Michigan area. Cool, wet conditions predicted for the next several days could increase bacterial canker populations. As green tissue develops, it becomes susceptible to canker infections if something happens to allow bacteria entry into tissue – this includes frost or freezes and pruning. Avoid pruning sweet cherries in cool, wet conditions predicted for the next several days.
Tree fruit insects
No activity to report for tree fruit insects at this time, but a few of the cool weather moths have been seen flying in the evenings for about a week now. Green fruitworm could start to fly soon. If you have the time, scouting for European red mite overwintering eggs should be done – there could be significant mortality of eggs due to the extra cold winter. Dormant oil sprays will help with San Jose scale, which was significantly higher in some blocks in recent years.
The annual Spring Spray Meeting on the Ridge will be held Thursday, April 16 from 4 to 6 p.m. at the Goodfellow Farm, 2267 12 Mile Rd, Sparta, MI 49345, as in recent years. Please use the orchard entrance near Laubach Road, west of the house drive. We will meet in the large white building located behind the houses. This meeting is sponsored by the Michigan State Horticultural Society and Michigan State University Extension.