Southwest Michigan fruit update – March 26, 2024
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EmailThis is the first fruit scouting report of the 2024 season.
Winter
The winter of 2023-2024 was warm. For much of Michigan, December through February was the warmest on record. Temperatures seldom dropped below 15 degrees Fahrenheit. A cold air mass entered Michigan on Jan. 13, 2024, followed by another one on Jan. 20. For much of the 10-day period around these events, low temperatures remained well below average. The coldest temperatures seen were on the night of Jan. 14-15 when the Southwest Michigan Research and Extension Center saw a low of -7.6 F. Other locations in Berrien, Van Buren and Cass counties saw temperatures around -8 to -10 F. Low temperatures for the six weeks before this event never dropped below the mid-20s. Due to the record warmth during the weeks leading up to the mid-January event, many crops had not reached their full cold acclimation potential. Some sensitive crops such as peaches and some wine grapes were damaged.
After the January cold event, temperatures returned to above-average trends. Another cold event on March 20-21 resulted in temperatures around 21 F. At that time, many fruit crops grown in the region had reached their chilling hour requirements and had begun spring development. Some additional crop damage has been observed in some of the most advanced tree fruits.
Winter precipitation was slightly above average. The start of winter was close to average, but from mid-January to mid-March, we are 3 inches ahead of our 20-year average. Except for a significant snow event on Jan. 10-12, much of this precipitation came as rain.
Below are the growing degree days (GDD) for the Southwest Michigan Research and Extension Center (SWMREC) near Benton Harbor, Michigan, for the last 15 years. Compare the 2024 numbers to the average for the last 15 years and you can see we are ahead of average. Note, an extreme warm event in March 2012 resulted in a statistical outlier. When the bias of 2012 is removed, we are well above average. At this time, we are very close to the weather trend of 2017. For more information, see “Understanding growing degree-days” from Michigan State University Extension.
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GDD summary from Jan. 1 through March 25 at the Southwest Michigan Research and Extension Center |
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Year |
Base 42 F |
Base 45 F |
Base 50 F |
|
Average |
121 |
87 |
48 |
|
Average without 2012 |
103 |
71 |
36 |
|
2024 |
215 |
160 |
95 |
|
2023 |
74 |
37 |
8 |
|
2022 |
125 |
87 |
45 |
|
2021 |
139 |
103 |
60 |
|
2020 |
90 |
57 |
22 |
|
2019 |
41 |
24 |
8 |
|
2018 |
64 |
39 |
15 |
|
2017 |
233 |
170 |
94 |
|
2016 |
170 |
121 |
66 |
|
2015 |
42 |
26 |
13 |
|
2014 |
17 |
6 |
0 |
|
2013 |
38 |
21 |
7 |
|
2012 |
395 |
327 |
233 |
|
2011 |
67 |
44 |
20 |
|
2010 |
90 |
59 |
26 |
|
2009 |
144 |
105 |
57 |
March weather
March temperatures have been quite variable. The region has seen high temperatures from the mid-30s up to above 70 F. Low temperatures have largely stayed between the low 20s and mid-40s.
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Southwest Michigan GDD summary from March 1-25, 2024 |
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|
Station |
GDD 42 F |
GDD 45 F |
GDD 50 F |
|
Benton Harbor (SWMREC) |
123 |
92 |
56 |
|
Lawton (Lawton) |
121 |
91 |
54 |
|
Fennville (TNRC) |
105 |
77 |
45 |
|
Average for the SW region |
118 |
88 |
52 |
The forecast for the upcoming week calls for low temperatures near freezing and highs near 50 F. Slight chances of scattered precipitation are forecast for Saturday, March 30, then again on Monday.
The medium range forecast for the first half of April is for average temperatures and higher than average chances of rain.
Tree fruit
The past winter was relatively mild in the southwest region until mid-January with significant dips on Jan. 15, 20 and March 21. Temperatures were generally colder in the southernmost tier of counties—Berrien, Van Buren, Cass, Kalamazoo, St. Joseph and Branch. The Jan. 15 lows damaged peach and apricot fruit buds. March 21 took its toll on the tart and sweet cherries and some king flowers of apple. In general, the hardest hit are peaches and apricots, with less but still significant damage on sweet and tart cherries.
Winter cold damage to branches and trunks has yet to be evaluated but is expected to be minor for healthy trees. Crop potentials for apple and pear are still good for this region. Dry conditions for the last month allowed growers to make good progress pruning. Check blocks for evidence of San Jose scale on branches to determine the need for oil sprays.
Apricots are at first bloom in central Berrien County. There are relatively few viable fruit buds in the area due to winter freezes.
Peach and nectarine buds were swelling in early March due to the mild temperature and prone to peach leaf curl infections. Infections require 10-plus hours of wetting with temperatures in the range of 46 to 55 F. Treatment now can help suppress additional infections when these weather conditions occur even past bud swell. Low levels of copper also suppress bacterial spot populations. Orchards with no crops will need at least moderate pruning to generate fruiting wood for next season. Typically, only half the normal nitrogen application is needed in years of no crop. Oriental fruit moth management is necessary post-bloom in young blocks to prevent branch end damage that distorts tree structure.
In cherries, sweets are at green tip and tart cherries at side green to early green tip in central Berrien County. Copper sprays can be safely applied to cherries. Copper applications may reduce bacterial canker in cherries.
In plums, Shiro Japanese plum fruit buds at tight cluster and Stanley European plum are at tip green. Prune out black knot and dispose of the knots by burning or removing from the orchard. Sanitation is an important step in managing this disease.
Apple early variety Zestar is at tight cluster, Macintosh and Gala are at half-inch green, Red Delicious and Jonagold are at 0.25-inch green in Berrien County. Some king bloom were damaged by the March 21 low temperatures. Scab sprays will be needed to protect against future rains as green tissue emerges. Protectants are preferred over systemic fungicides at this time of year for scab control.
Pear buds have expanded so that the blossom buds are exposed. Pear psylla adults are flying. Scab sprays are needed as green tissue emerges.
Small fruit
Grapes show little movement.
Blueberries are at bud swell in Berrien County. Growers still have time to apply copper, Sulforix or lime sulfur products to suppress early season diseases.
Strawberry overwintering mulches should be removed and raked between the rows. Some growers are putting out floating row covers. Growers are looking at early season herbicides to control overwintering weeds. When selecting an herbicide, check the preharvest interval.
Brambles. Many growers are dormant pruning. In summer bearing raspberries, last year’s primocanes should be headed (cut back) to the desired height and any remaining floricanes from last year should be removed. Fall bearing raspberries should be cut or mowed to the ground. Lime sulfur treatments for anthracnose can still be applied.
Upcoming meetings
Our regular southwest Michigan Monday fruit integrated pest management updates will once again be a hybrid format. The meetings will be held in-person at the Southwest Michigan Research and Extension Center, 1791 Hillandale Rd, Benton Harbor, MI 49022, with virtual attending available online. Our first meeting is Monday, April 15, at 5:30 p.m. See next week's southwest Michigan fruit update for signing up for the Zoom meeting. No advanced signup is needed for attending in-person. These meetings are free and one pesticide applicator credit is available for each meeting.
This work is supported by the Crop Protection and Pest Management Program [grant no 2021-70006-35450] from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.
