Mark Longstroth, Bill Shane and Diane Brown-Rytlewski

Weather
The 2009 growing season will be long remembered by fruit growers for various reasons. There was some winter damage due to several radiation freezes in mid-January (-10 to -24°F). These freezes affected lower portions of orchards and vineyards and blueberries located away from Lake Michigan in good blueberry sites, located in lower topographic conditions. Initially, it was feared that wine grapes and peaches would be severely affected. These crops suffered some damage, but still harvest respectable crops. Spring began early with a warm March, but April began with a snowstorm. Significant rain events with long, warm wetting periods occurred in April on April 19 and 27. This ignited significant disease problems in apples and blueberries. A light frost that caused scattered damage occurred April 23, between these two rains.

The 2009 growing season was generally cooler than normal with the GDD accumulation slowly falling behind normal. Rainfall was plentiful in April and May into mid-June. Major storms crossed the region on June 19. These storms were followed by dry conditions in July resulting in dry soils until late August, especially in the south end of the district. Wide spread heavy rains in late August relieved most drought stress symptoms, so drought was not a major factor for most fruit crops. GDD accumulations fell behind normal as the season progressed. In late August, GDDs were as much as two weeks (300 to 500 GDD) behind normal, but harvest timings were generally only a few days behind normal. September was a little warmer with warm days and cool nights and dry, good conditions for ripening fruit. Harvest quality for most crops was good in 2009.

Southwest Michigan GDD totals March 1 through September 20				Grapes, from April 1
Location	GDD 42	GDD 45	GDD 50	GDD 50
SWMREC	3648	3144	2352	2312
Fennville	3396	2903	2132	2106

Tree fruit
Insect pest development was relatively normal with no unusual pest outbreaks. Japanese beetle and rose chafer numbers were low. These pests have declined over the last several years. The cool season meant that there were no third generation of codling moth after Labor Day and third generation Oriental fruit moth was not a big problem either. 2009 was more of a disease problem year. The wet spring set up the early development of diseases such as apple scab, cherry leaf spot and bacterial spot in peaches that caused significant injury or crop loss.

Apricots were blooming by April 20 and generally suffered little spring freeze injury. Apricot yields and quality were good.

Peaches were little affected by the severe cold in January. Bloom was heavy and peaches seem to have suffered little damage from spring freezes. Many growers lost some fruit buds and bloom, but this generally reduced hand thinning after bloom. Peach leaf curl was not a big problem, but symptoms were seen on leaves that appeared in mid-summer. Bacterial spot was a common problem that continued to worsen as the season progressed. Some growers tried low rates of copper pre- and post-bloom to suppress bacterial spot, with some apparent success, but with some leaf loss due to phytotoxicity. Rusty spot was common in some plantings early. Brown rot was established early in some trees and rotted nearly all fruit on those trees, in spite of apparently strong fungicide programs.

Sweet cherries were at full bloom April 27. There was some winter damage, which resulted in poor development of fruit buds in sweet cherry and some tree mortality for young orchards. The cool, wet spring was good for bacterial canker development and collapse of spurs and branches due to bacterial canker was a problem in some plantings. Fruit brown rot and alternaria spot were common on fruit that cracked during rains before harvest. Generally, there was a good crop of sweet cherries and little brown rot during harvest.

Tart cherry bloom was in late April. There was scattered damage due to winter cold and spring frost. Many orchards had a light crop in the bottoms of the trees due to the freeze on April 23. Rains shortly before harvest helped to size fruit. A strong storm with high winds just before harvest (June 19) did blow down trees, blowing fruit off the trees and marking ripe fruit on the trees. Cherry leaf spot became a significant problem in some orchards, in part due to extended rain periods in the spring. Growers are reminded that resistance to sterol fungicide exists in cherry leaf spot and other fungicide materials need to be included in cherry leaf spot control programs.

In plums, bacterial canker symptoms on leaves and fruit caused fruit loss in some European plum orchards. Yields were fair to good for most plum varieties.

Apples bloomed in early May. Early development was scattered due to a generally cool spring with several warm spells. Heavy scab rains occurred on April 19 at tight cluster and April 27 during pink bud and early bloom. This was a foretaste of a wet spring marked by many long wetting events. Scab was common in area apple orchards. A Section 18 was granted for Kasumin (Kasugamyacin) for fire blight control. Bloom was generally cool. There were several rain events during bloom but they were generally cool. One warm, light rain occurred in isolation during an otherwise cool period on May 14 and resulted in a fireblight infection. This initial fireblight infection spread and many growers had significant fireblight in some orchards in 2009. Crop yields for 2009 were good.

Pear bloom was heavy and there were no significant problems in pears. A good crop of Bartlett was harvested in late August.

Small fruit
Many small fruits were affected by the winter cold and the cool growing season.

In blueberries, winter injury was widespread in central Van Buren County. The most common symptom was fruit bud death. Leaf and shoot development was normal. There was some shoot death, but no more than normal after a cold winter in fields that were not heavily pruned in the dormant season. The major variety affected was ‘Bluecrop.’ Other major varieties such as Jersey and Rubel showed less injury. This injury is distinctly different from bud death due to the infection of the bud by phomopsis. Many of the cold injured buds showed early swell, but no further growth. The areas most affected by winter injury were the low areas located away from Lake Michigan where cold air collected during the radiation freezes in mid-January. Growers reported lows of -20 to -24°F. The early heavy rains caught many growers before they had applied their first mummyberry sprays. Many blueberry fields were flooded from rains, forcing growers to rely on aircraft sprays for mummyberry control. In some fields, severe mummyberry shoot strike infections were restricted to early varieties that did not received their first spray before long rains during early bud break and shoot growth. Some growers reduced the number of sprays because of the weak blueberry market in 2008 and the large holdovers that promised weak prices in 2009. Mummyberry was a significant problem in 2009 for many growers. Phomopsis twig blight was a problem for a few growers but the canker and cane collapse phase of the disease was common. Phomopsis cane canker is usually serious following a cold winter. Anthracnose fruit rot was the most common fruit rot and was also the cause of some early twig collapse. This again was due to the wet spring. The cool spring also increased virus symptom expression. Blueberry shoestring, mosaic, tobacco ringspot and tomato ringspot were easy to find and growers reported large increases in these diseases. A virus survey of blueberry fields in Michigan found all the common viruses and also found new virus diseases such as blueberry shock and blueberry scorch as well as at least one unidentified disease.

Insects were generally not a problem in blueberries where controls were applied. Cherry fruit worm appeared first after bloom followed by cranberry fruitworm. Japanese beetle was generally not a significant pest. The cool growing season was excellent for fruit growth and quality. Early in the season, growers had to wait for fruit ripening and fruit maturity was somewhat delayed allowing for good spacing of harvests. Prices were very low in the mid-season for smaller growers who sold directly to smaller shipper packers, and some growers did not harvest all their fruit in the mid-season. Yields in fields not affected by winter injury were generally high and fruit quality was good.

Grapes have been the fruit crop most affected by the cool 2009 growing season. Widespread damage was reported in wine grapes from winter cold, but the severity varied widely. Initial growth was slow. Early diseases were not severe as the lateness of grape growth allowed them to miss many disease infection periods. Downy mildew and phomopsis were the major pre-bloom disease problems. Phosphorous acid materials were used in many vineyards to eradicate the early infections of downy mildew. Phomopsis shoot and leaf lesions were common, but few other diseases were common. Generally, there were few disease infections since bloom. Black rot fruit infections were common on backyard grapes. Botrytis fruit rots have been showing up in many vineyards even in ‘Concord.’ We have a very heavy crop of juice grapes. The recent warm dry weather of September may not be enough to ripen a very heavy crop. Niagara harvest began this week and Concord harvest is projected for early October when sugar levels are high enough.

Early insect pests such as climbing cutworm and flea beetle were not wide spread severe pests. Cutworm is no longer the severe pest that it was several years ago, but flea beetle seems to becoming more common. Grape berry moth developed two generation in 2009. Berry moth numbers were generally lower than in previous years but some vineyards did have high populations. The third generation was also very variable and a late harvest of a large crop may result in the rejection of some loads. Japanese beetles were not a major pest and grape leafhopper numbers were generally low all season. Multicolored Asian ladybug populations are high in some soybean fields in Berrien County. Growers should scout fields adjacent to grape vineyards. These beetles will move into fruit planting and are an unacceptable contaminate at harvest time.

Strawberries suffered some damage during bloom. Harvest was delayed in the northern areas of the region by the cool spring. Because of the cool weather, fruit size was not large and fruits were slow to ripen. Growers had a hard time supplying demand and often needed to close early or remain closed for several days to allow fruit to ripen. Harvest quality was generally good. Drought conditions after harvest and widespread potato leafhopper injury stunted some field after renovation.

Raspberries suffered some injury from the cold winter, but generally early season growth was good. Anthracnose was common in poorly sprayed summer berries. Bloom and early growth were good, but mid- and late harvests declined with the dry conditions in the mid-summer. Fall bearing raspberry harvest has been good so far with few reported fruit rots.

In blackberries, winter injury caused severe damage to thornless blackberries, killing many canes to the snowline. Damage was not always apparent at the beginning of growth but was soon apparent in the widely scattered weak growth. Thorny blackberries such as Illini Hardi did much better and harvested a full crop in a scarce market for good prices.

Cranberries did well as most plantings were under the snow during the extreme cold of mid-January. Some winter injury was reported where snow drifted in the beds causing problems with early spring growth. It appeared that the fruit buds in these areas were killed. No problems have been reported in cranberries and there appears to be a good crop awaiting harvest in October.