West central Michigan tree fruit update
Spring is finally arriving to west central Michigan.
Weather and crop development
Last week was relatively warm and dry. Temperatures were mainly in high 50s during the first part of the week. Over the weekend temperatures reached the 70-degree mark. Low temperatures were more unsettled ranging from a couple of nights with temperatures below and at the freezing mark up to the mid-40s. In terms of degree-day accumulation, this area is still 19 days behind normal. There was very little rain. Soils are getting dry since the evaporation exceeded precipitation. Rain at this point would certainly help newly planted trees as well as incorporate applied herbicides.
There has been an accelerated pace of fruit bud development. With temperatures into the 70s, buds have been going through two developmental stages in a 24-hour period. Apples are mainly in tight cluster with signs of some early flower bud separation within a cluster. By tomorrow, early blooming varieties will be in open cluster. Pears are in tight cluster with some early separation. Peaches are at late calyx green to early calyx red stage and showing half-inch long leaf tissue. Sweet cherries have been going through developmental stages at lightning speed. Tart cherries are showing white bud with possibility of seeing first bloom by tomorrow on sandy sites and in warmer parts of the district. Yesterday morning they were showing white bud and last night, first bloom started to appear. Apricots are in bloom. European plums are in open cluster and Japanese plums are starting to bloom.
West Central Michigan growing degree day totals since March 1, 2011. As of Monday, May 9.
|Last Week||Since 4/1|
Scouts are reporting increased insect activity. Pear psylla is observed flying but no eggs yet. Low numbers of European red mite eggs are present in many area orchards. Scales on plums and peaches have been found in a few blocks. We had first catches of spotted tentiform leafminers and redbanded leafrollers. This morning a call came in reporting finding 3 plum curculios in a trap.
Light rain that sprinkled across the area did not last long enough to satisfy requirement for scab infection. Rain produced light spore discharge. I am anticipating very heavy spore discharge with rain forecasted for the rest of the week. Historically this period between tight cluster and bloom produces the heaviest spore discharge. With stone fruit blooming and/or approaching bloom brown rot (Monilinia fructicola) control has become the focus of our attention. Plum growers are advised to spray for black knot (Dibotryon morbosum). With each wetting event, ascospores are ejected into the air and deposited onto young developing tissue.
More information can be found posted at Extension News for Agriculture website.