Sep 6, 2016

MSU studying high-density sweet cherries

High-density sweet cherries are one of the first research plantings to be funded by the Michigan Tree Fruit Commission (MTFC), and the project is rolling. More than 700 trees were planted at the Clarksville Research Center this spring, and 300 at the Northwest Michigan Horticulture Research Center near Traverse City.

The young trees are doing well, despite the dry weather.

“Dry weather means you have lots of sun,” said Greg Lang, Michigan State University professor of tree fruit physiology and lead researcher in the study.

As long as the roots have water, the leaves are photosynthesizing to provide energy for growth, Lang said. The dry weather also means less disease, which helps the trees establish.

The big goal for Lang and his team, which includes graduate student Jimmy Larson and student assistant Lance Wheatley, is to ensure the plants are given the right amount of drip irrigation to nurture new growth.

“Dwarfing trees perform better with a little water every day in irrigations of fairly short duration,” Lang said.

The $24,000 MTFC grant pays for trees, irrigation and trellising. The research locations are a good fit for the two areas in Michigan where sweet cherries are grown for the fresh market: Traverse City and west-central Michigan’s Fruit Ridge.

The research will look at the next generation of high-density training methods. The goals are better training efficiency, ways to partially mechanize pruning and eliminating ladders for easier, safer hand harvest. Some systems may also ensure a more even light distribution, more even ripening and large, high-quality fruit. The largest fruit picked this summer in an earlier trial was nearly an inch and a half in diameter.

The work goes hand-in-hand with the self-driving orchard platforms MTFC has funded for the two research stations. The orchard platforms will speed up the pruning, training and harvesting of the high-density blocks.

The new plantings all have Gisela rootstocks, and researchers will evaluate how the rootstocks perform in different systems. The semi-vigorous Gisela 6, semi-dwarfing Gisela 5 and the dwarfing rootstock Gisela 3 are all part of the study, with control trees on seedling Mazzard rootstocks.

By this fall, “we hope to see two strong leaders on every tree,” Lang said. “These will be the structural foundations for the future fruiting wall tree architectures.”

– Dean Peterson, FGN Correspondent