Harvest of 'sweets' meanwhile could start as soon as July 1

Nearly too small to be seen by the naked eye, the two-spotted spider mite is gaining a foothold in county orchards.

Crews from the Northwest Michigan Horticultural Research Station were in Northport and Leland Township yesterday sampling for mites, who are making their presence known as recent warm temperatures and drought-like conditions persist.

“We usually don’t have to worry about them this early in the season,” said Nikki Rothwell, research station director. “But with the hot, dry conditions they’ve moved in early.”

Spider mites typically stay in undergrowth and grass until later in the season. This year, however, they are moving up the center of the trees where they suck the liquid from leaves, bringing the process of photosynthesis to a halt and damaging trees in the process.

Mite sampling is painstaking and involves collecting leaves that are brought to the laboratory and brushed with a “mite brush” onto an oiled plate. The plate is then placed under a microscope for a better view.

“Our crews really hate mite sampling,” Rothwell said.

Findings from the samples will be used to help advise growers on when and whether to apply “mite-a-cide” in their orchards. This is a tricky venture given the short growing season and the fact that the mites don’t usually gain significant ground this early in the year. They are known to produce as many as five generations during one growing season.

“It will require growers to make decisions on the fly,” she said.

Some products are limited to application a minimum of 28 days prior to harvest. A newer, lesser known product is now on the market, which requires only seven days leeway. Unseasonably warm temperatures have hastened the maturation of the sweet cherry crop, which some growers have indicated they could begin harvesting as early as July 1.

“We have some test plots (at the research station) with sweet cherries I could eat right now,” Rothwell said. “But these are early experimental varieties.”

The sample findings will be available to growers on the station’s code-a-phone as well as the fruit network reports available to growers online.

The fieldwork is being done on the eve of the Cherry Industry Administrative Board’s release of this year’s fruit production estimate. The processor’s estimate was scheduled to be released yesterday afternoon.

Meanwhile, the county strawberry harvest is in full swing.