home Susbcribe About Us Contacts Past Issues Print this issue


Looking Ahead

Forages & Grains

Corn

Soybeans

Fruits

Vegetables

Nursery & Forest

Degree Days

Forages & Grains
Volume 61 Number 19 Date 12/08/2016


POTATO LEAFHOPPER - Populations in alfalfa remained low to moderate all season long. Migrants first arrived in Wisconsin during the week of May 19-25 and were distributed in low numbers across the southern half of the state by early June. Nymphs appeared in second crop alfalfa by June 14. Economic counts of two or more leafhoppers per sweep were not observed in any of the 591 alfalfa fields surveyed in 2016, and leafhopper control was not needed.

ALFALFA WEEVIL - Although a wet weather pattern in late May disrupted the first alfalfa harvest and permitted weevil populations to escalate, few growers reported significant problems. Larval emergence began in southern Wisconsin by May 11 and weevil defoliation subsided by late June as larvae pupated.

PEA APHID - Counts peaked at 28 aphids per sweep during the last week of May then abruptly declined after the first cutting. Surveys yielded very low aphid populations for the balance of the season and no direct damage to alfalfa was attributed to this pest in 2016.

-- Krista Hamilton, DATCP Entomologist


CEREAL CYST NEMATODE - Twenty-one soil samples collected from corn, 89 samples from wheat, three samples from oats, and one sample from a soybean field were analyzed at the Plant Industry Lab for cereal cyst nematode, Mediterranean cereal cyst nematode, and Mexican corn cyst nematode. All 114 samples were negative for the three target exotic species. Although no targeted nematodes were detected, 28% of the samples contained non-targets, including Cactodera rosae, a cyst nematode pest of barley in Mexico never before reported in the United States. Identification was confirmed by an authorized USDA nematologist. The significance of this find is still being determined, but no regulatory action is required.

Other nematodes found were the soybean cyst nematode in 29 fields, clover cyst nematode in five fields, and nematodes in the genus Cactodera in 12 fields. Sampling was conducted in the state's leading wheat producing counties: Brown, Calumet, Columbia, Dane, Dodge, Door, Fond du Lac, Green, Jefferson, Kewaunee, Manitowoc, Outagamie, Racine, Rock, Sheboygan, Walworth, and Winnebago.

-- Anette Phibbs, DATCP Plant Pathologist