Forages & Grains
Volume 58 Number 18 Date 11/21/2013
POTATO LEAFHOPPER - The first distinct migration of 2013 occurred from May 14-20 and leafhoppers were widely distributed over the southern two-thirds of the state by early June. Nymphs appeared in second crop alfalfa by June 16. Surveys found low to moderate numbers all season long, with representative counts consistently averaging below 1.9 per sweep statewide. Economic levels of 2.0 or more leafhoppers per sweep were not documented in any alfalfa field sampled this year and treatment was generally not required.
ALFALFA WEEVIL - Larvae were collected for the first time this season in Grant County on May 13, more than one month later than in 2012. Development accelerated in May and weevils were prevalent by early June. Persistently cold, rainy weather and competing corn and soybean planting schedules delayed the first alfalfa harvest and defoliation became pronounced in some fields. Counts peaked from June 6-13 at 5-10 larvae per sweep. Carryover of weevils into the second crop was common this year, but the damage subsided by early July as remaining larvae pupated.
-- Krista Hamilton, DATCP Entomologist
CEPHALOSPORIUM STRIPE - This fungal vascular wilt of wheat was verified from one wheat field in Calumet County in 2013, representing the second confirmed report in Wisconsin. The infected sample was collected on June 27 as part of standard wheat disease surveys. Cephalosporium stripe was first documented in the state two years ago in Rock County. The recent detections have no regulatory impact since the disease is widespread in the U.S. and occurs in parts of Canada.
-- Anette Phibbs, DATCP Plant Pathologist