|
|
|
Vegetables
Volume 59 Number 15 Date 08/14/2014 ONION MAGGOT - Late-summer flies are expected to begin emerging across southern and central Wisconsin in the next two weeks, following the accumulation of 3,230 degree days (base 40°F). Larvae from this third and final generation will overwinter in cull onions or bulbs left behind in fields. Proper sanitation and rotating to a non-crop host are recommended for growers who experienced onion maggot problems earlier this season. CABBAGE LOOPER - Migrants are appearing in low numbers in black light traps. Although the full extent of the current flight is unknown, weekly scouting is advised this month and through early September. A 10% infestation threshold should be used from early heading until harvest to protect the market quality of cabbage. The same threshold applies to broccoli and cauliflower once flowers or curds begin to develop. SQUASH BUG - Adults and nymphs are still very active in pumpkin and winter squash plantings across the state. Vegetable growers should continue to inspect the undersides of leaves for the metallic bronze eggs deposited in groups of 15-40 between leaf veins or on stems as long as small nymphs are present. Squash bugs are capable of damaging mature fruit, thus control may be needed as the crop nears harvest. Organically acceptable materials include PyGanic, insecticidal soaps and certain oils. -- Krista Hamilton, DATCP Entomologist 
|
|