As of May 28, no volunteer beans or rust sightings have been reported from the region. Base seeding rates on number of viable seeds needed to obtain a desired target plant population. As of May 28, no foliar onion diseases have been reported from the region. With the cool, moist weather that we have had lately, carefully scout transplanted and seeded fields for early signs of downy mildew. Symptoms appear on older leaves as elongated patches which are slightly paler than the rest of the foliage, and may become covered with a violet gray mycelium and spores.
Leaves generally fold over at affected areas and leaf tips die.
Mike Bartolo reports that thrips populations are increasing on the transplanted onion crop in the Arkansas Valley. Levels have not yet reached economic thresholds. However, growers should begin monitoring levels on a regular basis. Carefully follow label recommendations when applying postemergence herbicides to onions to avoid leaf damage which can predispose plants to colonization by pathogens which cause diseases such as Downy Mildew, Purple Blotch and Botrytis. Do not treat onions that are already injured by sand, insects or diseases.