Diseases making appearances

Insect pests continued to remain relatively light in major vegetable growing regions, although coastal PCAs reported that a delayed onset of disease pressures appears to giving way to more incidence of downy mildew.

PCAs said downy mildew showed up in lettuce in early to mid-August and has remained though pressures have been moderate and kept in check with regular sprays. In addition to standard materials, growers and PCAs were also rotating in a number of new materials available in California for disease control this year.

“There are plenty of materials, and we haven’t had any severe downy mildew pressure, which really drives the whole disease program in lettuce,” said Jim Dana, marketing manager for the coastal division of Western Farm Service.

In other regions of the state, sources in the Sacramento Valley reported that powdery mildew has become a major concern for many processing growers in the region. Fruit ripening had been slow on tomatoes in late July into mid-August, but UC Farm Advisor Gene Miyao said it appeared to be hastening for September deliveries.

Further south, the San Joaquin Valley canning tomato harvest was about half finished in early September. The crop had been about a week behind schedule going into August, but appeared to be normalizing by September. While contracted acreage was down nearly 10 percent in 2008 to 276,000 acres, strong yields overall pushed up production to meet levels near contracted production of 11.6 million tons. Crop conditions have generally been excellent with few reports of insect problems.

Processing tomato growers are increasingly turning to drip irrigation and other production strategies to boost tomato yields in the San Joaquin Valley, according to several PCAs.

On the insect front, sources said that thrips continue to show up as they have in recent years and lettuce aphid is also requiring attention, though worm pressures remain remarkably light this year.

Some freeze-induced delays in spring planted crops continue to make their mark with delayed maturity in some Central Coast lettuce, broccoli and cauliflower fields. Despite those hiccups, PCAs have described growing conditions as good overall, and by Sept.1, sources said harvests were catching up and back on track.

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.