Henry Carrasco, agronomist and PCA with Western Farm Service’s Salinas branch, said the sudden heat and increased irrigation/fertility have caused lettuce and other crops to develop quickly. As a result, by July 19 the Central Coast vegetable harvest was up to a week ahead of schedule in some cases. Many PCAs were changing their recommendations to treat pests such as aphid and leafminer with products that have shorter pre-harvest intervals.

“With the heat, plants are moving along more quickly and growers are irrigating and fertilizing more, so we’re having to adjust our days-to-harvest materials,” Carrasco says.

In some cases growers are choosing 7-day PHI materials, rather than more economical standards such as diazinon or dimethoate, which have a 14-day PHI. These shorter PHI products typically cost 25 percent more per acre, he says, which is tough for growers to absorb in today’s market.