Archive for May, 2012

The lovely month of May

May it’s a very busy month for a Plant Doctor in California. All pests seem to really get going in May. This year with the dry winter the herbicides used to keep weeds from coming up early didn’t work as long as hoped. That, along with rain in April brought up a flush of weeds that grew faster than most growers could keep up with. Rain delayed many sprays and weeds grew while it was too wet to spray or while applicants tried to catch up from delays.

May is also the time when many insect pests in the tree and grape crops hatch. Most tree fruit and nut crops get what we call a “May spray” because worms are hatching out ready to start feeding on the developing fruit or nuts.

Peach Twig Borer on a peach

Worm damage on grape flower

At the same time the grapes are blooming (yes, grapes have flowers) and sprays to combat mildew and worms also need to be applied on those crops as well.

We use traps to catch the moths that lay the eggs for the worms to tell us when they are present and use weather data and calculations to determine when the eggs will hatch. That way we are only spraying when a hatch is going to happen. We can tell based on the numbers of moths we catch and what kind of damage we had last season to let us know if we should spray or not. Sometimes we can skip the May spray and wait to see if the next generation hatch will be more and target that spray.

At the same time this is going on, workers are in the fields thinning the fruit, clearing away extra shoots and leave from around the grape bunches, driving tractors to clean the weeds from between the vine or tree rows, irrigating, etc. We have to make sure whatever we do it is safe for the workers.

There is a lot of juggling of people, equipment and figuring out what to do and when. Sometimes I wonder how we manage it all but it gets done and beautiful safe, nutritious fruit is provided to a hungry society.