Those interested in organic farming were dealt a good dose of tips in Tulare on topics ranging from use of cover crops, the future of bees, organic production of alfalfa and other subjects.

They also heard from a grower panel about the good and bad of growing organic, including the challenges of paperwork, finding labor and the scramble to meet market demand.

The program on Sustainable/Organic Production in the Southern San Joaquin Valley was presented by the Organic Fertilizer Association of California and the California Association of Pest Control Advisors for Tulare and Kings County.

Eric Mussen, an entomologist with the University of California at Davis, made it clear that “organic pesticides are not benign to honeybees” and that honey bees remain at peril of being compromised by even small doses of pesticides. “No pesticide is benign to bees or other living organisms,” he said.

At the same time, he said there are steps that can be taken to protect bees, including better communication with bee keepers so they can take steps to protect them.

“For example, hives can be covered temporarily to avoid pesticide exposure for a half or even a whole day” during pesticide applications, Mussen said.

The bees are vital for the pollination of many crops, most notably almonds, but their numbers have been diminishing over time – he said as many as 30 percent of colonies are lost each year.

“Sub-lethal effects can be subtle,” he said, leading to malformation of bees, shortening of the adult life span, interference with larval development and other hormonal effects on the brood.

Bee toxic pollens can be collected from flowers sprayed with pesticides or from systemic pesticides provided to the plant on the seeds, through the soil or in irrigation water. Leaky chemigation systems give bees the highest doses, Mussen said.

Diminished availability of some flowering plants is another problem, Mussen said. That can be countered in a measure with use of cover crops.

Tom Johnson, with Kamprath Seed, talked of the value and challenges of growing cover crops and how they can be used to attract beneficial insects, cut down on dust and mites and otherwise benefit crops.

Johnson defines cover crops as generally “non-economic” but having value, when planted within a permanent crop or in rotation with field crops. They can control erosion, add organic matter to the soil, add or conserve nitrogen and improve soil structure or water infiltration.

Challenges of cover cropping in Central California include determining whether that is the best use for the land, water availability, availability of equipment to manage the cover crop and the time spent doing so.

Cover crops can be plowed down, they may reseed themselves and they may be perennial, Johnson said. An advantage of a plow-down cover is that it is the easiest to plant, establish and manage and it offers flexibility for rotation and “fine tuning,” he said.

Cover crops can also provide something to drive on during the wet season, Johnson said, along with reducing dust in the summer, and they can be managed for frost protection.

One slide he showed depicted a cover crop growing on a road through an orchard. Johnson pointed out some irrigation may be needed to keep the cover alive during the searing Valley heat.

Covers can also be used to reduce water runoff and to act as buffers. And alfalfa can be used as a trap crop for lygus in cotton and strawberries.