Water Management Crucial Before Almond Harvest

Water, water and more water.

That’s what field scout Jenna Mayfield sees in almond orchards throughout the Valley.

In fact, Jenna hasn’t stepped into many orchards lately because of the wet and muddy conditions.

Almond orchards are getting the last irrigation before harvest.

“Growers are doing a lot of work to prepare for hull split,” she says, pointing out that the start of harvest is just about a month away. “A lot of people are going to start managing their watering.”

Yes, timing the last pre-harvest irrigation is important, according to David Doll, University of California Cooperative Extension adviser and pomologist for Merced County. Of course, Dollis better known as the Almond Doctor among local farmers.

He points out that growers first need to set a target harvest date before mapping out their final watering schedule. The last irrigation should end about two weeks before the start of harvest activities to allow “dry down” of the trees to minimize bark damage from shaking. Also, trees could be damaged at the roots if the ground is too wet during shaking.

One thing to note is the dry down period depends on the type of soil in the orchard. Sand requires less time for the soil to dry out while clay needs more time.

Proper "dry out" of soil can avoid tree damage during shaking.

The reason is sandy soil has a lower water holding capacity. In that case, growers might need to irrigate between harvesting the different varieties in the orchard. In his Almond Doctor blog, Doll explains “proper water management between varieties is just as critical as water management before harvest because during this period the tree is developing the fruit bud for the coming season. Any moderate to severe water stress during this period will reduce the formation of fruit bud.”

When determining the harvest timing, growers should consider:

·         The need to avoid damage from ants or navel orangeworm.

·         The ability to remove the most nuts and maintain yield and quality.

·         Keeping tree damage at a minimum

·         Access to harvesting equipment

Growers should watch for spider mites.

 On the pest front, Jenna says the biggest worry is spider mites due to the heat wave. The pests have been dormant so far, but everyone is bracing for a potential outbreak.

The hot weather continues to drive up lygus populations in cotton fields. Field scout Damien Jelen has snagged as many as 9 to 12 lygus bugs per 50 passes of his sweep net – more than twice the treatment threshold for this time of year.

One grower already has treated for lygus. Damien says growers will continue to closely monitor for lygus – as well as the hot weather.