Favorable Conditions Yield Good Harvest for Valley Almond Growers

Almond expert Walt Bentley offers tips at a past field day.

Editor’s note: This week, we are featuring a guest blog by one of our long-time collaborators, recently retired UC IPM entomologist Walt Bentley, whose specialty included managing pests in almonds.

For San Joaquin Valley almond growers, the 2012 season would be considered a normal year. In fact, across California you could say producing 2 billion pounds of almonds for a second straight year is becoming the norm across California.

Yes, conditions were good this season for growers to approach the record 2.03 billion pounds of almonds harvested in 2011. The crop has shaped up well again this year.

Spider mites were an issue in 2012.

The spring was warmer than in 2011.  We did have some rain and cold weather during bloom. However, I think the wintry-spring weather reduced nonpareil pollination and, ultimately, hurt this season’s yields for that variety.

Certainly the summer was above average with 25 days of 100-plus temperatures in July and August. This hot weather did impact trees, leading to  water stress and subsequent spider mite problems.  Spider mites became an issue during the hullsplit period. Orchards that are well irrigated usually don’t suffer from mite problems.

Wintry-spring weather hurt nonpareil pollination.

Remember, mites reproduce fast during the warm-weather months from June to September. In fact, mites can develop within a week with 8 to 10 generations a season, according to the University of California Integrated Pest Management.

High yields expected in '12.

Mites will damage foliage by sucking cell contents from leaves. Leaves can become yellow and fall off. When there are large populations webbing can be found on the tree terminals. There can be a crop reduction in crop a year after the damage occurs.

I don't believe there were any surprises other than the poor yields on nonpareils. Overall, yields of the hardshell varieties are good. Nonpareil yields are more varied. Next time, I will recap the pest management issues for the 2012 season.