|Young almond trees were whipping in the wind last week.|
|Heavy canopies can increase humidity in almond orchards.|
|Mist from sprinklers also can create orchard humidity.|
Here’s what UC IPM says about rust: “The development of rust is favored by humid conditions, and the disease becomes worse when rain occurs in late spring and summer. Trees can be defoliated quickly when rust becomes severe. The rust fungus survives from one season to the next in infected leaves and possibly also in infected twigs. The disease causes leaves to fall prematurely and will weaken trees, reducing the following year's bloom if not controlled. Rust is often observed in second- and third-leaf nonbearing orchards where fungicides have not been applied.”
|Rust is caused by humid conditions. - UC IPM photo|
UC IPM points out that orchards with a history of rust, should “apply sulfur or manebfive weeks after petal fall and follow four to five weeks later in late spring and summer with a Quinone outside inhibitor fungicide (FRAC Group number 11) to control leaf infections. Two or three applications may be needed in orchards that have had severe rust problems.”
On scab, UC IPM says: “severe scab infections cause early defoliation; if left uncontrolled for several years, infected trees become weakened. The disease often occurs in sprinkler-irrigated orchards where water reaches foliage.”
|Scab can cause early defoliation in almonds - UC IPM photo|
Jenna reminds growers to be proactive and monitor their orchards regularly. “Stay ahead of the game,” she says. That investment in time will yield dividends at harvest time.
Field Day Alert: Here’s a final reminder about Tuesday’s Cotton Field day scheduled from 10 a.m. to 12:30 p.m. at the D&V McCurdy Farm, Highway 33 in Firebaugh. Cotton growers can learn valuable insights about insects and water and weed management from these speakers: Dr. Pete Goodell of UC Statewide IPM, Dan Munk of UCCE Fresno County, Kurt Humbree of UCCE Fresno County and Bob Hutmacher of the Westside Research and Extension Center. Mark the date on your calendar. For more information, contact Marcia Gibbs of the San Joaquin Sustainable Farming Project at (530) 370-5325. See you there.