June 29, 2015

This report covers conditions and observations made between Monday, June 1 and Sunday, June 28, 2015. The next report is scheduled for Monday, August 3, 2015. However, in the event of any significant occurrences prior to that date, this site will be updated as soon as possible.

Taken in Madera County, the first of our photos for this report present an orchard west of Madera under increasing water stress and a planting near Chowchilla receiving a treatment to control Navel Orange Worm. Our third image shows the degree of damage incurred in an orchard in Tulare County, the result of irrigating with excessively salty water, while our featured image shows the hull split of the Nonpareil in Tulare County. Note the degree of wilting obvious in the first image, where the amount of water applied has been greatly reduced.

The relatively mild temperatures recorded during May gave way to much hotter conditions during June, particularly in the period’s final week. Daytime highs in the opening days of the period continued the trend established during May, with readings widely reported in the 80’s. Temperatures rose dramatically, however, with readings rising to 105 degrees by June 8th, then varying between the mid 90’s and 106 degrees for the balance of the period. Morning lows were also reported at warm levels, with readings ranging between the upper 50’s and upper 60’s. An unusual point in the southern region’s weather included showers produced by monsoonal moisture flung northward from Mexico, which brought a few hundredths of an inch of precipitation to isolated areas of Kern County on June 10th.

Hull split has begun the southern San Joaquin Valley, heralding the approach of the 2015 harvest. Treatments to control Navel Orange Worm, NOW, started at mid-month in the most advanced plantings as growers work to reduce populations of this serious insect pest. The poor mummy shaking conditions during the winter of 2014/15 has growers concerned about the potential for damage in the 2015 crop. Many are planning on multiple treatments, hoping to “bracket” the timing of the insects’ susceptible life stages to ensure adequate control. Growers are also adding materials to control web-spinning mites in plantings with increasing populations and/or weak predator populations. Time is also being dedicated towards bait applications designed to control damage species of ants, particularly Southern Fire Ants, which can feed on the nuts as they lay on the orchard floor during the harvest. All of these treatments are being conducted between operations need to prepare the orchard floor for harvest as well as irrigations.

Water concerns continue throughout the region. Observers are reporting that growers in Merced and Madera counties are facing particularly critical issues as the productive yields from their private wells continue to fall. Both areas are totally reliant on groundwater this year, given that there are no supplies of surface water available from local irrigation districts. However, recent precipitation in the Sierra Nevada watershed serving as the source of water for the Fresno Irrigation District has allowed the district to provide water for a single irrigation. Nevertheless, ground water remains the prime source of water needed to produce the 2015 crop. As shown in the photos accompanying this report, orchards around the region are showing significant signs of water stress. Salt damage, wilting trees and pre-mature defoliation can be observed in a significant proportion of the region’s orchard, particularly in Madera County.

The next few weeks will see a continuation of harvest preparations. Growers are anticipating sending shakers into the first orchards between the 15th and 20th of July, 5 to 7 days ahead of last year’s timing.

Current weather at the National Weather Service
Ernie Reichmuth
Matt Willson

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