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.

This report’s photos for the central region present an example of a particularly strong Nonpareil planting in the Los Banos area of Merced County and the hull split observed in a Nonpareil planting in the Westley area of Stanislaus County. As a comparison, our final image shows the splitting hulls in a Nonpareil planting in the foothills area near Hickman in eastern Stanislaus County, which normally runs a week or so behind the Westside. Our featured image shows a backhoe preparing the individual tree sites for an orchard to be planted this winter.

Following an extended period of relatively mild conditions during May, temperatures were much more variable during June, with generally higher temperatures dominating much of the period. Temperatures ranged from the lower 80’s in the period’s opening days to the as high as 110 degree during the final week of the month. The region briefly escaped the impacts from the heat on June 10th, when a weakening weather system dropped a few hundredths of an inch of rain in the northern Stanislaus and San Joaquin County area. Meanwhile, morning lows followed a similar trend, with readings ranging from the lower 50’s to the mid and upper 60’s. Winds during the period were relatively calm, rarely exceeding 10 mph.

The hull split has begun in the northern San Joaquin Valley. First nuts to split were observed along the I-5 corridor on the west side of the region during first week of June, 5 to 7 days ahead of last year. Splitting hulls can now be observed in all areas of the region, prompting growers to begin their hull split treatment programs for Navel Orange Worm, NOW, control. Tractor-drawn spray rigs can now be observed in many orchards around the region as growers work to control this serious insect pest. The poor mummy shaking conditions during the winter of 2014/15, resulting from the lack of rainfall has prompted growers to be very mindful of the potential for damage to the 2015 crop and they have been monitoring their orchards closely. Pest Control Advisors have been variable trap counts, in both the traditional egg traps used to monitor egg laying by female NOW moths and the new pheromone traps used to monitor populations of the male moths.

As has been reported continuously this year, water remains a focal point for growers in the central region. An announcement by the State Water Resources Control Board curtailing diversions of water for those with rights dating back to 1903 called water supplies for several irrigation districts, as well as landowners drawing directly from river flows into question. With the start of the hull split, growers can now withhold water from their orchards, increasing the stress levels. However, most are reluctant to do so, wanting to preserve as much weight in the kernels as possible. In many cases around the region, stress levels are already running high. This is best demonstrated in the first of this report’s photos, wherein the trees are carrying a good crop, but growth rates have been limited by the lack of water. Spur development, the growth that produces buds for the following crop varies with the variety. However, given the proper nutrients and adequate water, the tops of the trees will always have a cover of lush growth. If not, it is a sign that spur development within the canopy is also limited and that the potential production of subsequent crop has also been affected.

Observers are reporting that growers in the Le Grand area of Merced County have seen the productive yields of their wells reduced over the past months as water levels drop. Growers in districts with reduced supplies of surface water available are working to secure from other sources. Some districts are making limited supplies from wells available in order to get the orchards through the harvest.

Growers along the I-5 corridor, where the crop is more advanced are expecting to begin shaking in mid-July, commensurate with last year. Many are already preparing harvest equipment for the upcoming harvest. Field operations during the coming weeks will focus on making sure that the orchard floors are prepared to receive the crop. Ant bait applications have already begun in orchards with excessively high populations, as have a few treatments for web-spinning mites, where needed. Beyond harvest preparations, growers will continue to make the hard decisions required by the limited amount of water available to get them through the balance of the season.

Current weather at the National Weather Service
Mel Machado
Jereme Fromm
KC Stone

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