Southern California - April 15, 2013
This report covers conditions and observations made between Monday, March 25 and Sunday, April 14, 2013. The next report is scheduled for Monday, April 29, 2013. 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 southern region present a down-the-row view of the Butte and Padre in the Chowchilla area of Madera County, followed by the developing nuts of the Nonpareil and Padre in Kern County.
Weather in the southern San Joaquin Valley turned a bit cloudy and windy during the period, with rain reported during the final week of March and first of April. Morning low temperatures remained at comfortable levels, with readings reported predominately between the mid 40’s and low to mid 50’s. While the preponderance of daily maximum temperatures were reported in the 70’s, coolest readings in the upper 60’s were recorded on the cloudier, wetter days with warmest readings reported under clear skies in the lower 80’s.
Some degree of rainfall was reported in all areas of the region, with 0.2 to 0.4 inch reported in the Madera and Fresno County areas. Precipitation was a more sparse in the region’s southern areas where official reports placed totals between a few hundredths of an inch to as much as 0.25 inch. As with the northern and central growing regions, blustery winds blew through the southern San Joaquin during the first week of April, particularly in the northern half of the region. Sustained speeds in excess of 20 mph were reported in Madera and Fresno County, with gusts reaching in excess of 35 mph in the windier areas. While observers reported some degree of nut loss and blown-over trees, the overall losses have been minimal.
Observers are reporting excellent nut development under the near-perfect growing conditions. While the winds and rain received during the period caused growers to alter their work plans, there have been little to no adverse impacts on the crop. Growers have been fertilizing and irrigating their orchards to support the developing crop and spent the days following the blustery winds removing blown-over trees and broken branches from the orchards. Irrigation schedules were altered in advance of the winds as growers worked to provide better anchoring for their trees.
Irrigation has become a prime concern for the region’s growers as they face restricted supplies of surface water from irrigation districts. This has increased reliance on privately owned deep wells. Growers have been re-working existing wells and preparing additional wells as they struggle to ensure adequate water supplies. Some have reported rising bicarbonate levels in the water supplied by their wells, which can be toxic to the trees. Nut development and tree health to this point in time is reported as being quite good. The above normal temperatures the region has experienced this year has resulted in excellent growth rates and nuts that are quite well sized for the date.
While little to no evidence of infectious disease is found in the region’s orchards at this time, growers are treating plantings with a history of Scab and Rust infections. Treatments for these potentially serious summer-time fungal diseases must be completed prior to the visible infection can be observed and growers have begun treatments to their most susceptible plantings. There have been reports of Leaf-Footed Plant Bugs in the Sanger area of Fresno County. Growers are monitoring their orchards for signed of this potentially serious pest, particularly in their Sonora, Aldrich and Fritz plantings which the insect prefers. Growers in Madera County have also reported increasing activity of web-spinning spider mites. While not at treatable levels, growers will be monitoring their orchards, hoping that predatory insect populations can maintain mite levels below economic thresholds. Pest control advisors are reporting very high counts of Navel Orange Worm in the typically used egg traps. For the first time, growers and their advisors have the ability to deploy pheromone traps to monitor Navel Orange Worm adult populations within the orchards, which will be very useful in timing proper treatments to control this serious pest.
Growers with plantings of the Carmel variety have noted that Non-Infectious Bud Failure has become quite pronounced this year, with most of the region’s planting showing some degree of symptoms. Delayed and altered growth are typical symptoms which can significantly reduce crop loads. The Carmel is most susceptible to this genetic disorder, which never gets better once it’s expressed in the tree.
Growers will spend the next month intent on meeting their orchards water requirements in order to safely get the crop to harvest.
Current weather at the National Weather Service
Photos: Ernie Reichmuth and Gerald Guthrie, 4/15/13
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