Central California - September 3, 2012
This report covers conditions and observations made between Monday, August 6 and Sunday, September 2, 2012.
The next report is scheduled for Monday, October 1, 2012. However, in the event of any significant occurrences prior to that date, this site will be updated as soon as possible.
Taken in the Ripon area of San Joaquin County, the first of our photos for the central region presents a close up of the spider mites infesting many orchards around the region. Note the heavy webbing and the concentration of mites at the tip of the uppermost leaf. Our second image shows a sweeper preparing the crop for harvest in a heavily mite-infested orchard, which has lost a significant proportion of its leaves, while our final image displays the hull split in a healthy example of the Butte variety east of Modesto.
High temperatures dominated the weather during much of August, providing uncomfortably hot conditions for growers and the region’s orchards. Daily maximum temperatures rose above the 100 degree mark for approximately ten days during the first half of the month and remained in the mid and upper 90’s until the final days of the period. At the same time, morning lows increased from the norm in the upper 50’s to lower 60’s recorded early in the period to the lower 70’s during the hottest days of the month. Minimum readings then returned to their normal values during the final week of the period.
Harvest operations proceed at “full throttle” during the transition from August to September. Throughout the region, growers have been busy harvesting the Nonpareil variety and are quickly moving into the pollenizer varieties as well. Growers are reporting that the high temperatures have taken a bit of a toll on the crop harvested thus far and on the orchards. Combined with the depleted soil moisture levels as a result of the dry winter, which growing season irrigations have not been able to fully compensate for, the high temperatures experienced during the period have increased the moisture stress in many orchards. The dry, stressed conditions and high temperatures have over-powered previously applied control measures for spider mites, producing blossoming mite populations within many orchards. This has caused a significant leaf loss in the most heavily infested plantings.
Elevated stress levels have also impacted the Nonpareil crop harvested thus far. Growers around the region are reporting that kernel moisture levels are running at very low levels. The standard moisture level for kernels is 5.0%. In the 2011 harvest, when delayed maturity levels produced a situation in which it was difficult to get kernel moistures below 5.5%, moisture levels in many orchards this year are running down to 4% and lower in some cases. The end result is reduced kernel sizes and lower than expected yields on the orchards harvested thus far. While many in the region expected Nonpareil yields to be lower than those harvested in 2011’s exceptional crop, growers are reporting that production levels so far are running below their already reduced expectations.
Some growers are also reporting increased damage by Navel Orange Worm, NOW. While many crops are running very clean, with low reject levels, losses caused by NOW are apparently running higher than last year’s very low reject levels.
Growers and observers are reporting that there will be no delay in harvest activity between the Nonpareil and balance of the region’s varieties. As soon as the Nonpareil has been removed from the fields, growers are quickly providing an irrigation in an effort reduce the level of stress and are planning on shaking pollenizer varieties as soon as possible. Sonora and Price plantings have already been shaken and shakers will move into the Carmel and Aldrich in short order. Growers with Butte and Padre plantings will also begin shaking in the coming week. Huller/sheller operations are now running around the clock, with product that is unable to be shelled upon arrival being diverted to stockpiles for shelling after the harvest has been completed.
Current weather at the National Weather Service
Photos: Mel Machado, 9/3/12
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