Central California - August 5, 2013
This report covers conditions and observations made between Monday, July 1 and Sunday August 4, 2013. The next report is scheduled for Monday, September 2, 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 central region show the start of the harvest in the Tracy area of San Joaquin County as a side-mount shaker moves through an orchard, followed by the nuts drying on the orchard floor and finally, the splitting hulls of the Independence variety waiting to be shaken.
Variable and occasionally hot temperatures dominated the weather in the central region during July. Skies were mostly clear during the month, with periods of cloudiness produced by several pulses of monsoonal moisture that traveled northward from Mexico. While the greatest impact from the moist air was a noticeable and uncomfortable increase in humidity levels, a few thunderstorms were generated that dropped sparing amounts of rainfall on the valley floor at mid-month. Daily maximum temperatures varied greatly, with highest temperatures reported over the century mark in the period’s opening days as the heat wave experienced during last week of June continued to exert its influence. Readings moderated significantly after the 4th of July holiday, ranging from the upper 80’s to mid and upper 90’s for the balance of the period. Morning lows were reported at their warmest levels in the mid and upper 60’s to just over 70 degrees in the period’s opening days. Readings then dropped to the mid 50’s to mid 60’s for the balance of the period.
Growers spent much of the period focused on pre-harvest activities. Irrigation and weed control have been prime activities during the period as they prepared the orchards for the upcoming harvest. With the initiation of the hull split, those with sprinkler, drip or micro sprinkler irrigation systems withheld water to 50% of consumptive use in an effort to reduce the potential for infection of fungal organisms on the splitting hulls. This period coincided with the warmest temperatures of month, making close management a bit more difficult as growers do not want to subject their plantings in too much stress, which can adversely affect the crop. In spite of grower’s best efforts, the high temperatures created enough stress to seemingly stop the progression of the hull split at the start of the period. However, moderating temperatures and renewed irrigations allowed the split to resume its normal pace by mid-month. Growers have been very protective of their limited water supplies this year, wanting to retain enough to provide the irrigations needed after the harvest.
Hull split treatments for the control of Navel Orange Worm, NOW, have been completed, as have miticide treatments to a few orchards having populations that built to damaging levels. While mild infestations requiring treatment can be found around the region, the northern San Joaquin Valley has largely escaped the serious difficulties encountered by many producers in the southern San Joaquin. There has been much discussion this year regarding the large number of NOW moths captured in the newly available pheromone traps. When combined with poor conditions for winter sanitation during the past winter, which left a high number of mummy nuts in many of the region's orchards, this has produced a bit of anxiety among growers as they consider potential reject levels in the crop. However, observers are reporting that the shell seal among the nuts to split thus far appears to be quite good. This will go a long way towards inhibiting the NOW's ability to reach the kernel and portends of potentially low reject damage levels.
As the time for shaking comes closer, final preparations include mowing of the orchard floor to ensure efficient nut removal and treatments with ant bait formulations in orchards having excessively high populations of damaging species. Oil feeding ants are very attracted to the almonds as they lay on the ground after shaking and can inflict significant crop losses as a result of their feeding should the nuts have any opening in the shell. As mentioned above, shell seal is an important factor, which is unfortunately beyond a grower's control.
With the shaking of the first orchards along the I-5 corridor during the last week of the period, harvest operations have begun in the central region. As is normally the case, Nonpareil orchards were the first to be shaken. However, harvest of the Independence, Price and Sonora along the west side will also begin shortly. Most growers report that they expect to begin shaking orchards along the eastern foothills within about two weeks, with those along the Highway 99 corridor planning on starting about one week later. However, some have already begun shaking of the most advanced or stressed plantings. Observers report that hull split has also begun in several pollenizer varieties, including Price, Sonora, Aldrich, with hulls on advanced Padre plantings along the west side also showing the first signs of splitting.
Current weather at the National Weather Service
Photos: Mel Machado, 8/5/13
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