Blue Diamond Almonds Bloom Report

April 28th, 2014

This report covers conditions and observations made between Monday, March 31 and Sunday, April 27, 2014. The next report is scheduled for Monday, May 26, 2014. However, in the event of any significant occurrences prior to that date, this site will be updated as soon as possible.

Generally good weather reigned over the almond growing region during April, with storm systems bringing clouds and rainfall to the orchards in the period’s opening and closing days. Daily maximum temperatures climbed quickly from their chilliest levels in the low to mid 50’s as the period began, reaching into the upper 70’s to mid 80’s where they remained for the majority of the period. Readings finally dropped back into the upper 50’s and lower 60’s during the period’s final days as a new Pacific weather system delivered widespread rain and occasional hail to the Sacramento Valley.

Official rainfall totals ranged from 1.0 inch to as much as 2.5 inches in the north to 0.5 to 1.0 inches in the central part of the region, with additional amounts falling from thunderstorms that roamed the region, dropping heavy rain and occasional hail. While some growers reported locally significant hail damage to their crops, widespread losses have not been reported.

Owing to its geographic location, the southern part of the region’s rainfall totals for the month was much lower than in the other growing regions. Nevertheless, the region received a few tenths of an inch to as much as one inch of rain, with some growers reporting additional amounts from storm cells that passed through the region on Friday, the 25th. Observers noted that hail was reported in areas of Madera, Fresno and Kings Counties on the 25th, but widespread damage had not been reported as this reported was being prepared.

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Almond crop developing well - Observers have reported that the almond crop in the Sacramento Valley is developing well under the influence of the generally good weather conditions. Above average temperatures and adequate sunshine have combined to provide good support for the crop while also helping to reduce disease pressure. Many orchards have been shedding nuts that the trees are unable to carry to maturity, a normal process that typically occurs in greater amounts in the Carmel, California types and Butte/Padre plantings than in the Nonpareil. Observers and growers alike are reporting that they believe the crop to be approximately ten days ahead of last year.

In the central region, Nonpareil nuts along the west side have reached their full size and have begun to solidify. The date at which the first nuts are fully solidified will provide the best reference of maturity and an indication of the start of the harvest. Growers and observers in this area believe that the crop is running approximately one week ahead of last year. However, as a comparison, growers in the Patterson area of Stanislaus County have begun harvesting apricots two weeks ahead of last year.

Cut-away view of the Nonpareil almond

Cut-away view of the Nonpareil almond

Beneficial weather conditions for the majority of the period have allowed growers to complete required orchard tasks with few difficulties. Fertilizers have been applied as needed, as have fungicide treatments designed to prevent disease infections on the crop as well as the trees. In the north, pressure from insect pests has been low this year and to this point, few difficulties have been encountered.  However, the coming weeks will bring additional focus on insect management as the crop grows closer to harvest and growers focus their attention on Navel Orange Worm and ants.

In the south, some growers have reported damaging populations of Leaf-Footed Plant Bugs and have treated accordingly. Still more have noted that Navel Orange Worm, NOW, trap counts have been rising and are making plans to begin treatments according to the life cycle stage of this serious insect pest.

The lack of winter rainfall and the corresponding few days of fog resulted in very poor conditions for the removal of mummy nuts remaining in the trees after the 2013 harvest. These mummy nuts serve as over-wintering sites for NOW and can greatly increase the potential for damage in the subsequent crop. Given “the hand that they have been dealt”, growers are monitoring the insect’s life cycle closely to determine the correct course of action and minimize damage to the crop. Growers are employing the newly developed NOW pheromone trap to attract adult male moths in addition to the traditional egg traps used to lure female moths and monitor their egg laying activity.

In the pest management arena, growers in the San Joaquin Delta, where approximately 1,200 to 1,500 acres of almonds have been planted in recent years have noted damaging infestations of Leaf-Footed Plant Bugs feeding on the Aldrich and Fritz varieties. This insect caused significant losses in individual orchards near the eastern foothills in 2013 and has been reported in some Eastside plantings again this year. Growers in all areas of the region also reported isolated cases of pseudomonas bacterial infections on the Padre variety, which was causing a slight degree of leaf loss. Special attention is being given to the number of Navel Orange Worm adult males being caught in the new pheromone trap, now in its second year of use. Growers and Pest Control Advisors are running the new traps alongside of the traditional egg trap, designed to monitor egg laying by female moths as they work to learn how to employ the new pheromone trap to monitor insect populations and life cycles.

Water remains a prime concern – for all in the Sacramento Valley. Rainfall during March and April has provided some degree of relief in the form of a small amount of additional run-off captured for storage. Both the State Water Project and the federal Central Valley Project have increased allocations to 5% of contracted amounts, while Sacramento Valley growers sourcing their water from districts known as the Settlement Contractors have seen their allocations increased to 75%. For the growers served by the state system, the 5% allocation will not be available until after September 1. Most growers have been working to ensure that their privately owned wells are in good condition as they will be depending heavily upon groundwater in order to complete the 2014 growing season.

In the central part of the region deliveries from local irrigation districts began during the period, with farmers in the Turlock Irrigation District seeing their canals filled on April 10 while those in the Modesto District were able to receive water on April 15. Growers in the Merced Irrigation District did not receive their first deliveries until April 21 and will receive only a six inch allocation this year. During the final week of the period, management of the State Water Project increased its allocation to growers from zero to 5% of contracted amounts. Most believe that the increased allotment will help only those growers north of Fresno and even then not significantly as the water will not be available until after September 1.

Obviously, many growers are highly dependent on privately owned deep wells for their water this year. In addition to being quite expensive, ground water can also be of questionable quality, with the most serious problems presented by high pH and dissolved salts which can create  a significant yellowing of the leaf tissue as the excessively alkaline water ties up the nutrients needed for crop development. In addition to the rather striking color, these orchards are exhibiting a lack of spur development.

Growers in the most severely impacted areas are managing what water they do have very tightly. For some, rather than managing with an eye towards maximizing yield, the goal has become to maintain the orchard and keep the trees alive. Some plantings are already exhibiting moderate signs of stress as their owners implement deficit irrigation strategies.

Further south, the puzzle of water rights and allocations that make up the San Joaquin Valley, the Exchange Contractors on the valley’s west side have rights to the water in Millerton Reservoir near Fresno if they are unable to secure their normal supplies. Millerton’s water normally supplies growers along the east side of the valley, serving the Madera and Fresno Irrigation Districts as well as other districts to the south via the Friant-Kern Canal. According to published reports approximately 410,000 acre feet of water has been pumped from the Delta and stored in San Luis Reservoir near Los Banos on the west side of Merced County as the run-off from the March and April storms passed through the Delta. If an additional 300,000 acre-feet could be pumped and stored, the Exchange Contractors would not need to source supplies from Millerton, making that water available to east side growers.

Clearly, groundwater supplies will be critical to growers in the southern San Joaquin. Some have already reported difficulties with their wells. Pump and well companies are working around the clock to maintain systems and have been unable to keep up with the demand for service. A tour of the west side of the region will find miles of 10 and 12 inch aluminum pipe running from wells in one orchard to other orchards as growers work to meet their orchard’s needs. Excessive stress has not yet been reported, but will most certainly appear as we move into the late spring and summer months.