Originally Published in the May – June Almond Facts
DAVID DOLL, UCCE Nut Crop Pomology Farm Advisor, Merced County
Almond kernel development is ahead of schedule. Kernel fill for Nonpareil was completed in many locations of the northern San Joaquin Valley around mid-May, suggesting that the season is progressing two to three weeks ahead of “normal.” This means that hull-split and harvest will occur earlier than normal, impacting nutrient, irrigation and insecticide timings. Every orchard will progress differently depending on location and varieties, so it is important to monitor the progression on an orchard basis.
Irrigation prior to hull-split
Research has shown that a mild to moderate water stress applied prior to and maintained through the first week of hull-split may help with harvesting and reduce hull rot. This practice is known as regulated deficit irrigation (RDI). Irrigation durations should be reduced and plant stress should be monitored using the pressure chamber until a stem water potential of -15 bars is achieved.
Depending on soil and irrigation practices, this may take a few days to several weeks and may require a 10 to 50 percent reduction in water applied. The moderate stress should be maintained for two weeks. Once hull-split is progressing, then full irrigation should resume until the pre-harvest programs begin.
Operations successful with the application of RDI typically begin to cut water at a small percentage (10 to 20 percent) after the completion of kernel fill and three to four weeks prior to hull-split. As stress and soil moisture levels are monitored, the water reduction is adjusted. Heavy soils may require a larger initial reduction and a longer duration of curtailment. Soils with a lower water-holding capacity or under-irrigated orchards may have a smaller or shorter period of reduction…[Click here to read the entire article]
To read other articles from David Doll, Please visit his website at: www.TheAlmondDoctor.com