jul-aug-2020

Long, hard shaking risks barking trees regardless of how long the irrigation has been cut off. Bark strength is not related to tree water stress levels, but naturally and gradually increases through August and September. If the crop is ready, trees should shake clean without excessive shaking and, possibly, barking. This could be an important issue in a big crop year where there is understandable pressure to start shaking before the crop is ready. Take a preharvest sample and check for NOW damage as 100 percent hull split timing approaches if considering inshell production of Nonpareil, Independence, and/or Sonora. Cleaner inshell loads (less foreign material) result from longer drying in the tree and so more fully open, dried hulls at shake. This longer “hang” can result in increased NOW damage compared to timely harvest. Talk with your Blue Diamond regional manager about your options to maximize income per acre based on NOW damage in preharvest samples and possible quality premiums tradeoffs between inshell and shelled product. Hard to shake varieties such as Winters, Padre and Independence should be shaken when the hulls are 100 percent split, but still green and heavy. Stockpiles The subjective and objective forecasts are not for just a record crop, but a 25 percent increase in production since 2018. That should mean a lot of nuts will sit longer in stockpiles waiting for processing. How the stockpiles are constructed and managed could have an impact on the quality of the final product, and so grower returns. UC research and industry experience suggests the following best management practices for stockpiles. Locate stockpiles on ground that is in a position free of water accumulation – a high spot or on a slope, not in a depression where water can accumulate. Don’t stockpile wet nuts. Kernels should be under six percent moisture, hulls less than 12 percent moisture and whole nuts (in hull) should be less than nine percent moisture when stockpiled. To limit condensation under protective tarps, use white on black tarps (white facing out) and flatten humps on the ridgeline of the stockpile resulting from separate elevator stations while building the stockpile. Condensation accumulates in the valleys and promotes more mold growth than if condensation was evenly spread across the ridgeline. Removing the tarps in dry weather to allow moisture to escape the stockpile and recovering the stockpile when rain or increased humidity threatens can help limit mold and moisture in the stockpiles. Finally, stockpiles should be oriented north to south to avoid excessive moisture and mold found on the shaded (north) side of an east to west oriented stockpile. Harvest Sample A harvest sample, 500 whole nuts (hull, shell and kernel) per orchard, taken between shake and windrowing and kept in the freezer until crackout, is the best way to assess your crop protection program along with irrigation and certain nutrient deficiencies. Knowing what production and protection issues are costing you money is worth the extra effort to sample and process this end-of-season sample. Keep in mind that the processor’s quality statements reflect the reject level after hulling and shelling. Hulling and in particular shelling can easily eliminate one-half of the reject kernels in the final product, underreporting the actual losses. Further, damaged nuts are lighter than sound nuts and can be lost during harvest. Some commercial consulting companies offer harvest sample analysis for a fee. 3 5 J U L Y – A U G U S T 2 0 2 0