Nuts: Garbage In, Garbage Out

If we learned anything from the almond harvest in 2010, it was that the quality of almonds exiting the huller/sheller was largely dependent on the quality entering it. By that I mean, nuts that were of poor quality entering due to unacceptable moisture or maturity conditions were the ones most likely to have problems or off-grade issues.

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With the bloom in 2011 being both late and very drawn-out, it is almost a certainty that harvest will be late and nut maturity uneven as in 2010. Some of this can be altered slightly contingent on the spring temperatures we see in the next few weeks; however it is very likely we will see dry nuts, splitting nuts, and green nuts simultaneously on the same trees again. This was a particular problem for those with later maturing varieties, such as Carmel, Monterey, and Fritz.

In blocks with Butte/Padre, the Padre created a challenge for those trying to harvest both varieties together since Padre needs to be knocked slightly greener than most varieties so they won’t get sticktights. This resulted in a larger separation between the two maturities than normal, and some blocks required separate Butte and Padre harvests.

Add rain to this equation and you have the perfect storm for numerous harvest time problems. Nobody enjoys having their almonds rained on during harvest, especially if it happens multiple times as in 2010. Although we cannot control the weather, we do have some control over the cultural practices that affect the quality of the harvest after the rains. Every effort should be made to deliver the driest possible nuts to the huller/sheller as possible to minimize handling problems. The attitude of “the problem is out of my hands now” when the nuts are loaded in the trucks and leave the fields is not the way to approach harvest.

Best Practices

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To start with, nuts should be harvested at the optimum maturity where they will shake well, and dry in a reasonable amount of time under normal conditions. Those who shook by the calendar because they “always start shaking Monterey on this date” or those who shook green to “get the nuts out before the rain this weekend” were taking the wrong approach. Shaking nuts at their optimum maturity results in better quality, even if it means harvesting later than normal “starting dates.”

Next, if nuts get rained on, every effort needs to be taken to expedite their drying. In some cases, nuts are better left on the tree if a big rain is forecast in the next day or two. If nuts are already on the ground, as soon as the field is accessible, they need to be turned and shifted around to accelerate drying. If windrowed already, consider “de-leafing” with a pickup machine to remove wet leaves and turn the nuts. True, these are added expenses, but they do reduce the risk of nut quality problems at the
huller/sheller.

If nuts were rained on multiple times and are starting to look like mold is going to be a problem, they need to be taken out of the field for further drying. Many growers spread wet nuts out on field roads or cement or asphalt slabs that allowed nuts to dry sufficiently for shelling.

Drying at the handler level is needed when moisture levels are too high and adds considerable expense to the grower. It must be remembered that this is not the only consideration when nuts get wet. Everybody is “calling for trucks” at the same time when rain is forecast, so prepare for delays in your management plan.

Managing Wet Nuts

Be more conscious of trucking weight overloads with wet nuts. Remember it takes the huller considerably longer to empty a double with wet versus dry nuts. More mud and leaves stick to the load, slowing the hulling and shelling process. Embedded shell and skin flaking problems are also increased when handling wet nuts. I have not even touched on potential “concealed damage” problems with the kernels or fire hazards with the piles as this is another separate topic for discussion.

In 2010, I had to turn nuts, de-leaf windrows and move some outside the field to dry, and I still incurred some drying costs. I did avoid any moisture related quality issues, though. The key is to work closely with your harvester and handler to discuss the best possible strategies to manage wet nuts.

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