Get Cracking on Almond Nut Harvest Sampling This Season

 If you spotting a woman gathering a sack full of nuts from the ground in almond orchards around the Valley, that person might have been field scout Jenna Horine.

Once again, Jenna is taking almond samples to help growers prepare for next season’s orchard management strategy.  These harvest samples will let growers what pests are in their orchards and helps them compare results from the grade provided by the huller.

UC Integrated Pest Management recommends taking 500 nuts from each orchard block as a representative sample. The nuts are cracked and checked for pest damage.

Growers should get nut samples soon after tree shaking.

Jenna tries to collect nuts quickly, trying not to leave them on the ground too long. Otherwise, ants might get to some of the nuts and skew the findings. Jenna collects several thousand nuts from orchards stretching across Madera, Merced and Fresno counties.

She puts the samples in large paper bags and keeps them in a freezer. This preserves the nuts until she begins cracking the nuts and then inspecting each one for pest damage.

Sounds easy? Try peeling off the green “jacket” or hull to check for surface damage and then carefully manually cracking each nut without crushing the kernel.

Peel, inspect, crack, inspect, record results … Peel, inspect, crack, inspect, record results …

Jenna notes the pest damage is quite distinct. Here is how UC Integrated Pest Management describes the pest damage:
 

NOW damage. (UC IPM photos)

·         Peach twig borer (PTB) and navel orangeworm (NOW) often like to infest the same nut. But NOW bores into the nut and PTB doesn’t. The NOW damage will cover over the PTB damage. NOW damage is represented by a webbing and powder-like remnants.

Ant damage. 

 

·         Ant damage is evident by the big bites taken out of the kernel – like something took a miniature melon ball spoon and took a scoop out, according to Jenna.

Leaffooted bug damage.

 ·        Leaffooted bugs will leave dark spots on the kernel

 ·        Peach twig borer leaves shallow channels and groves on the surface.

·         The Oriental fruit moth also produces shallow channels and surface groves.

Peach twig borer damage.

Jenna’s assessment will indicate the amount of pest damage during the season. But it also lays the groundwork for next year’s pest management plan.

Oriental fruit moth damage.

Peel, inspect, crack, inspect, record results… Peel, inspect, crack, inspect, record results…