Harvesting Mesquite A quick guide on how to safely harvest mesquite BY DR. JACQUELINE A. SOULE | ILLUSTRATION BY ANNIE WOLF
Harvest Early, Harvest Dry
Harvest mesquite pods before the summer rains, and never wet or wash your pods. Harvesting dry pods and keeping them dry reduces the growth of molds (fungus) on pods. The problem is an invisible fungus (Aspergillus flavus) which forms the chemical aflatoxin B1, a known carcinogen. Recent research at the University of Arizona by Dr. Nick Garber, Dr. Sadhana Ravishankar, and the Mesquite Harvest Working Group showed a clear correlation between aflatoxin levels and rainfall. Many mature pods harvested after the monsoons started were unsafe due to high aflatoxin levels. These same studies found mesquite pods harvested before the rains had safe aflatoxin levels—well below the minimum levels allowed by aflatoxin sampling of food products.
Harvest off the Tree
Ripe pods range in color from yellowish tan to reddish or purplish (not green), and are dry and brittle. They come off the tree easily. Always harvest pods from the tree, not the ground. When you harvest from the ground there is greater risk of the pods having come into contact with fecal matter, herbicides, pollutants, fungus from the soil, or irrigation water that may increase the amount of fungus or mold on the pods. You can find quality pods on trees that grow in washes, small drainages, backyards, and along low-traffic neighborhood streets. Often, city trees are the most abundant producers because they receive supplemental water in the form of runoff from nearby rooftops, patios, and streets—especially when people have set up water-harvesting earthworks around or beside the trees.
Harvest
Pick ripe pods from the tree. Taste one! Always judge sweetness before continuing to harvest from that particular tree. Flavor varies from tree to tree. The sweeter the better! A good-tasting pod will have no chalkiness, no slight burning sensation in the throat, no drying out of your mouth, and no bad aftertaste. Pull gently and the pods should come right off. If you have to pull hard, they’re not ready yet! Pick only those pods that are good-tasting, clean, and nice-looking (free of black mold). Annie Wolf is a writer and artist from the Gold Canyon area who specializes in nature watercolors and acrylic animal portraits. She has been painting for as long as she can remember, and wants to use her art to help support the Boyce Thompson Arboretum and its endeavors.
14 | Boyce Thompson Arboretum | Summer 2018
