mar-apr-2020

recommendation is for 20 percent of annual N budget to be applied between petal fall and by full spur leaf out, 30 percent of total N budget applied between full leaf out and shell hardening (roughly first half of April) and 30 percent of the total N budget applied between shell hardening and the end of kernel fill (mid to late May). Application of the final 20 percent of the annual N budget is recommended to go on between hull-split and early postharvest. There is an online nitrogen calculator available through the Almond Board of California’s website, almonds.com/nutrients/ calculator, to help with calculations and documentation. Potassium (K) Beware of K deficiency developing in heavy crop years. Almonds use 15 to 25 percent more K than N for the same crop, with K use running between 80 and 100 lbs. K2O per 1,000 pounds of kernel crop. Heavy crops remove large amounts of K and can push the orchard into deficiency if K inputs are not applied to offset this loss. If a complete K replacement program is not in your budget this year (for example, 480 pounds SOP per acre applied to replace K lost in a 3,000 pound per acre crop), consider that almond orchards treated annually with 250 pounds SOP per acre didn’t drop below the 1.0 percent leaf K deficiency threshold in several UC studies, each lasting two to three years. A spring leaf sample is a good idea in a heavy crop year to keep your nutrition program from drifting into the red. Information on the UC Early-Season Sampling program is available at ucanr.edu/sites/scri/files/189631.pdf. Samples should be taken 36 to 48 days after full bloom and analyzed for all nutrients and all data fed into a computer model to give a prediction of July leaf N level. With spring leaf sample results, growers and PCA/CCAs IN YOUR ORCHARD 3 6 A L M O N D F A C T S