If you told your pruning crew to take out half the wood they normally do, you'd cut your pruning cost in half. If you told your spray applicator to spray only every other row, you'd cut your spray costs in half. Similarily, if you cut the workload for bees in half, you can cut your bee costs in half. Read on.

Most growers, and all nurseries, know that there are a few incompatible almond variety combinations (varieties that won't set a crop with each other because both of their genes, one from each parent, are identical). These varieties are 100% incompatible. Not as well known is that there are a number of 50% incompatible varieties. These varieties share a single gene (out of 2) which means they require 2 pollen grains to set an almond rather than one. Pollinizer varieties that are only 50% compatible with Nonpareil (and with each other) include: Aldrich, Avalon, Butte, Carmel, Merced, Monterey, NePlus, Price Sonora, Tokay and Wood Colony.

Varieties that are 100% compatible with Nonpareil require the transfer of only 1 pollen grain, thus 50% compatible varieties double the workload of honey bees. The large number of almond varieties that are only 50% compatible with Nonpareil is due to the Nonpareil parentage of these varieties. Nonpareil was used as a cross to develop new varieties because the quality of the Nonpareil nut is, well, nonpareil, and highly prized by handlers. The varieties that are 100% compatible with Nonpareil and bloom at the same time are very limited, with Fritz currently being the main one (Fritz is believed to be a cross between Mission and Drake*). A new variety, Winters, is 100% compatible with Nonpareil and blooms with Nonpareil and shows some promise (it yielded well in the Chico plot, not so well in Kern, and it's susceptible to alterneria, lack of winter chilling and navel orangeworm).

There are thousands of acres of 50% compatible almond plantings in California - quite possibly the largest almond test plot ever undertaken! These plantings (mainly Nonpareil:Carmel) have produced 3000+ lbs/acre using 2 (8-frame) bee colonies per acre and show that pollination is not a problem on 50% compatible plantings. If 3000#/acre can be achieved on 50% compatible plantings using 2 bee colonies per acre, then 1 colony per acre should be sufficient for 100% compatible plantings. Cut the workload in half, reduce the work force by half - the math isn't that difficult.

What about the mentoring effect - that 100 or more pollen grains must be deposited on a stigma to stimulate the growth of the pollen grain that reaches the ovule? Not a problem. This "mentoring pollen" can be incompatible pollen, including self pollen and since individual almond flowers produce around 50,000 pollen grains, 100 or more grains should be deposited on one visit by a pollen-collecting honey bee.

Growers with Nonpareil-Fritz or Nonpareil-Winters plantings should be able to get by with 1 bee colony per acre. Plantings where Fritz comprises 25% of the acreage (e.g., Nonpareil-Fritz-Sonora plantings) should be able to get by with 1.5 colonies per acre. With significant bee shortages looming in coming years as almond acreage increases and the U.S. bee supply remains the same, cutting back to 1 colony per acre could go a long way towards ensuring a dependable bee supply for all California almond growers.

- Joe Traynor