Solid Orchard:  Spike one limb of a percentage of the trees with a mix of some of the above pollinators - suggested 25%.

Combination Plantings:  36P999 could be planted in conjunction with several of the above pollinators.  Typical plantings on an alternating 4 row spacing will require the addition of extra pollinators for the unconfirmed directions.  It would be cheap insurance to spike the center two rows with additional pollinators, perhaps 10% to 25%.

NOTES:

Spiking a pollinator means to graft a central limb of the commercial variety with one of the confirmed pollinators.  The recommended method would be to spike each tree once, but alternate more than one confirmed pollinator throughout the commercial orchard.  Some growers prefer to interplant the pollinator in the same row between two trees of the preferred variety and grow them in a flagpole or or very upright V-style, often pulling and tying a limb toward the center of each adjoining tree.

Combination plantings are made of 2 or 3 varieties that usually benefit each other for pollination.  Alternating 4 rows of each is most common, alternating 2 rows of each gives better pollination, but does not harvest as efficiently.  Also, it is usually beneficial to insert pollinators along the center 2 rows of a 4 row planting.