Plum tree named `Compact Friar`

#This petition is for a new cultivar of Japanese plum (Prunus salicina). As research partner of a tree breeding enterprise, I directed an experimental program to breed new cultivars of stone fruits by treating budwood with cobalt 60 Picowave radiation in dosages ranging from 1,500 rads to 18,000 rads to induce mutations and then budding the treated buds onto Nemaguard peach (unpatented) rootstock in an experimental plot in San Joaquin county. One of the trees resulting from such budding, being a mutation of Friar plum (unpatented) was observed by me upon maturity to have novel characteristics. It was around half the size of regular Friar, offering a potential for high density plantings and reduced costs for cultivation and harvesting. At my direction, buds from it were then further budded on other Nemaguard rootstock in the same experimental plot. These later asexual reproductions have been true to the tree from which the buds were taken. I have personally also reproduced this new cultivar by budding onto peaches and plums in my facilities in Alameda County, Calif.

#This new cultivar of plum tree is a productive regular bearer of yellowish amber fleshed, purplish black skinned, oblate fruit ripening in late July. It is similar to Friar, except that this tree is genetically dwarf in size. By its dwarf tree size and ripening of fruit in late July, it is distinguishable from Majestic M plum (U.S. Plant Pat. No. 6,975), also a mutation of Friar, which has a regular size tree and fruit ripening in late October.

#The accompanying photographs show two trees of this new cultivar in their fourth summer, a twig with detached leaves, and fruits both whole and divided in half, with the stone in one half.

#Following is a botanical description of this new variety with fruit in firm condition based on Jul. 17, 1990 observation of two specimen trees in San Joaquin County, Calif. Color names and plate numbers are by reference to Inter-Society Color Council--National Bureau of Standards Centroid Color Charts, except where common color names are used.

#Tree: Dwarf size (5 feet in 4th summer), dense, medium vigor, regular bearer, precocious, highly productive (around 50 fruits in 4th summer) form upright spreading to round with wide angle crotches on branches. Friar, in comparison, is twice as tall, less dense, more upright, with narrower angled crotches. Third generation trees of the new variety budded on myrobolan root appeared less dwarfy in the first year than those budded on Nemaguard.

#Trunk: 11/2 inches in diameter, normal texture of plum bark, average number of white lenticels.