General considerations and some bibliographic tools for the identification of apple varieties were previously outlined in POMONA No. 1, Vol. XV, 1982, which is No. 58 if you have numbered your POMONAs consecutively. In that issue it was assumed that a variety can be either recognized spontaneously by comparing it to pictures in printed matter or memory, or by leafing through variety descriptions laboriously until recognition clicks. Both methods can be successful, frustrating or inconclusive. Not only may a given cultivar vary in ripening time, colouring, shape and other morphological details depending on the growing environment, but Coxe's terminology varies from Downing's, Beach's from Hedrick's and Bultitude's from Brooks' & Olmo's.

The idea of a botanical deductive key is appealing and, as Hedrick demonstrated, workable for limited numbers of varieties. Pre-grouping by phenotypical "families" is also helpful. Both become confusing and deadended with large numbers, such as the 3,000 plus varieties in the 1981 USDA Germplasm Resources Inventory. The most positive method appears to be the "chemical fingerprinting" developed at Washington State University. The method is called analysis by "electrophoretic isozyme banding patterns" and produces stunning results which can be expressed in simple graphics.

Further fine tuning is in the works because 'Spartan' and 'Wijcik' could not as yet be differentiated but, on the other hand, virus-free and virus-infected specimens of the same cultivar could be separated. With this method the nurseryman who, thirty years ago, sold me my first 'Golden Delicious' trees under the name of `Yellow Delicious' to avoid paying royalties, could be put out of business today. NAFEX should consider supporting this promising project financially to get some of the unresolved identities sorted out, such as `Yellow Newton' vs. 'Green Newton', 'Simirenko' vs. `Wood Greening', `Rome Beauty' vs. 'Morgenduft' vs. `Hoary Morning', 'Zoba' vs. 'Lobo', and others.

Because "chemical fingerprinting" requires a sophisticated laboratory set-up, this article outlines another identification method which can be practised with pencil and paper. Its results, the Apple Passport Numbers (APN) can be arrived at and compared at the kitchen table and, if one chooses, processed and identified by PC. It is based on the probability that the more characters of an apple are compared the more positive will be the identification, provided the characters are similarly determined and expressed. The apple characters are reduced to easy-to-process numbers.

The APN of the `Merton Beauty' apple in our example consists of 24 one, two or three digit numbers separated by dashes. This replaces about 450 letters of descriptive wording or 2,500 letters in descriptive sentences and also eliminates semantic flaws. I can think of many uses of the APN resulting from the original purpose of "nailing down"varieties for comparison with each other.

The check-list (Fig. 1) can be marked as one pleases as long as the letters in the left-hand column are followed by the applicable numbers as shown in the completed checklist (Fig. 2). These numbers in their sequence make up the APN. The letters of the character groups may be retained for fast locating or replaced by dashes. In an identity search the number 0 is used after a group letter to indicate "unknown" i.e. undeterminable, nonexisting or "no choice applicable".

Thus AO means that the actual growing district of an apple specimen is not known. WO means that its actual harvest time was not given. In many character groups more than one choice can and should be made whenever characters are coexisting, mixed or variable. Thus A37 means that a given specimen was grown in Plant Hardiness Zone 6 in the Midwest, and C145 means "round-conic to oblong" which is the shape of the 'Baldwin' apple. The APN of the 'Merton Beauty' apple is 26-4-13-1-345-238-19-2-2-36-78-38-258-8-56-3-28-89-34-3-3-8-3-123.

The morphological terminology is essentially that used and described by Q.B. Zielinski in Modern Systematic Pomology. The organoleptic terminology was derived from various authors.

I invite all NAFEX members to send me ideas on how to improve function, accuracy or simplicity of the checklist and to give some thoughts to a central database where any Adam could phone in with an APN, and instantly find out what variety his Eve is holding in her hand.