Some carbohydrate and nitrogen constituents of alternate-bearing sugar prunes associated with fruit bud formation

Abstract does not appear. First page follows. Introduction The horticulturist uses the term “alternate-bearing habit” to designate the tendency of certain fruit trees to produce a heavy crop in one year, followed the next year, by a much lighter crop. Although this condition of alternate bearing is perhaps more marked in some varieties of apples than in other fruits, a tendency toward alternate bearing does exist in fruits other than the apple, and the degree of the alternating habit may be determined by the degree to which a given internal condition exists. Practically all of the investigations concerned with alternate bearing have been made with apple trees. Although a number of conditions have been described to account for this habit in the apple, very little work has been done with other fruits which have a pronounced alternating habit. The Sugar prune, under the conditions existing at Davis, California, is a very pronounced biennial bearer. Yield records and observations at blcoming time show that a tree which produces a heavy crop in one year will produce almost no crop the following year—possibly only a dozen or so blossoms. The climatic conditions at Davis are such that they rarely interfere with the normal bearing habit. The Sugar prune (P. domestica), under these conditions, would seem to be an especially fit subject for the investigation of any chemical differences which might be associated with the alternate-bearing habit and fruit-bud formation.