86 BUTLER: ALTERNATE BEARING IN THE APPLE 
fruit are only produced biennially and that in the northern fruit 
sections the productive year has become more or less fixed on the 
even year. Alternation of bearing may be brought about by 
overproductiveness resulting in an exhaustion of the tree which 
then requires one or more years to develop flower buds again, or 
it may be due to climatic agencies. 
According to Maynard the bearing year may be changed: Ist, 
by removing part or all the fruit; 2d, by manuring the orchard 
during the productive year with bonemeal and potash, or bonemeal 
and wood ashes, or by using nitrate of soda or stable manure in 
the unproductive year; 3d, by seeding the orchard to grass during 
the bearing year; 4th, by ploughing the land in the unfruitful year 
and cultivating during the productive year; sth, by canker worms 
or vernal frosts destroying the blossoms. 
Powell* observes that the alternate bearing habit once acquired 
will in all probability be kept up indefinitely. Alternate bearing 
is brought about by unfavorable climatical conditions, such as 
hibernal cold or damp weather at blossoming time. 
Waughj notes that alternate bearing is particularly marked 
in the Baldwin apple and believes that more regular productiveness 
could be obtained by thinning the fruit. 
What is the cause of biennial bearing in the apple and what is 
the raison d’étre of the methods proposed to equalize fruitfulness? 
IJ 
The biennial bearing of apple trees was credited to its proper 
cause by Jules Courtois in a lecture before the Horticultural 
Society of Seine-et-Oise. Hardy{ quotes at length from the 
report of this lecture, and from this quotation I translate the 
following passages bearing on the question of the alternation of 
bearing in the apple: 
Again one often sees in pear and apple trees flower buds forming like bouquets 
de mai§ of the stone fruits the second year and expanding the third. 
There is even a kind of an eyel|, the eyes of the purse (bourse), of which this is 
* Powell, E. P. The orchard and fruit garden, 14. New York. 1905. 
+ Waugh, F. A. The American apple orchard. New York. 1912. 
t Hardy, J.-A. & A.-F. Traité de la taille des arbres fruitiers, Ed. 12, 123. 
1S. 
§ Floral development on a spur, lambourde. 
|| In horticultural literature an “‘eye” is a bud that will produce a leafy axis, 
and a “bud,” or “‘fruit-bud,” is a bud that will produce a floral axis. 
