Fruit-hearing is a great drain upon the msources of the twig. The spur that hears a cluster of a dozen flowers does well if it brings a single fruit to maturity. The bearing spu• often lengthens hut a fraction of an inch. It cannot ripen its fruit and produce fruit buds for the next year. Instead it makes a leaf bud on the side. Next year a leafy shoot is produced and the little stein ends in a fruit bud. This is the way to account for the alternation of years of beanng in apple and pear orchards.
Let us look at a winter apple twig and see if we can read its past and its future. It tells not so clear a story as was told hy the elm twig. Four builds of scars tell of the April starting of buds into shouts. They are at o, b, c and d. The twig is apparently four years old. The shout, that started at n was a lusty one that grew to 1, in the season of 189S and Gilded in a leaf bud. bad seven side buds, at least. In 1899, the top bud grew from b to e, where it funned a fruit bud. The side bds, all but the upper one, started, bore each a leaf or two, and ended in leaf buds, except one, which funned a fruit bud at ,r.
In I!)1111, a large cluster of apple blossoms opened at c, two of which produced fruit. A small cluster opened at x, and a single fruit sear shows where an apple hung. During this season the fruit, matured, the spurs between 0 and it lengthened a little and formed terminal leaf buds. a side laid prolonging the shoot at .r. The dormant bud below 1, remained asleep. But the strongest growth \vas made by the side bud that rose at r and ended in a leaf bud at d. In 1901 the spurs below grew inure strongly than before, and formed plump fruit buds for next year. Buds between e and (1 formed short spurs and ended in leaf buds. The top bud grows from (/ to e and made a good terminal fruit bud. The four-year-old apple twig formed fruit buds at the end of its second and fourth years, with a resting year between each two years of bearing. Any variation from this rule must be due to extra feeding \vhich enables one tree to exceed the normal bearing capacity of apple trees.
Not all apple twigs will tell their story as clearly as this one dues. Old trees grow very slowly, and the rings of bud scars are often so crowded that we cannot be sure of our count ing. The very lusty young shoots may mislead us by a strange habit of growth, common to many other trees. The white oak twig illustrates it. Here are apparently two years of growth. But not a bud below the point m has started. Strong buds like
these should not remain dormant for a year. Our suspicions are aroused. The explanation usually accepted is this: an early cessation of the sap-flow from the roots warned the tree to expect no more supplies. The buds funned for next spring. Later, rains came and ended the early summer drought. Sap-flow was resumed, and the terminal bud was forced into growth. It made a good start, bore leaves and matured buds before the growing season was past. This double growth in one season is often seen on apple twigs in well-tilled orchards. This oak twig was cut from a vigorous young' tree.
The pear twig pictured here bears the promise of five flower clusters next spring. Each living spur ends in a fruit bud. The twig seems to have been six years in growing. The yearly growths starter at (1 f.; / u, u, c, , . . 1 t5 it 1 1Jit1111 scale scars at each of these points. The side spur that is alive is live years old. The yearly addi flints on bearing twigs of pear trees are usually short and stout. Two fruits have been borne. Just below 1) and at d are projecting platforms where the fruit stems were attached. It is plain to be seen that this twig bears fruit in alternate years, just as the apple does. The second, fourth and now the sixth years of the twig's life are years of bearing, with the third and fifth as resting years between. The alternation of fruit and leaf 1 1 • • __ • 1 o 1 • nuns is not an unvarying in twlgs, nor o various branches in .? given tree, nor the trees in a given orchard bear in alternate years only. The impulse to form fruit buds together is sufficiently strong in the twigs of individual trees, however. to cause the trees to yield alternately heavy and light cr(q);;.
When all the secrets of the early-blooming trees are nut, when elm seeds are ripened and shed, and the fallen petals of orchard blossoms show that the trees have settled down to the more prosaic business of maturing their fruits—then the conservative late-blooming trees begin to show that they are alive. They open their buds, lengthen young shoots. and along the sides of these or on the ends of them the blos soms of the year are borne. Thus, basswood and the hard maples do not tell the prospe•ts for fruit in the winter time. The development of their flowers into distinguishable form and size waits till the coming of spring. Among orchard trees, the quince illustrates this late opening habit. Hickories and walnuts and chestnuts are familiar examples among forest trees.