Garden and Forest. 3(120): 392
(August 13, 1890)
Earliness With Unripe Seed
F. C. Arthur
La Fayette, Ind.
THERE seems to be a fair amount of evidence to prove that seeds from immature fruit will give a product requiring less than the usual time to ripen, and that the earliness thus gained can be increased by continuing the selection. The strain of Tomatoes from green seed, mentioned by Dr. Sturtevant in his timely notice of the subject in a recent number of GARDEN AND FOREST (page 355) is still grown in the garden of the Indiana Experiment Station, and with increasing interest. The present season is the fifth generation. A report on the result of this study will eventually be published. Some information gathered from this and other attempts to investigate the subject of the relation of unripe seeds to the development of divergent characters in the product makes clear some points which it will be well to bear in mind in any attempt to apply such a method to the production of early varieties.
It is not the slightly unripe seeds that give a noticeable increase in earliness, but very unripe seeds, gathered from fruit scarcely of full size and still very green. Such seeds do not weigh more than two-thirds as much as those fully ripe. They germinate readily, but the plantlets lack constitutional vigor and are more easily affected by retarding or harmful influences. If they can be brought through the early period of growth and become well established and the foliage or fruit is not attacked by rots or blights, the grower will usually be rewarded by an earlier and more abundant crop of slightly smaller and less firm fruit. These characters will be more strongly emphasized in subsequent years by continuous seed propagation.
In the observations so far made, it has been found that the plant as well as the fruit tends to early ripeness, and so the period of fruitfulness—that is, the time between the first and the last ripe fruit—is much shortened.
With the increase in the amount of fruit there is also a corresponding decrease in the size of the vegetative parts of the plant-that is, the stems and foliage. A Tomato plant grown from green seed in the fourth generation was found to bear three and a half times as much fruit as tops—that is, stems and leaves together—while a similar plant from ripe seed had but one and an eighth times as much fruit as tops.
It therefore follows logically that while earliness may be considered as a usual condition in all crops from unripe seed, an increase in the amount of the crop only occurs when the true fruit is the part harvested, as in Tomatoes and Peas, and a decrease in the amount of the crop occurs when any part besides the fruit is harvested, as in Turnips and Potatoes.
Whether any method can be found to counteract the enfeebling of the plant and yet preserve earliness remains to be seen.