PLANT BREEDING. Ill 



THE INFLUENCE OF THE SOIL. 



One of the most commonly recognized factors in environment 

 is that of soil conditions. It has been observed by tomatO' 

 growers, and is commonly taught, that more fruit is obtained 

 on relatively poor soil than on rich.* It should be borne in 

 mind, however, that this increased fruitfulness — at least in the 

 case of the tomato — is relative rather than absolute ; that while 

 the proportion of vine is greater on rich soil, the actual amount 

 of fruit is also much greater, and the individual fruits are larger 

 and fairer.f 



With this supposition in view, some have thought to produce 

 fruitful varieties by a process of selection and the transmission 

 of the characters of fruitfulness thus acquired. Certain of the 

 small fruits are known to flourish on particular soils or under 

 definite conditions and nowhere else. Particularly is this true 

 of the strawberry, the raspberry and some grapes. 



THE USE OF THE UNRIPE SEED. 



As a means of checking too vigorous growth and increasing 

 fruitfulness, the method of using immature seed has been 

 employed with a certain measure of success. It has been found 

 that the use of immature seed increases the productive parts at 

 the expense of the vegetative and thus it comes about that more 

 fruit is formed in proportion to the foliage than is normal. In a 

 series of experiments conducted through several generations by 

 Goff and Arthur,^ it was found that a tomato plant selected as 

 a representative of the series grown from unripe seed bore 33^ 

 pounds of fruit to one pound of vine (leaves, stems and roots 

 taken together) ; while a plant of the same variety grown each 

 year under the same conditions but always from ripe seed gave 

 only lys pounds of fruit for every pound of vine. We have 

 here then an enormous relative increase of fruitage from unripe 

 seed which in fact " was quite apparent to the casual observer 

 upon looking at the plants of the two series as they grew in the 

 garden, although it required the scales to disclose how surpris- 



* Allen, American Garden, Vol. 11, p. 358, 1890. 



t Cornell Experiment Station, Bui. 10, 1889; also Ibid., Bui. 21, 1890. 

 + American Naturalist, Vol. 29, p. 905, 1895; also Rpt. Wis. Expt. 

 Station, 8, pp. 152-9, 1891. 



