I^Ew York Agricultural Experi:mext Station. 439 



SUGGESTIONS FOR GROWING HYBRID SEED. 



1. Desirable results have been obtained by selecting plants in- 

 discriminately, but better results would undoubtedly have been 

 obtained if high-yielding mothers had been selected for one or 

 more generations previous to the first crossing. This selection 

 can be easily accomplished, as tomatoes are readily self-fertilized. 

 The high yielding strains or pure lines having been isolated, they 

 should be preserved for future crossing, and then the crosses can 

 be duplicated at any future date. This is a very important con- 

 sideration for the grower who is desirous of putting the same 

 grade of product on the market from year to year. As tomato 

 seed remains fertile three to seven years, a grower does not need 

 to make his crosses oftener than once in three years. The seeds- 

 man, as well as the farmer, can profitably raise Fi generation 

 seed, provided a guarantee is not given for more than one genera- 

 tion, for the buyer, to maintain his quality of product, will have 

 to purchase seed every year. 



2. Too violent crosses should be avoided, as they are conducive 

 to weakness and sterility. In a cross between Jerusalem cherry 

 (SohnUni pseudo-capsicwn Linn.) and the common tomato 

 (Lycopersicum esculentum Mill.) no seed was produced, and yet 

 the application of pollen grains of the former caused the develop- 

 ment of small tomato fruits — the reciprocal pollination had no 

 such' stimulating action, as the Jerusalem cherry blossoms 

 dropped without any noticeable swelling of the ovarian tissue. 

 This example is of course an extreme case, but it is only one of 

 several in which sterility is known to take place — the mule being 

 a classical case in the animal kingdom. 



3. The best results of crossing can probably be obtained by 

 keeping within a species and crossing the distinct varieties and 

 the distinct strains. For the insurance of securing a desirable 

 commercial tomato, one must keep in mind the inheritance of 

 such qualities as smoothness, color, size, shape and earliness. To 

 obtain smooth fruits, one should cross only varieties with smooth 

 and even surfaces, as roughness will appear in the first genera- 



