432 Report of thp: Department of Horticulture of the 



produced by each lot and the periods of picking are divided into 

 intervals of about ten days. The total yield of ripe and green 

 fruit is given for each lot, the average amount of ripe and green 

 fruit produced per plant, and finally the total yield of 2,722 

 plants — one acre v^ith plants set 4' x 4' each way — based on 

 the average yield of one plant. The results are discussed later in 

 the bulletin. 



WINTER experiment, 1908-1909. 



The seed used for the winter crop was obtained during the sum- 

 mer of 1908 by self-fertilizing clusters of blossoms on four or 

 more vines of each lot, namely, the Dv/arf Aristocrat, Livingston 

 Stone, and the crosses. Dwarf Aristocrat x Livingston Stone, and 

 Dwarf Aristocrat x Hedrick. It will be noted that two crops of 

 tomatoes are grown in one year — the winter crop in a forcing 

 house. This experiment differed from the preceding one in that 

 the crosses belonged to the F2 generation, and, therefore, a direct 

 comparison of the results is impossible. All the dwarf plants 

 that appeared in this second generation were discarded. Accord- 

 ing to the Mendelian law of segregation, one-third of the stan- 

 dards appearing in an F, generation are in a homozygous con- 

 dition, and two-thirds, or the remainder, of the standards are in 

 a heterozygous condition. The homozygous standard plants will 

 always breed true to the standard type, while the heterozygous 

 standard plants will split into one-fourth dwarf plants and three- 

 fourths standards. It is thus very evident that we are dealing with 

 a smaller proportion of heterozygous individuals in the F2 genera- 

 tions than in the Fi generation. The heterozygous and the homozy- 

 gous plants were so similar in appearance that no separation could 

 be made by inspection, and, therefore, both kinds were planted in- 

 discriminately. Owing to the smaller number of heterozygous 

 plants in these crosses, one would expect less difference in yield 

 between the standard parent and the crosses. The results of this 

 crop agreed with this expectation, except that the differences in the 

 yields of the crosses and the parents were less marked than ex- 

 pected. Early maturity favored the crosses. The yield of this 



