LYCOPERSICUM ESCULENTUM 



565 



quality" because it contains the highest percentage of dry material, 

 the highest percentage of insoluble solids, and possesses the 

 sweetest taste owing to its high percentage of reducing sugar. 



The time elapsing from the setting of the fruit until its maturity 

 depends upon the variety as well as cultural and climatic condi- 

 tions; but from seven to nine weeks may be regarded as an average 

 period. Growth studies by Gustafson (12.) for two varieties 

 indicate that the growth curve for the fruit is very much like that 

 found in the vegetative parts; that is, "there is a period of slow 

 growth, gradually becoming more rapid until a point of maximum 

 growth is reached, and from that time there is a slowing up." The 



Fig. 196. Fruits of Santa Clara Canner variety. (Courtesy of the Ferry-Morse Seed Co.) 



moisture content increases throughout the growing period, 

 especially as the fruit passes from the green mature stage to the 

 ripe condition; but increase in the size of the fruit occurs without 

 an increase in the per cent of dry matter. The per cent of dry 

 weight is highest in the immature ovary, decreases rapidly during 

 the first two weeks of growth, and at no time is there an increase. 

 In one variety, Gustafson found the young ovary had 17 per cent 

 dry matter, 6.7. when two weeks old, and 5 per cent when mature, 

 six weeks later. MacDougal Q2.1.) reported a similar situation, 

 although the differences were not as great. 



Pigmentation of the Fruit. — The color of the mature fruit 

 results from the presence of carotenoid pigments, lycopersicin 

 (lycopene) and carotin (carotene). Their distribution in the 

 tissues of the pericarp and the proportionate amounts of each 



