The quality of the fruit is largely dependent upon varietal differences, to be spoken of later, but it is also influenced by conditions of growth--such as the proportion of the nutritive elements found in the soil, the proper supply of moisture, the degree and uniformity of temperature and, most of all, the amount of sunlight. Sudden changes of temperature and moisture often result in cracks and fissures in the skin and flesh, which not only injure the appearance but affect the flavor of the fruit. [Illustration: FIG. 11--TYPICAL BUNCH OF MODERN TOMATOES Contrast with Figs. 9 and 10] CHAPTER IV Essentials for Development =Sunlight.=--Abundant and unobstructed sunlight is the most essential condition for the healthy growth of the tomato. It is a native of the sunny South and will not thrive except in full and abundant sunlight. I have never been able to grow good tomatoes in the shade even where it is only partial. The entire plant needs the sunlight. The blossoms often fail to set and the fruit is lacking in flavor because of shade, from excessive leaf growth, or other obstruction. The great difficulty in winter forcing tomatoes under glass in the North comes from the want of sunlight during the short days of the winter months. Were it not for the short winter days of the higher latitudes limiting the hours of sunshine, tomatoes could be grown under glass in the northern states to compete in price, when the better quality of vine-ripened fruits is considered, with those from the Gulf states. Growers are learning that tomatoes can be profitably grown under glass during the longer spring days, and consumers are beginning to appreciate the superior quality of fruit ripened on the vine over that picked green and ripened in transit. At no time is this need of abundance of light of greater importance than when the plants are young and, if they fail to receive it, no subsequent favorable conditions will enable them to recover fully from its ill effects. It is not so much the want of room for the roots as of light for the leaves that makes the plants which have been crowded in the seed-beds so weak and unprofitable.