Tomato seed runs about 125,000 to 150,000 per pound. An ounce of seed is usually depended upon for plants for an acre. For growing seedlings, seed may be sowed up to 100 or more per foot of row. For a maximum number of strong seedlings from a small amount of seed, thinner sowing is desirable. Rows are usually about two inches apart, and a quarter of an inch is sufficient cover. The seedlings break ground in a week or [ten days].
Figure 13.—Tin can prepared for sowing tomato seed.
Uniformity of depth of rows and of covering is important. Otherwise, seedlings will come up unevenly and there will be considerable waste.
Care of Seedlings
Water and heat should be provided to permit a steady and moderate rate of growth in plants. Over-watering and high temperature yield soft and spindling plants and also plants that are overgrown and that are liable to severe checking before field setting. Under-watering and low temperature give stunted plants. The thermometer at the earlier stages of growth may well stand around 70 to 75 degrees by day and 10 degrees lower at night. A reasonable range of temperature and moisture gives opportunity for the skillful grower to forward or retard his plants as seems best. Great care should be exercised to water evenly. It is necessary to watch the plants constantly to detect the slightest variations in growth. The watering may then be modified and even progress insured.
Ventilation finds its chief significance as a means of controlling temperature and humidity, though actual change of air may be a factor.
High soil moisture, high humidity, high temperature, and faulty ventilation, all favor the ravages of the various damping-off fungi mentioned above which cause little plants to rot off near the ground.