Tillage

Crop rotations are useful in tomato seed production because of the crop's susceptibility to a variety of diseases. Fields used in tomato seed production should be Fall plowed to a depth of 20 cm. This practice not only improves the physical structure of the soil but also encourages the decay of roots and other plant parts thereby enhancing the level of soil organic matter. After plowing, beds are prepared, it allows more uniform fruit ripening and better drainage following heavy rains.

Planting

Tomatoes can be planted either by direct seeding or transplants. When 152 cm rows are used, seed is planted to give a spacing of 20 to 30 cm or 30 to 40 cm if double rows are used. Planting should not begin until the soil temperature has reached 10℃ since germination will not occur below this temperature. The optimum range of soil temperatures for seed germination is between 15℃ and 29℃.

Advantages of direct seedling over transplants are: 1) reduced cost, 2) less diseases, and 3) flexibility of planting time, variety selection, and plant population. Transplanting, when properly done, offers the advantage of more rapid plant establishment and higher seed yields.

Fertilization

Soils that are sandy, light, well-drained, and high in organic matter and mineral nutrients produce the best quality and highest fruit yields. Optimum soil pH should range from 6.0 to 6.5. Tomatoes require an abundance of the three major elements: nitrogen, phosphorus, and potassium. Adequate nitrogen is important to enhance foliage growth which has a major bearing on crop maturity and protects fruits from sunscald. Phosphorus influences fruit quality by stimulating vigorous root growth that enables more nutrients to enter the plant thereby promoting sturdy stem growth and healthy leaf formation. Tomatoes use large amounts of potassium. This element is important in stimulating early plant growth and regulating normal carbohydrate and protein metabolism.

Weed and Pest Control

Tomatoes are subject to a variety of disease and insect pests. Crop rotations on a two to three year cycle with nonsolanaceous species reduce pest problems and are a sound seed production practice. Very few of these diseases infect the seed directly but they can reduce seed yields and cause decreases in seed quality as a result of reduction in vegetative growth.

Fermentative Extraction

Fermentative extraction is the preferred method for producing commercial-grade seed. The process basically consists of breaking or mashing up the fruit into pulp, seeds, and juice, and then pouring the mixture (“mash”) into a large container where it ferments for a period lasting usually three days. After fermentation is complete the seed is separated by washing, and then the seed is dried.