Tomatoes are among the most popular crops cultivated across the globe and maximizing their potential requires farmers to essentially understand the basics of growing them successfully and profitably.
Moreover, as the seasons transition from winter to spring, this presents conducive weather conditions for growing tomatoes.
The starting point is for a farmer to understand that tomatoes have varying types (cultivars) that can be produced. There are fresh market varieties that a farmer can grow for household and fast-food establishments such as restaurants. Furthermore, there are cultivars best suited for processing or canning purposes, and those used in cuisines and beverages such as cherry tomatoes. To this end, it is important to consider the type of tomato demanded by your target market before you venture into production.
Another essential point to note is the ideal sowing time for tomato seeds, which is conventionally around mid- August and transplanting can be done in early September. At the sowing stage, it is vital to sow tomato seeds in seed trays, at a depth of 1 cm. Once the seedlings commence growth in the seed trays, it is essential to prepare the soil in the garden where the tomatoes will be grown until they reach maturity. The soil must be cultivated to a depth of 20 – 30 cm and should incorporate NPK 2:3:4 (38) + 0.5% ZN at a ratio of about 100 grams per m2.
Moreover, the soil must be prepared and irrigated daily. After 3 weeks, the seedlings in the trays can be transplanted into the garden and this must be done in the evening to avoid heat stress. At transplanting, it is essential to follow spacing recommendations of 40 cm between rows and 30 cm within rows when growing indeterminate varieties. On the other hand, determinate tomatoes can be grown at spacing recommendations of 70 to 140 cm between rows and 40 cm within rows.
Once transplanting is done, it is essential to follow a water requirement of about 500 mm throughout a 90 to 120 day growing cycle. Therefore, each plant needs about 5.56 mm per day if grown over a 90-day period, and about
4.17 mm per day over a 120-day period. Essentially, farmers must develop a fixed irrigation programme as uneven irrigation may cause fruit cankering (cracking). During the growing period, it is important to understand the beneficial effect of fertilizer application for the successful growth of tomatoes.
To this end, during the first 3 weeks after transplanting, applying Nitrogen and Phosphorus based fertilizers to stimulate foliage (leafy) growth and a successful establishment of a robust root system, is essential. This can be maintained until the tomatoes start flowering, then Potassium based fertilizers such as KSO4 (Potassium Sulphate) to ensure fruit quality, must be applied.
Furthermore, it is vital to ensure that the plants are pruned to ensure that only the vines with flowers are left, to concentrate the supply of Potassium to fruit development. At flowering, it is essential to offer support to the tomato plants by staking. This is done by securing the plant with a stick to ensure it stays upright when bearing fruit.
Essentially one must keep pests (red spider mites, cutworms, whiteflies & tomato rust mites) and fungal diseases (early and late blight) at bay by implementing a spraying and dusting plan. Moreover, farmers are encouraged to scout for pests and diseases daily to swiftly respond to outbreaks. Furthermore, after growing tomatoes, it is advisable to plant a different crop to minimize overutilization of nutrients.
Lastly, always remember that when the basics are done correctly from the start, it enables the plants to grow optimally and offers a farmer good yields, sales, and a sustainable income.
*Hanks Saisai is Technical Advisor: Crops & Poultry at Agribank
