Lesson 3: Healthy and Strong Plants
Irrigation
Tomatoes must be regularly watered especially during critical periods like flower-setting and growth of the fruits. Watering should be reduced towards the end of a crop. Excess moisture on the leaves can lead to diseases especially early blight.
Weed Management
Depending on the type of weeds and growth stage of both the weeds and the crop, appropriate control measures can be adopted. Manual weeding can be done on small fields but use of herbicides can be considered in extensive farming.
Plant Nutrition
To optimize performance, soil nutrition amendment is necessary. It is a requirement that farmers do a soil analysis which will serve as a base for coming up with a fertilizer program. Apply farmyard manure at a rate of 8 tonnes per acre during land preparation to improve soil structure.
A guideline to fertilizer application will include:
• Basal application of Phosphorus during the early stages for root and shoot development. This can be applied before transplanting.
• Top dressing with Nitrogen based fertilizers such as Urea and CAN for vegetative growth.
• During flowering and fruit formation use of compound fertilizers (NPK) is recommended. Plants require the three primary nutrients; Nitrogen, Phosphorous and Potassium at various levels; fertilizer with high K (Potassium) in formulation will give best results.
• Weekly application of foliar feeds (can be mixed with pesticide sprays) can also foster better plant development.
• Magnesium and Calcium fertilizers can be applied to ensure better fruit development but also when symptoms of blossom end rot manifest.
Staking and Pruning
This is done to reduce excess canopy as well as to get rid of old leaves, which contribute to high moisture accumulation leading to increased disease incidences. This can be done using sticks and strings to give the plant an upright growth.
Advantages of staking
Increase in the percentage of marketable fruit, easier harvesting and reduced injury to both plants and fruit in harvesting. A farmer may opt not to stake but it’s highly recommended.