By JAMES TABABA
Tomato ((Lycopersicon esculentum) or kamatis is a widely cultivated crop in the Philippines and worldwide. It is a common ingredient in Philippine dishes. Tomatoes can also be eaten raw, in salads, or processed into paste or sauces.
Tomatoes are known to have carotene and lycopene. Both are antioxidants that help prevent cancer. It is also a good source of vitamin C.
In low-elevation areas in Luzon, tomatoes are planted from October to March when the weather is cool and the climate is dry. Planting is done in slightly elevated areas such as Laguna and Quezon from January to February. Certain areas in Laguna, Quezon, Batangas, Nueva Ecija, Bukidnon, and Misamis Oriental, grow tomatoes during the wet season to take advantage of the low supply.
Here is the production guide for tomatoes:
Soil and climate
The ideal soil type for growing tomatoes is sandy loam, but it can still grow in other soil types as long as there is good soil drainage. Tomato plant grows best in 6-6.8 soil pH.
The ideal climate is cool and dry because high night temperature negatively affects the fruiting of tomatoes. However, heat-tolerant varieties can be grown even during the hot season in low-elevated areas.
It is discouraged to plant tomatoes during the wet season due to the prevalence of fungal and bacterial diseases.
Seedbed/seed box preparation
Seeds are sown first on seedbeds or boxes to facilitate easy management and monitoring of seeds to increase germination and survivability. The seedbed should be raised 20-30 cm to allow good water drainage. Seed boxes can be used for small production.
A suitable planting medium for seedling production is a mixture of compost, coir dust, and carbonized rice hull.
A plastic roof should be installed above the seedbed or seedbox to protect seedlings from heavy rains.
Sowing of seed
The seedbed should be watered first before sowing the seeds. Outline small furrows across the surface 2-4 cm deep and 15 cm between furrows. The seeds are planted every 2.5cm and then thinly covered with compost.
Cover the seedbed with paper, coconut coir, rice hull, or rice straw to conserve water moisture. The cover should be removed after 4-5 days when the seeds emerge. Water the seedbed daily.
Care of seedlings
After ten days, the seedling has now fully emerged. Seedlings planted too close to each other are removed carefully and transferred to facilitate uniform spacing (2.5cm). This process is called pricking.
For seedling trays or boxes, pricked seedlings are transferred to another seedbox. Pricking is done to allow enough space for growth and to prevent disease emergence.
Watering is only done in the morning or the mid-afternoon. Watering late in the afternoon or evening may cause the development of diseases.
To prepare the seedling for transplanting, the seedlings are gradually exposed to sunlight, and the watering is reduced. This is done one week before transplanting to acclimatize the seedlings to the environment.
The soil is plowed manually or two to three times using a tractor at 20-30 cm deep, followed by leveling of the soil. Create furrows with a distance of one meter.
Two weeks before transplanting, animal manure can be applied as a basal fertilizer.
Seedlings are ready for transplant three to four weeks after seed emergence. Select seedlings that are healthy with 3 to 5 leaves. Transplant 1 seedling 50-70 cm apart with rows 1 meter apart. Press the soil gently around the base of the seedlings. Water immediately. Replant missing hills 5-7 days after transplanting. Cover the soil with rice straw or plastic mulch to conserve water and control weed growth.
Tomatoes can also be planted in plastic bags or containers if space is limited.
It is recommended to analyze the soil first to determine the available nutrients before applying fertilizer.
Complete basal fertilizer (14-14-14) is applied at 20 grams per hill 3-5 days after transplanting. After two weeks, 10 grams of urea (46-0-0) and muriate of potash (0-0-60) combined with the ratio of 2:1 is applied 6-8cm from the base of the plant. Lastly, this combination of fertilizers will be applied again after two weeks.
Organic fertilizers can also be applied monthly. Calcium nitrate or calcium phosphate is applied at the rate of 1-3 bags/ha at the onset of flowering.
Vermitea, fermented plant juice (FPJ), fermented fruit juice (FFJ), fish amino acid (FAA), and water-soluble calcium are sprayed every 2-3 weeks, depending on the plant’s vigor.
Trellis is a structure built to support the vertical growth of the plant. It is usually made out of bamboo or ipil-ipil poles as a post. Trellising is done one week after transplanting by tying branches to the post and training it using plastic straws. Trellising is essential in preventing the fruit from touching the soil.
Training of branches is done about six times throughout the growing season. The ‘A’ type is the best trellis to construct.
Water irrigation is dependent on the weather and soil type. Covering the soil with rice straw or plastic mulch will help in conserving soil moisture during the dry season.
During the fruiting stage, irrigation is done once a week. At the harvesting stage, irrigation is reduced to every 10 days.
During the wet season, construct drainage canals to avoid waterlogging
Pruning is the selective removal of side shoots to improve fruit size and uniformity. It also improves air circulation within the canopy to reduce the development of diseases.
Remove the old leaves below the fruit cluster. New sprouting branches are pruned and only leave 3-4 main branches.
Remove weeds near the base of the tomato plants to avoid competition for water and nutrition. Mulching with rice straw and black or silver plastic helps minimize weeds. For non-mulched plots, weeding is done 2-3 times during the growing season
It is recommended to only trim the weeds along the rows to encourage natural enemies of pests.
First harvest usually starts 50-60 days from transplanting. Harvesting can be done 2-3 times per week.
The stage of maturity at harvest depends on the season and distance of the market. Tomatoes for long-distance markets are harvested at the mature green stage. For farms close to the market, fruits are harvested at the breaker stage or when there is a tinge of orange/red color on the peel.
The best stage to harvest the fruit is at the red ripe stage but fruits are prone to postharvest losses at this stage.
Place the harvested tomato in plastic or wooden crates lined with banana leaves or used newspaper to minimize mechanical damage. Bruised and damaged fruits are removed immediately. It is also recommended to pack the fruits with similar maturity in one container.
The Tomato Production Guide by Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development (PCAAARRD) and Institute of Plant Breeding (IPB) can be downloaded for free from the DOST-PCAARRD eLibrary at https://elibrary.pcaarrd.dost.gov.ph/.