Lactuca sativa L.
Lettuce is an annual plant of the family Asteraceae. It is most often grown as a leaf vegetable, and used for salads. It is also seen in other kinds of food, such as soups, sandwiches and wraps; it can also be grilled.
Climatic requirements/ Areas suitable for cultivation
Can be grown throughout the year in Upcountry Wet and Upcountry Intermediate Zones as it requires cool climate. The optimum temperature for growth should be less than 20°C. In hot climates, lettuce has a bitter taste, early flowering, and the internodal length will be high and the plant grows taller.
A well-drained sandy loam soil with a loose structure and rich in organic matter is essential for good growth.
Plough the soil to a depth of about 30 cm and compact the soil finely. Then make raised beds about 1 m wide and a manageable length.
Prepare the soil to a fine texture and apply organic manure to the nursery beds. Apply the seeds in rows at 10 cm spacing. Seedlings can be planted in permanent ground about three weeks after germination.
Transplant in raised beds at a spacing of 30 cm between rows and 15 cm between plants. Since lettuce is often grown as a mixed crop with carrots and leeks, there it can be planted at a spacing of 20 cm between plants.
Time of application
Two weeks before planting
3-5 days before planting
Poultry manure/cattle manure/compost
Time of application
One day before transplanting
Irrigation/ Water supply
Good water supply is required for good growth and quality harvest. Therefore, water daily, in the first few days after planting. At about two weeks of age, water every four days according to rainfall.
Proper growth of the crop should be maintained in the field without weeds. Hand weeding is advisable.
The larvae, which hatch from eggs, damage the root and lower parts of the stem and enter into the plant through the stem.
Capturing and destroying adults using yellow or blue sticky traps
Caterpillars cut the seedlings at the base
Inspect the crop and apply the recommended pesticides when there is a severe damage.
Can be severe with high atmospheric humidity. Infection occurs when lower leaves of plants contacted with soil. Rot starts from the lower leaves and move upwards.
The disease can be controlled by planting seedlings in the field at proper spacing and preventing the lower leaves of the plant to touch with the soil.
Applying polythene mulch to the soil surface will also reduce this infection.
Rotting occurs in the lower leaves and stems and then spreads to the upper leaves. White mold growth can be observed under high humid conditions
The disease can be controlled by improving drainage, planting at proper spacing and preventing the lower leaves of the plant from touching with the soil.
Can be harvested in 50-60 days after transplanting. At harvest, the entire plant can be removed and the roots cut off. At the time of harvesting a well grown plant should weigh about 200 – 400 g. In home gardening, the leaves can be cut separately and used for consumption as required.
If cultivated as a single crop, the yield is about 15-17 tons per hectare.