Lettuce is most popular of the salad crops and is of great commercial importance; first-time Lettuce cultivated in ancient Egypt.
Earlier Europe and North America were the leading producers of lettuce however since the late 20th century the production and consumption of lettuce had spread throughout the world. In present-day China is the leading producer of lettuce in the World, followed by the USA.
India rank 3rd in commercial production of lettuce occupying 4% of World’s total production. The Nilgiri mountain of South India emerging as Iceberg lettuce production hub for the multinational food giant McDonald’s.
Ooty Farms and Orchards joined the McDonald’s family and became one of the three suppliers of Iceberg lettuce to McDonald’s India.
The demand for lettuce is growing very fast. The restaurant industry is booming steadily because the country’s young generation preferring international cuisine like a burger, pizza, sandwiches, tacos, spring roll, etc. where lettuce is an integral part.
Lettuce is classified into four major types namely
- Head lettuce (Lactuca sativa var. capitata),
- Leafy lettuce (Lactuca sativa var. crispa),
- Cos or Romanian lettuce (Lactuca sativa var. longifolia)
- stem lettuce (Lactuca sativa var. aspergina).
Among the cultivated varieties, Iceberg and Great Lakes are the popular head type lettuce grown in India.
The head of iceberg lettuce is light green, round in shaped and tightly packed with lettuce leaves like cabbage head. Lettuce is an excellent source of different vitamins and minerals.
Iceberg lettuce has high water content (95 percent) and very low in calorie (13 k cal/100g), which is very effective for weight loss efforts. Iceberg lettuce helps in fighting heart diseases and strokes, as well as protecting infants from neural tube defects during pregnancy.
Regular inclusion of lettuce in salads is known to prevent osteoporosis, iron-deficiency anemia, and believed to protect from cardiovascular diseases, age-related macular disease (ARMD) in the elderly, Alzheimer’s disease
Soil and Climate for lettuce Cultivation
Well-Drained fertile soil with a pH of about 6.0 is most suitable for the growth of lettuce.
It is moderately salt tolerant. Lettuce is a cool season crop requiring a mean air temperature of 10 – 20°C. Cool nights are essential for good-quality lettuce.
Lettuce is grown mainly in areas having cool summers and mild winters.
Lettuce seeds are very thin and delicate. Approximately 325 grams required for one-hectare Lettuce cultivation.
Since the seed is very fine, plant the seedlings on the bed.
There are approximately 800 seeds of lettuce in one gm.
Nursery raising for lettuce cultivation
prepared raised bed for nursery a well rotten FYM or compost mix with soil at the rate 4 kg/m2.
Make Nursery beds with 100 cm wide and 30 cm in height.
Mix fertilizers, 100 gms of sulphate, and 50 gm of thiamat on each bed and mix them with soils on the bed.
The seeds of Lettuce should be sown in lines at a spacing of 5 cm between rows and 1.5-2 cm depth. The seed should be covered with sand and FYM mixture.
Plants are ready for planting in approximately 21-28 days.
To prevent diseases or pests. Monocrotophos 1 ml and copper oxychloride, mixed with 2 gm/liter of water, spray two sprayers at a span of 15 days
seedlings of Lettuce is ready to transplant in 4 to 5 weeks.
Seedlings should be hardened before transplanting. Hardening is done by withholding water for about 68 days. Seedlings are transplanted in flat beds at a spacing of 45 × 45 cm or 45 × 30 cm.
Approximately 66665 seedlings required to cultivate in the one-hectare area.
Fertilizer management in lettuce farming
The application of fertilizers influences the growth and yield of lettuce. For growing lettuce, 150-200 q/ ha of farmyard manure add with 25 kg of both Nitrogen and potassium and 90 kg of phosphorus per hectare.
On sandy and sandy loam soils without manure, 40-50 kg of Nitrogen and 75-100 kg each of phosphorus and potassium per hectare should be applied.
For good growth on silt loam and clay loam soils, 25 kg each of Nitrogen and potassium and 50-75 kg of phosphorus per hectare may be used.
However, fertilization would depend upon the nutrient availability and the status of soil fertility with respect to essential nutrients. About one third to one half of the nitrogen should be applied at the time of seeding and the rest after thinning operation.
There are various systems of irrigation, which include furrow irrigation, drip irrigation, and sprinkler irrigation.
Frequent and light irrigations have been found to be more effective in achieving high yield and quality production in lettuce farming.
After planting, crops should be irrigated at 8- to 10-day intervals.
Drip irrigation increased yield about 30% over furrow irrigation
Roots of lettuce crop are shallow, so weeding should be done carefully without distributing lettuce. Usually, weeding. After 15 days or according to need.
Maturity and Harvesting
Harvesting of lettuce begins as soon as plants reach acceptable size and firmness and should be completed before the leaves become tough and bitter and before seed stalks start to bold.
The stage of harvest maturity depends on the variety of lettuce and the purpose for which it is grown. In Head lettuce for the market is allowed to grow to full size and to develop a solid head, but for home use, it is often harvested before the head is well formed.
Leaf lettuce plants may be thinned at various times, removing the largest leaves for use and leaving smaller ones to develop.
Lettuce is usually cut with a long-handled sharp knife. lettuce should be packed carefully into a thick cardboard box