User blog:Balancedune3/mushroom

Lettuce (Lactuca sativa L.) is a popular salad vegetable belongs to family Compositae having chromosome number 2n=18. The crop is originated in Eastern Mediterranean region (Rubatzky et al. 1997). Lettuce is classified into four major typesnamely Head lettuce (Lactuca sativa var. capitata), Leafy lettuce (Lactuca sativa var. crispa), Cos or Romanian lettuce (Lactuca sativa var. longifolia) and 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 in color, round in shaped and tightly packed with lettuce leaves like cabbage head.

Lettuce is an excellent source of different vitamins and minerals like vitamin A (276 IU/100g), B1 (0.057mg/100g), B2 (0.062mg/100g), B5 (0.15 mg/100g), B6 (0.082mg/100g), vitamin C (3.7mg/100g ), vitamin K (102.3 μg/100g) as well as calcium (35 mg/100g), iron(1.24 mg/100g), magnesium (13 mg/100g) etc. The high cellulose content (1.1g/100g) of leaves facilitates digestion of food. It also contains lactocin and lactucopicrin which reduced insomnia. Iceberg lettuce has high water content (95 per cent) and very low in calorie (13 kcal/100g), which is very effective for weight loss efforts. Owing to higher folate content (73μg/100g), Iceberg lettuce helps in fighting heart diseases and strokes, as well as protectinginfants 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 cardiovasculardiseases, age-related macular disease (ARMD) in the elderly, Alzheimer's diseaseand cancers.

Chicoric acid is a major phenolic compound found in lettuce that can be accumulated in significant amounts in response to various abiotic stresses including, heat shock, chilling, mild water stress and high light (Annonymous, 2016).Earlier Europe and North America were the leading producer of lettuce however since late20th century the production and consumption of lettuce had spread throughout the world.

Inpresent day China is the leading producer of lettuce in the World, followed by USA. India

ank 3rd in commercial production of lettuce occupying 4% of World’s total production

(Anonymous, 2011). The Nilgiri mountain of South India emerging as Iceberg lettuce

production hub for the multinational food giant McDonald’s. Ooty Farms and Orchards, now

known as Green Earth Fresh Produce, joined the McDonald’s family and become one of the

three suppliers of Iceberg lettuce to McDonald’s India. Starting with 100 tonnes for only six

months in a year, the supply from the Nilgiris has increased to nearly 1,250 tonnes a year

now (Anonymous, 2014).

The demand of lettuce is growing very fast. The restaurant industry is booming steadily

because the country's young generation preferring international cuisine like burger, pizza,

sandwiches, tacos, spring roll etc. where lettuce is an integral part.[

The growing public concern about safety and quality of food and the high awareness of the

health problems motivating farmers to focus on organic vegetable production. Consumers

showing interest towards consumption of organic food with perception of being safe, healthy

and hazard free besides having superior organoleptic quality. India has vast potentiality to

compete the emerging International market. Although the demand for organic products is

high, particularly in export markets, the rate of farm conversion to organic production

systems is relatively slow. There is an emerging need to create public awareness regarding ill

effect of chemical farming and benefits of organic products and production system on soil,

environment and animal health.

Nutrient source played important role in organic lettuce production. Among the

different organic manures, farmyard manure and vermicompost are commonly used in

organic leafy vegetable production. Vermicompost is the cast obtained from the ingested

biomass by earthworm after undergoing physical, chemical and microbial transformations. It

contains nutrients in forms that are readily taken up by the plants and water soluble

components of vermicompost such as humic acid, growth regulators, vitamins and

micronutrients increases the availability of plant nutrients resulting in increased growth,

higher yield and better quality produce (Attiyeh et al, 2002)

Humic acid is an organic biostimulant which is the biochemically active ingredient

of humus used as a growth promoter of different leafy vegetables. Humic acids have been

shown to stimulate plant growth in auxins, gibberellin and cytokinin bioassays (Phuong and

Tichy, 1976). The addition of humate products increase microbial activity and root

development has been noticed which will help in the uptake of iron and zinc and maintained

adequate levels of other micronutrients. Humic acid affects the membranes resulting in

improved transport of nutritional elements, encouraged better photosynthesis and respiration,

enhanced protein synthesis, enzymatic activities and plant hormonal activities (Vaughn et al.

1985).

Seaweed extract is an organic growth stimulants derived from the seaweed

(Ascophyllum nodosum). In recent years the use of these marine macro-algae in modern

agriculture has been investigated by several researchers (Rama Rao, 1990; Rama Rao, 1991;

Manimala and Rengasamy, 1993; Whapham et al., 1993 and Lopez-Musquera and Pazas,

1997). The use of seaweeds as manure improves the seed germination, seedling development,

plant growth and yield, plant height, shelf life, better quality of shelf life, plant tolerance to

environmental stress (Zhang et al. 2004; Hang et al. 2007). The carbohydrates and other

organic matter present in seaweeds alter the nature of soil and improve its moisture retaining

capacity (Crouch and Staden, 1993).

Vermiwash, a liquid plant growth promoter obtained from epigeic and anecic

earthworm varieties (Ismail, 2005). It is the collection of celomic fluid and mucus secretion

of earthworms which is clear, transparent, pale yellow in colour and rich in enzymes,

vitamins and hormones like auxins, gibberellins etc along with macro and micronutrients

(Ismail, 1997). It stimulates the crop growth, enhances the yield and productivity of crops and

also acts as mild biocide. There have been several reports on the use of vermiwash and its

growth promoting effects (Fathima and Sekar, 2014).

The climatic condition of terai zone is highly suitable for lettuce cultivation. Farmers

are gradually adopting lettuce during winter season. To grow organic lettuce farmers are

mostly used farmyard manure or vermicompost an organic nutrient sources. But systematic

work on the performance of different nutrient sources particularly Biostimulants on lettuce

crops is meager for this region.

source: Lettuce cultivation Guide