Lettuce

  Lettuce, botanically known as (Lactuca sativa L.), the only domesticated Lactuca species belonging to family Asteraceae or Compositae. It is the world’s most used salad crop and is a major and extensively grown cool season vegetable best adapted to temperate locations. Records show that cultivation of this herb dates back 500 B.C. In some countries, lettuce consumption is large enough to make a significant nutritional contribution. Its early usage was probably on medicinal field and for edible seed oil (Rubatzky and Yamaguchi, 1997). According to various authors as cited by Ybañez (1981), it has been derived from a wild species – L. scariola and some type do not thrive in hot, dry weather.

  Like some other crops, lettuces are grown in a wide range of soil types. Soils having good moisture retention qualities with adequate drainage, such as sandy loams or organic soils are preferred. Lettuce is sensitive to soil compaction and acidity. Seedlings have a low tolerance to salinity, whereas older plants are more tolerant. Growth optimized by uniform moisture supply and prolonged soil saturation should be avoided (Rubatzky and Yamaguchi, 1997).


 From the studies of Deanon and Celestino (1959) as cited by Ybañez (1981), they found out that sub-irrigation produces more vigorous lettuce plants with higher yields. Moreover, in the country, Sarian (1973) as cited again by Ybañez (1981) said that the best production of lettuce is usually from September to February, when it is relatively cool. He further stated that price heading lettuce can be grown successfully here. This statement is correlated with Tindal’s view (1968) as mentioned by Ybañez (1981), that the country is one of the areas in which lettuce is widely grown, with reference to leafy types, and for the heading to be protected from excessive sun and rainfall.

The prime consideration of this study is to observe the growth performance of lettuce as affected by decayed rice straw.