Growth and yield of lettuce (Lactuca sativa L.) grown under two types of cultivation systems as influenced by different organic soil amendments

Lettuce production in the lowland part of the Philippines is considered impractical due to its tropical climate; however, the need to produce is important due to the increasing demand. A study was conducted to assess the performance and profitability of tunnel type structure and open field grown lettuce with different organic soil amendments. This was carried out in split-plot arranged in randomized complete block design with 3 replications. The type of cultivation as open field and protected cultivation using tunnel structure covered with net served as the main plot and soil amendments consisting of control, carbonized rice hull, vermicast, chicken dung, wokozim^TM and biogreen^TM as the sub-plot. The protection provided by the tunnel type-structure roofed with net to lettuce plants was manifested by the significantly higher percent survival of 87.27% compared to 78.47% in the open field grown plants. The protection likewise resulted to a very low percent bolting of only 0.23 to 4.86% in the open field. The yield and yield components of lettuce however were not significantly affected by the type of cultivation due to the absence of heavy rains during the period of experiment. Among the organic soil amendments used, biogreen^TM produced the most number and heaviest marketable heads and total yield.