A study on the performance of two lettuce varieties in soils from Malta

Abstract

Two lettuce varieties, Cos Romaine and Red Oak Leaf, were grown in peat and in three different soils from Malta in order to determine the best medium for cultivation. Seedlings were planted in medium sized pots that were then placed under tunnels. Depending on meteorological conditions, the pots were watered between two and four times a week in order to maintain soil moisture content of approximately 8.5%. The diameter of the Red Oak Leaf and the length of the Cos Romaine were measured approximately every 7 to 12 days. The Red Oak Leaf lettuces were harvested after 38 days and the Cos Romaine after 60 days. The mass of lettuces of both varieties was measured after harvesting. The results indicated that the best medium for the cultivation of these lettuce varieties under local conditions is peat. This is followed by Terra Rossa soil and the San Biagio soil. Lettuce matured much later in the clayey San Lawrenz soil. A number of farmers were interviewed in order to establish which type of soil is preferred by local lettuce growers, which lettuce varieties are mostly popular with Maltese farmers, and which type of lettuce they believe is the most profitable. Local farmers strongly suggested Terra Rossa soil and to a lower extent the San Biagio soil as the best soil for lettuce production. Farmers did not refer to either the San Lawrenz or Peat as ideal. The experiment together with data from the "Pitkali Markets" strongly suggests that farmers also consider cultivating new varieties.