THE EFFECT OF SOIL AND PLANTS COVERING WITH THE POLYPROPYLENE NON-WOVEN ON THE QUANTITY AND QUALITY OF YIELD OF STEM LETTUCE (Lactuca sativa L. var. augustana Irish)

Abstract

The aim of study was to estimate the effectiveness of polypropylene woven (PP-17) covers usage in growing of stem lettuce. The seeds of ‘Karola’ cultivar were sown in non-heated green-house in the middle of March. The seedlings were planted in the last ten days of April at spacing 40 × 30 cm . The plants were grown in the soil mulched with black cover propylene non-woven. Some plants were covered with a transparent propylene non-woven, others remained not covered (control group). A significant effect of polypropylene non-woven usage was found regarding quantity and quality of stem lettuce. The harvest was forced by 4 days earlier (on average) and the increase of marketable yield of stems was 20.9% in comparison with open-field production. The plants grown under covers showed higher unit weight and the diameters of edible stems as well as higher dry weight content and total sugar content including reducing sugar. The mulching of soil with black propylene non-woven did not affect considerably productivity and yield quality of stem lettuce compared to control group (open-field).

Keywords

• stem lettuce
• covers
• yield quantity and quality