Uticaј nastiranja i pokrivanja biljaka agrotekstilom na prinos i kvalitet zelene salate | The influence of mulching and covering of plants with agrotextile on yield and quality of lettuce | Утицај настирања и покривања биљака агротекстилом на принос и квалитет зелене салате

Mulching and plant covering are the agrotechnical measures used in the production of lettuce. The aim of the research was to assess the effect of mulching and covering of plants with agrotextile on yield and nutritive quality of lettuce, in spring production in a greenhouse and in an open field. Moreover, the form of nitrogen in the soil was assessed (nitrate vs. ammonium). The experiments were set up by random block system, with six treatments in four repetitions during 2011, 2012 and 2013. The cultivar Nizzi was used in all experiments. In the study, black and white foil were used for mulching, and agro-textile for plants' covering. The following treatments are included: control (without mulch and plant cover), black foil, white foil, black foil and agrotextile, white foil and agrotextile and agrotextile. Mulching and plants' covering, in the greenhouse and in the open field, reduced the content of N-NO3 - in the soil. The largest number of lettuce leaves, in the greenhouse and in the open field, was recorded where mulching with black foil was applied and the smallest one when the plants were covered with agrotextile. The number of leaves in the production of lettuce in the greenhouse was 13.6% higher compared to the open field. The applied treatments significantly influenced the increase of lettuce yield. The yield in the greenhouse was significantly higher than in the open field. The content of dry matter in the lettuce produced in the greenhouse was 26.3% higher than in the open field. The highest content of dry matter, in the greenhouse and in the open field, was recorded when mulching with black foil was applied. Nitrate and beta carotene content in the leaves of the lettuce were higher in lettuce produced in greenhouse than in the open field. The highest beta carotene content was found in black foil treatment in both production methods. The highest content of N in the leaves of the lettuce, in the greenhouse and in the open field, was determined in the treatment with black foil. In the greenhouse, the P content in lettuce leaves was 32% higher than lettuce produced in the open field. The mulching and plants' covering increased the content of Ca in the greenhouse and in the open field with regard to the control. The content of Ca in the leaves of lettuce produced in the greenhouse was 12.5% higher than in the open field. The K content in the lettuce produced in the greenhouse was 3.44% higher than the lettuce produced in the open field. The content of Mg at the lettuce leaves produced in the greenhouse was 13.3% higher than the lettuce produced in the open field. The Zn content in the lettuce leaves in the greenhouse was 78% higher than at the lettuce produced in the open field. In the lettuce produced in the greenhouse, plant covering with agrotextile reduced the Mn content in the leaves. It can be concluded that in the greenhouse lettuce production the significantly higher yields are achieved, in the tretament by mulching with black foil compared to the lettuce production in the open field. Mulching and plants' covering had a positive effect on increasing the yield, dry matter content, vitamin C content and K content in lettuce leaves in greenhouse and open field production. In the production of lettuce in the greenhouse, mulching with black and white foil influenced the increase of N-NO3 - content in lettuce leaves, while in the open field, the lowest N-NO3 - content was registered in these treatments.