Greenhouse experiments were conducted in winter growing seasons in order to
evaluate the effects of genotype and production methods on yield and
nutritional quality of lettuce (Lactuca sativa L.). A three-year (2009-2011)
study was conducted by randomized block system in a greenhouse without
additional heating. The trial included three genotypes of lettuce (Archimedes
RZ, Santoro RZ, Kibou RZ). Each row with these genotypes was exposed to the
following variants of covering: control-planting on bare soil, mulching
before sowing with PE-black foil, agro textile-covering plants after planting
with agro textile (17 g), a combination of mulching + agro textile.
Throughout of all the three years of the trial, it was continuously evidenced
that the genotype ?Santoro RZ? had the biggest heads and the highest yield
(15.33 kg 10 m-2), which leads to conclusion that the yield of lettuce is a
genotype characteristics. Moreover, the nutritional value (ascorbic acid
concentration) has shown that, depending on the method of production, in
average, the combination of mulching + agro textile (26.77 mg 100 g-1) had
the highest content while the control variant had significantly lower vitamin
C content (21.10 mg 100 g-1). The three-year researches have shown that the
production method and genotype significantly affect the nitrate content. An
average nitrate content was 2196.33 mg kg-1 on the control variant, and
2526.24 mg kg-1 on agro textile. Leafy lettuce of genotyp ?Kibou RZ? had
lower nitrate content (2176.85 mg kg-1) compared to ?Archimedes RZ? (2843.05
mg kg-1) and ?Santoro RZ? (2221.37 mg kg-1). However nitrate concentration in
all treatments remained within the European Union?s permissible levels.
FOLIAGE APLLIED GIBBERELIC ACID INFLUENCES GROWTH, NUTRIENT CONTENTS AND QUALITY OF LETTUCES (LACTUCA SATIVA L.)
