The experiment was carried out to determine the effects of different irrigation water levels on yield and some quality parameters of lettuce (Lactuca sativa L. Var. Longifolia cv.) under greenhouse conditions. Irrigation water was applied through drip irrigation method with 7 days interval during the total growing season. Irrigation treatments consisted of six different water levels (I1: non-irrigation, I2: 25 %, I3: 50 %, I4: 75 %, I5: 100 % and I6: 125 % of cumulative evaporation measured from Class A pan). The amount of irrigation water ranged between 0 and 106.3 mm among the treatments. Evapotranspiration (ET) values varied from 69.1 to 158.5 mm for the treatments. The highest yield was obtained from the I5 followed by I4. A significant polynomial relation (R2=0.77) was obtained between the yield and irrigation water, and linear relation (R2=0.99) was obtained between the yield and ET. This indicated that when irrigation water increased, yield also increased to a certain point. However, when the amount of irrigation water exceeded the plant water requirement, lettuce yield decreased. Yield response factor (Ky) was determined as 1.97. Since Ky ˃ 1, lettuce was very sensitive to water deficiency. In addition, the highest water use efficiency (WUE) and ...
The aim of the study conducted in the years 2014-2016 was to determine the effects of different irrigation systems and doses of different organic fertilizers on the yield of crisphead lettuce. The experiments were conducted in a certified organic field of the Research Institute of Horticulture in Skierniewice. The study compared micro-sprinkler irrigation, drip irrigation and the control combination (without irrigation). The fertilization combinations involved the use of compost at 30 t/ha, Ekofert L in a dose corresponding to 50 and 100 kg N/ha, Fertilan L in a dose corresponding to 50 and 100 kg N/ha, and the control (no fertilizer).It was found that the use of irrigation in the first and third year of the study did not produce positive results, which was due to sufficient rainfall that fully satisfied the water requirements of lettuce plants. However, with a total rainfall not exceeding 80 mm (in 2015), the use of the irrigation systems had a significant impact on yield. Compared with the control, the irrigation with micro-sprinklers in 2015 increased the yield of lettuce by 35%, and in the case of drip irrigation by 40%.The response of lettuce plants to the applied organic fertilization varied in the individual years ...
