Effect of perforated foil and polypropylene fibre covers on development of early potato cultivars

The effect of perforated polyethylene foil and polypropylene fibre cover on the development of the early potato cultivars Aksamitka and Cykada was investigated. The use of the covers resulted in an increase in the soil temperature at the depth of 100 mm on average by 2.2°C at 8 a.m. and by 4.0°C at 2 p.m. in the year with warm spring and by 1.5°C and 3.2°C in the year with cold spring, respectively. A higher increase in the soil temperature, on average by 1-2°C, was caused by the use of the perforated foil than by the use of the polypropylene fibre. The increase in the soil temperature as a result of covering forced the plant emergence on average by 5 days and shortened the period from planting to tuber setting by 5 days in comparison with the cultivation with no plant covering. The higher favourable effect of covering was obtained in the year with the lowest air and soil temperatures in May. The use of the covers at that time forced the plant emergence and shortened the period from planting to tuber setting on average by 6 days. A higher soil temperature increase was observed under the perforated foil than under the polypropylene fibre, which resulted in an earlier occurrence of the successive plant development phases, on average by 1-2 days.