Effects of soil matric potential on tuber yield and evapotranspiration of potato.

This study has been carried out through field trials with irrigation in the river valley of Southern Morava, near Nis, at the alluvium soil type, in the period 2008-2009. The experimental field consisted of three treatments with irrigation (soil matrix potential of 20, 30 and 40 kPa), as well as unirrigated, control. Irrigation schedule was determined by tensiometers on the basis of the observed soil matrix potential values. The highest potato tuber yield (48.30 t ha -1 ) was observed at the variant where soil matrix potential of 30 kPa was kept. Potato tuber yield was the highest when water consumption for evapotranspiration amounted from 491.3 to 498.6 mm, while at higher or lower values of water consumption for ET tuber yield dropped. Water use efficiency of potato during the studied period ranged from 81.23 to 98.21 kg ha -1 mm -1 . The data concerning tuber yield, evapotranspiration and WUE of potato point to the fact that, in order to reach high potato tuber yield and quality, one ought to keep soil matrix potential at levels around 30 kPa for the conditions of south Serbia.