Irrigation levels significantly affected mean tuber weight in both years (P < 0.01), while
the effects of irrigation methods and method level interaction on mean tuber weight were
significant only in 2000 (P < 0.05) (Table 7). In 2000, the mean tuber weight increased
with increasing water amount under both irrigation method, and higher mean tuber weight
values were obtained with SD irrigation at all irrigation levels except of I0 (Table 7).
However, the highest mean tuber weight was obtained from I66 treatment for both irrigation
methods in 2002. Karafyllidis et al. (1996) also reported an increase in mean tuber weight
with the irrigation at 65% soil moisture availability. Irrigation method level interaction
on plant yield was significantly affected (P < 0.01) by irrigation applications in the both
years (Table 6).