EFFECT OF TEMPERATURE AND WATER POTENTIAL ON SP ROUTING OF POTATO (Solanum tuberosum L.) SEED TUBERS FROM DIFFERENT SEED LOTS

A study was conducted to test the germination of several lots of potato seed tubers at different temperature and water potential. The experiment was performed in controlled growing environment using a thermo-gradient table Terratec at the School of Agricultural Science, University of Tasmania, Australia. Seed tubers (grade 45-65 g) of three different seed lots (330, 370 and 340 days after harvest) were planted at four temperature treatments (10, 15, 20 and 25 °C) and three different water potential (-0.6, - 0.4 and -0.02 MPa). Growth media used in this experiment was vermiculite (Grade 2, vermiculite Australia and Perlite Co-P / L). The water potential treatments were prepared based on the relationship of water content and water potential by Whalley et al. (2001). Two seed tubers are planted in each plastic container containing growth media at a depth of 10 cm and covered by the growing medium and sealed. Analysis of Variance and further test of Least Significant Difference (LSD) were performed using SPSS version 14.0 to determine the response of the seed lots to temperature and humidity. Temperature and soil water potential significantly affect the number of sprouts of potato tubers.No significant differences were found in the seed lot used in both the number of sprouts produced and sprout vigor expressed as sprouting capacity (fresh weight (FW) sprouts / FW tuber). Sprout vigor increased with the water potential treatments with the greatest response was observed in the highest temperature treatment. Temperature and humidity interacted significantly (p <0.01) in influencing the sprout vigor of potato seed tubers that show great effect of moisture conditions at high temperatures.