| Abstract: | Starch content of potato tubers in relation to K nutrition and tuber growth In a pot experiment with potato (cv Saturna) K content in tubers increased from 1.0 to 2.6 % of tuber-DM due to increasing rates of K fertilizer. Simultaneously starch in tuber fresh matter decreased from 21 to 15 %. Highest starch content in tuber dry matter was obtained in that K treatment which gave the highest yield in dry tubers. Measuring starch accumulation during tuber growth revealed that already in the flowering stage differences exist in the starch contents of the tuber dry matter between the lowest and highest K treatments, namely 69 % for K1 as compared with 64 % for K5. The rate of starch accumulation between flowering and final harvest, however, was similar in all K treatments. This suggests that K supply affects the storage tissue at an early stage of tuber development probably via different water relations of tubers. |
