EFFECT OF CALCIUM METAPHOSPHATE AND TREBLESUPERPHOSPHATE ON YIELD AND CHEMICAL COMPOSITION OF KENNEBEC POTATOES

A 2 × 5 factorial involving five rates (0, 33, 66, 99, and 132 lb P per acre) of two P sources (calcium metaphosphate and treblesuperphosphate) was conducted with Kennebec potatoes for each of 2 years on Bodenburg silt loam near Palmer, Alaska. Each increasing P rate tended to increase visual rating of plants in July, tuber P content, and P uptake and tended to decrease the foliage K content. P application increased US No. 1 tuber yield, tuber specific gravity, and N, P, K, and Mg uptake by the tubers and tended to increase the Mg content of the potato foliage. Calcium metaphosphate proved equal to treblesuperphosphate as indicated by tuber yields and composition of foliage and tubers. © 1968 Springer.