EFFECTS OF DIFFERENT AMOUNTS OF POTASSIUM ON GROWTH AND ASH CONSTITUENTS OF ANANAS COMOSUS (L.) MERR

Abstract

The plants of the high-K cultures in the nitrate series weighed 40% and in the ammonium series 73% more than those of the low-K cultures. The differences in stem wts. between the high- and low-K cultures were much greater than those of plant wts.; being greater for the high-K cultures, 94% in the nitrate and 185% in the NH4 series. Ash values and succulence, the latter as measured by the water content of tissues, were generally higher in the high-than low-K cultures. K was 2-7 times higher in the tissues of the high- than of the low-K plants. The Ca and Mg content of tissues was many times higher in the low- than in the high-K plants. However, the Ca content of the tissues was appreciably lower in the plants supplied with NH4- than with nitrate-N. The phenomena of antagonism between K on the one hand and Ca and Mg on the other are discussed. P was more abundant in the high- than in the low-K plants. The P content of the plants in the NH4 series was greater than in the nitrate series. The plants in the high-K cultures contained more Fe than in the low-K cultures. Also, those of the NH4 series contained more Fe than of the nitrate series, indicating that the higher H-ion concs. in the NH4 series had favored the absorption of Fe by increasing its solubility. The results are compared with those of other workers, the differences are indicated and their significance is discussed.