1. Methods are given for obtaining in the field quantitative records of plant weight, number and dimensions of leaves, and percentage deficiency, if any, of stored water in the leaf of the pineapple plant. 2. The potential absorptive capacity of the root system is indicated by records of root anchorage in pounds and percentage of main roots and lateral rootlets displaying white non-suberized tips. 3. Only white, semi-meristematic tissue at the leaf base is analyzed for nitrate, potassium, and phosphorus. Regardless of age in months, prior to blossom-bud development, the leaf employed for analysis is always in precisely the same easily recognized stage of development (fig. 6). 4. After emergence of the determinate blossom cluster, no more analyses for nitrate are made, for the external nitrogen supply after budding is essentially without influence upon the development of the original plant and the fruit it may produce. 5. Until the specialized storage tissue of the leaf becomes practically depleted of water, the white basal tissue does not fluctuate materially in percentage of moisture. 6. Macrochemical analyses for starch, the major carbohydrate reserve expressed as percentage of either green or dry material, completely failed to indicate to what percentage of capacity the plants were supplied with starch. This was owing to the fact that relatively xeromorphic yellow-green plants contained such a high proportion of inert lignified elements that, even though essentially all nonsenescent starch-storing parenchymatous tissue was filled to capacity with starch, expression as percentage of the fresh or dry material indicated relatively small amounts of starch. With respect to nitrate nutrition, such a plant is not considered to be deficient in carbohydrates, even though the absolute amount is low. 7. In contrast, black-green, soft, succulent plants containing only about 25 per cent of the starch which their tissues were potentially capable of storing actually had much more starch than the woody ones, whether this content was expressed on the per cubic centimeter basis or as percentage of fresh or dry material. With respect to nitrate nutrition, plants in this category are therefore considered deficient in carbohydrates even though the absolute amount of starch is higher than in the former case. 8. It was determined by means of microchemical observations that the degree of greenness of the leaves reflected what percentage of the total capacity of starch reserves the plant possessed. The greater the degree of yellow-green color of the plant, provided it did not approach senescence, the higher the relative starch content in the sense noted. By employing suitable standards of color (fig. 7), the relative greenness, quantitatively recorded, supplied a sufficiently precise index of carbohydrate content. Without this index, studies on nitrogen nutrition of pineapple, given in part in this paper, would have been of less significance. 9. It is essential to maintain an adequate reserve of nitrate in the plant. If the concentration of nitrate is relatively low, even though measurable amounts are present, its reduction is not so efficiently or freely effected as when it is higher. Sufficient carbohydrates must be available for oxidation as nitrate is reduced. 10. Plants which had been allowed to accumulate a high carbohydrate reserve and to become temporarily deficient in nitrate, when again supplied with nitrate, apparently absorbed and reduced it much more vigorously than other plants continuously higher in nitrate and lower in carbohydrates. Probably for this reason, provided the time until budding was adequate for plants to recover in content of nitrate and synthesize new protein, there was relatively little loss in yield of fruit, as compared with other plants that were at no time deficient in nitrate relative to carbohydrates. 11. If at any time prior to emergence of flower buds, nitrate reserves were deficient in relation to carbohydrates for any considerable length of time, yields of fruit were less than when the deficiency had been promptly corrected. 12. Even when the concentration of nitrate in the plants was extremely low and carbohydrates were also deficient, the addition of nitrogen-whether or not it increased the nitrate reserve-did not result in materially increased yields. In some cases there was an apparent decrease in yield. 13. There was some evidence to indicate that soil temperatures of 68⚬ F. or lower result in limitation of absorption of nitrate by the roots. 14. During seasons when minimum temperatures are not low, plants deficient in nitrate and high in carbohydrates may fruit months earlier than others that contain a more liberal nitrate reserve but a lower concentration of carbohydrates. Following a single night of relatively low temperature or several nights when the temperature was not so low, however, plants comparatively high in nitrate-as well as others that are lower-may apparently differentiate flower primordia simultaneously.