THE EFFECT OF pH AND OE CERTAIN MINOR ELEMENTS ON THE GROWTH OE PINEAPPLES IN WATER CULTURES

Abstract

1. A pH value of 4.0 to 4.5 was found to be favorable for the growth of the pineapple plant in water cultures. 2. At pH values above 5.0 chlorosis became increasingly severe. 3. The higher pH values promoted excellent root development while those below 4.0 caused a short, stubby root system. 4. Manganese and zinc tended to cause chlorosis which is due to the nonfunctioning of iron in the plant. 5. Aluminum and boron tended to counteract the effect of the manganese and zinc and tended to cause a normal condition of the pineapple plants. 6. Copper added at the rate of 2 p.p.m. controlled a root fungus that caused stunting of the pineapple plants. 7. No correlation between pH value or minor element composition and gummosis of the fruit could be determined.