Page:Report of the Puerto Rico Experiment Station (IA CAT31294391015).pdf/27

 R.. Ferrer Delgado

No significant difference in growth was observed in an experiment where different fertilizer treatments were applied to various bamboo species except Bambusa tulda. The culm growth of fertilized clumps of this species was consistently better than the checks. The other species may show response to the fertilizer as time goes on.

An experiment was started in October 1947 to observe and measure the effect of annual applications of filter-press cake, ammonium sulfate, superphosphate, and potassium chloride on Bambusa tulda. The data obtained to date show marked differences between treatments as compared with the checks, especially between the ammonium sulfate and the unfertilized clumps. The growth and vigor of the clumps fertilized with ammonium sulfate was almost double that of the checks.

F. Montalvo Durand In 1946 a planting of Bambusa tulda was made at three different spacings: 15×15 feet, 20×20 feet, and 25×25 feet on the square, on a Mucara silty clay loam at Cidra. The object of this experiment was to determine the most desirable planting distance for this species. Recent growth measurements show that the clumps planted at 25×25 feet have more and bigger culms per clump than those planted closer.

R. H. Hageman, H. E. Warmke, and E. P. Hume

The major portion of the water used in the greenhouses comes from the spring at Las Mesas, via the station storage reservoirs. This water has a total solids content of 125–150 p. p. m., and a pH of 8.8.

Continuous application of this water to greenhouse plants produced iron chlorosis, apparently induced by the high pH. Another source of water supply for the greenhouses has been the pond water that drains from La Jagua. This water has been shown to contain high concentrations of water-soluble manganese (1 p. p. m.) at certain seasonal periods. The high manganese content plus the fact that the water may be contaminated with pathogenic organisms makes it undesirable for continued use in the greenhouse.

The installation of a 750-gallon storage tank on top of the new head house and the use of other existing equipment has made it possible to neutralize the Las Mesas water. The unchlorinated waste water from the chlorinator is piped to two separate 500-gallon cement tanks located in the greenhouse. When one of these two tanks is full, 170 ml. of H2SO4</chem?, acid (1–10) is added and mixed and the contents pumped into the storage tank. By alternate use of the two cement tanks an adequate supply of water with a pH ranging from 6.6 to 6.8 is maintained for use in the greenhouse.

J. Leria

Yields of the Columnaris variety of Coffea arabica L., from Java, and the West Indian variety were compared for the fifteenth crop year