El efecto de las deficiencias de potasio, calcio y magnesio sobre los constituyentes intermediarios de nitrógeno en las hojas de cacao

This investigation determined the soluble nitrogenous compounds in leaves of cocoa seedlings at three different ages, grown under conditions of K, Ca and Mg deficiencies, and combinations of these deficiencies. Under greenhouse conditions the plants were grown in sand with nutrient solutions. At the end of four, months, samples of 30, 60 and 90 day old leaves were taken and analized for soluble nitrogenous compounds using two directional paper chromatography. The effect of leaf age was the following: For total soluble N there was no significant difference between the means of 30 and 60 day old leaves but the means for 90 day old leaves, were higher than those of either younger age. The effect of the treatments was a follows: In general the lack of K and Mg caused the accumulation of intermediary nitrogenous compounds: the lack of Ca did not have such influence. Asparagine was responsible for much of this accumulation but there were also a sharp increase in aspartic acid, glutamine, argenine and proline.