A pot experiment was conducted in a green house in piracicaba, Brazil, in order to determine the visual symptoms of deficiency, and the effects of macronutrients omission in P. caribaea var. hondurensis, P. caribaea var. bahamensis and P. caribaea var. caribaea seedlings dry matter production

Abstract

The following treatmente were employed: complete, without nitrogen, without phosphorus, without potassium, without calcium, without magnesium, and without sulphur. Washed sand was used as a substrate, being the plants watered twice a day with the correponding nutrientsolution. After the deficiency symptoms establishment, the plants were cut and separated in upper needles, lower nedies, branches and roots, dried at 75 ºC and weighed. Seedlings dry matter productions are depressed by omission of N, P and S for P. caribea var. hondurensis,by omission of N and S for P. caribae var. caribaea and by omission of N for Pcaribae var. bahamensis, being upper needles' and branches' dry matter productions the major depression sources. P. caribaea seedlings dry matter productions aren't significantly affected by low levels of K, Ca and Mg in nutritive solution.