Jl. Valenzuela et al., EFFECTS OF NITROGEN, PHOSPHORUS AND POTASSIUM TREATMENTS ON PHOSPHORUS FRACTIONS IN MELON PLANTS, Communications in soil science and plant analysis, 27(5-8), 1996, pp. 1417-1425
The effects of nitrogen (N), phosphorus (P), and potassium (K) treatme
nts on the P fractions in muskmelon plants (Cucumis melo L. cv. Galia)
are presented. Plants were grown under greenhouse conditions with dif
ferent NPK treatments. Leaves were sampled every two weeks from the mi
ddle third of each plant. After washing in nonionic soap and distilled
water, the leaves were dried in an oven at 70 degrees C and then grou
nd. The foliar contents of several P fractions [inorganic P (Pinorg),
organic P, lipid P, RNA-P, DNA-P, and proteic P] were determined. Inor
ganic and organic P were found to be the major fractions. For both N a
nd K treatments, the Pinorg content increased, although at high doses
(N24 and K30), there was a reduction in leaf content. With the P treat
ments, the contents of the fractions increased steadily, but with the
highest doses (P15 and P20), the leaf content of the fractions was ver
y similar, indicating a saturation phenomenon. Evolution of the fracti
ons over time showed similar behavior. Constant export occurred in all
the fractions, with the only difference between them being in the ins
tensity of the export effect. The data presented highlight the need to
consider the effects of NPK treatments when P fractions are being use
d as tools for nutritional diagnostics.