Abstract:

Abstract：【Objective】The perennial cultivation of annual cotton is very important for maintaining genic male sterile lines, producing hybrid seeds, fixing heterosis and preserving special germ plasm. The contents of N/P/K and soluble sugar in leaves and stems for perennial cultivation of annual upland cotton was researched to supply the theory of perennialcultivation technique.【Method】Random block design and orthogonal arrays were set up to investigate the contents of N/P/K and soluble sugar in functional leaves and stems of triennial and biennial cultivation of annual upland cotton among 4 varieties of upland cotton, with annual cultivation as contrast ,in Nanning Guangxi from 2005 to 2007.【Result】The contents of N/P/K and soluble sugar in leaves for perennial cultivation of annual upland cotton in all treatment was 3.13%～3.50%、0.49%～0.67%、1.47%～1.78%、4.23%～5.48%，the contents of them in stems was 0.56%～0.82%、0.21%～0.28%、1.14%～1.42%、0.95%～2.15%；There were no significant differences between the contents of N/P/K in functional leaves of different perennial ages, the contents of soluble sugar in leaves for annual upland cotton of most varieties is very significantly higher than that of perennial cotton；The contents of N/P/K in leaves of high yield varieties was moderater and of soluble sugar was less than of low yield varieties ,the contents of N in leaves of low yield varieties was less and of P/K、soluble sugar was high ；The contents of total N in different month changed from higher in prophase to lower in anaphase, of soluble sugar from lower to higher，with growing process. And the contents of total P and soluble sugar changed stably.【Conlusion】It indicates that there were no significant change on the contents of N/P/K in perennial ages，but nitrogen fertilizer was increased in mid-later growing period of perennial cultivation to improve nutritive growth and delay aging for plates.