Growth and yields of kenaf varieties in central Greece

Kenaf is a rapidly growing crop of great interest as a source of low cost natural fiber. Kenaf fibers can be used in the manufacture for a wide range of pulp, paper and paperboard products and may be a substitute for fiberglass and other synthetic fibers. The purpose of this work was to study the adaptability, growth and yields of three early (PI 3234923, PI 318723 and PI 248901) and four late-maturity kenaf varieties (Everglades 41, Everglades 71, Tainung 2 and JT1) in central Greece. In a period of 3 years (1994, 1995 and 1997), three kenaf field trials were conducted in two fertile sites (Kopais and Aliartos) in central Greece. In the first experiment (1994), the density of the trial was 240 000 plants/ha, while in the second (1995) two plant populations were tested (320 000 and 170 000 plants/ha). Due to the fact that in 1995 the higher plant population (320 000 plants/ha) resulted in higher yields, the following trial of 1997 was decided to be designed only for the high plant density. Data collected in all experimental fields included canopy height, leaf area index (LAI), basal stem diameter, fresh and dry yields and yields components. In contrast with the early-maturity varieties, the late-maturity ones resulted in higher values for all the tested parameters. In all trials, this superiority was statistically significant (LSD Test, P = 0.05) from early August until the end of the growing period. Early varieties exhibited 33.34 t/ha fresh biomass yields (PI 248901, 1997) and late varieties 88.66 t/ha (Tainung 2, 1994). The corresponding values for dry matter yields varied from 9.40 t/ha (PI 318723, 1997) to 23.95 t/ha (Tainung 2, 1994). Between the two plant populations, the high (320 000 plants/ha) was more productive than the low one (170 000 plants/ha), but this difference was statistically significant only until the flowering phase. (C) 2000 Elsevier Science B.V. All rights reserved.