Potential growth and biomass productivity of kenaf under central Greek conditions: I. the influence of fertilization and irrigation

ABSTRACT: The adaptability, growth and productivity of the kenaf varieties Tainnung 2 and Everglades 41 were studied under two different sowing dates and two plant populations in a field experiment carried out under constraint free conditions in central Greece in 2003. Plant height, LAI and biomass production were measured in subsequent harvests throughout the growing period. It was found that both varieties performed similar growth, whereas growth and biomass yields were almost identical for the two different plant populations. On the contrary, significant differences were found with respect to the two different sowing times. The early plantings performed significantly (P ≤ 0.05) greater growth trates (plant height, LAI, dry matter yield) throughout the growing period, reaching a maximum dry biomass yield of 22.74 t ha-1 by mid-October (17.35 t ha-1 dry stem), whereas the late crops did not exceed 16.08 t ha-1 (11.58 t ha-1 dry stem) by November. Considering that in both cases, similar growth rates were recorded during the growing period (maximum values about 240 kg ha-1d-1), the difference in biomass production was attributed to the larger period available for the early crop for maximum growth