Effects of different fertilizer application level on growth and physiology of Hibiscus cannabinus L. (Kenaf) planted on BRIS soil

Hibiscus cannabinus L. or Kenaf is one of the most potential annual crop planted throughout the world. Being fast growing and multipurpose, it has been utilized as a substitute of jute and, more recently, as raw product for the production of pulp and paper. With strong and long fiber yield, mass production of Kenaf throughout Malaysia is critical. The utilization of less fertile soils such as BRIS soils is important to increase the Kenaf production throughout Malaysia. Thus, the objective of this study was to determine the effects of different level fertilizer application on growth and physiology of Kenaf planted on BRIS soils. V36 variety was used and planted in three different plots by treatments with fertilizers namely high (1960 kg/ plot), medium (1260 kg/ plot) and low (700 kg/ plot) respectively. Each plot comprises 106,000 trees where trees were planted on 20 lines. There were contrasting results on the effects of fertilizer on growth and physiology of Kenaf in the dry (41 days) and wet season (64 days). Significant effects were only observed for diameter, height, leaf number and area during the wet season. Similar results were also found for biomass. The increasing trends with increasing the rates of fertilizer were observed in the wet season for growth and biomass parameters. The correlation analyses between total aboveground biomass with diameter and height were more pronounced in the wet season. AGR, RGR and EG calculated from the differences between the dry and wet season readings for aboveground biomass showed that the higher rate of fertilizer recorded the higher values of AGR and RGR. However, no trend was observed for EG