The Effect of Plant Growth Promoting Rhizobacteria, Chemical Fertilizer and Humic Acid on Morpho-physiological Characteristics of Basil (Ocimum basilicum var. thyrsiflorum)

Abstract

The application of chemical fertilizers and investigating the effect of plant growth promoting rhizobacteria and humic acid on morpho-physiological parameters of basil, studied by factorial experiment based on randomized complete block design with three replications at experimental farm of Shahid Chamran University in 2015. First factor was 6 types of fertilizer treatments (control, Azetobarvar1, Phosphatebarvar2, combination of biological fertilizers, chemical fertilizer, combination of biological fertilizers+chemical fertilizer (50%)) and second factor included humic acid (0 and 20 kg.ha-1). Morphological (plant height, leaf number and leaf area, fresh and dry weights of aerial parts) and physiological traits (chlorophyll a, b, total, carotenoid, net photosynthesis rate (Pn), transpiration rate (E), water use efficiency (WUE) and radiation use efficiency (RUE)) were measured at onset of flowering stage. The result showed that interaction between biofertilizer and humic acid on plant height, leaf area, fresh and dry weights of aerial parts, chlorophyll total, Pn and QY was significant. Also, the simple effect of biofertilizer leads to a significant increase in leaf number, chlorophyll a, b, and carotenoid. In often parameters, combination of biological fertilizers+chemical fertilizer (50%)+humic acid caused significant increase in compare with control but did not show significant difference with chemical fertilizer and combination of biological fertilizers+chemical fertilizer (50%)+humic acid. The application of biological fertilizers can be consider as a suitable way to replace part of chemical fertilizers.

Keywords

• Azetobarvar-1
• Leaf Area
• Net Photosynthesis
• Radiation Use Efficiency
• Transpiration