Biofertilizers effects on some agromorphological parameters and harvest stage on nutrients composition of ginger (Zingiber officinale Rosc.)

Abstract

Biofertilizers application may influence growth, productivity and nutrients content by harvest period of Zingiber officinale. These rhizomes are one of the highest value spices in the world for nutrition and health. Experimental field with 2 plots of Z. officinale was carried out (one plot for treatments and other without treatment for dosages according to the harvest period). On first plot, five treatments were applied as follows: Control, Indigenous Microorganisms (IMO), Efficient Microorganisms (EM), Arbuscular Mycorrhizal Fungi (AMF) and Chemical Fertilizer (NPK). Growth parameters investigated including number of leaves, height of the stem, leaf area and collar diameter were recorded during growth period as well as yield and nutrients composition of rhizomes at 6 months after planting. Globally, growth parameters did not vary significantly with the treatments. However, IMO significantly increased yield (14.68 T/ha) and other biofertilizers (>13 T/ha) compared to control (11.13 T/ha). Biofertilizers application significantly increased carotenoids (0.64-0.91 mg/100 g), total phenolic compounds (3508.83 mgGAE/100 g), flavonoids (1420.04-1542.36 mgQE/100 g) and ashes (3.33 g/100 g) contents as well as moisture and micronutrients compared to the control and NPK. On second plot, harvest after 08 months significantly increased ashes, Fe, Ca and Mg contents in rhizomes compared to 6 months but slight decrease in carotenoids, vitamin C and phenolic compounds. These results show the importance of using biofertilizers to promoting Ginger plants and therefore can be a sustainable alternative to the use of chemicals. Then to overcome the problem of some nutrients deficiency, it can be recommended to harvest Ginger at 8 months which is a right harvest period for the synthesis of certain essential nutrients.