The Influence of selected arbuscular mycorrhizal fungi on growth of Curcuma longa and Cymbopogon citratus grown on biochar amended soil

Abstract

The composition of active compounds in medicinal plants is mostly influenced by their growth period and factors that either facilitate or mar their growth. This study assessed the growth of Curcuma longa (Tumeric) and Cymbopogon citratus (Lemon grass) inoculated with two species of arbuscular mycorrhizal fungi (AMF) (Funneliformis mosseae and Rhizophagus irregularis) and grown in soil augmented with biochar. The physicochemical properties of the soil were determined using standard methods. Standard methods were used to measure the growth parameters of both plants and mycorrhizal colonization assessment was examined using standard methods. The physicochemical properties of the soil used were: light intensity (5.00) and pH (7.00). For growth parameters, C. longa responded better to AMF inoculation and biochar application for shoot length and leaf area (17.70±0.56cm; 230.00±6.56 cm2) than C. citratus (16.30±0.00cm; 53.23±4.28 cm2). The number of leaves on C. citratus was higher (68.00±0.00) when compared to C. longa (9.33±0.67). For total photosynthetic Pigment (TPP), C. longa inoculated with F. mosseae recorded (62.60±18.58mg/kg) and C. citratus inoculated with a combination of R. irregularis + biochar recorded (64.57±1.87mg/kg). For total fresh weight; C. longa inoculated with F. mosseae yielded 259.03±1.64g compared to C. citratus, treated with R. irregularis + F. mosseae + biochar (189.63±0.49g). For mycorrhizal colonization percentage, C. longa inoculated with a combination of R. irregularis, F. mosseae and biochar recorded the highest AMF colonization (56.60%) when compared to C. citratus inoculated with F. mosseae (4.85%). The increase in growth observed in both plants could influence their significance and use in pharmaceutical, herbal and food industries. Inoculation of aromatic and medicinal plants with AMF species and soil amended with biochar can contribute positively to increase its medicinal value and potency for human use.