Investigations on the bio-stimulating potential of some selected local flora on growth and productivity of Lemongrass (Cymbopogon citratus)

Abstract

For increased yield per unit area, growers intensified the use of agricultural chemicals which is hazardous to humans and environment. In conformity with the growing interest in the use of botanicals as alternatives to these chemicals in Sudan ,this study was undertaken to investigate the bio-stimulating potential of shoot powder and water extracts of Henna (Lawsonia inermis), Moringa (Moringa oleifera), Hargel (Solenostemma argel Del. Hayne),and Haza (Haplophyllum tuberculatum) on growth attributes and productivity of Lemongrass (Cymbopogon citratus) . Besides synthetic hormones namely; Gibberellic Acid and Benzyladenine were also tested for stimulation of growth and productivity of lemongrass. All treatments were conducted under nursery conditions at Khartoum, Sudan. Henna, Moringa , Hargel and Haza powders were tested as soil dressing for Lemongrass in doses of: 0, 4, 8, 12 and 16 g/ plant, while tap water extracts of their powders were tested as foliar applications on Lemongrass in concentrations 0, 4, 8, 12 and 16 g/l. All tests were arranged in complete randomized design. Each treatment was replicated six times. Data were collected 6 months after treatments for number of leaves, leaf length (cm), leaf width (cm), leaf chlorophyll content, leaf fresh weight (g), leaf dry weight (g), root fresh weight (g),root dry weight (g),and leaf oil contents (%). Data were subjected to analysis of variance . Means were separated by Duncan’s Multiple Range Tests at 95% confidential tests. According to the test of bio-stimulating potential of Henna powder and water extracts on the growth and oil yield of Lemongrass ‚ considerable gains in growth parameters were obtained upon soil dressing with 16g of Henna powder, whereas these parameters were enhanced substantially by the 8 g/l foliar treatment. On the other hand, the impact of Moringa applications on the growth attributes and yield of Lemongrass plant were obtained upon soil dressing with 4g of Moringa leaves per plant whereas these parameters were enhanced substantially by the 8 g/l foliar treatment. Also the results of this study confirmed that applications of Hargel as a bio-stimulant source had a positive effect and enhanced the growth attributes of lemongrass. The best growth result in adding Hargel as soil dressing was obtained with 16g Hargel / plant ,while the 4g/plant hargel resulted in the best significant increase in shoots and roots fresh and dry weights. The best results of adding Hargel as foliar applications were 8g /plant . The Impact of Haza ( Haplophyllum tuberculatum) applications on growth attributes of Lemongrass revealed a general increase in growth parameters in the treated plants comparing to the control ,the highest values of all growth parameters were obtained upon soil dressing with 4g of Haza leaves per plant whereas these parameters were enhanced substantially by the 8 g/l foliar treatment. The results of hormones experiment indicated that Gibberellic Acid and Benzyladenine altered the growth of Lemongrass. The highest values of leaves number, leaf length , width , Chlorophyll content , shoot fresh and dry weights were obtained with BA treatment, while roots fresh and dry weights were obtained with the combination treatment (BA+GA3). These results elucidated the signification of these uses of the tested plants as bio-stimulators for Lemongrass plants .Yet further confirmatory tests are needed coupled with phyto-chemical studies to define the active constituents responsible for these enhancements.