Influence of nutrients and bio-stimulants on growth attributes of Periwinkle (Catharanthus roseus) plant

Abstract

This study aimed to investigate the impact of the chemical fertilizers nitrogen, phosphorus, and forms of bio-stimulants mainly Argel (Solenostemma argel Del. Hayne) and Haza (Haplophyllum tuberculatum L.) at various rates on the growth attributes and quality of Catharanthus roseus plants under nursery conditions. Experiments were conducted in Sudan University of Science and Technology, College of Agricultural Studies, Shambat, Khartoum North, Sudan. The study was composed of four independent trials as illustrated sequentially: Five levels of; urea 0.0, 2.5, 5, 7.5 and 10 g/plant, triple super phosphate 46% P2O5) 0.0, 2.0, 4.0, 6.0 and 8.0 g/plant. Argel foliar and soil treatments were also evaluated. The foliar treatments were cold, hot and boiled water extracts of 10 g dry leaves of Argel per litre while the soil-dressing test was for 0.0, 5.0, 10.0, 15.0 and 20.0 g/plant dry Argel leaves per plant. The Haza foliar and soil treatments; the foliar treatments were for cold, hot and boiled water extracts of 15 g dry shoots of Haza per litre and the soil application test were for 0.0, 5.0, 10.0, 15.0 and 20.0 g/ plant dry Haza shoot treatments. The treatments were arranged in a completely randomized design where each treatment was replicated seven times. Data were collected after 4 months from treatments, analyzed and the results obtained indicated that: The high urea doses enhanced vegetative growth parameters, while flowering and fruiting of the plant were boosted by the lower urea doses. The encouraging results obtained from urea treatments in this study elucidated an economical potential for possible large-scale production of the plant under Sudan conditions. A general increase was obtained in growth parameters in phosphorus treated plants compared to the control. The result also showed that, the 6 g per plant phosphorus treatment was the most enhancive for vegetative growth, flowering and fruiting parameters. The improvements in growth and yield are indicators of the benefit of Phosphorus applications. Also, there was a general increase in growth parameters in the Argel treated plants compared to the control. Except for the root fresh and dry weights, the highest values of all growth parameters were obtained from the boiled Argel water extract and the 7.5 and 10 g/plant soil dressing treatments. Relatively, there was a general increase in growth parameters in Haza treated plants compared to the control. The highest values of all growth parameters were obtained from the boiled Haza water extract and the 7.5 and 10 g soil dressing treatments. The improvements in growth and yield are indicators of the agronomic benefit of Haza applications; a step towards organic farming.