RÉSUMÉ
In this research the cell membrane stability (CMS), relative water content (RWC) and effect of different water interval on Cymbopogon citratus (lemon grass) was assessed. The cell membrane stability and relative water content of the plant shows the physiological activity of the plant. The plant sample was subjected to three different watering regimes viz: one, two- and three-days intervals with a control sample irrigated daily for a period of twelve months. Uniform stalk of lemon grass plants were planted into a depth of 7.5 cm composted soil, each treatment was made in triplicate. The evaluated growth parameters where height of the plant, number of leaves and tillers, which were taken weekly for period of twelve months (year). The height shows a significant difference from first to twelfth month after planting. The height of the plant increases simultaneous with the age of the plant. First month after planting show significant difference in height of sample watered daily and treated samples. The results shows that the RWC (07.14%) and CMS (52.58%) was low in samples under water stress respectively when compared to well-watered samples (55.41%). No significant difference was observed between samples under one, two and three days interval. The number of leaves differs significantly in the first MAP except in the samples watered daily and three days interval. Maximum number of leaves was achieved at twelfth MAP under one day interval (137.33) followed by samples watered daily (126) and two days interval, while three days interval has the least number of leaves (leaf number). The number of tillers shows significant differences between the means at fifth and sixth MAP, (fifth MAP = 73.33 and sixth MAP = 126) and the treatments under one day intervals (fifth MAP = 18.33 and sixth MAP = 35.67). In the research, samples watered daily and under one day intervals shows high productivity when compared to the remaining treatment.