Performance of ornamental and medicinal periwinkle under saline environment

A field experiment was conducted to explore the possibility of growing ornamental and medicinal periwinkle on degraded calcareous soil irrigating with saline water of high and low salinity and alternate mode of the two waters after growing in furrows. It was found that when it was irrigated with high salinity water (EC 15 to 18 dS m⁻¹), the biomass reduced to 50% as compared to low salinity water (EC 8 to 10 dS m⁻¹), while in alternate mode with the two waters the biomass reduction was only 11%. The salinity development in furrows was less as compared to edges and inter-spaces of furrows. When two varieties (pink and white flowered) were grown in pots irrigating with water of different salinity (EC ranging from 4 to 20 dS m⁻¹), it was found that all growth parameters including biomass decreased with increase in salinity. The biomass reduction with water of EC 8 dS m⁻¹ was only 15 to 21% while at EC 12 dS m⁻¹ it was 26 and 41%. The pink-flowered variety was more tolerant than white flowered. The ionic absorption in plant parts in both varieties indicated that absorption of all (Na, K, Ca & Mg) elements increased with increase in salinity. The chlorophyll contents also decreased with increase in salinity. On alkali soils of different pH, the biomass decreased with increase in soil pH. The results indicated that it could be cultivated with success on moderate alkali soil up to pH 9.4 without application of any amendment while on higher pH the yield reduction was very high. Seed germination studies of both varieties showed that most of the seeds germinated within 3–4 days and the germination was decreased with increase in salinity but good number of seeds germinated in water of EC up to 8 dS m⁻¹.