CULTIVATION OF MEDICINAL ISABGOL (PLANTAGO OVATA) IN ALKALI SOILS IN SEMIARID REGIONS OF NORTHERN INDIA.

There is growing global demand for medicinal drugs including isabgol (Plantago ovata). With increasing demand of food for an ever-increasing population in India, it is not possible to bring arable lands under cultivation for aromatic and medicinal plants. Salt-affected lands (both saline and alkali) occupy about 8∙6 million ha. Due to poor physical properties and excessive exchangeable Na⁺, most of these lands do not support good vegetation cover. The marginal and salt-affected lands could be successfully utilized for the cultivation of aromatic and medicinal plants. We achieved almost complete germination of isabgol seeds using up to 5000 ppm salt-solution. Grain yield (including husk) was 1∙47 to 1∙58 t ha^-¹ at pH 9∙2 showing no significant yield reduction as compared to normal soil. At pH 9∙6 the grain yield was 1∙03 to 1∙12 t ha^-¹. At higher pH there was significant reduction in yield. Sowing in good moisture (at field capacity) of soil was found best, but to save time sowing at shallow depth in dry soil, followed by irrigation was also suitable as compared to broadcasting seeds. The chlorophyll content was greater 70 days after sowing compared to younger stages (50 days after sowing). The total chlorophyll and plant biomass were lower from crops grown by broadcasting methods of sowing as compared to two other methods of sowing. The leaf area index (LAI) was higher for the broadcasting method of sowing as compared to the other two methods. Na⁺ absorption increased and K⁺ and K⁺/Na⁺ ratio decreased with increase in pH. Results reported in this paper clearly indicate that isabgol can successfully be grown on moderately alkali soils up to pH 96 without the application of any amendment. [ABSTRACT FROM AUTHOR]