Variation in Growth and Survival of Five Seed-sources of Pinus roxburghii Sarg. under Various Stages of Water Stress

Five seed-sources of Pinus roxburghii were evaluated for their water stress tolerance behaviour. The water stress was developed by withholding watering at daily, weekly, fortnightly and monthly interval. Overall, the growth and survival of the seedlings of all the seed-sources decreased with increasing water stress. The survival percentage was generally unaffected upto weekly watering interval at initial stages (upto two months). However, it started declining afterwards at fortnightly and monthly watering intervals in all the seed-sources. Compared to Sankri, Uttarkashi and Tehri seed source, Gaucher and Mussoorie showed 100% survival at monthly watering interval in the month of September. It has generally been observed that Chir pine is moderately drought tolerant species and could be grown under stress sites without watering upto one month, but it needs irrigation or rainwater in the subsequent months, otherwise, casualties may occur in the plantations. Overall, Uttarkashi, Gaucher and Mussoorie seed-sources were found better in growth as well as for dry matter production as compared to Sankri and Tehri seed-sources.