EFFECT OF DROUGHT STRESS ON SOME MORPHOLOGICAL TRAITS AND SEED YIELD OF INDIGO (INDIGOFERA TINCTORIA L.) UNDER DIFFERENT LEVELS OF NITROGEN

Drought stress in arid and semi -arid regions of the world, including Iran, more than any other factors decline the plant growth and production. So selection the drought tolerant and resistant plants for arid and semi -arid areas is the major importance. Indigo (Indigofera tinctoria L.) is one of the resistant plants to drought which is suitable for sowing in dry and hot areas of the country. Therefore, considering the above mentioned, this study was carried out in order to effect of drought stress and nitrogen on yield and some physiological characteristics of Indigo in Jiroft area. The study consi sted of experiments using randomized complete block design with three replications. The main factor was considered to be irrigation treatments including optimum irrigation and severe stress in which irrigation was done after depletion of 90% and 50% of fie ld capacity, with three replications in Jiroft and Kahouj Agricultural Research Center during 2011. Results showed that no stress + 150 kg nitrogen ha -1 increased plant height, No. of Shoot/plant and No. Pod/plants of indigo as 70.98 cm, 8.73, 381.1. Levels of Water deficit stress had different ef fects on plant. Results showed that drought stress + 50 kg nitrogen ha -1 and no stress + 150 kg nitrogen ha -1 increased No. of Seed/pod of indigo as 3.47 kg/h. The most grain yield of about 224 kg ha -1 obtained from the highest density at optimum irrigation treatment.