EVAPOTRANSPIRATION EFFECTS ON SALT RELATIONS OF LEPTOCHLOA FUSCA (KALLAR GRASS)

Abstract

St u d i es were co ndu c t e d to c haracterise Na and Cl extru s ion by the l eave s o f ' Kal lar ' grass subj e ct ed to various mo i sture l evels a nd an a ntit ran s pir an t (PMA ) . PMA decr eased t he t r ansp iration rates of 'Ka l lar' grass leaves substantially 24 hours after application . Seventytwo hours af t er it s application some dec r ease in t he tr a nspir ation rat es was ob served , though diff ere nces between the treat ed and non - t reated pl a nts we r e sma ll . Increasing NaCl cau sed re du ction in tr a nspirat i on rat e at fie ld capacit y, and wat er def i c i t both i n (PMA) tr eat ed and no n -t r eat e d p l ants . Howe v e r , r e d u c t ion in transp irat ion with inc reas ing NaCl in t he me dium was not appar e nt at f l ooding . In general , r e lative water content s wer e s u b s - tantiall y de creased in NaCl tr e atme nts. At fl oo din g, application of a nt it r an s p irant (PMA) s li g htl y d e c r e a s ed the dry wei ght s of t o p s a t both s alt l evels . This dec r ease in dry weights was also observed in plants at fie l d capacity and water deficit. Application of PMA did not seem to have s ub stanti al effect on the extrusion o f Na + and Cl by the 'Kallar' g rass leaves. The absolute amounts of Na + a nd Cl extruded by the leaves s ubstanti a ll y increased at hours 72 with increasing NaCl in the medium at flooding and field c ap acity. However , this trend was reversed at water deficit. Low ava il ab il · it~ of wat er may have affected the tr a n sport of salt to the l eaves t hu s affecting extrusion.