| Popis: |
In a field experiment three irrigation treatments were given to twelve peanut genotypes through drip. At 80 days after sowing (DAS) the amount of irrigation applied was 20 % higher than the evaporative demand (ET) in T1, 25 % less than ET in T2 and 48 % less than ET in T3 against the cumulative evaporative demand of 412 mm. The relative water content (RWC) of peanut leaves reduced by cutting irrigation from 93.5 % in T1 to 91.1 % in T2 and 77.2 %i n T3 but, net photo- synthetic rate (PN) was higher in T2(29.6 μmol m -2 s -1 )thanT1 (28.6 μmol m -2 s -1 ) and T3 (24.3 μmol m -2 s -1 )a t 75-80 DAS. Peanut genotype ICGV 91114 showed the highest PN (30.9 μmol m -2 s -1 ) which was statistically at par with GG 20, ICGV 86590, TAG 24, SB XI, TMV 2 and TPG 41. The non- photochemical quenching (NPQ) varied with different irriga- tion treatment with lowest in T2 and highest in T3. The de- epoxidation state (DeS) was 38 % in T1 and T2 but, increased to 47 % in T3 due to the sever water deficit stress. Applying 20 % higher irrigation than the ET demand (T1) does not war- rant any extra benefits in terms of higher photosynthesis in peanut at 75-80 DAS. Further, a reduction of 25 % of the ET (T2) in peanut seems to be the ideal condition for photosynthe- sis and desirable chlorophyll fluorescence parameters at 80 DAS. Girnar 3 and ICGV 91114 showed NPQ value above 2.2 and higher de-epoxidation state, maintained least deviation in Fv/Fm and Fv'/Fm' under severe water deficit condition are promising peanut genotypes. |
