Yield and Osmoregulation of Sorghum Grown in Saline Soils

Abstract

An experiment was conducted to check the performance and osmoregulation of three commonly grown sorghum varieties (Hytech, Laxmi and Mahalaxmi) at different salinity levels in a factorial complete randomized design with three replications during Rabi 2015-2016 at Department of Soil Science and Agricultural Chemistry, Agricultural College, Bapatla. The proline and total sugar in leaves and calcium, magnesium, sodium and potassium in the diacid extract of plant samples were analysed following standard methods. Considerable reduction in yield was observed at the highest salinity tested. The per cent reduction in grain yield from lowest to highest salinity level was 60.92 while, the per cent reduction in stover yield from lower salinity level to higher salinity level was 51.07. The maximum grain (21.93 g pot^-1) and stover (48.23 g pot^-1) yield was observed in treatment combination 1.5 dS m^-1 x Hytech variety. Proline and sugar content followed an increasing trend with salinity at all stages of plant growth. The cultivar Hytech recorded maximum proline content at all stages of plant growth while, it contained maximum sugars at flowering and intermediate values at other two stages. Significantly higher Ca^2+/Mg²⁺ and Na⁺/K⁺ ratios at 30 DAS, flowering and maturity were recorded at higher salinity level of 12 dS m^-1 than at other salinity levels. The Ca^2+/Mg²⁺ ratio was high at flowering and maturity, while Na⁺/K⁺ was intermediate in Hytech variety compared to others. The study indicated that the Hytech variety performed better at high salinity compared to Laxmi and Mahalxmi due to its high capacity to maintain higher proline and Ca^2+/Mg²⁺ ratio.