PHENOLOGY AND GROWTH OF TWO GROUNDNUT (ARACHIS HYPOGEA L) GENOTYPES AT ELEVATED ATMOSPHERIC CO2 CONCENTRATION

The groundnut is one of the important oilseed crops of tropical and semiarid tropical countries, which provides a major source of edible oil and vegetable protein. It is a self-pollinated crop whereby flowers are produced above ground and after fertilization, pegs move towards the soil and seed-containing pods are formed and developed underneath the soil. Two popular groundnut genotypes in Andhra Pradesh, India i.e., Dharani and K-9 were selected to evaluate their growth and flowering pattern at ambient (398ppm) and elevated (550ppm) CO2 conditions in the Open Top Chamber (OTC) facility. Higher number of flowers at elevated CO2 (eCO2) was recorded with both genotypes at 60 DAS as compared to ambient CO2 (aCO2) and increase was 158% in K-9 and 80% in Dharani. The morphological and biomass parameters such as plant height, number of branches, root length, root volume, leaf number, leaf area, flower number, dry weights of shoot, root and leaf were higher at eCO2 with both genotypes, however the magnitude of response differed