EFFECT OF SOIL-TEMPERATURE ON THE SEED COMPOSITION OF 3 SPANISH CULTIVARS OF GROUNDNUT (ARACHIS-HYPOGAEA L)

The influence of the soil temperature regimes 20/14 (T1), 26/20 (T2), 32/26 (T3), and 38/32 degrees C (T4) (day/night) on seed composition of three Spanish genotypes of groundnut (Arachis hypogaea L.) was investigated. From T1 to T2 the oil concentration increased and the starch concentration decreased remarkably, but only slightly to T3. The protein concentration was higher in the two warmer soil temperatures than in the colder temperatures. There was no difference between T3 and T4 for oil, starch, and protein concentration. The total soluble sugar concentration was higher in both extreme temperature regimes than in the intermediate treatments. The oleic/linoleic acid ratio increased from T1 to T3. The results show that soil temperature has a marked effect on the proximate composition and fatty acid profile of these groundnut cultivars.