Evaluation of the influence of nitrogen fixing, phosphate solubilizing and potash mobilizing biofertilizers on growth, yield, and fatty acid constituents of oil in peanut and sunflower
Three biofertilizers nitrobein, phosphorein, and potash, containing nitrogen fixing, phosphate solubilizing, and potash mobilizing microorganisms, respectively were studied in peanut (Arachis hypogea L.) and sunflower (Helianthus annuus L.). Amendment with each of these biofertilizers enhanced different growth parameters of 30-day-old peanut and sunflower plants. Dry matter in both plants was generally correlated with enhancement of chlorophyll a and b pigments with the three used biofertilizers. The carotenoid contents of these plants were approximately comparable to those of the corresponding controls. In the field experiment, total biomass and seed yield showed superiority in peanut and sunflower cultivated in soil incorporated with potash. The enhancement effect was followed by supplementation of nitrobein in peanut and phosphorein in sunflower plants. The percentage increase in seed yield, compared to the corresponding controls were 122.03, 120.11, 176.62 in peanut and 149.22, 168.75, and 173.44 in sunflower for nitrobein, phosphorein and potash amendments, respectively. The oil content produced per plant was also increased as a result of application of nitrobein, phosphorein and potash in a similar trend to that obtained with biomass gain and seed yield. Generally, saturated fatty acid levels (palmitic, stearic and arachidic acids) were decreased and unsaturated ones, particularly the polyunsaturated essential fatty acids linoleic and linolenic were evoked with these biofertilizer amendments. Maximum increase in linoleic and linolenic acid were exerted by phosphorein and nitrobein, respectively in peanut oil and by potash and phosphorein, respectively in sunflower oil.
Key words: Peanut, sunflower, biofertilizers, growth, yield, oil, fatty acids, sodic soil.