EFFECT OF DIFFERENTIAL IRRIGATION ON OIL CONTENT AND ITS COMPOSITION IN SUMMER GROUNDNUT (ARACHIS HYPOGAEA L.)
Loading...
Date
1988
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
AAU, Anand
Abstract
Groundnut (Arachis hypogaea L.) is an important oil seed crop contributing to a large share of the vegetable oil needs of the country, especially that of the State of Gujarat. Different agronomic practices are known to affect the yield and quality of oil in groundnut. In present studies an attempt was made to understand the influence of different levels and frequencies of irrigation on the oil content and lipid composition of the oil. GG-2 variety of groundnut was grown in replicated plots and subjected to either no irrigation or given excess of irrigation at selected and critical stages of plant life. The content of oil in the kernels from harvested pods and its lipid class composition by thin layer chromatography was estimated. The proportion of different fatty acids in the oil, triglyceride (TG) fraction and free fatty acid fraction (FFA) were measured by Gas Liquid Chromatography. The results showed that oil content tended to be low when either water was withheld or given in excess at critical stages of plant life such as pod filling and pod maturity when compared to a schedule of regular irrigation at 10-15 days interval with a total of eight irrigations. The composition of different lipid classes did not show any significant changes due to differential irrigation. Triglycerides tended to be lower when no irrigation was given in the flowering and peg formation period (94.33 and 94.37%) compared to normal irrigation schedule (96.37%). The oil fatty acid profile did not show any difference while the same in TG and FFA fractions showed minor but inconsistent changes in response to differential irrigation. Generally the oleic acid increased while linoleic acid decreased in FFA fraction resulting in higher 0/L ratio under restricted and excess irrigation conditions. Correlations among fatty acids of TG and FFA fractions showed similar inverse relationship between oleic and linoleic as well as oleic and linolenic acids. Germination of the seeds was in the range of 83.3 to 97% at the end of 8 months of storage in pods from different irrigation treatments indicating that viability was relatively unaffected by differential irrigation in present experiments. To summarize, differential irrigation at selected and critical stages of plant life did not seriously affect the oil content or composition in the present experiment except for a trend for decreased oil content and altered oleic/linoleic acid ratio under both restricted and excess irrigation conditions compared to normal schedule of irrigation. The high germinability of the seeds aptly supports the lack of large changes in lipid profile in the oil.
Description
Keywords
BIOCHEMISTRY
Citation
No. of references 111