The effect of systemic insecticides and nitrogen on oil‐filling in developing seeds of toria (Brassica campestris cv. toria)

The systemic insecticides Metasystox and Temik reduced the oil content and increased the free fatty acid and phospholipid contents of the oil of toria seeds at early stages of their development. The oil level was, however, restored when the seeds were sown in soil supplied with nitrogen. At a later developmental stage (30 days after fertilisation), Temik increased, and Metasystox decreased the triacylglycerol content in the oil. Both insecticides increased the relative proportion of erucic acid in the oil, however this increase levelled off in the developing seeds when the toria crop was supplied with nitrogen fertiliser. In in‐vivo studies, Metasystox at 10 μg ml−1 was sufficient to lower the rate of [1‐14C]acetate incorporation into lipids of developing seeds. The effect of Temik on lipid biosynthesis was not as pronounced as that of Metasystox.