Resistance induction in lima bean plants by silicon and ascorbic acid

Abstract EN

Abiotic elicitors of plant defense can induce plant resistance effective against various insect pests.

Vegetable crops are currently infested with several lepidoptera caterpillars causing economically devastating crop losses.

To date, there is no one treatment or technique has been found to be effective in all cases to control insect pest infestations.

In this study the possible effects of silicon and ascorbic acid to induce resistance in lima bean against feeding activity of Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae) larvae were evaluated under greenhouse and laboratory conditions.

Results indicated that the foliar spray of silicon (1%) and ascorbic acid (0.2%) as individual application on lima bean 30 days after seedlings emergence reduced the feeding activity of the third instar larvae at 5 days after treatment by 29.6 and 19.2%, respectively.

The best efficacy was obtained using a combined treatment by soil drench of silicon 1% and foliar spray by a mixture of (silicon 1% and ascorbic acid 0.2%) (1:1 v/v) showed feeding inhibitory activity of 35.7% and larval mortality of 32.7%.

This combined treatment exhibited also significant increase in the activities of two enzymes (polyphenol oxidase and peroxidase) involved in plant defense mechanism.

Consequently, the use of silicon and ascorbic acid for induced resistance of plant to insects could be contributed in reducing the use of conventional insecticides.