MITIGATION OF CLIMATE CHANGE ADVERSE EFFECT BY ACCELERATING FENNEL GROWTH AND FLOWERING

The present experiment was conducted during 2014/2015 and 2015/2016 seasons in the Farm of Medicinal and Aromatic Plants Research Department in El Kanater El Khairia, Egypt to study the effect of ascorbic acid (AA) and citric acid (CA) individually and in combination on Foeniculum vulgare var. vulgare plants, in order to alleiviate climate change adverse effect by induce early flowering and to stimulate the growth and yield. Ascorbic acid and citric acid were sprayed at two rates 100 and 200 ppm. The following results were recorded: In general, Indian fennel plants were significantly responded to ascorbic and citric acid. Ascorbic acid at 100 and 200 ppm and citric acid at 200ppm increased the vegetative growth (plant height and number of branches/plant), number of umbels/plant, fruit yield/plant and essential oil production. Ascorbic and Citric acid each of them at 100 and 200 ppm decreased the time to flowering, this means that, the antioxidant ascorbic and citric acid stimulating fennel growth, shortening the juvenility stage and induce early flowering. The treated plants by the combination of ascorbic and citric acid at 200ppm gave the highest vegetative growth (plant height and number of branches/plant), number of umbels/plant, fruit yield/plant, essential oil production and accelerating flowering by 27 days in the 1st season and 22 day in the 2nd one in comparison with control. Ascorbic acid at 200 ppm plus CA at 200 ppm gave the highest anethole content and the lowest fenchone. Ascorbic acid at 200ppm with CA at 200 ppm produced the least time to flowering. The application of the combination of ascorbic and citric acid at the highest rate 200ppm had a promotion effect in growth traits and inducing early flowering, therefore accelerating fruiting of fennel plants before the sharp fluctuations of climate that occurred in the spring which in turn had a bad effect in fruiting of umbelliferous plants.