Improving growth and yield of Roselle (hibiscus sabdariffa l. )‎ plants by using tyrosine and glutamine acids under different sowing dates

Abstract EN

In order to improve the growth and yield of the roselle plant under Sharkia Governorate conditions, a split-plot experiment was conducted during the two consecutive summer seasons 2018 and 2019.

The two experiments included two main factors where the first factor was sowing date (15^th April, 1^st May, 15^th May and 1^st June), the second factor was amino acid concentrations (tyrosine and glutamine acids at 100 and 200 ppm) and control (Sprayed with tap water) as well as their interaction treatments.

Following data were recorded: plant height, number of branches per plant, number of leaves per plant, dry weight of leaves per plant and root length as plant growth parameters as well as number of fruits per plant, fresh and dry sepal's yield per plant and dry sepal's yield per faddan as yield components.

Results revealed that roselle planted on 15^th April produced taller plants and more branches and leaves as well as heavier leaf dry weight per plant compared to the other dates.

Also, the early sowing date (April 15) recorded higher values of roselle yield components with significant differences than the other dates under study.

Moreover, glutamine acid at 200 ppm concentration significantly increased plant growth and yield components compared to the other concentrations in both seasons.

In conclusion, sowingroselle seeds on 15^th April and sprayed with 200 ppm glutamine four times per season appears to support growth and is adequate for achieving the highest roselle yielding under Sharkia Governorate conditions.