Effect Of Harvesting Intervals On Growth And Oil Content Of Spearmint

Abstract

The study was carried out to investigate the effect of harvesting intervals on growth, herbage yield and oil content of spearmint (Mentha spicata L.) plant. The experiment was carried out in local commercial farm at Kuku area –Khartoum North – Sudan; in four harvesting intervals15, 30, 45 and 60 days. The experiment was repeated twice. The first period from the fist of April to 30th of May 2003, the second period from the first of June to 30th of July 2003. The obtained result revealed that the growth and yield parameters such as plant height, number of leaves, number of branches, fresh weight, dry weight and weight per square meter were increased from stage one to stage four during the two experiments. On contrast, oil content decreased from stage one to stage four during the two experiments. The different intervals resulted in no significant changes in physical characters; such as Refractive index and specific gravity.