Experimental Study on Connection Strength between Tobacco Stem and Leaf

Abstract

HighlightsThe connection strength between tobacco stem and leaf was obtained for ‘Zhongyan-100(CF965)’ variety.The connection strength between tobacco stem and leaf relates to the leaf growing location and maturity of the leaf.The tobacco leaf is easier to be separated from the stem with an oblique force than a vertical force.The distance between the harvesting tool and the leaf base was suggested to be less than 50 mm for the tested variety.Abstract. Harvesting of tobacco leaves is an important and basic tobacco production process. With the increase of labor costs and the development of agricultural mechanization, mechanical harvesting of tobacco leaves will inevitably replace manual harvesting. The connection strength between tobacco stem and leaf is a key mechanical parameter for tobacco harvester design. In this study, one tobacco cultivar, “Zhongyan-100(CF965)” was selected as an experimental plant. Experiments were designed and carried out by collecting mature and immature tobacco leaf samples to test the connection strength between the leaf and stem. The experimental results showed that the connection strength between tobacco stem and leaf was related to the position of the leaf on the stem and the maturity level of tobacco leaf. The connection strength obtained from the experiments was in the range of 0.64 to 2.76 MPa. The connection strength had a linear relationship with its water content. The connection strength was higher at higher moisture content or lower maturity level. Besides, experimental results indicated that the tobacco leaves were more easily detached from the stem when the oblique force was applied to the tobacco leaf. The maximum horizontal distance between the harvesting tool and the leaf base should be 50 mm to ensure the integrity of the tobacco leaf after harvesting. The results of this study could be applied to the design of tobacco harvesters. Keywords: Connection strength, Mechanization, Specialty crop, Tobacco harvesting.