An Innovative System for Picking Mango Fruit

Abstract

A mango picking machine was manufactured from selected light materials to be capable to reach to the high position of mango fruits. The innovated design was depended on confirming the right cutting of the stem position to decrease latex bleeding, protecting the fruits from injures and preventing the fruits from fallen down. The picker cutting mechanism was consisted of two circular saws rotated vice versa towards inside direction and faced a counter sharp blade along the two centers of the cutting discs. The machine was tested on three cultivars of mango trees Keitt, Kent, and Tommy Atkins from low-stemmed trees cultivars and distinguished of big fruit volume. Also the fruit stem cross section was measured. The maximum dimensions of the fruits were taken to design the machine. Four types of circular saws at five cutting speeds of (2.78, 4.17, 5.56, 6.97 and8.34 m/s) were tested and studying the stem cutting efficiency (%) at each treatment. The results indicated that the optimum cutting circular saws were the 100 teeth saw discs with sharp edge when working at linear speed of 8.34 m/s that gave correct cutting stem percentage of 95% and only 5% undercut stems. Also, the results indicated that the optimum counter blade position was underneath the discs with over lapping 5 mm that gave the same cutting efficiency. The calculated power required to cut a fruit stem with a cross section of 87.5 mm2 with two circular saws was 3.56watts, meanwhile, the results indicated the measured power was 4.8 watts, while the available power was 5.2 watts. Comparing the effect between manual picking by hook type stick and using the picker the on the fruits injures. In manual picking, the results indicated that the average percentages of (fallen fruits, injured fruits, and latex fruit) were (15.07%, 6.85%and 30.82%) respectively meanwhile, the innovated picker indicated injured percentage (2.28%, 2.43% and 4.86%) respectively. The total fabrication cost of the picker was 1500 LE with 2017 price level. The total operating costs was 21.37 LE/h. The rental value of mechanical was 22.82 LE/h. The picker indicated (NPV) of 844.3 LE at 14 % interest rate. The picker payback period (PBP) was about 1.3 year.