Evaluating of a prototype machine for carrot crop harvesting suitable for small holdings

الملخص EN

The aim of this paper is evaluating the performance of prototype carrot harvester recorded, as patent that specialized in carrot crop harvesting using lifting belts technique.

Two groups of practical experiments were performed to evaluate the prototype machine.

The first one is the preliminary experiments to find out the maximum length of the cultivated carrot variety to determine the optimum digging depth in addition to the optimum moisture contents of soil and foliage as well as the catch zone height.

The second one is the main experiment that aims to evaluate the performance of the harvester under four forward speeds (1, 2, 3 and 4 km/hr.), four lifting- belt speeds (1, 2, 3 and 4 m/sec.); three belt tilt angles (30°, 35° and 40°) and three rake angles share of the digging share (15°, 20°, 25°) with taking into consideration the performance indicator that including the field capacity, field efficiency, harvesting losses, lifting efficiency, specific energy requirement and total harvesting cost compared to the manual harvesting.

According to the preliminary experiments, the prototype carrot harvester should be used under soil and foliage moisture content of 17.7 and 27.8 %, respectively at catch zone height of 15 cm and digging depth of 25 cm.

Regarding the field experiment, the operation of carrot harvester using forward speed of 2 km/hr., belt speed of 2 m/sec., in other word the kinematic factor of 3.57 under belt tilt angle of 30° and share rake angle of 15° achieved the lowest losses of 0.18 Mg / fad., highest lifting efficiency of 98.54% , field efficiency of 92.50 % with minimum total cost of 424.32 LE/fad., at actual field capacity of 0.0148 fad/hr.

Ultimately, using of the carrot harvester reduced the harvesting cost with about 80.74 % compared to the manual harvesting method.