Date of Award


Document Type


Degree Name

Master of Science (MS)

Committee Chair/Advisor

Bulent Koc

Committee Member

Guido Schnabel

Committee Member

Juan Carlos Melgar

Committee Member

Michael Vassalos


Armillaria root rot (ARR), primarily caused by the soilborne fungus Desarmillaria tabescens, has become the number one cause for peach tree decline in the Southeastern United States. Research has shown that planting peach trees on shallow berms and excavating the soil around the root collar two years after planting lessens the effects of ARR. However, berms make orchard operations such as pruning, thinning, and harvesting more cumbersome and cause cultural concerns as channels of water at their base can lead to erosion and the slope of the berms leads to herbicide and fertilizer runoff. The objective of this research was to develop an implement that would flatten soil between peach trees planted on berms after two passes. A rotary tillage tool (paddle wheel) with paddles 20.3 cm in height and 30.5 cm in length was designed and retrofitted on a mechanical weeder that removes the soil with a rotary head. A hydraulic flow meter, an RTK-GPS receiver, and a wireless data acquisition system were installed to monitor the rotational speed and the ground speed. The effects of paddle wheel rotational speed (132, 177, 204 RPM) and tractor ground speed (1.65, 2.255, 3.08 km/h) on torque requirement of the paddle wheel and the smoothness of the soil were determined in two orchards. The experiments showed that a ground speed of 3 km/h and rotational speed of 177 RPM provides the smoothest soil surface with minimum torque requirement in this soil type.



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