Evaluation of skidder productivity and costs among 30.5L-32 (78-cm), 67x34.00-25 (86-cm), and 66x43.00-25 (109-cm) size tires under wet conditions was conducted in a clearcut harvest during the Spring of 1998 on an Upper Coastal Plain site in southeast Alabama. There was not a significant difference in adjusted mean whole-tree skidder production among the three tire sizes at the 0.05 level. Adjusted mean whole-tree skidder production for the 78-cm, 86-cm, and 109-cm tires was 32.7, 35.8, and 32.9 green tonnes per Productive Machine Hour (PMH), respectively. Total whole-tree skidding costs were $1.96, $1.80, and $1.97 per green tonne for the 78-cm, 86-cm, and 109-cm tires, respectively.
