Effects of kaolin particle film and rootstock on tree performance and fruit quality in 'Doyenne du Comice' pear

Tree growth and productivity in 'Doyenne du Comice' ('Comice') pear were not affected by kaolin (Surround WP) treatment programs consisting of applications at 30 or 60 g(.)L(-1) of water applied either three or six times per growing season and repeated for 3 years. In 2 of 3 years, kaolin treatment programs reduced the extent of russet on the fruit surface, although the comparative effectiveness of different concentrations or numbers of applications was not consistent. It appears that kaolin treatment programs can be used in 'Comice' pear production without adverse effects on tree growth and performance. In a relatively high density planting (1098 trees/ha), 'Comice' pear trees growing on Pyrus calleryana rootstock were less yield-efficient and had lower bloom and crop density and fruit set than trees growing on Quince A (Cydonia oblonga) rootstock. Fruit from trees growing on P calleryana were generally smaller and had less surface russet than did fruit from trees growing on Quince A.