Abstract:
Many cultivars of European plum grow vigorously unless worked on a dwarfing rootstock such as Pixy (Webster, 1980) and in light cropping years even trees on Pixy grow more vigorously than is desirable.
Vigour control of plums by pruning is rarely practised in the UK; winter pruning increases the risk of disease infection (Silver Leaf or Bacterial Canker) and summer pruning has often resulted in reduced cropping.
A chemical method of shoot growth control would therefore be most useful.
Preliminary experiments at East Malling showed that paclobutrazol (Cultar) applied to several plum cultivars, either as a spray to the foliage or to the soil beneath the trees, effectively suppressed shoot growth (Webster and Quinlan, 1984). Continued studies are outlined.
|