Chemical control of seedling growth in forest extension nurseries.  J. D. Morris.  March 1985.  10 pp. (unpubl.)

SUMMARY

The effects of four growth retardants on container-grown seedlings of Eucalyptus camaldulensis Dehnh. (river red gum), E. sideroxylon A. Cunn. ex W. Woolls (red ironbark), E. melliodora A. Cunn. ex Schauer (yellow box) and Acacia melanoxylon R. Br. (blackwood) were examined over a six-month period.

MORPHACTEN^† effectively retarded the growth of all four species, but caused damage to leaves and growing tips, especially in A. melanoxylon; CYCOCEL^† was also damaging at concentrations high enough to retard growth. In contrast, ALAR^† had little effect on height growth; whereas ATRINAL^† reduced growth and caused relatively little damage in eucalypt seedlings, but was ineffective in A. melanoxylon.

Growth retardants could provide an alternative to top pruning for preventing excessive growth of native seedlings held over in nurseries during summer, though further research is necessary before suitable treatments can be recommended.

^†Registered Trade Name. Use of trade names is for the information and convenience of the reader. Such use does not constitute official endorsement or approval by the State Forests and Lands Service of any product to the exclusion of others that may be equally suitable.