Effects of irrigation on Pinus radiata seedling development in the Benalla Nursery.  G. Minko.  September 1973.  22 pp. (unpubl.)

SUMMARY

This study has shown that P. radiata seedlings raised in a well-drained nursery soil at Benalla should be maintained at a soil moisture content of about pF 3.0 for optimal development.

Seedlings so raised showed better survival, greater resistance to pathogens, better height, diameter, and root-surface areas, and had greater numbers of mycorrhizae than seedlings grown in drier soil.

The gain achieved by maintenance of soil moisture at about pF 3.0 was approximately 7 weeks of the production period, compared with seedlings grown in unirrigated soil.

Mulching with hardwood sawdust was shown to be a successful practise for conserving soil moisture, and may be useful where it is not possible to achieve good soil drainage. Good drainage is mandatory if irrigation is to be used for accelerated seedling growth.

Irrigation at Benalla allows considerable flexibility in nursery management by reducing the resistance of the nursery soil to mechanical appliances, shortening the production time, and thus allowing production of seedlings of the desired size for a range of outplanting environments.

Also published:

Minko, G. (1975)  Effects of soil physical properties, irrigation and fertilisation on Pinus radiata seedling development in the Benalla Nursery.  For. Comm. Vic., For. Tech. Pap. 22: 19-24.