Root disturbance and washing effects on shoot and root growth in four plant species : a thesis presented in partial fulfilment of the requirements for the degree of Master of Applied Science at Massey University

Abstract

Bare-rooting techniques have been widely use in New Zealand nursery production for the preparation of live plants for export to overseas or domestic markets. Bare-root transplants can fail quality requirements due to death or deterioration of regrowth following repotting. The potential for improving bare-root nursery stock quality has prompted study of the morphological effects of removed medium treatment on plant. Two experiments were conducted to explore the effects of physical root disturbance by shaking and washing on the growth and development of camellia (Camellia x saluenensis cv. 'Donation'), pittosporum (Pittosporum tenuifolium cv. 'Kohuhu'), pumpkin (Cucurbita pepo cv. 'Crown Hybrid'), and coleus (Coleus blumei). The shaken plants in both dry and wet conditions suffered a reduction in the growth rate of their leaves compared to the unshaken controls. Root washing influenced the vegetative growth of four species and reproductive growth of pumpkin. The two woody species were more sensitive to treatment stress. Very short time of washing (three seconds) affected camellia bud break and new shoot growth, and inhibit pittosporum root and shoot growth. Similar effects were not sosevered in coleus and pumpkin.