Search Results
Abstract
Dormant rhubarb crowns do not force well until their rest period or physiodormancy (7) has been broken by sufficient chilling in the field during late fall. There are many reports that during exposure of dormant plants to cold, the free amino acids contents change. Asen and Stuart (1) found that dormant leaves and buds of Hydrangea macrophylla showed an increase of some free amino acids after 6 weeks of storage at 4 to 5°C. Another worker (8) reported that in one alfalfa variety there was a 20% increase of acids from August to December. Schneider (4) found that the levels of some free amino acids in leaves of Ilex crenata nigra rooted cuttings changed during storage at cool temperatures. In this study buds and roots of dormant rhubarb crowns were analyzed to determine the free amino acids present and also possible changes in acids levels that might indicate the end of the rest period.
Abstract
A semi-log plot of time and temp, representing treatment conditions successfully used for the heat curing of ‘Wedgwood’ iris bulbs, resulted in a wedge shaped distribution of points. A line passing through the lower side of this distribution was interpreted as the locus of min time values at given temp for the successful heat treatment of iris bulbs. Several time-temp treatment combinations from points along this line and other combinations were selected for forcing trials with ‘Ideal’ iris. After subtraction of correction values based on a 2-day period of delayed bulb response, the corrected equivalent units showed positive correlation with the earliness of the 50% flowering date, the decreasing lengths of first and fifth leaves, and the decreasing number of leafy plants. The per day effect of treatment at 32°C declined beyond the 10th day. The equivalent unit method is a new procedure for calculating the heat curing response for bulbous iris,