ANALYSIS OF COLD ACCLIMATIZATION IN TWO ASPARAGUS CULTIVARS WITH VARYING PATTERNS OF FALL SENESCENCE

E.J. Landry , D.J. Wolyn
Adequate winter hardiness is paramount for optimal performance of Asparagus officinalis L. cultivars in Southern Ontario, Canada, and may be influenced by fall senescence. Cultivar ‘Guelph Millennium’ (GM) turns yellow by mid-October prior to ‘Jersey Giant’ (JG), which will often ‘freeze green’. Timely fall senescence may contribute to freezing tolerance and result in the enhanced stand longevity and yield observed for GM compared to JG. In order to understand the relationship between fall senescence and cold acclimation, a field experiment was conducted to assess phenological parameters in plant tissues through the late summer and fall. Once photoperiod and night temperature decreased below 12 h and 10°C, respectively, both cultivars showed increased storage root LT50 values as well as carbohydrate, nitrogen and proline concentrations, while fern chlorophyll and crown water concentrations decreased. Cultivar differences were found for some traits; GM initiated nitrogen and proline accumulation in the roots and chlorophyll catabolism in the fern two weeks prior to JG. Freezing tolerance of storage roots, however, was not significantly different between cultivars. LT50 values were correlated with carbohydrate concentrations and percent water, but not chlorophyll concentration or percent nitrogen. A greater percent of storage roots nitrogen in GM than JG through the fall could help explain the stand longevity of GM.
Landry , E.J. and Wolyn, D.J. (2012). ANALYSIS OF COLD ACCLIMATIZATION IN TWO ASPARAGUS CULTIVARS WITH VARYING PATTERNS OF FALL SENESCENCE. Acta Hortic. 950, 229-234
DOI: 10.17660/ActaHortic.2012.950.25
https://doi.org/10.17660/ActaHortic.2012.950.25
total non-structural carbohydrate, proline, nitrogen, winter hardiness, freezing tolerance
English

Acta Horticulturae