Growth and development of potato (Solanum tuberosum L.) crops after different cool season storage.
|Keywords:||growth and development; harvest index; physiological age; radiation interceptance; radiation use efficiency; seed potato storage; seed potato ???vigour???; specific leaf area; stolon length; tuber distribution; tuber yield|
|Full text PDF:||http://hdl.handle.net/10182/6494|
Growth and development of potato (Solanum tuberosum L.) crops after different cool season storage. Tuber yield variation has been attributed to seed potato physiological age in numerous studies on potato. Seed potato physiological age has been defined as the developmental stage of a seed potato, or physiological state which influences production capacity and causes major impacts on potato yields. Physiological age is reportedly determined by genotype, chronological age and environmental conditions (especially temperature) during the storage phase. The temperature sum (or thermal-time) accumulated by the seed potato during the storage period can been used as a measure of physiological age. Manipulating seed potato physiological age may be an effective method to alter tuber yield and yield distribution for many cultivars. One important way to manipulate physiological age is to expose the seed potatoes to different temperature regimes during the storage phase. Therefore, an assumption of this study is that physiological age can be measured through quantification of accumulated thermal-time through development processes, from harvest to planting. These, in turn, are then expected to impact potato yield and size (or the grade size of each potato, which determines the yield size distribution). The rationale of the research is that contrasting seed potato storage regimes will provide different physiological ages at the time of planting. This may affect crop growth and development in the field and potentially affect tuber yield and yield distribution for different cultivars. The hypothesis to do this is; if seed potato physiological age is an important source of yield variation it must impact on at least one of the parameters of yield; i.e. cumulative amount of radiation intercepted by the canopy (Rcum), radiation use efficiency (RUE) or partitioning (harvest index; HI). First, a field experiment (Experiment 1, or Benchmark experiment) under non-limiting growth conditions benchmarked the mechanisms of potato growth, development, yield and yield distribution for three commercial cultivars (???Bondi???, ???Fraser??? and ???Russet Burbank???). In New Zealand, ???Bondi??? has high yield ability, which interests growers. However tubers may be too long, which is a complaint of processors. ???Fraser??? has excellent long-term storage attributes with resistance to cool temperature sweetening. However, the difficulty of getting high tuber yields is seen as a disadvantage by the potato growers. ???Russet Burbank??? was included in Experiment 1 to benchmark results internationally because is used worldwide as the standard for French fries and consequently there is extensive scientific literature about this cultivar. The objective of Experiment 2 was to generate ???Bondi??? and ???Fraser??? seed potatoes of different physiological ages from contrasting storage regimes (treatments). At the end of storage the seed potatoes from the different treatments had accumulated 972 and 2249 ??Cd and their sprouting patterns were assessed for…