This article was written by Jorge Luis Alonso G., an Agricultural Insights Specialist
Scientists at Plant Production Systems and the Centre for Crop Systems Analysis at Wageningen University and Research (WUR) in the Netherlands conducted a study to develop a model to quantify the physiological aging of potato seed tubers. This model takes into account the effects of storage conditions and growth history of different potato varieties. The results of the study was published in a scientific paper in the journal Environmental and Experimental Botany and made available online 9 January 2024.
The following article is intended as a brief summarization of the scientific paper. The full paper can be accessed here. It is titled “Using sprouting behaviour to quantify physiological ageing of seed tubers of potato (Solanum tuberosum L.)”
Focus on physiological aging of potato seed tubers
The research focuses on the physiological aging of potato seed tubers, which is critical to both yield and quality of the crop. These tubers, which are biologically active by nature, undergo several physiological phases as they age. This complex process is influenced by various factors such as the growth history of the tuber and the storage conditions. Crucially, the study examined how different storage temperatures affect the physiological age of different potato varieties, to improve our understanding and measurement of this process.
At the heart of potato production are seed tubers. Their life cycle begins with a dormant phase during which no sprout growth is observed. This phase is further subdivided into endodormancy, ecodormancy and paradormancy. As the tubers age, they go through several stages: breaking dormancy, sprout development, and finally entering a senescence phase. These stages are critical because they significantly affect the sprouting ability and vigor of the tubers, which directly affects crop yield and quality.
The study highlights that the physiological age of a seed tuber is influenced not only by its chronological age but also by a combination of factors. These include the growth conditions of the parent plant, environmental conditions, post-harvest handling, and the duration and conditions of storage. In addition, cultivar-specific responses add to the complexity of physiological aging in potato seed tubers.
Focus on the storage phase of potato tubers
In this research, experiments were conducted over three cycles, focusing primarily on the storage phase. The researchers selected four potato varieties, each with different physiological characteristics, and subjected them to different storage temperatures. The aim was to introduce variations in physiological age within the same variety. Throughout the storage seasons, the sprouting behavior of these tubers was periodically evaluated. This provided valuable data on aspects such as the number and weight of sprouts and tuber weight.
The results were revealing. Seed tubers stored at higher temperatures began to germinate earlier, signaling an accelerated end to (eco)dormancy. Interestingly, over time, tubers stored at cooler temperatures caught up in terms of number of sprouts.
In particular, tubers stored at the lowest temperature, 4 ˚C, remained largely in (eco)dormancy and showed minimal sprouting by the end of the storage season. This variation in sprouting behavior across temperatures and cultivars necessitated a dynamic method to quantify physiological aging.
A novel mathematical model was developed by the researchers: the piecewise sprouting behavior function to meet this need. This model effectively described the different sprouting patterns across varieties and storage conditions. It not only accurately captured sprouting behavior, but also provided significant parameters for analyzing trends specific to each variety. These parameters were sensitive to both storage temperature and growth conditions, revealing distinct physiological phases.
Study results have practical applications. Understanding how storage conditions affect the specific aging characteristics of different varieties can greatly assist seed dealers and growers. With this knowledge, they can make more informed decisions about storage regimes.
For example, knowing the different aging rates of varieties allows storage conditions to be optimized to meet specific needs. In addition, ware producers can use the germination test to determine the physiological state of their seed lots and select appropriate physiological ages for different planting seasons.
In summary, this research significantly improves our understanding of the physiological aging of potato seed tubers. The development of a flexible and effective method for quantifying physiological age is not only beneficial for improving storage practices and crop production but is also invaluable in the context of climate change. Such knowledge is critical to optimizing crop yields and reducing resource waste in agriculture.
Source: Zou, C., Van der Putten, P. E., Mossink, L., Lommen, W. J., Van Ittersum, M. K., & Struik, P. C. (2024). Using sprouting behaviour to quantify physiological ageing of seed tubers of potato (Solanum tuberosum L.). Environmental and Experimental Botany, 105648. https://doi.org/10.1016/j.envexpbot.2024.105648
Cover photo: Credit AHDB Storage Hub