Epsilon Archive for Student Projects

Abstract

The domestication and subsequent cultivation of potatoes have shaped ancient civilisations and continues to be a cornerstone in today’s modern economies. Through hybridisation, breeders and farmers have exploited the potato’s genetic versatility to overcome the need to produce higher yields while being resistant to biotic and abiotic factors. However, with temperatures set to increase and the rapid onset of drought jeopardising potato production, methods that are faster at selecting superior cultivars and genotypes will be highly sought after to reduce the time it takes to release a new cultivar to the market.
In this study, different potato cultivars were selected and grown in South Africa under varying drought conditions. Through the implementation of a non-destructive handheld proximal sensing device and remote drone imaging, the plants photosynthetic systems displayed minor variably when exposed to (i) drought stress during tuber initiation and (ii) drought stress during tuber bulking in real-time. However, both measuring systems displayed plant recovery post stress, indicating delayed maturity and partial growth inhibition. Drought during tuber bulking had the highest decrease in yield by up to 33% however it also decreases the tuber deformity frequencies for most cultivars except for Crop60 and Magnum Bonum that had an increased frequency of internal brown spot formation when drought stressed. The destructive harvest analysis revealed that the potato cultivar Sound had a continually high yield in all treatments with drought and without, in addition to low tuber deformities, however it also had one of the lowest dry matter content and specific gravity. Cultivar selection should therefore not be solely based on yield but also should consider what commercial and industrial purpose for the tuber is such as high specific gravity tuber being more applicable for French fry use.
This paper aims to highlight the valuable addition of remote sensing for academia and private enterprise for cultivar selection and evaluation. Remote sensing had a clear advantage when surveying a large field quickly however although proximal sensing was slower, it provided more detailed measurements on the different aspects of the photosynthetic system such as the yield, efficiency and the flow of electrons within the system. Both notably, provides real-time time-series and is remarkably easy to use, empowering potato breeders, farmers, and researchers to make informed decisions and enhance their productivity.
Keywords: multispectral imaging, drought stress, vegetative indices, photosynthetic parameters, tuber evaluation, potato yield.
Abstract