The distribution of dry matter and nitrogen in the potato tuber. Variety, King Edward

Mary D. Glynne, Violet G. Jackson
1919 Journal of Agricultural Science  
THE following investigations arose out of certain work undertaken at the Rothamsted Experiment Station in 1918 in connection with the Food Production Department. This involved sampling a large number of tubers. Investigations into the best method of sampling suggested the advisability of studying in detail the distribution of dry matter and nitrogen in the different parts of the tuber. PREVIOUS INVESTIGATIONS. As early as 1892 M. Douillet(i) discussed the uneven distribution of starch in the
more » ... ferent parts of the tuber. He showed that chemical analysis and microscopical examination reveal the fact that starch is much more abundant near the periphery than in the inner part of the potato, and that the grains appear to be formed in the neighbourhood of the vascular system. He also showed that the two ends of the tuber vary in starch content but not always in the same direction. At the time of lifting the starch content is higher towards the point of attachment than towards the sprout end, but the reverse is true when the buds are sprouting. M. Douillet used the coring method for sampling, but this was later criticised by Coudon and Bussard who point out the difficulty of directing a core exactly along an axis. Slight deviation from the axis might cause serious error. Doerstling(2) in 1895 arrived, by a completely different method, at conclusions which agree in the main with those of later workers. He took a core along one of the axes of the tuber, divided it into discs 2 mm. thick and determined the specific gravity of each disc. He argued from Journ. ol Agric. SoL ix 16
doi:10.1017/s0021859600004810 fatcat:znf6yapk6nealjfqd655pmvzyy