Influence of fertilisation on potato growth functions
Estonian Research Institute of Agriculture, Teaduse 13, 75501 Saku, Estonia; e–mail: email@example.com
Aimed at elaboration of a soil fertility module for the potato production model POMOD, the determination of growth functions was carried out for the late potato variety ‘Anti’ at different fertilisation levels. These functions characterise the distribution of growth between plant organs and redistribution of the biomass of vegetative organs at their late growth stage. Results of the field experiments in 2002–2003 revealed that fertilisation decreased the maximum of root growth function and shifted the maximum of leaf growth function forward. The bigger amount of fertiliser slows down the decrease of leaf and stem growth functions and the increase of tuber growth function. Moreover, it leads to a break in the tuber growth function occurring with secondary maximums in leaf and stem growth functions. Variability of growth functions induced by fertilisation is dominant during the second half of growing period. At an early growing stage, variations between years exceed variability between fertilisation plots.