JIP-test as a tool for early detection of the macronutrients deficiency in Miscanthus plants

The optimization of cultivation process and improving the yield of perspective energy crops in Europe could be one of the ways to overcome the problem of limited amount of conventional fuel. The aim of this work was to check if the use of JIP-test, as a noninvasive method for early detection of the changes in photosynthetic apparatus, can be applied to detect nutrients deficiency in miscanthus (Miscanthus x gigantheus Anderss.) plants. The experiment was performed in fully randomized design with the following experimental variants: CaNPK (full fertilization, control), NPK (without calcium), CaKN (phosphorus poor), CaPK (nitrogen poor), CaPN (potassium poor), and Ca (without NPK). Our results revealed that the reaction of photosynthetic apparatus of miscanthus plants grown under certain macronutrient deficiency was associated with exclusive significant modifications in the measured chlorophyll fluorescence signals, analysed further by JIP-test. Analysis of chlorophyll fluorescence induction curves discovered substantial deficiency of phosphorus and potassium ahead of the standard chemical method.