Monitoring of plant-induced electrical signal of pepper plants (Capsicum annuum L.) according to urea fertilizer application

Abstract

Plant-induced electrical signals (PIES) can be non-destructively monitored by inserting electrodes into plant stems, which reflect plant nutrient and water uptake. The main objective of this study was to evaluate the growth of pepper plants with different urea applications (low fertilizer: N0, Control: N1, and high fertilizer: N2) in soil by monitoring PIES. The PIES value was found to be low in the low urea treatment group while the two times higher urea applied pepper had the highest PIES value. The nutritional content of the stem, leaves and soil did not correlate with PIES because of dilution effect by high biomass with high urea application, but principal component analysis showed that the PIES was positively associated with pepper biomass and soil EC. The high fertilizer did not affect chlorophyll and proline contents in pepper leaves. The assessment of plant growth by PIES has advantages because non-destructive, real time and remote monitoring is possible. Therefore, PIES monitoring of different plants grown under various cultivation environments is useful method to evaluate plant activity and growth.

Figure 1

Plant induced electrical signal (PIES) of pepper plants according to different urea fertilizer applications in a greenhouse (a) and in field (b).

Figure 2

Chlorophyll content of pepper leaves treated with different urea fertilizer applications; greenhouse experiments (a) and field experiments (b).

Figure 3

Proline content of pepper leaves treated with different urea fertilizer applications; greenhouse experiments (a) and field experiments (b).

Figure 4

Biplot of PC1 and PC2 for growth parameters of pepper plants grown in different amount of urea applied soils (low fertilizer: N0, control: N1, high fertilizer: N2, numbers after dash indicate replicates).