Effects of hydrolyzed animal protein application on nitrogen translocation, phenolic and volatile profile of Ocimum basilicum L. under salinity conditions

Abstract

The application of biostimulants based on hydrolysed animal protein to leaves (foliar) or nutrient solution was studied on hydroponically grown Genovese 'Marian' basil grown under salinity conditions. The effect on N yield and N fertilizer utilization was tested with the stable isotope 15N, which indicated the part of the plant that accumulated the highest amount of N. The use of the biostimulant in the nutrient solution produced the best results regarding N fertilizer utilization and N yield, being about 13 % higher than the foliar application and 24 % higher than the salt control (SC) treatment. In general, basil leaves contained the most N from the fertilizer. The total analysed phenolic content (TAPC) was 270.1 % higher in the nutrient solution-applied biostimulant (NSB) than in the control (C) treatment and 211.9 % higher than in the SC treatment. Foliar application of the biostimulant (FB) showed lower efficacy than NSB regarding phenolic contents. The most abundant individual phenolics in basil were dihydroxyphenyllactic acid dimer, caffeic acid hexoside derivatives, and rosmarinic acid. NSB increased the total sesquiterpene content by 25.2 % and the total alcohol content by 31.8 % compared to SC treatment. In addition, NSB increased the total aldehydes content by 27.0 % compared to SC treatment. The total volatile content was less variable than the individual volatiles. The results of our study show how different application methods of the biostimulant affect nitrogen conversion and utilization in different plant parts of basil and how they influence the internal quality of basil.