Fish Hydrolysates as Potential Biostimulants for Growing Legumes and Cereals to Reduce Temperature Stress

Abstract

Introduction This study aimed to develop an optimal method for the production of fish hydrolysates and to test their effectiveness as plant biostimulants under low-temperature growing conditions. Methods To obtain fish hydrolysates, the waste of a rainbow trout was used. Hydrolysates were prepared by enzymatic hydrolysis using fish entrails as a source of enzymes. Differences in the methods of obtaining fish hydrolysates: samples І, ІІ, ІІІ, and IV were placed into a water bath at +37°C, and sample V was left at room temperature. Further nitric, phosphoric, and acetic acids were added to samples I, II, and III, respectively, while distilled water was added to samples IV and V. The effectiveness of hydrolysates on the germination and growth of corn and beans under low-temperature growing conditions (+15/8°C) was determined. Results Hydrolysate I showed a positive effect on the germination and growth of beans and corn. Hydrolysate V stimulated germination and plant growth; however, it caused the abnormal development of some seedlings. The same deformations were observed with hydrolysate II. Hydrolysate III inhibited mold but also germination and the growth of crops. The greatest effect for both crops was found with the use of hydrolysate IV. The optimal concentration for beans was 1% and for corn - 10%. Conclusion A positive result was obtained from the use of fish hydrolysate to stimulate the germination and growth of beans and corn at low growing temperatures. Therefore, the use of hydrolysates will allow for less yield loss in case of unforeseeable temperature drops after seed sowing.