Effects of the biostimulants application at castor bean crop

Castor bean (Ricinus communis L.) is an oil plant of great importance worldwide. It has a very low share in the structure of agricultural crops in Romania, but with a tendency to grow, due to multiple economic advantages. In the context of climate change new approach to cultivation technology is needed. Improving the effects of stressors is the benefit of using biostimulants. Under this circumstances, the aim of this paper is to present the results of the researchers performed in South Romania with respect to the application of biostimulants at castor bean crop.In the years 2019, 2020, and 2021, at Agricultural Research and Development Station Teleorman (ARDS Teleorman) located in South Romania, a multifactorial field experiment of type 2 x 2 x 2 was set up, having the following factors: Factor A -biostimulant product: a1 = product containing auxins (Kelpak); a2 = product containing amino acids (Amer Micro); Factor B -application phase: b1 = application at 4-5 leaves; b2 = application before the appearance of the main raceme; Factor C -application rate: c1 = 1 l/ha; c2 = 2 l/ha.The application of the studied biostimulants determined significant increases in seed yield at castor bean. The obtained results in the three experimental years show that the application of the biostimulants should be done before the appearance of the main raceme and in the rate of 2 l/ha. The effects determined by Amer Micro biostimulant (based on amino acids) was more consistent than those of Kelpak biostimulant (based on auxins).