The effect of the microelement fertilizers and biological preparation Terra Sorb Foliar on spring rape crop

Abstract

In 2009–2011 field trials were completed at the Experimental Station of Aleksandras Stulginskis University. The aim of the trial was to establish the effect of additional leaf spray fertilization with sollutions of the microelement fertilizers ARVI and biological free amino acid preparation Terra Sorb Foliar on spring rape (Brassica napus L. oleifera annua Metzg.) seed yield and quality indices. SW ‘Landmark’ spring rape was under the trial in the experiment. Before the trial, the field was fertilized with complex fertilizers NPK 16:16:16 250 kg ha–1 and ammonium saltpetre (N34) 150 kg ha–1 (basal fertilisation – control). Spring rape was sown in the third decade of April. The seed norm was 7 kg ha–1. At the bud stage of the spring rape (stage 53–54 according to BBCH scale), the trial plots were leaf sprayed with ARVI of the microfertilizer solution (6 l ha–1), solution of the preparation Terra Sorb Foliar (2 l ha–1), and the mixture of the ARVI microfertilizers + Terra Sorb Foliar solution. Other agrotechnical applications were carried out according to the spring rape growing technologies applied at the experimental station. Rape seeds were harvested by a combine harvester and samples for the chemical analyses were taken. Trial results were estimated by means of the dispersive analysis, employing the computer program ANOVA. The trial results revealed that the additional leaf spray fertilization with the ARVI microfertilizers at the bud stage resulted in the statistically significant increase in the spring rape yield by 0.08 t ha–1 or 3.5%. The application of the Terra Sorb Foliar solution resulted in the statistically significant increase of the seed yield by 0.09 t ha–1 or 4.0%. In comparison to the control, leaf spray fertilization of the spring rape with the ARVI micro + preparation Terra Sorb Foliar solution mixture resulted in the significantly higher 0.11 t ha–1 or 4.9% higher seed yield. The additional leaf spray fertilization contributed to higher accumulation of fats in the rape seeds. The leaf spray fertilization of the rape with ARVI microfertilizers, Terra Sorb Foliar, and ARVI micro + Terra Sorb Foliar solution mixture resulted in the significant increase in the fats accumulated in the rape seeds by 0.76%, 0.40%, and 1.23%, respectively. The effect of the Terra Sorb Foliar contributed to the reduction in glycosinolades by 0.71–0.81 μmol g–1, and increase in erucic acid by 0.17–0.28%. In comparison to the control, the additional leaf spray fertilization with the ARVI microfertilizers resulted in 0.26% higher amount of the erucic acid.