Efficacy of foliar boron-containing fertilisers on sunflower plants

Abstract

This paper explores the effectiveness of boron-containing fertilisers on the structural elements of sunflower yield, and the economic benefits associated with their use. It is recognised that farmers often apply such fertilisers to sunflower seeds either as part of mono- or multi-element compound fertilisers or through foliar feeding. The fertiliser market is oversaturated with various microfertilisers with different boron concentrations. The effectiveness of these fertilisers must be assessed across multiple soil types, climatic conditions, and farming practices. Consequently, researching boron-containing fertilisers is highly relevant because of the increasing availability of such products on the global market. These fertilisers come with varying percentages of boron and pH indicator, often including nitrogen and other macro- and microelements. Our experiment was conducted in the fields of Sumy National Agrarian University, Sumy, Ukraine. There have been studies on the effectiveness of using three fertiliser types in the foliar feeding of sunflowers plants in the phase of 5-6 pairs of leaves: in liquid form, polyborates Quantum Boron 14% B and Speedfol Boron 17% (acidify the solution) and in crystalline granular form CrystallMax 20.8% B (neutral and alkaline pH). The mid-early sunflower hybrid LG 50479 SX (Limagrain) was sown on the experimental plots. It was determined that applying foliar boron-containing fertilisers influenced the height of plants. The tallest plants were recorded using Quantum boron active, resulting in a 4.85 % increase compared to the control treatment. Boron fertilisers enhanced the weight of seeds produced by the plant, with the most significant increase observed after applying Quantum boron, yielding an additional 10.5 g. The weight of the thousand seeds from the experimental plants ranged from 70 g to 75 g, and with the use of Quantum Boron, this indicator was the highest. It was the lowest among the boron-fertilised treatments (increase from the control of 3.4 g) with the application of Speedfol. Furthermore, it was established that boron fertilisers positively impact sunflower yields. The yield was 2.84 t/ha on the control plots, without fertilisers, while Quantum boron active increased it to 3.18 t/ha. Quantum boron active was the most cost-effective option for plant nutrition with boron-containing fertilisers, with a cost-effectiveness rate of 75.6 %. In comparison, Avangard CrystallMax achieved a rate of 74.7 %, and Speedfol reached 70.2 %.