Effects of Trichoderma Harzianum and boron on spring broccoli

Abstract

This paper deals with the effects of Trichoderma harzianum application and boron (Nitrabor) topdressing on the growth, yield, and quality of spring broccoli. A field experiment was carried out in central-eastern Poland, in 2014-2015.The experiment was established as a split-block design with three replicates. There were the following combinations of Trichoderma harzianum treatment: added to the nursery substrate; added to the nursery substrate and as topdressing in a form of spray after seedlings were planted out; as pre-planting treatment just before seedlings were planted out, followed by topdressing in a form of spray; control without Trichoderma harzianum. Two types of late topdressing for broccoli were used: nitrogen topdressing or Nitrabor to the soil. The treatment significantly increased the marketable yield of broccoli curds. This increase relative to control ranged from 17 to 49%, depending on the Trichoderma harzianum treatment. The best results were obtained when boron topdressing was combined with Trichoderma harzianum added to the nursery substrate and then the fungus was applied in a form of spray after seedlings were planted out. Broccoli inoculation with Trichoderma harzianum also increased L-Ascorbic acid content in the plants. Topdressing with boron significantly increased the marketable yield of curds, their weight, the diameter of their circumference, the diameter of the stem, the leaf greenness index value (SPAD), as well as the content of dry matter, total sugars, and L-Ascorbic acid.