Influence of natural complex organic fertilizers of boron, based on organic fertilization, on some qualitative parameters of watermelons on psamosols

Abstract

Boron fertilization is an efficient technological work, especially when boron is applied on organic background. The obtained results pointed out the role of boron in plant metabolism: it stimulated the accumulation of some biochemical components in leaves (chlorophyll and carotene), intensified the activity of some enzymes (catalase) and improved fruit quality. In the variants where boron compounds were applied, greater chlorophyll content, 4.31-4.46 mg/g fresh matter, was recorded, compared to 2.14 mg/g fresh matter in the unfertilized variant and 4.00 mg/g fresh matter in the variant where only manure was used. The carotene content of leaves was of 0.73-0.79 mg/g fresh matter, compared to 0.49 mg/g fresh matter in the unfertilized variant and 0.63 mg/g fresh matter in the variant where only manure was used, in 2005. The quantity of total DM from fruits has increased from 9.35% in the unfertilized variant to 10.20-10.35% in the variants fertilized with manure + Folibor 5 l/ha - two treatments. On the organic background of 30 t/ha manure, by the leaf application of Folibor, yield increase was of 10.7 t/ha.