Mulching effect on yield and quality of asparagus (Asparagus officinalis L.)

Abstract

The research revealed that the largest total and marketable productivity of spears was in treatment where the asparagus had been applied with mulch in spring. Harvesting of asparagus sprouts started on 28 April 2014 and ended on 14 June 2014. The largest quantity of spears (157 pcs per Gijnlim plant and 154 pcs per Avalim plant in average) was produced by the plants of the treatment where mulch was applied in spring. The chemical analysis of the spears revealed that substantially the highest quantities of vitamin C and the lowest quantities of nitrates were detected in the spears of the control treatment (without mulch), respectively: 82.49 mg kg-1 of vitamin C was in Gijnlim and 79.35 mg kg-1 in Avalim spears; 164.9 mg kg-1 of nitrates was in Gijnlim and 146.9 mg kg-1 in Avalim spears. The largest quantities of dry materials were found in sprouts where the mulch was applied on asparagus in autumn: Gijnlim - 7.3 per cent; Avalim - 6.8 per cent. In case of variety Gjinlim, the substantially largest quantity of potassium (1789 mg kg-1) was in spears where mulch was applied in autumn, and in case of Avalim (1806 mg kg-1) it was without mulch. The research revealed that mulching of asparagus in spring leads to earlier and higher productivity of spears. Asparagus (Asparagus officinalis L.) is very valuable vegetable, which becomes more and more popular in Lithuania and produces good yield in our climatic conditions. Young asparagus spears give yield in early spring when choice of fresh vegetables is not wide. However, Lithuania still has not researched sufficiently effect of environment and growing conditions on yield and quality of asparagus. Asparagus is not frost resistant, especially in spring when some part of yield is lost sometimes. It is supposed that mulching of plants may advance yield of spears and to preserve productivity. The research is carried out in order to find out what effect the peat mulch has on the earliness, extent and quality of asparagus yield. The research of asparagus mulching has been performed in the Nursery of the Faculty of Agronomy of ASU and the chemical composition of spears was determined in the Laboratory of Quality of Plant Raw Materials in 2013-2014. The asparagus of the varieties Gijnlim and Avalim have been researched: without mulch; with autumn 5 cm mulch, and with spring 5 cm mulch. Productivity of spears was calculated and the chemical composition was determined after harvesting.