EFFECT OF NaCl ON ASPARAGUS QUALITY, PRODUCTION AND MINERAL LEACHING

Previous research has shown that the incidence of Fusarium oxysporum and F. redolens on asparagus roots was reduced by field applications of NaCl. F. oxysporum and F. redolens are important diseases in asparagus crops causing physiological rust (brown discoloration on the harvested spears), reduced yields, smaller spears, plant losses and may be implicated in asparagus decline. Since 2001 research has been carried out in Lelystad with asparagus plants grown in large wooden containers filled with a typical asparagus replant soil to study the effect of applications of Asparagus Salt (NaCl with addition of Mg) on asparagus quality, production and mineral leaching. In 2003 and 2004 the trial was harvested for a period of 35 days each year. In 2004 spears were graded into standard sizes to identify differences between treatments and to start with an economic evaluation. In both years Asparagus Salt had a positive effect on total yield, marketable yield and number of spears. Field applications of NaCl stimulated earliness in production. The higher loss of Mg due to leaching is compensated by adding Mg to the salt. In this experiment leaching of Mn was also studied in combination with adding Mn to Asparagus Salt.