EPICUTICULAR WAXES OF KOHLRABI PLANTS AS AFFECTED BY NUTRIENT SOLUTIONS WITH A LOW PH

In Kohlrabi (Brassica olercrcea var. gongylodes L.) plants the influen ce of nutrient solutions with a low pH on micromorphology and producti on of epicuticular waxes was investigated. The experiments were conduc ted in the greenhouse with potted plant material grown in sand. Plants were randomly assigned to four treatment groups and provided with nut rient solutions of pH 6, 5, 4, and 3, respectively. During the experim ental period of 6 weeks vegetative growth of the Kohlrabi plants was o nly slightly affected, as documented by measurements of leaf area, bul b diameter and dry matter production of the leaves. A decrease in the pH of the nutrient solution resulted in a lower concentration of Ca, M g, and K in the leaves, leaf content of N and P was unaffected. Microm orphology of leaf surfaces was investigated by scanning electron micro scopy. However, no distinct differences in fine structure of epicuticu lar waxes could be detected among the 4 treatment groups. Also wax pro duction, as related to leaf area unit, revealed to be unaffected by de creasing pH of the nutrient solution.