Effect of manure doses and growth media on the productivity and mineral composition of rocket leaves (eruca sativa)

Abstract

Rocket (Eruca sativa) is a member of the Brassicaceae family. It is found endemic in most Mediterranean countries and in Northern and Eastern Europe. According to 1996 records, the annual production of rocket in Turkey was nearly 1100 t green fresh leaves which are mostly used as appetisers with traditional Turkish foods like “pide” (Turkish pizza) or “Kisir” (Turkish wheat meal) or to prepare fresh salads. Rocket was also believed to have aphrodisiac properties. It is used in traditional pharmacopoeia for many different purposes. In this study, three different levels of farmyard manure (4 t da⁻¹; 8 t da⁻¹; 12 t da⁻¹) were applied to experimental soil; experimental soil mixed with pumice and perlite. Five kg da⁻¹ N; 2 kg da⁻¹ P₂O₅; 1.5 kg da⁻¹ K₂O were applied to growth media as basic fertilisation.

The highest yield of rocket (2717 g m⁻²) was found at the first cutting in soil + 20 % pumice + 4 t da⁻¹ manure treatment. It was followed by 2483 g m⁻¹ yield in soil + 20 % perlite + 41 da⁻¹ manure and soil + 41 da⁻¹ manure with 2420 g m⁻² yield. The increasing levels of manure gave the lowest rocket yield. Addition of different levels of manure to different growth media was responsible for statistically significant variations in yield and mineral composition of rocket. It can be said that for rocket production the optimum level of manuring is 41 da⁻¹.