Influence of organic fertiliser on yield and quality of cabbage (Brassica oleraceae var. capitata L.).

摘要

The use of organic fertiliser as an alternative to inorganic fertiliser increased among subsistence farmers in rural areas in KwaZulu-Natal, South Africa. No clear recommendations exist for the application of different organic fertilisers on vege-tables. A field trial was conducted at Umsunduze Training Centre, KwaZulu-Natal, during 2005 and 2006. The effect of three different organic fertilisers (chicken manure, kraal manure and compost) were investigated on the growth, yield and quality of cabbage cv. Conquistador. Four application rates were used for each organic fertiliser (chicken manure: 0, 6.25, 12.5 and 25 kg 10 m-2; kraal manure: 0, 12.5, 25 and 50 kg 10 m-2; compost: 0, 25, 50 and 100 kg 10 m-2). Each treatment combination was replicated four times. Organic fertilisers were incorporated into the soil one month before planting. Number of leaves and plant height were measured for the first 8 weeks after transplanting. Yield components that include head fresh and dry mass and head diameter were measured at harvesting. Cabbage heads were graded into 3 classes according to their external appearance. Chicken manure applied at 12.5 or 25 kg 10 m-2 showed a significant increase in the growth rate of cabbage during the first 8 weeks after transplanting in both seasons. During 2005, fresh mass of cabbage that received 12.5 or 25 kg 10 m-2 chicken manure was significantly higher and of better quality than the other organic fertiliser treatments. In 2006, the fresh mass and quality of cabbage that received 50 kg 10 m-2 kraal manure, 25 kg 10 m-2 chicken manure or 100 kg 10 m-2 compost was significantly higher than the other organic treatments. Organic fertiliser clearly had an positive influence on cabbage growth and yield but chicken manure between 12.5 and 25 kg 10 m-2 yield the highest and best quality cabbage.