Effect of steaming on yield and nutrient content of tomatoes grown in three substrates and on physical properties of the substrate

Summary Steam sterilization increased the yield of tomatoes grown on peat over 3 years. The increase becomes more pronounced with time. The effect of steaming was greater in the summer crop which has a duration of 6 months than in the autumn crop which has a duration of 4 months. Similar yield patterns were evident in tomatoes grown in sand and soil. Manganese levels in the growing media and in the foliage rose as a result of steaming, but toxic levels were reached only in plants growing on steamed soil which caused yield reduction. Leaf nitrogen content was increased as a result of steaming. Steaming over three years did not cause a breakdown of the structure of the peat.