Effect of compost and animal manure with phosphorus and zinc fertilizer on yield of seed potatoes
This study was carried out to investigate the effect of compost and manure with phosphorus and zinc on potato yield (Solanum tuberosum L.). The experiment was conducted in the Kerman agricultural and natural resources research centre (Iran) by using a factorial design in randomized complete block in two independent experiments with three replications. In the first experiments compost with phosphorus and zinc were used, and in second experiment animal manure with phosphorus and zinc were used. The three levels of compost (0, 10 and 20 ton ha-1) and same level of animal manure were used as main. Four levels of phosphorus (0, 75, 150 and 225 kg ha-1) and two levels of zinc (0 and 50 kg ha-1) used as the sub factors. Results showed that the main factors of compost and animal manure application had no significant effect on any of the all evaluated traits in the experiments. Effect of zinc on number of small tubers was significant in the first experiment. The highest number of large tubers were found in 20 ton ha-1 compost + 225 kg ha-1 phosphorus + 50 kg ha-1 zinc in first experiment and 20 ton ha-1 animal manure + 75 kg ha-1 phosphorus + no zinc in second experiment. Tubers dry matter was significantly affected by the interaction effect of zinc and phosphorus, the maximum dry matter being obtained with the application of 225 kg ha-1 phosphorus +50 kg ha-1 zinc.