Effect of farmyard manure and mineral fertilization on growth and yield of early potato (Solanum tuberosum) under the Mediterranean conditions in Turkey

A field experiment was conducted during the winter and spring months of 2000 and 2001 at Hatay, Turkey (36degrees 39. N, 36degrees 40' E), to study the effects of farmyard manure (0, 10, 20, 30, 40 and 50 tonnes/ha) and mineral fertilization (no or 200-90-90 kg/ha N-P-K respectively) on growth and yield of early potato (Solanum tuberosum L.) crop. Mineral fertilization significantly increased values of morphological traits and tuber yield, while it had negative effect on dry matter content of tuber. The application of farmyard manure also had positive effects on growth and yield with or without mineral fertilization. The farmyard manure also increased the efficiency of mineral fertilization. Tuber yield increased as the farmyard manure levels increased under non-mineral fertilized conditions while no significant increase obtained from 40 and 50 tonnes manure/ha rates in mineral-fertilized plots. Aplication of farmyard manure significantly increased the dry-matter content of tuber and this was more evident in mineral fertilized plots.