Effect of farmyard manure and planting depth on phenological stages and tuber yield of potato

Effects of farmyard manure and planting depth on (Solanum tuberosum L. var. Agria) was examined in a field study in Faculty of Agriculture Ferdowsi University of Mashhad in 2004. The experimental design was a split plot with four complete randomized blocks. Farmyard manure was allocated to main plots with 4 levels (0, 20, 40 and 60 ton/ha) and planting depth were randomized in subplots with 4 levels (6, 12, 18 and 24 cm). Farmyard manure and planting depth had significant effect on phenological stages. Emergence and maturity was accelerated and delayed, respectively with increasing farmyard manure or decreasing planting depth. Number of tuber per plant was increased with increasing farmyard manure or decreasing planting depth. Tuber weight was not affected by farmyard manure but with increasing planting depth this parameter increased. With increasing farmyard manure, yield was increased and the highest tuber yield (29.01 ton/ha) was obtained with 60 ton/ha farmyard manure. The highest tuber yield was obtained in 18 cm planting depth. The interaction effect of farmyard manure and planting depth was not significant on phenological stages, yield and yield components