Investigating the effects of manure and soil solarization on saffron and population of bulb mite, Rhizoglyphus robini

Saffron is one of the most valuable agricultural products. Saffron, as other crops, could be affected adversely by several factors, including Rhizoglyphus robini. This mite is a polyphagous pest and can remain in soil for a long time. R. robini is known as the main limiting agent in saffron cropping. The present experiment was carried out in randomized complete block design with three replications on the farm of Gonabad Agricultural Research Station during growing season of 2007. Manure levels, i.e. 0, 20 and 40 ton/ha, were placed in main plots. Subplots consisted of five treatments of duration of solarization i.e. 0, 10, 20, 30 and 45 days, performed by transparent plastic laminate before planting. Results revealed that both factors can significantly affect the mite population and flower production. During first year of the experiment, as solarization duration and manure level increased, mite population decreased while after that, mite population increased gradually. Soil solarization for 30 days was the most effective treatment in mite population control. Maximum total yield and minimum mite density was obtained with 20 ton/ha of manure and 30 days of solarization.