The statistical analysis of the drought mutual effects on micro dust intensification and wheat production performance in Lorestan dry farming lands

Dust is one of the drought consequences which during recent years has been emerged as one of the important factors affecting wheat growth and its production yield beside other climatic fluxions. In this research, the drought intensity has been studied at nine synoptic stations of Lorestan province, during a ten years period of 2000-2009 and its dominant effects on dust frequency rate and its effects during seasons on the wheat cultivation performance rate, as one of the most important agricultural products sensitive to climatic variations,. The drought intensity analysis has been conducted by SPI index, for a six months’ time scales led to January and its relation with dusty day’s frequency distribution has been examined in horizontal sight less than 2000 m at the province stations. Also, the mutual correlation rates have been analysed using Pearson correlation test and multiple regression method with SPSS software and clustering was studied using Ward method in S-plus software. Results demonstrated that even during normal wet-spell, dust days happen and wheat performance in drylands falls below1000 kg ha-1 (2004, 2005 and 2007). Whereas, the dust days reached to zero and the wheat performance exceeded kg ha-1 (2006), when the wet-spell exceeds its normal rate and reaches to reduced domain. The frequency of dust days and wheat performance are directly correlated in most stations like Khoramabad, Koohdasht and Broojerd with a rate of 0.784, 0.626 and 0.933, respectively and completely adverse in Azna with a rate of -0.926.