| چکیده انگلیسی مقاله |
In order to evaluate the effect of crops rotation on agronomical and non agronomical characters of cotton in Karkandeh Station in Golestan Proviences.The first and second years planted cotton and stems were cut to pieces and ploughed in soil.In the third and fourth years 15 treatments includes :soybean,barley, onion, ploughing,ploughing+100kg nitrogen,tomato,wheat,lettuce,broad bean ,green bean,green pea,sesame,sorghum,Ceolsa were planted based on randomized complete block design with four replications.The yield, boll weight, percentage of earliness, sympodial length, monopodial number, monopodial length, disease indexes of wilt and Verticillium wilt percent were measured .Population of Verticillium dahliae,in dried soil were assessed before and after treatments by using semi selective Alcohol agar medium.The results were compared using Duncan's multiple range test.The results showed that the highest yield of cotton was in "cotton + urea + cotton,"plowing + plowing+cotton,"cotton +sorghom+cotton,"rotations.The lowest yield was observed in "canola + forage barly + cotton"and Cotton + Cotton + garden cress,succession.The widest monopodial length forage was in "barly + Cotton + Cotton"and the highest of sympodial length was in "cotton+sorghom +cotton,"rotations.The highest of monopodial number,was seenin"barely+spinach+cotton"succession.The highest percentage of earliness was measured in"barely+ spinach+cotton"rotations.Percent increase in the population of Verticillium dahliae in cotton +Cotton+Cotton+Cotton+Cotton" sequence was observed from first to fifth year 52/5, 25, 5/13, 5/6 and 0,respectively.The results showed that, population ofVerticillium dahliae,were incresed after cotton in first year(35%-70%),in second year(14%-36%),third year(12%- 15%),fourth year(4% -9%) and fifth year without increase.Population of Verticillium dahlia , were increased after wheat (66.7%) , barley (68%) , Ceolsa (33.3%) , forage barly (48.5% - 54.5% ) , lettuce (25% -39%) , onion (52%) , soybean (36%) , ploughing (36%) , ploughing + 100kg nitrogen (50%) , green bean (12.5%) and sorghum(62.5%). population of Verticillium dahliae, were decresed after tomato(6.6%),and sesame(26.6%). |