The Effect of Weed Interference Periods in Cotton Crop on the Yield and Yield Components of Cotton

In order to assess the effect of weed interference periods on yield and yield components of cotton, an experiment was carried out in the form of a randomized complete block design with six replication sin the Delgosha research field of Ferdows. In this experiment, the effect of six interference treatments including two control treatments - one during the weed period and the other during the weed-free period– and four intervention treatments – 30-day, 60-day, 90- day and 120-day treatments, was examined on the yield and yield components of cotton in the year 2012. In the end, the results were analyzed using Duncan’s new multiple range test through the SAS software. The results of this study showed that the six interference treatments had a significant impact on the yield and yield components of cotton, including cotton production, cotton fiber weight, the weight of a thousand seeds, and the biological yield per hectare. An evaluation of correlation coefficients also suggests a negative correlation between cotton seed harvest index per hectare and other measured factors. A comparison of means showed that 30 days of weed interference in cotton crop reduced the yield for 28.5percent. The results also showed neglecting to fight weeds can reduce cotton yield per hectare for up to57.3percent.

Keywords— cotton, interference periods, weed, yield and yield components