بررسي تداخل گندم و علف هاي هرز به روش وايازي چند متغيره

A Survey of Wheat and Weeds Interference by Multiple Regression

To examine intra and inter species weeds interference in wheat cultivation by multiple experiment was conducted at the field fourteen hectares of ghaemshahr azad university during 2001-2002. For the purpose. 27 samples of 5 * 5(m) were selected from the field and in some stages, the weeds density species widow was counted, also at the end of the season dry weight all species were separately measured. In wheat plant yield reciprocal model that was used to analysis interference, because of presence correlation between independent variables (weeds), for adjusting regression coefficient, Ridge regression was used. It was seen that, considering the equation coefficient, the weed interference effect on wheat can be divided in two groups; inhibition (positive sign) and stimulation (negative sign). The share of the wheat intraspecies competition was more than interspecies competition. Two species of turnip weed (Rapistrum reugosum) and wild oat (Avena fatua) had the most share in wheat yield loss, while species with least interference time played on inferior role in it. Creeping thistle (Circium wvense), common lambsquartes (Chenopodium album), little seed Canavy gross (Phalaris minor) as well as two species of matter pea (Lathyrus annus and L. aphaca) not only had no inhibitory effect on wheat yield, but also caused its improvement. This effect resulted from their inhibitor effect on oat growth, which had the most share in wheat yield loss in this test