Multiple regression analysis for studied traits in intercropping of popcorn and cowpea

Abstract

The goal of multiple regressions is to enable a researcher to assess the relationship between a dependent variable and several independent (predictor) variables. In order to determination of some popcorn yield characteristics with higher effect on yield an experiment was conducted as factorial based on RCB in Islamic Azad University of Tabriz. Studied factors included maize sowing dates (12 th , 19 th and 26 th May) and sowing percentage of cowpea as 12.5%, 25%, 37.5%, 50% and 100% of recommended density rate (5, 10, 15, 20 and 40 plants per square meter). Based on results weight of 300 seed in corn ranged from 33.6 g in intercropping of popcorn + cowpea with 50% of recommended density rate up to 39.5 g and 39.7 g in intercropping of the crops with 12.5% and 25% of recommended density, respectively. Weeds biomass in intercropping of the crops with 12.5% and 25% of recommended density rate experienced reduction of 4.5 g m -2 compared to the maize mono-cropping and 6 g m -2 compared to the mean of intercropping of the crops with 37.5% and 50% of recommended density rate. Increasing of cowpea density when intercropped with maize caused to earlier flowering. The stepwise regression analysis verified that the LAI, 300 seed weight and weeds biomass had a marked increasing effect on the corn seed yield in intercropping with cowpea.