The effect of undersowing time of clover crops and weeds on silage maize yields

In field experiments conducted on loamy luvic chernozem (170 m altitude, 48°34' N 17°45' E), the effects of undersowing time (5 days after maize was sown and into emerged stand) of lucerne, red clover and sainfoin on silage maize dry matter have been studied. The total dry matter yields were affected by time of undersowing of clover crops. The stands undersown after emergence of maize gave higher yields than former time of undersowing. The late time of undersowing improved conditions for growth of maize and formation of its yield. The number of maize plants had already insignificant effect on yields there. The dry matter weight, height, and number of maize plants and dry matter weight of weeds were main factors of formation of the total yield. The depressive effect of weeds on total yields was applied indirectly particularly through the decrease in the dry matter weight of maize plants. The path analysis in spite of the insignificant effect of clover crops undersown on total yields indicated some differences in the formation of yield. The number of maize plants reached the significant level of effect on yield only at stands with red clover undersown. On the contrary, the negative correlation of weeds dry matter weight with the number of maize plants reached level of significance in stands with lucerne undersown only.