Effects of Johnsongrass (Sorghum halepense L. per.) densities on potato (Solanum tuberosum L.) yield

Abstract

The effect of 3 Johnsongrass densities (131: 17 pl/m^-2; D2: 34 pl./m^-2 and D3: 51 pl./m^-2) on potato (Solanum tuberosum L.) tuber yield and biornass production was studied. The work was carried out in metalic containers with a loamy soil under high water and nutrient availability. At harvest, crop biomass was reduced 28% for D1, 57% for D2 and 68% for D3. Dry weight of tubers was the parameter most affected by Johnsongrass competition. Tuber weight clecreased 80, 85 and 95% at D1, D2 and D3, respectively. Tuber number per plant was reduced 45, 55 and 65% by the same densities. It was evident that the weed generated high competitive conditions that affected all the parameters measured, particularly tuber dry weight.