Influence of Different Densities of Johnson-grass [Sorghum halepense (L.) Pers.] on the Yield of Middle Early and Late Varieties of Potatoes

Abstract

 Durin g the period 2009 – 2011 year was conducted a study of the competitive relationship between Johnson-grass [Sorghum halepense (L.) Pers.] and mi mi ddle early and late varieties of potatoes in in order to establish the extent of the harmful effects of the weed on the culture. Two-factor field experience has been done accordin g to the method of fractional parcels with four varieties of potatoes and a different density of Johnson-grass – from 0 to 8 numbers per m2 in in geometric progression. The data for the in fluence of the weed density on the yield of potatoes show the followin g. The potato production grown without Johnson grass competition is highest and ranges from 1414.3 kg/da for Agria variety to 2367.3 kg/da for Markiz variety. As expected, the yield of potatoes with density 8 numbers per m2 of Johnson-grass is lowest. In this option the lowest average yield for the period is for Agria variety – 393.67 kg/da. The reason about this is due to more limi ted potential abilities of the variety in field conditions. Relatively the high yields of the experim im ental conditions are due to the fact, that the experim im ental plots are main in tain in ed free of weeds throughout the growin g season of the culture.