Population dynamics of Rumex obtusifolius under contrasting alfalfa cropping systems

Population dynamics of Rumex obtusifolius was studied in an alfalfa-winter cereal crop rotation by means of a matrix population model that takes into consideration two crop rotation periods: the alfalfa cropping period and the cereal cropping period. Several transition matrices based on life-cycle stages were calculated for each cropping period, and these were used in the construction of a model that analyzes R. obtusifolius population dynamics under different harvesting calendars and alfalfa cropping lengths. Results show that R. obtusifolius population increases during alfalfa cropping for all harvesting calendars and decreases during cereal cropping. The intrinsic rate of population increase is clearly dependent on both the harvesting calendar and the length of the alfalfa cropping period. The significance of results in relation to the biology and the non-chemical control of the species is discussed.