THE INFLUENCE OF BROOMRAPE ON THE GROWTH AND DEVELOPMENT OF SUNFLOWER IN CONTROLLED CONDITIONS

Maria DUCA*, Steliana CLAPCO*, Ion GÎSCĂ*,**, Rodica MARTEA*, Ana MUTU* *Universitatea de Stat din Moldova, ** Seedeco Semences SRL, Chișinău

Abstract

The present study aimed to evaluate, under controlled conditions, the effect of the holoparasite Orobanche cumana (broomrape), with different levels of aggressivity, on the agro-morphological parameters, accumulation and distribution of biomass in the host plant Helianthus annuus. The obtained results highlighted the non-essential impact of the parasite on the height and length of the host plant root and a considerable effect on the biomass accumulation process, being noticed a decrease of about 20.4-57.1% compared to the uninfested control. The parasite exerted a more pronounced impact on the aerial part, being revealed strong negative correlations (r = -0.52) between the intensity of the attack and the mass of the aerial part of the host plant. It was found that the parasitic plants, also, change the biomass distribution pattern, the root parasite influencing the host shoots more strongly than the roots, which is confirmed by the values of the Shoots : Root ratio, which was lower compared to the uninfested control. At the same time, strong correlations (r = -0.54) between the rate of the combined biomass allocated into the aerial part of the host and the incidence of broomrape were highlighted. Keywords: sunflower, broomrape, agro-morphological parameters, biomass, biomass distribution, attack intensity.