Brassica crops and a Streptomyces sp as potential biocontrol for clubroot of brassicas

Abstract

Two glasshouse experiments and a field trial were carried out to evaluate the potential of brassica crops which contain high levels of glucosinolates for control of clubroot of brassicas Brassica rapa crops were grown for about 70 days in a field which was infested with Plasmodiophora brassicae In the first glasshouse experiment the leaf and stem of the plants were harvested chopped into small pieces and mixed with clubrootinfested soil in punnets Chinese cabbage seedlings were then transplanted into the punnets In the second glasshouse experiment soil samples were taken in punnets from plots where the B rapa crops had been rotary hoed and left to decompose for about three weeks Chinese cabbage seedlings were transplanted into the punnets In both experiments B rapatreated soil reduced (P<0001) the clubroot severity on the root systems of the seedlings compared to the untreated control A field trial was carried out on clubrootinfested soil to evaluate B rapa B napus and a Streptomyces sp for clubroot control The two brassicas crops and Streptomyces sp reduced (P005) clubroot severity on root systems of Chinese cabbage plants except where B napus was planted at a lower rate (8 plants/m²)