Clubroot control in cabbage and cauliflower using mechanised transplanting drenches

Mechanised transplant drenching was as effective in controlling clubroot in cabbage and cauliflower as manual transplanting and drenching. Commercially available transplant watering equipment did not accurately meter out or correctly place the fungicidal drench. In 3 separate trials, cabbage (cv. 'Golden Acre') given a benomyl transplant drench yielded better than those treated with a benomyl pre-plant root dip, with heads averaging 1.2 kg and 1.0 kg respectively. When root dipping and transplant dipping were combined, benomyl phytotoxicity occurred which depressed yields. Benomyl was found to be too phytotoxic to cauliflower (cv. 'Phenomenal - 3-month') but zineb and captafol were effective alternatives. Soil pH affected results, with c1ubroot control increasing as soil pH was raised from 5.8 to 7.9, but curd weights were severely reduced at pH levels below 7.0.