EPIDEMIOLOGY AND CONTROL OF SOME DISEASES AFFECTING PROTEACEAE CROPS IN CHILE

Abstract

Since the introduction of Proteaceae crops in Chile, there have been at least seven diseases described caused by fungi (Phytophthora, Fusarium, Alternaria, Botrytis, and Cladosporium) and bacteria (Pseudomonas and Xanthomonas). Additionally, some wood-associated pathogens such as Botryosphaeria, Phoma and Phomopsis have also been described. Due to important losses associated with these diseases, both chemical and biological control alternatives were evaluated for some of the above pathogens. Field and greenhouse experiments were conducted over different seasons. Trichoderma harzianum as a drench application resulted in an effective preventive control of Fusarium, with incidence and severity levels similar to the fungicide Benomyl. On the other hand, epidemiological studies indicated that the pathogen inoculum remained both in the soil and in weeds (Daucus carota and Rumex acetosella). According to field experiments, Trichoderma virens appears to be a good control alternative for Cladosporium and Alternaria. Trichoderma parceanamosum sprayed over the plants proved to be the most effective control treatment for Botrytis cinerea. Finally, cupric fungicides and Bacillus subtilis isolates did not provide an effective control against Pseudomonas in field conditions. New experiments should be conducted to obtain more conclusive results.