A survey of cultural practices associated with soilborne diseases in greenhouse production of floricultural crops in North Carolina

Floriculture crops are economically important in North Carolina. Management practices that suppress or prevent soilborne diseases in floriculture production under greenhouse conditions are known based on empirical studies. However, the extent that these practices are employed by floriculture crop producers in North Carolina is unknown. Further, identifying associations between management practices and the occurrence of disease has not been conducted under actual crop production conditions. A thirty-five question, in-person survey that included topics related to soilborne disease occurrence such as storage conditions of potting media, re-use and treatment of pots, and irrigation water source and treatment was administered to growers from thirty-two selected greenhouses across seventeen counties in North Carolina. The objectives were to: 1) assess current practices used to manage soilborne diseases by greenhouse floriculture crop producers in North Carolina; 2) determine practices associated with the incidence of soilborne diseases in greenhouse production; and 3) identify research or extension needs for floriculture growers to mitigate soilborne diseases under greenhouse conditions in North Carolina. Our results indicate that most growers are employing practices that suppress soilborne diseases. However, the incidence of soilborne disease on annual vinca or petunia were significantly (p-value < 0.0029) greater when some conducive practices such as storing potting media near the cull pile, not treating recycled irrigation water, and poor drainage were employed in production. Disease conducive practices, such as not inspecting propagation material before transplanting and not removing diseased plants from production, were associated with increased disease occurrence. These results highlight the need for continued research and extension efforts, particularly in integrated pest management techniques to reduce crop losses to soilborne diseases.