The potential impact of flower infecting botrytis bud rot (Botrytis cinerea pers.) on hemp (Cannabis sativa L.) selective breeding

Abstract

The aim of this paper is to examine the possible adverse phytopathological effects of the selection of hemp (Cannabis sativa L.) plants with altered inflorescence morphological characteristics. We have created the conditions for an accelerated method to judge the offspring of our hemp crosses. The late-autumn growing environment requires additional heating and ventilation. Despite all those controlled environmental conditions the incidence of flower bud rot increased. The application of fungicides is not recommended during breeding as it has a detrimental effect on the selection processes. Fungicides against flower and storage diseases at later stages can not be used in the final product either, due to food health regulations. So in case of our available plant material for variety production the expected rate of fungal infection was evaluated in a greenhouse environment. A preliminary study was conducted to assess the extent of natural resistance to artificial infection. We attempted to examine the critical plant phenological stages. No bud rot resistant individuals were found in our plant stock, although the severity of symptoms was very different.