Eastern black walnut ( Juglans nigra L.) is a nut-producing tree species that breaks dormancy late in the spring, allowing a winter alley crop to ripen before substantial canopy shade is formed. However, there is a high level of variation in the timing and structure of tree canopy development within the black walnut cultivar collection maintained at the University of Missouri Center for Agroforestry (UMCA). To identify cultiva...

Background and aims Sorghum ( Sorghum bicolor ) is able to exude allelochemicals with biological nitrification inhibition (BNI) capacity. Therefore, sorghum might be an option as cover crop since its BNI ability may reduce N pollution in the following crop due to a decreased nitrification. However, BNI exudation is related to the physiological state and development of the plant, so abiotic stresses such as drought might modify...