Caragana rhizobia reisolated from nodules they formed on Trifolium pratense retained the ability to nodulate Caragana. Throughout the life of a Caragana nodule, the volume of tissue functionally active in N-fixation remains more or less constant. As the nodule becomes larger, the ratio of the N-fixing volume to total nodule mass becomes smaller. Of particular interest is the coexistence of juvenile and senescent tissue in close proximity for long periods. Nursery stock may need pesticides to prevent damage by spiders, blister beetles, and other leaf-eating insects.
Grasshoppers are especially destructive, sometimes completely defoliating the plants.
References Agriculture Handbook 165. 1960. Index of plant diseases in the United States. Agriculture Handbook 450. Seeds of woody plants in the United States. Allen, O.N. and Allen, E.K. 1981.