Relationships between inflorescence size and the presence and size of ball galls on goldenrod

A plot with a substantial population of Tall Goldenrod (Solidago altissima) and visible ball galls from Eurosta solidaginis was censused on a weekly basis throughout the summer and fall for the diameter (mm) of galls established throughout May and June. Plants with a single gall from E. solidaginis were censused in August for their stage of inflorescence development and then collected throughout September along with 20 plans without a gall. After drying for at least a month, the flowerheads were weighed along with combined weight from the inflorescence, and the length (cm) of the inflorescence was recorded. Statistical analysis determined the greater length and weight of inflorescences and flowers of plants with and without ball galls is not due to random chance, and there is a significant relationship between the diKerences in flower weight (g) between damage type categories, specifically plants with no damage compared to those with apical bud damage and/or a ball gall. It was unexpected to see plants with both damage types present have greater inflorescence and floral weight (g), but lower inflorescence length (cm).