Fruit Splitting in Raspberry
I was called by a local raspberry grower to figure out the situation depicted below. In short, the fruit has split and both the groups of druplets and the receptacle has separated. Seems to be occurring in similar percentages in both the soil and adjacent substrate production blocks, and loss is around 5% or so. Also, it's notable that the splitting seems to be limited to one cohort of fruit, meaning previous fruit to this set and newly forming ones not splitting very much.
I checked in with Dr. Bernadine Strik from Oregon State University, and she says this is very likely related to irrigation management, meaning that there was an excess of water during the development of this fruit.
Furthermore Dr. Strik says that in her experience excess irrigation during a key time of berry development leads to the receptacle splitting. She finds it more prevalent in substrate production where good irrigation management is more difficult. Additionally, she finds some varieties are more sensitive to this issue than others.
Split raspberry fruit with unsplit, less mature fruits.
Split raspberry fruit together with unsplit fruit of similar maturity.
Receptacle remaining behind from split fruit.