Strawberry Shipments
I can't shed much light on shipments of strawberries from California to the East Coast in the 30s. I suspect that due to the limited time that strawberries would be at their best after being picked and the distances involved, that there wasn't much shipment of a highly perishable cargo like that that across the country. Most of the strawberries consumed East of the Mississippi were grown in the South with huge growing operations in Louisiana.
The Illinois Central ran special trains composed entirely of express reefers that followed the harvest North. The railroad started routing express reefers to Hammond, LA in the weeks immediately before the harvest started. There the reefers were cleaned and pre-cooled. When the harvest started the reefers were loaded and sent North at passenger train speeds. Often the fruit had not been sold yet and the fruit companies sent special "messengers" with the shipment. The railroad provided a drovers type or a banana messenger caboose or more often then not hung the markers on an old coach because they were worried about a derailment of a light caboose at the speed the trains operated.
Wholesalers would bid on the cars while the rain was moving and the strawberry messengers would be notified by wire what cars had been sold and where they would be dropped off. These weren't "milk train" stop at every station trips, the sold carloads were dropped off at major interchanges in Memphis, TN and Carbondale and Mattoon, IL. From there they made connections running East and West.
As the harvest moved North along with the weather, the starting point of the trains moved North. The IC called these trains "The Crimson Flyer and they ran from the 1930s thru the 50s. They were first class trains and given priority over just about everything else on the mainline. One article I read even stated that the premier train on the line, The Panama Limited, waited in the hole for the Flyer to pass.
The IC did a lot to support this traffic including hiring experts from the University of Illinois to work with farmers on the line to help them produce the crop.