Destroyed crops dupes items at exponential rate

Crops that are destroyed by jumping on them ( or having mobs do it ) isn't destroyed - the land stops being farmland but the crop is still displayed, every so often crops will "pop off" creating x crops.

I initially ignored it as it was somewhat usefull, how ever the rate at wich the items are created seems to be exponential, I ended up having to move the world to my computer as I could not type /kill @e[type=items] fast enough to kill the potato storm