Cursing with eggs in Irish folklore:
Egg to steal crops:
"One day he found in his turnip drills a boiled goose-egg. The superstition in connection with this is that the person who puts the egg in the crop will be able to steal the crop."
Source
"Certain families are believed to be able to take a great lot of the profit from a field of corn by planting eggs in each corner of the cornfield on May Day.
The people suspected of butter taking are suspected of working magic with the eggs."
Source
"Dheir sé soiléir annsan gur do phiseogaibh a bhí sé ag tagairt agus mhinigh se gur scaipeadh uibheacha go fóir leathan i ngairdínibh prátaí agus sna móinfheárachaibh comh maith, agus sna cocaibh agus sna giobólaibh féir,"
Source
"It happened one day about that time, however, that a stranger came into the place from a good distance away and spend some time about the district. From that day on the practice of planting eggs, pig's heads, slings (aborted calves) and the clearings of slinger cows, and other things too, in the soil of the gardens, and in the meadows and wynds of hay, as well as dumping the (?) articles in bags on farms, grew for years until it destroyed itself."
Source
It appears that the placing or burying of eggs on someones property or place of growth allowed a user to reduce and obtain the effected crops. This could have modern implications with wider ideas of crops. Eggs are not the sole material for this magic but they seem the most common. The use of this magic appears to have been a widespread issue at some point.
