well technically there is no carry on the new crop, since it is still in the ground or just a gleam in a corn/bean farmers eye
Cost of carry is not so much an old crop/new crop matter. It is the cost related to holding grain from one month to another. This cost is primarily interest and storage but also includes shrink and insurance. Depending on the grain/market, some specific rules may apply. One can plug the quick formula in a spreasheat: current futures price * days/365 * IR% + days/365 * 12 * monthy storage * 100
at anyrate, if you can show me a guy that is paying storage on new crop July wheat, let me know , that sounds like an interesting story. The only people I know storing July wheat are the farmers, and it is all safely tucked in the ground, and the only way you can bet on it is to know what the weather will do.