Slow Rot

This spell increases the amount of time that fruits, vegetables, and grains remain wholesome and ripe. The spell will not take effect upon meat of any kind.
The caster can affect as much as 100 cubic feet of plant material per level. Thus, even a low level priest could effectively keep a farmer's grain from rotting while in storage or keep the fruit on the trees in his orchard ripe until they are harvested. This spell does not prevent pests (such as rats) from eating the food.

[Tome of Magic]

Sphere: Plant
(Abjuration)
Level: 3

Range: Touch
Components: V, S, M
Duration: 1 week/ level
Casting Time: 1 round
Area of Effect: Special
Saving Throw: None

Material Components:
a pinch of sugar