If it will take over 24 hours to fill a grain bin for fumigation, what should be done?

Fumigating the grain bin only after it is completely filled is the most appropriate action to take in this scenario. When fumigating, it’s essential for the fumigant to be evenly distributed throughout the space being treated. If the bin is not fully filled, there may be spaces where the fumigant cannot effectively reach, potentially leading to ineffective treatment and leaving some areas untreated, which can cause pest survival.

Waiting until the bin is completely filled ensures that the entire volume is treated uniformly, allowing for proper gas concentrations to develop throughout the grain. Additionally, gases used in fumigation require containment within the structure to work effectively, and filling the bin allows the fumigant to create a consistent atmosphere.

It's important to note that fumigating before filling the bin could compromise the effectiveness, as there wouldn't be enough material to hold the fumigant, and skipping fumigation entirely would defeat the purpose of controlling pests. While a different fill method might seem efficient, it may not guarantee proper gas distribution, which is critical for successful fumigation.