Maturity tests must be made as near to the time of picking as is practicable under the circumstances. “At time of picking” does not necessarily mean the instant the fruit was separated from the tree, but may be construed to mean the time when the product reaches the packing location, provided that the product has been brought from the orchard or field to the packing location within a reasonable time. The term “at time of picking” cannot be extended to include allowing the product to stand either in the orchard or any other place for the purpose of permitting the produce to undergo a ripening process.