The sign is a subtle joke. The shop is called "Sneed's Feed & Seed", where "feed" and "seed" both end in the sound "-eed", thus rhyming with the name of the owner, Sneed. The sign says that the shop was "Formerly Chuck's", implying that the two words beginning with "F" and "S" would have ended with "-uck", rhyming with "Chuck". So, when Chuck owned the shop, it would have been called "Chuck's Feeduck and Seeduck".

𝓜𝔂 𝓭𝓮𝓪𝓻𝓮𝓼𝓽 𝓫𝓻𝓸𝓽𝓱𝓮𝓻, 𝓘 𝔀𝓻𝓲𝓽𝓮 𝔂𝓸𝓾 𝓲𝓷 𝓭𝓮𝓮𝓹 𝓶𝓮𝓵𝓪𝓷𝓬𝓱𝓸𝓵𝔂. 𝓘𝓽 𝓪𝓹𝓹𝓮𝓪𝓻𝓼 𝓽𝓸 𝓶𝓮 𝓽𝓱𝓪𝓽 𝓽𝓱𝓮𝓻𝓮 𝓲𝓼𝓷'𝓽 𝓪𝓷𝔂 𝓬𝓸𝓬𝓴 𝓵𝓮𝓯𝓽