Reference for Bava Batra 107:1

דשדא ליפתא בי פילי דארעא דגר לא הוי חזקה מאי טעמא בעידנא דשדא לא הוי שבחא השתא דקא שבח ממילא קא שבח

throws vegetable seeds into the crevices of a proselyte's land, this act does not confer a title of ownership. The reason is that at the time of his throwing [the seeds] no improvement is effected, and the subsequent improvement<span class="x" onmousemove="('comment',' When the vegetables grow. ');">¹</span> comes automatically.

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