On this daf, we find that Rabi Akiva was unsure whether Bais Hillel holds that the new year for trees is the first or the fifteenth of Shevat.
The Chiddushei Harim teaches a practical application from this question: “According to Bais Shammai, the first of Shevat is the new year for trees. Bais Hillel holds that it is the fifteenth of Shevat. On Tu B’Shevat, the seraf or sap rises in the trees. The word seraf is an acronym for shishim ribui peirushim, six hundred thousand explanations. On Tu B’Shevat, we draw down the ability to say chiddushei Torah for the entire year.
The Avnei Neizer adds, “Although the halacha follows Bais Hillel, Bais Shammai is also correct regarding special people who serve Hashem in an aspect of the middas hadin. They draw down this special influx from the first day of the month of Shevat” (Chiddushei Harim; Neos Hadesheh).