Laudator Temporis Acti

H.J. Rose, "The Folklore of the Geoponica," Folklore 44 (1933) 57-90 (at 75-76):

Perhaps the most interesting charm is that in x.83, 1-2, for making a barren tree bear. "Gird yourself and take an axe, double or single-bladed. Go angrily towards the tree, as though you would cut it down. Now let someone approach you and beg you not to cut it down, saying that he will guarantee it to bear in future. Pretend to believe him and to spare the tree. It will then bear freely." It is to be noted that the Parable of the Barren Fig-tree (Luke xiii.6) assumes the existence of this very custom.

The Greek is on p. 319 of Heinrich Beckh's edition, Geoponica sive Cassiani Bassi Scholastici De Re Rustica Eclogae (Leipzig: B.G. Teubner, 1895), with the chapter heading Δένδρον ἄκαρπον καρποφορεῖν. Ζωροάστρου:

[1] Συζωσάμενος καὶ ἀνακομβωσάμενος, καὶ λαβὼν πέλεκην ἢ ἀξίνην, μετὰ θυμοῦ πρόσελθε τῷ δένδρῳ, ἐκκόψαι τοῦτο βουλόμενος. [2] προσελθόντος δὲ σοί τινος, καὶ παραιτουμένου τὴν τούτου ἀποκοπήν, ὡς ἐγγυητοῦ περὶ τοῦ μέλλοντος καρποῦ γινομένου, δόξον πείθεσθαι καὶ φείδεσθαι τοῦ δένδρου, καὶ εὐφορήσει τοῦ λοιποῦ.

Luke 13.6-9:

[6] A certain man had a fig tree planted in his vineyard; and he came and sought fruit thereon, and found none. [7] Then said he unto the dresser of his vineyard, Behold, these three years I come seeking fruit on this fig tree, and find none: cut it down; why cumbereth it the ground? [8] And he answering said unto him, Lord, let it alone this year also, till I shall dig about it, and dung it: [9] And if it bear fruit, well: and if not, then after that thou shalt cut it down.

[6] Συκῆν εἶχέν τις πεφυτευμένην ἐν τῷ ἀμπελῶνι αὐτοῦ, καὶ ἦλθεν ζητῶν καρπὸν ἐν αὐτῇ καὶ οὐχ εὗρεν. [7] εἶπεν δὲ πρὸς τὸν ἀμπελουργόν, Ἰδοὺ τρία ἔτη ἀφ’ οὗ ἔρχομαι ζητῶν καρπὸν ἐν τῇ συκῇ ταύτῃ καὶ οὐχ εὑρίσκω. ἔκκοψον αὐτήν· ἱνατί καὶ τὴν γῆν καταργεῖ; [8] ὁ δὲ ἀποκριθεὶς λέγει αὐτῷ, Κύριε, ἄφες αὐτὴν καὶ τοῦτο τὸ ἔτος, ἕως ὅτου σκάψω περὶ αὐτὴν καὶ βάλω κόπρια· [9] κἂν μὲν ποιήσῃ καρπὸν εἰς τὸ μέλλον – εἰ δὲ μήγε, ἐκκόψεις αὐτήν.

Richard Chenevix Trench, Notes on the Parables of our Lord, new and rev. ed. (New York: D. Appleton and Company, 1878), p. 256, n. 1:

Rosenmüller (Alte und Neue Morgenland, vol. v. p. 187) quotes from an Arabian writer this receipt for curing a palm-tree of barrenness: 'Thou must take a hatchet, and go to the tree with a friend, unto whom thou sayest, I will cut down this tree, for it is unfruitful. He answers, Do not so, this year it will certainly bear fruit. But the other says, It must needs be,—it must be hewn down; and gives the stem of the tree three blows with the back of the hatchet. His friend restrains him, crying, Nay, do it not, thou wilt certainly have fruit from it this year, only have patience, and be not overhasty in cutting it down; if it still refuses to bear fruit, then cut it down. Then will the tree that year be certainly fruitful and bear abundantly.' Compare Rückert, Brahmanische Erzählungen; S. de Sacy, Chrest. Arabe, vol. ii. p. 379; the same reappearing in the collection of tracts De Re Rusticâ, entitled Geoponica.

Note that Geoponica attributes the charm to Zoroaster.

J.G. Frazer, The Golden Bough, Vol. II (London: Macmillan and Co., Limited, 1911), pp. 21-22 (footnotes omitted):

Near Jugra in Selangor there is a small grove of durian-trees, and on a specially chosen day the villagers used to assemble in it. Thereupon one of the local sorcerers would take a hatchet and deliver several shrewd blows on the trunk of the most barren of the trees, saying, "Will you now bear fruit or not? If you do not, I shall fell you." To this the tree replied through the mouth of another man who had climbed a mangostin-tree hard by (the durian-tree being unclimbable), "Yes, I will now bear fruit; I beg of you not to fell me." So in Japan to make trees bear fruit two men go into an orchard. One of them climbs up a tree and the other stands at the foot with an axe. The man with the axe asks the tree whether it will yield a good crop next year and threatens to cut it down if it does not. To this the man among the branches replies on behalf of the tree that it will bear abundantly. Odd as this mode of horticulture may seem to us, it has its exact parallels in Europe. On Christmas Eve many a South Slavonian and Bulgarian peasant swings an axe threateningly against a barren fruit-tree, while another man standing by intercedes for the menaced tree, saying, "Do not cut it down; it will soon bear fruit." Thrice the axe is swung, and thrice the impending blow is arrested at the entreaty of the intercessor. After that the frightened tree will certainly bear fruit next year. So at the village of Ucria in Sicily, if a tree obstinately refuses to bear fruit, the owner pretends to hew it down. Just as the axe is about to fall, a friend intercedes for the tree, begging him to have patience for one year more, and promising not to interfere again if the culprit has not mended his ways by then. The owner grants his request, and the threatened Sicilians say that a tree seldom remains deaf to such a menace. The ceremony is performed on Easter Saturday. In Armenia the same pantomime is sometimes performed by two men for the same purpose on Good Friday. In the Abruzzi the ceremony takes place before sunrise on the morning of St. John's Day (Midsummer Day). The owner threatens the trees which are slow to bear fruit. Thrice he walks round each sluggard repeating his threat and striking the trunk with the head of an axe. In Lesbos, when an orange-tree or a lemon-tree does not bear fruit, the owner will sometimes set a looking-glass before the tree; then standing with an axe in his hand over against the tree and gazing at its reflection in the glass he will feign to fall into a passion and will say aloud, "Bear fruit, or I'll cut you down." When cabbages merely curl their leaves instead of forming heads as they ought to do, an Esthonian peasant will go out into the garden before sunrise, clad only in his shirt, and armed with a scythe, which he sweeps over the refractory vegetables as if he meant to cut them down. This intimidates the cabbages and brings them to a sense of their duty.