CHEMICAL INDUCTION OF FEATHERS ON “CONFERENCE” PEAR TREES IN THE NURSERY

Four new chemicals: Butralin, NC 9634, PP 528 and PP 938 were applied in the nursery on "Conference" pear trees (60 cm height) in comparison with Off-Shoot-T and "hand pinching" at the end of May.

Feathers were induced on more than 90% of the treated trees by Off-Shoot -T, PP 528 and NC 9634 (13% only on the check trees); the two latters promoted more than five but quite short feathers per tree.
With Butralin, feathers were less in number and on 77% only of the trees.

All the chemicals caused initially a 2–3 weeks of growth retardation and, in the fall, an earlier rest of the shoot growth.
Off-Shoot-T and Butralin caused also a slight damage to the young leaves as well as the temporary suppression of the apex bud.

Two physiological patterns seem to exist for the feathers induction; the first can be considered as a "chemical tipping" (i.e.
Off-Shoot-T and Butralin), with an immediate effect similar to that of "hand tipping": the feathers originate only or mainly from buds developed before the treatment; and the second, more complex, related to a progressive removal of the "apical dominance"; for example, NC 9634 induced also a later development of feathers above the height reached by the shoots at the treatment time.

II International Symposium on Pear Growing

S. Sansavini, M. Antonelli, M. Grandi

https://doi.org/10.17660/ActaHortic.1977.69.28