Effects of different mechanical treatments on quercus variabilis, Q. wutaishanica and Q. robur acorn germination

Abstract

Delayed and uneven germination of acorns has a negative effect on seedling quality and yield in seedlings. To address this issue, the effects of different mechanical treatments were studied, including a control (CK), removal of cup scar (RS), removal of pericarp (RP), removal of pericarp and 1/2 of the cotyledon (HC) and removal of pericarp and 2/3 cotyledon (TC), on the germination of Quercus variabilis, Q. wutaishanica and Q. robur acorns and pericarp thickness. The results showed that (1) RP and HC treatments significantly decreased root and shoot mean germination time, increased rooting and shooting germination percentage, and improved the root and shoot synchronization and vigor indexes of the three species’ acorns; (2) the acorns from the TC treatment significantly reduced root and shoot mean germination time and significantly induced the root and shoot synchronization index for all three species; and (3) the RS treatment significantly reduced the root and shoot mean germination time of the three species. Therefore, RP and HC treatments can effectively accelerate germination and regular seedling, which are important in the propagation of Q. variabilis, Q. wutaishanica and Q. robur seedlings. Even and quick germination help reduce acorn predation.