Effects of sowing methods on growth and root deformations of containerized cork oak (Quercus suber L.) seedlings in nursery

Abstract

This work consists on the study of the effects of some sowing methods of cork oak acorns on seedling performances. We studied the effects of acorns which germinated during storage, acorns which did not germinate during storage, acorns which germinated after moist stratification, arrangement of acorns in container and orientation of the radicle on seedling survival, growth and types of root deformations. To do so, a completely three-block randomized design was installed in nursery. After eight months of growth, the whole roots of the 1,166 seedlings which survived were visually inspected for eventual deformations. A sample of 25% of these seedlings was randomly selected to evaluate the effect of sowing methods on seedling growth. The data obtained shows that : 1) seedlings produced by germinated acorns and radicle directed downward grow better than seedlings supplied by intact acorns, 2) acorns germinated during storage provided nearly 36% of seedlings with deformed roots half with detrimental deformations, 3) acorns germinated after moist stratification provided 28% of seedlings with deformed roots dominated by sticks in the collar, and 4) intact acorns provided 20% of the seedlings with deformed roots but mainly no detrimental deformations.

Radicle length and container size effects on root deformities in the Mediterranean oak <i>Quercus suber</i> L.

“…Although, both treatment combinations cause root deformation, the germination status of acorns at the time of sowing was shown to exert the most significant effect. In accordance with a previous research (Chouial and Benamirouche, 2016), the greatest number of deformed roots was observed on seedlings grown from sowing of germinated acorns than on seedlings grown from direct sowing of intact acorns with respective percentages of 91% and 9% of the inspected seedlings. Thus, direct sowing of intact acorns could significantly reduce the occurrence of root deformations.…”