REGULATION OF VIVIPARY IN PECAN

Crop loss to vivipary (i.e., germination of nuts on the tree) is potentially a major profit-limiting problem affecting yield and quality of nutmeats from certain pecan [Carya illinoinensis (Wangenh.) K. Koch] cultivars at certain locations.
Improved orchard management tools and strategies are needed to avert major economic loss.
Field research on ‘Cheyenne’ pecan assessed the possibility of controlling vivipary via supplemental irrigation and nitrogen (N) management.
The incidence of vivipary on irrigated trees was 25-fold greater than that on non-irrigated trees, and incidence on trees receiving excessive N fertilization was 21-fold greater than that of trees not receiving N. There was a strong ‘Irrigation × N’ interaction, with trees receiving ‘Irrigation + N’ exhibiting 41-fold more vivipary than did ‘Non-irrigated – N’ trees.
The incidence of vivipary in orchards therefore appears amenable to management via an appropriate irrigation and N fertilization strategy.
Treatment of developing ‘Oconee’ fruit with (±)ABA [(2-cis, 4-trans)-5-(1-hydroxy-2,6,6-trimethyl-4-oxo-2-cyclohexen-1-yl)-3-methyl-2,4-pentadienoic acid) or fluridone [1-methyl-3-phenyl)-5-3-(trifluoromethyl) phenyl-4(1H)-pyridinone)], an inhibitor of ABA biosynthesis, reduced and increased the incidence of vivipary, respectively.
Additionally, treatment of developing ‘Sumner’ fruit with fluridone reduces the germination time of harvested pecan nuts.
This indicates that the influence of supplemental irrigation and N on incidence of vivipary is likely via alteration in ABA metabolism within developing fruit.

I International Symposium on Pecans and Other Carya in Indigenous and Managed Systems

B.W. Wood

Carya illinoinensis, nutrient disorder, nitrate, fluridone, ABA, phytohormones, water, stress, nut, seed, germination, pre-germination

https://doi.org/10.17660/ActaHortic.2015.1070.3