Cranberry Fall Nitrogen Fertilization Promotes Subsequent Season Vegetative Growth

Authors: ROJAS-BARROS, PEDRO - University Of Wisconsin; BOLIVAR-MEDINA, JENNY - Washington State University; WORKMASTER, BETH - University Of Wisconsin; Zalapa, Juan; ATUCHA, AMAYA - University Of Wisconsin

Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/26/2022
Publication Date: 12/9/2022
Citation: Rojas-Barros, P., Bolivar-Medina, J., Workmaster, B.A., Zalapa, J.E., Atucha, A. 2022. Cranberry Fall Nitrogen Fertilization Promotes Subsequent Season Vegetative Growth. HortScience. 58(1)6-10. https://doi.org/10.21273/HORTSCI16848-22.
DOI: https://doi.org/10.21273/HORTSCI16848-22

Interpretive Summary: Plant energy reserves play a key role in woody perennial plants' winter survival and growth resumption during the spring. In fruit crops, these reserves are critical for yield production in temperate climates when nutrient uptake is minimal and energy production is limited in newly emerged leaves. Fall nitrogen (N) fertilization can be used to increase the availability of plant energy reserves to support and enhance vegetative growth and fruit production the following growing season. The objective of this study was to test the effect of fall N fertilization on fruit production by evaluating yield and their relationships with vegetative growth. An experimental design was established in three ‘HyRed’ cranberry production beds at a farm in central Wisconsin. Fall N treatments consisted of plots receiving 0, 10, 20, and 40% of the standard N application (67 kg/ha) used during the growing season. Yield was not affected by either the fall or summer fertilization treatments, but there was an increase in berry weight and a reduction in the number of fruits per unit area under the 40% fall N fertilization treatment. The lower number of fruits resulted from an increase in the proportion of vegetative uprights, a phenomenon related to an increased length of uprights. Prolonged growth may have affected the flower bud induction window which occurs in early fall. Fall N fertilization effect of increased vegetative growth may have been due to an increased availability of N in spring. This result could be advantageous in the establishment of new beds or the recovery of vines that have experienced stress.

Technical Abstract: Plant energy reserves play a key role in woody perennial plants' winter survival and growth resumption during the spring. In fruit crops, these reserves are critical for production in temperate climates when nutrient uptake is minimal and photosynthate production is limited in newly emerged leaves. Fall nitrogen (N) fertilization can be used to increase the availability of plant reserves to support and enhance vegetative growth and fruit production the following growing season. The objective of this study was to test the effect of fall N fertilization on fruit production by evaluating yield components and their relationships with vegetative growth. A split-plot design was established in three ‘HyRed’ cranberry production beds at a farm in central Wisconsin. Fall N treatments were the main effect and consisted of plots receiving 0, 10, 20, and 40% of the standard N application (67 kg/ha) used during the growing season. Summer N fertilization treatments were applied as subplots and consisted of a complete (100%) and a balance (60, 80, and 90%) of the standard N application (67 kg/ha) used during the growing season. Yield was not affected by either the fall or summer fertilization treatments, but there was an increase in berry weight and a reduction in the number of fruits per unit area under the 40% fall N fertilization treatment. The lower number of fruits resulted from an increase in the proportion of vegetative uprights, a phenomenon related to an increased length of uprights. Prolonged growth may have affected the flower bud induction window which occurs in early fall. Fall N fertilization effect of increased vegetative growth may have been due to an increased availability of N in spring. This result could be advantageous in the establishment of new beds or the recovery of vines that have experienced stress.