@article{shi_hernandez_hoffmann_2021, title={Impact of Nitrate and Ammonium Ratios on Flowering and Asexual Reproduction in the Everbearing Strawberry Cultivar Fragaria x ananassa Albion}, volume={7}, ISSN={["2311-7524"]}, DOI={10.3390/horticulturae7120571}, abstractNote={Ever-bearing (EB) strawberries are long-day cultivars that show perpetual flowering behavior. Compared to June-bearing short-day cultivars, EB cultivars can initiate flowers with less dependency on light and temperature levels. This leads to a more consistent flowering and fruiting pattern, making EB cultivars favorable for areas with long growing seasons. However, this flowering pattern also brings significant challenges to open-field strawberry nurseries. Consistent flower development in EB cultivars frequently leads to increased labor cost for manual flower removal on nursery ground. The alteration of flowering behavior via fertilizer regimes could be a cost-effective tool for strawberry nurseries. However, while it is known that the source of nitrogen (N) impacts strawberry flowering, its effect on strawberry propagation rates needs further investigation. The objective of this study was to investigate the impact of nitrate (NO3−) to ammonium (NH4+) ratio on flower and daughter plant production in the EB strawberry cultivar ‘Albion’ (Fragaria × ananassa c.v. ‘Albion’). Strawberry plants were grown in a completely randomized design under greenhouse conditions (26.6 °C, 16 h photoperiod). Four treatments of NO3−:NH4+ were implemented: (1) 100%:0%; (2) 80%:20%; (3) 60%:40%; (4) 50%:50%. Strawberry plants fertilized with a 60%:40% NO3−:NH4+ ratio produced 17–31% fewer inflorescences than those fertilized with 100%:0% (8.8 ± 1.19) and 80%:20% (10.3 ± 1.85) ratios. The production of daughter plants remained similar in all four treatments. Our results show that increased ratios of ammonium in combination with decreased ratios of nitrate reduce flowering of EB strawberry cultivars, while propagation rates remain consistent. These results could potentially lead to the development of fertilizer regimes for strawberry nurseries to reduce flower production in EB cultivars.}, number={12}, journal={HORTICULTURAE}, author={Shi, Xiaonan and Hernandez, Ricardo and Hoffmann, Mark}, year={2021}, month={Dec} }
 @article{shi_hernandez_hoffmann_2021, title={The influence of stolon harvest frequency and nitrate: ammonium ratio on asexual reproduction of day-neutral strawberries (Fragaria xananassa 'Albion')}, volume={1309}, ISSN={["2406-6168"]}, DOI={10.17660/ActaHortic.2021.1309.41}, journal={IX INTERNATIONAL STRAWBERRY SYMPOSIUM}, author={Shi, X. and Hernandez, R. and Hoffmann, M.}, year={2021}, pages={283–288} }
 @article{shi_hernandez_hoffmann_2021, title={Timing of Stolon Removal Alters Daughter Plant Production and Quality in the Ever-bearing Strawberry 'Albion'}, volume={56}, ISSN={["2327-9834"]}, DOI={10.21273/HORTSCI15624-20}, abstractNote={Commercial strawberry (Fragaria ×ananassa Duch.) plants propagate through the development of stolons (runners) with attached daughter plants. While it is known that temperature and photoperiod affect strawberry propagation, little knowledge exists on whether cultural methods may influence stolon and daughter plant development. The objective of this study was to characterize the impact of three stolon removal treatments on the development of daughter plants in the ever-bearing strawberry ‘Albion’. Treatments included 1) stolon removal every 7 days, nine times total; 2) stolon removal every 21 days, three times total; and 3) one-time stolon removal after 63 days. Strawberry plants were grown in a controlled environment (26 °C, 507 μmol⋅m–2⋅s–1 photosynthetic photon flux density, 14-hour photoperiod) in soilless media and fertilized with a customized nutrient solution. Mother plants in the 63-day treatment produced more daughter plants (102 per plant), than in the 21-day treatment (33 per plant) and the 7-day treatment (16 per plant). In the 63-day treatment, daughter plants and stolons accumulated to 86.6% of the total biomass, to 42.9% in the 7-day treatment and to 60.6% of total biomass in the 21-day treatment. Mother plant organs (including roots, crown, and leaves) had less dry weight in the 63-day treatment compared with the 7-day treatment and 21-day treatment, respectively. Furthermore, the daughter plants produced at the 63-day treatment had smaller crown diameters (0.65 cm) and less dry weight (0.51 g) and a higher number of fully expanded leaves (2.9) and visible roots (13.4) compared with the 21-day treatment and the 7-day treatment. The results of this study show daughter plant production of strawberry plants declines significantly with shorter stolon removal intervals, indicating the need to adjust stolon removal in strawberry nurseries for optimal daughter plant production.}, number={6}, journal={HORTSCIENCE}, author={Shi, Xiaonan and Hernandez, Ricardo and Hoffmann, Mark}, year={2021}, month={Jun}, pages={650–656} }