Project Detail
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Date Completed
Evaluate the use of NAA and Ethephon to increase return bloom in apples and pears
Objectives and Rationale
The original objective of this project was to determine the effect of NAA and Ethephon application on return bloom in heavy bearing ‘Fuji’ and ‘Abate Fetel’ orchards. The research was expanded to ‘Cheeky’ pears in 2015/16.
Methods
| The following treatments were applied on both ‘Abate Fetel’ and ‘Fuji’ in Vyeboom during the 2012/13 season:
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The following treatments were applied to ‘Fuji’ and ‘Abate Fetel’ at the Fontein farm in 2013/14 and ‘Fuji’ at the Ouwerf farm and ‘Abate Fetel’ at the High Noon farm in 2014/15: |
| Control (no spray) | Control (no sprays). |
| Four 5 ppm NAA two weeks apart 40 days afb | Ethephon at 150 ppm 40 days afb. |
| Three 5 ppm NAA two weeks apart 40 days afb | Four NAA at 5 ppm two weeks apart 40 days afb |
| Two 5 ppm NAA two weeks apart 40 days afb | Four NAA at 5 ppm two weeks apart 68 days afb. |
| Two 5 ppm NAA two weeks apart 68 days afb | Four NAA at 5 ppm two weeks apart 40 days afb and NAA at 150 ppm 40 days afb |
The following treatments were applied to ‘Cheeky’ pears in Wolseley during the 2015/16 season.
| 1. Control (no sprays) |
| 2. Ethephon at 50 ppm applied in week 45 |
| 3. Ethephon at 50 ppm applied in week 45 and 47 |
| 4. Ethephon at 50 ppm applied in week 45, and NAA at 5 ppm in week 47 and 49 |
| 5. Ethephon at 75 ppm applied in week 45 |
Key Results
NAA and Ethephon treatment yielded one positive effect on return bloom in ‘Abate Fetel’ and once enhanced return bloom in ‘Fuji’ over the three assessments done on these two cultivars. However, in general, NAA and Ethephon were rather ineffective in enhancing return bloom and increasing cumulative yield in ‘Abate Fetel’ and ‘Fuji’. The application of Ethephon and NAA sprays on ‘Cheeky’ pear trees in 2015/16 did not significantly increase return bloom and cumulative yield in the 2016/17 season.
Key Conclusions of Discussion
The application of NAA and Ethephon did not have any substantial effect on yield and return bloom in both ‘Abate Fetel’ pears and ‘Fuji’ apples over three assessments. While treatment with Ethephon and NAA showed a trend to enhance return bloom in ‘Cheeky’ pear trees, the effect was not statistically significant and the cumulative yield over the seasons of the application were not affected by treatment. Our results do not provide sufficient support for the application of NAA and Ethephon to increase return bloom and yield.
For Final Report, please contact:
anita@hortgro.co.za