Researchers in New Zealand studied avocado flower morphology and fruit set. They found that hand pollination increased fruit set by 30 times compared to natural pollination. Removing flowers from the tips of inflorescences increased fruit set 5 times more than removing flowers from the bases. While determinate and indeterminate trees showed no difference in fruit set, adding pollen was found to be limiting and increasing pollination can help boost avocado production.

1. The New Zealand Institute for Plant & Food Research Limited
Avocado – Fruit set
Mark Goodwin, Lisa Evans and Heather McBrydie

2. Aim:
To see if we can determine which flowers will set
fruit.
The New Zealand Institute for Plant & Food Research Limited

3. Introduction:
• Morphology
• Pollinators
• Fruit set
• Summary
The New Zealand Institute for Plant & Food Research Limited

5. Female phase Male phase
The New Zealand Institute for Plant & Food Research Limited

6. The New Zealand Institute for Plant & Food Research Limited

7. Morning - Female
Day 1
Morning –
Male
Closed
Afternoon –
Female
Day 2 Morning - Male
The New Zealand Institute for Plant & Food Research Limited

8. Morning - Female
Day 1
Morning –
Male
Closed
Afternoon –
Female
Day 2 Afternoon - Male
The New Zealand Institute for Plant & Food Research Limited

9. Afternoon - Female
Day 1
Morning –
Female
Closed
Afternoon –
Male
Day 2 Morning - Male

10. The New Zealand Institute for Plant & Food Research Limited

13. The New Zealand Institute for Plant & Food Research Limited

14. The New Zealand Institute for Plant & Food Research Limited

15. Determinate vs. indeterminate
Treatment No. of No. of flowers No. of fruit Average %
trees (19/02/09) fruit set
Determinate
Indeterminate
The New Zealand Institute for Plant & Food Research Limited

16. Determinate vs. indeterminate
Treatment No. of No. of flowers No. of fruit Average %
trees (19/02/09) fruit set
Determinate 20
Indeterminate 20
The New Zealand Institute for Plant & Food Research Limited

17. Determinate vs. indeterminate
Treatment No. of No. of flowers No. of fruit Average %
trees (19/02/09) fruit set
Determinate 20 29865
Indeterminate 20 23793
The New Zealand Institute for Plant & Food Research Limited

18. Determinate vs. indeterminate
Treatment No. of No. of flowers No. of fruit Average %
trees (19/02/09) fruit set
Determinate 20 29865 56
Indeterminate 20 23793 40
The New Zealand Institute for Plant & Food Research Limited

19. Determinate vs. indeterminate
Treatment No. of No. of flowers No. of fruit Average %
trees (19/02/09) fruit set
Determinate 20 29865 56 0.18
Indeterminate 20 23793 40 0.24
The New Zealand Institute for Plant & Food Research Limited

20. 0.7
0.6
0.5
Percent fruit set
0.4
0.3
0.2
0.1
0.0
2 4 6 8 10 12 14 16 18 20
Inflorescence
The New Zealand Institute for Plant & Food Research Limited

21. Inflorescence removal
Treatment No. of trees No. of fruit (19/02/09) Average % set
Tip 20
Base 20
Control 20
The New Zealand Institute for Plant & Food Research Limited

22. Inflorescence removal
Treatment No. of trees No. of fruit (19/02/09) Average % set
Tip 20
Base 20
Control 20
The New Zealand Institute for Plant & Food Research Limited

23. Inflorescence removal
Treatment No. of trees No. of fruit (19/02/09) Average % set
Tip 20 32 0.398
Base 20 7 0.087
Control 20 35 0.225
The New Zealand Institute for Plant & Food Research Limited

24. Hand pollination
Treatment No. of No. of No. of No. of Average
trees replicates flowers fruit % fruit set
(19/02/09)
Determinate 11 14 277
Indeterminate 11 14 287
The New Zealand Institute for Plant & Food Research Limited

25. Hand pollination
Treatment No. of No. of No. of No. of Average
trees replicates flowers fruit % fruit set
(19/02/09)
Determinate 11 14 277 16 5.7
Indeterminate 11 14 287 13 4.6
The New Zealand Institute for Plant & Food Research Limited

26. 8
6
Percent fruit set
4
2
0
0 1 2 3
Control Hand pollinated
The New Zealand Institute for Plant & Food Research Limited

28. Summary
• No determinate/indeterminate effect
• Base tip effect 5X
• Pollen added effect 30x
• Suggests pollination limiting
The New Zealand Institute for Plant & Food Research Limited

29. Conclusion
We can increase fruit set by adding pollen
The New Zealand Institute for Plant & Food Research Limited

30. Next season
Repeat last season
Distribution of fruit on trees relative to pollinizers
Repeat pollinations - 5 Flowers per inflorescence
Check hand pollinations
Possibly look at bee movements
The New Zealand Institute for Plant & Food Research Limited

31. The New Zealand Institute for Plant & Food Research Limited
www.plantandfood.com
mark.goodwin@plantandfood.co.nz