Successful recover for the exhausted ancient camellia tree in Wenzhou China

Wang J.¹, Li J.*²
1: Wenzhou Yunfeng Camellia Research Institute, Wenzhou 325000, Zhejiang, China;
2: Research Institute of Subtropical Forestry, CAF, Fuyang City, Zhejiang 311400, China.
E-mail: jiyuan_li@126.com

Introduction

According to the survey of 2001, the trunk of this ancient camellia had a circumference of 111cm at ground level and was 35.5cm in diameter at breast height (You 2010). Almost half of the trunk was heavily decomposed due to artificial factors, but no protection measures were undertaken until 2004. Concrete was used to cover the decomposed side of the trunk, which resulted in the subsequent deterioration of this ancient camellia. Mr. Wang Jiayun, the director of Wenzhou Camellia Society and village doctor, set up an institute of camellia plants and focused especially on recovering ancient camellias using traditional Chinese medicine (TCM) theory in his town district. He began the recovery of this camellia tree from 2011 with the support of local government (Li and Wang 2012).

 
Principles for recovering this ancient camellia

Reducing requirements of water and nutrition by the camellia

It is important to prune some big shoots from the upper canopy of the camellia to reduce the absorption of water and nutrition by its root system, and to reduce the evaporation of water from the leaf surfaces, because majority of trunk and root system have been damaged. As we know, there is a very high compatibility rate between scions and rootstocks originated from relative species. We used air layering on big shoots at diameter from 3-8cm during winter season and carefully grew them in nurseries. We will use them as approach grafting scion stocks after they produce well-developed root systems. We illustrate the procedures in Figure 4.

Figure 4. A Damaged tree with full canopy; B Air layering;
C Grown on in a nursery; D Pruned canopy

Repairing the damaged trunk   

It is a great challenge to repair the damaged trunk because majority of it was heavily decomposed and exposed for long time. In order to do this, we are planning to use different grafting methods, one of which is approach grafting. We illustrate the procedure of approach grafting using the air-layered stocks in Figure 5.

Figure 5. A- Exposed wound trunk side; B Healthy stocks used for approach grafting;
C Approach grafting to healthy trunk with healthy scion stocks; D Cutting scion stocks after healing

Techniques used

Air-layering

During the winter season in 2011 and 2012, we began to do air-layering on 20 big shoots in the upper canopy. We investigated the layers in the winter of 2013 and found that 16 shoots had produced good root systems. Next year, we will cut them and transplant in a nursery for use of repairing trunk cover by approach grafting.

 
Figure 6. Air layering in winter of 2012

Increasing supply of water and nutrition

It is very difficult for the tree to supply enough water and nutrition through its own injured root system and trunk, especially during the summer season. We believe that healthly stocks will improve matters. We used approach grafting in the early summers of 2012 and 2013, and achieved 90% survival one year later. The scion stocks were propagated from this camellia tree by root cutting more than 10 years ago. These scion stocks were placed near to the main trunk, on the steel pipes in upper canopy; we will cut the upper parts of the scion stocks after one year once they have fully healed (Fig.7).

Careful cultivation

We suffered from a very hot summer and autumn in 2013, the maximum temperature recorded was up to 43C. It was very difficult when the small spring ran dry in mid July 2013. It was a great challenge to water the tree half way up the hill in the summer. Mr. Wang had to bring water in a plastic bucket from a water reserve at the foot of the hill, by himself, in the very early morning every day from mid July. I had to climb the hill 3 or 4 times and carry enough water for the tree every day. I also sheltered the camellia tree with a dark net.

Figure 10. Mr. Wang is watering in early mornings
during the very hot summer

Healthy status of this camellia tree

It is great! A new shoot has sprouted from lower part of the trunk during the summer. It measured about 20cm long at end of this year.

This is a good sign to know that this camellia tree is getting better and better even though it suffered from a very dry and hot summer and autumn this year. We further analyzed some important physiological indices of this tree, compared with young plants propagated by root cuttings taken 10 year ago (Table 1). The results indicated that these important diagnostic indexes are almost the same between the ancient camellia and one of young camellia trees at ten years old. 

Figure 11. A new shoot sprouting at lower part of trunk this spring

Table 1. Comparison of healthy indices between the ancient and young camellia tree

Further practices for recovering and protection

There is a long way to go road to repair the decomposed trunk of the ancient camellia. Survival is the first step to full recovery. We spent a very hard and difficult summer and autumn of 2013, with this ancient camellia tree.
We will continue air layering and growing more camellia stocks for approach grafting around the side of the healthy trunk.

Figure 12. A video camera in the steel frame in 2013

Acknowledgements

This work was financially supported by National Key Twelfth Five-Year Sci.& Tech. Program (2012BAD01B0703), MOST international Sci. & Tech. Program (2011DFA304903), Zhejiang Key Flower Breeding Program (2012C12909-6) and Zhejiang-CAF Cooperation Project (2012SY02)
References
Hudson T. Hartman, Dale E. Kester, 175. Plant Propagation Principles and Practices (Third Edition). Prentice Hall, Inc. 300-350
Li JY, Wang JR,2012. A challenge way to save the ancient camellia tree at Mt. Daluoshan in Wenzhou China. International Camellia Journal, 64-65
You MX, 2010. Tracking down Chinese ancient camellia trees for ten years. Zhejiang, China: Zhejiang Sci. & Tech. Press. P.43-4