Choice of quality planting stock of teak: The question of a 'genetic business plan '

Abstract

The paper examines the potential options for procuring high quality planting stock of teak for planting programmes. A dedicated effort for procuring high quality planting stock is most likely to prove very profitable. As part of a plantation programme, it is suggested to develop a ‘genetic business plan’ to procure the best possible planting material and to develop a programme where new knowledge on performance of genetic material specific for the relevant planting locality is continuously captured and used to improve adaptation, production and quality. Thus the choice of good planting material is not an initial ‘one time decision’ - rather it should be an iterative process based on expanding knowledge base.

Keywords: Teak plantation programme, planting stock, genetic material, genetic business plan

Introduction

High quality planting material is an important component in small and large scale teak plantation programmes. In this connection, it is necessary to examine the quality of the provenance selected. The level of knowledge with regard to growth, stem form, heartwood percentage, and stem straightness of teak is often insufficient to recommend choice of a seed source for establishing plantations outside its natural range. The genotype-environment interaction makes it difficult to develop specific guidelines on choice of best planting stock. However, regional trials and testing for identifying better clones have their value in establishment of teak plantations outside its natural range.

Options: What? and how much? Can we gain from selection and breeding?

The variation between provenances can be substantially concerning adaptation, growth, stem form and wood quality and the choice of provenance for the given site can have important impact on the success of the plantation programme. However, one may also conclude that the level of knowledge at present rarely will be sufficient to recommend choice of seed source for a given site outside the natural range of teak.

Genotype by environment interaction: Can one clone fit all localities?

Field trials show difficulties of predicting how a provenance will perform based on the interaction between seed source and climate. The genotype-environment interaction need not be necessarily at the same level for individual genotypes as observed for provenances, but it is likely that the ranking in adaptation and performance between individual genotypes may differ between sites. Thus, local testing of applied planting material is, in many cases, of relevance. Genotype- environment interaction makes it difficult to develop specific guidelines on choice of best planting stock, and speaks in favour of developing local ‘genetic business plans’ that include simple data harvesting and adoption of management decisions according to the harvest experience. It also speaks in favour of local or regional efforts in development of superior seed sources/clone collections and coordinated testing programmes across sites in a given area.

The genetic business plan

Results from decades of field trials tend to show: 1. Differences, especially in survival and growth performance, can be very large between potential seed sources 2. The degree of provenance environmental interactions may be substantial. 3. The potential value of improving the applied planting stock may be substantial The prediction of performance of a certain provenance or clone at a given planting site based on climatic conditions is uncertain and makes it necessary to set up local tests to find the most suitable genetic material. Results from the international field trials can be used to concentrate on a manageable number of genetic materials that could be of interest. The tests can be of two types:
1. Traditional tests coordinated by research organisations or as a cooperative effort between teak planting companies and organisations in the areas.
2. Local testing set up by teak planters by keeping precise track of applied planting stock at each planting site and including alternative seed sources in a way that will allow easy comparison and simple future data harvest.

Planting of genetic material tested and selected in other growing conditions than the planting site will involve some uncertainty, especially if plantings are based on a single – or a set of few clones - because genetic diversity will be limited in such planting stock, which increases the risk of a sudden, large scale damage from new pests and pathogens. In comparison, when planting a provenance, there is at least a chance that some trees within the provenance will survive and grow well. The use of less diverse genetic material is feasible once tested in the region, but it will still be advisable to maintain some genetic diversity in the plantations.

The business plan should not only ensure a systematic collection and use of local experience with different available seed sources, but should also include a seed source/germplasm development component. Combined small and large scale activities can lead to establishment of multiple breeding populations, which can be an easy and cheap approach to test genetic material and to secure future genetic improvement. Potentially superior clones can be identified and tested in this process.

To summarize, the choice of good planting stock for a given plantation programme is not an initial ‘one time decision’ - rather it should be an iterative process based on expanding knowledge base. It should therefore be based on:
(1) what is generally known from international research
(2) what is known from local experience in the area including local tests (if any),
(3) an overview of potential seed sources / selected clones that are available locally or internationally (relevant in terms of time frame, scale and costs),
(4) experience and data generated as part of the on-going activities,
(5) a pro-active approach to development of new seed source options (or clones) based on local (smart but low input) selection and/or more advanced coordinated effort,
(6) continuous adoption of the genetic business plan based on new information available locally and internationally.

It is also important to consider how to handle genetic diversity both at the levels of the single programme and at regional level, and such consideration should therefore also be included at the plantation level. On the regional level, a coordinated effort will be required when it comes to actual ex situ genetic conservation activities on large scale. Local seed source development activities as discussed above can play an important role and add resilience to the gene pool by reducing the risk of rapid genetic erosion.

 

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