Domestication of Meliaceae species in Southeast Asia and Australia, particularly management of the problem of Hypsipyla robusta attack

Whilst the proposed start date for this project was the 1st July 2005, the project only started in March 2006 following the completion of contractual agreements between the various parties. This report therefore reflects project activities between March and June 2006. As a result of these time delays a number of project activities have had to be rescheduled. Key activities have been
1. Inception meeting through visits by Ensis project staff to meet with project staff in the collaborating countries ie. Thailand, Laos and Vietnam. These meetings serve to discuss the activities under the project, their scheduling and staff involved and visits to field trial sites established under the previous ACIAR project FST1996/005.
2. Visit to Vietnam by Dr Manon Griffiths as part of a training workshop in assessing influence of shade on Hypsipyla damage in Chukrasia trials.
3. In Vietnam, RCFTI have continued to maintain the Chukrasia trials at Cam Quy and Binh Thanh companion trials. Clonal material has also been maintained in the Ba Vi nursery with work underway to bulk up the number of plants required for the establishment of two clonal trials under the project. The trial site for the two clonal trials., one as pure species and a second companion planting with Acacia hybrid, has been selected. The Acacia hybrid was planted in September 2005.
4. In Thailand, RFD has continued to maintain three Chukrasia provenance trials at Ratchaburi, Kuiburi and Kanchanaburi, Preparation of rooted cuttings material for clonal trials is underway.
5. In Laos, the Chukrasia provenance trial at the Agroforestry Research Station at Thongkhang, Luangprabang continues to be maintained although there have been heavy plant losses. An assessment of the trial was carried out in 2005 as part of a university student assignment focusing on basic information on growth and survival. More detailed assessment will be carried out by project personnel during the reporting period.
6. In Queensland DPI&F have continued to maintain sites at Imbil (Genetic Resource trial) and north Queensland (two shading trials). Assessments have been made at Imbil (August 2004) and north Queensland (October 2004, October 2005).

Vietnam
Two adjoining clonal trials of Chukrasia were established at Cam Qui (Ba Vi) on the same site that the provenance was established under ACIAR Project FST1996/005. Both trials contain the same genetic material. However, the one trial does not have any tree canopy while the second trial was initially planted with A. mangium hybrid then several months later planted with Chukrasia.

The Ba Vi nursery carried out a decapitation trial of 30 clones across the three categories of recovery from hypsipyla attack. The results of this trial showed no difference between Chukrsaia's ability to recover. They all produced a clear single leader.

The Ba Vi nursery has been preparing cuttings of selected clones of Chukrasia for shipment to Thailand in order to compliment the clones in that country.

Thailand
A Chukrasia companion trial was established in May 2007 under an Acacia mangium planting in May 2006. The trial will look at the effects of Hypsipyla attach on Chukrasia grown under/ companion to A. mangium.

Grafting was undertaken to establish a hedge garden representing 20 selected trees from the Chukrasia field trials at Kanchanaburi nursery. Cuttings taken from the hedge garden has commenced. Additional plant material is being sourced from Vietnam selections.

Laos
The Chukrasia trial at the Agroforestry Research Station at Thongkhang, Luang Prabang was weeded during the course of the year.
A one week training course in trial design, establishment and analysis was undertaken at Luang Prabang in October 2006. 10 participants attended.

Vietnam
The two adjoining clonal trials of Chukrasia established with identical genetic material at Cam Qui (Ba Vi) were assessed for height growth and level of Hypsipyla attack. One trial is a mixed planting with acacia hybrid and the second pure Chukrasia. In the mixed species planting, the acacia hybrid was planted 12 months prior to the interplanting of the Chukrasia clones. There were 19 Chukrasia clones made up of 3 categories: (1) tolerance to hypsipyla attack (9 clones), (2) recovery with a new leader after hypsipyla attack (5 clones), and (3) loss of a clear leader after hypsipyla attack (5 clones). The results showed that

In the pure species plots almost all the clones have been attacked by the hypsipyla short borer, regardless of the original selection of the trees in the three categories. The wide spread attack is reflected in the low axis persistence.
In the mixed species planting, there were very few incidences of hypsipyla attack in the three categories.
Mean height of the pure species plot was greater than that is the mixed planting.

Thailand
Clone trial. One clone trial has been established in Kanchanaburi province where Hypsipyla is known to be wide spread. In total there were 20 clones from the three categories, 9 clones (all category 2) selected from original provenance trials in Thailand and 11 imported from Vietnam. Hypsipyla began to attack the Chukrasia trees about 7-8 months after planting. Based on the one year assessment (July 2008) all but 3 trees (ramets) in this clone trial have been attacked by Hypsipyla, indicating that clonal variation in Hypsipyla resistance is unlikely. It appears that the capability of the trees to reproduce a new leader after the attack is a key characteristic.
Provenance trials. Two provenance trials established in 1999 under the previous project have been maintained and measured. In addition to height and diameter growth, axis persistence and pilodyn penetration were also undertaken to assess the stem form and relative wood density. Data are being analysed and a report will be prepared for presentation at an international forestry conference (FORTROP II) to be held in Bangkok in November 2008. There are clear differences between C. velutina and C. tabularis in all parameters. In brief C. velutina grew much faster than C. tabularis with greater bole length and higher wood density.

Laos
An assessment was made of height, diameter, and stem form (axis persistence) in the Chukrasia trial at the Agroforestry Research Station at Thongkhang, Luang Prabang. This trial had overall survival of less than 50 %, but is still being maintained as it is the only existing trial in Laos. Data from the measurement are being processed and analysed.

Queensland
Clone trial. The clonal trial, incorporates four "low damage" trees, four "tolerant" trees, three "high damage" trees and one "good tree" of unknown history. The trial was first damaged in December 2007, at five months age. At this time 17% of trees were damaged at between one and two points. By six months 72% of trees were attacked with between one and 17 damage points and by seven months 82% of trees were damaged at between one and 22 damage points. Trees from the "high damage" category of clonal material generally had higher levels of shoot borer damage, although this difference was not always significant. The number of damage points differed between clones at the six and seven month assessments. On both occasions the two most heavily damaged clones (41825 and 41708) were from trees scored as "high damage" following field assessments, while the least damaged clone (61942) was scored as "tolerant" during field assessments.
Provenance trial. The provenance trial established in southeast Queensland under a previous project has been maintained and a full assessment recently completed, recording height, bole length, dbh, stem persistence and stem straightness.
Underplant trials. Although the underplant trials in North Queensland were abandoned following extensive damage by Cyclone Larry in March 2006, they were visited during April 2008. For the Pinus caribaea underplant only 71 of the original 135 Toona ciliata trees remain alive and a further 9 of these were severely damaged by falling timber. Average dbh of trees in the more open plots was significantly higher than that in the more shaded.