Provenance trials of E. “decaisneana” at Bulolo

Provenance trials of E. “decaisneana” at Bulolo

With the possibility that I would be able to create hybrids between E. deglupta as the female parent and E. “decaisneana” as the male parent, 55I decided to follow up on the early history of the introduction of the E. decaisneana to PNG at Bulolo.

On 20 April 1970, John Turnbull of the Forest Research Institute, Canberra, despatched four seedlots of E. “decaisneana” to the “Assistant Director, Silviculture, Department of Forests, Konedobu, Papua”.

Seed lot no.* Species Quantity (ounce) Locality Latitude Longitude Altitude (feet) Soil Viable seeds/ounce

9003 (336) Euc. decaisneana 4 Nr. Dili, Port Timor 9008 (337) Euc. decaisneana 2 Flores, Indonesia

9010 (339) Euc. decaisneana 1 Indonesian Timor

9016 (338) Euc. decaisneana 1 Portuguese Timor 8° 47’ 125° 25’ 3,600 Schist 14,000

8° 40’ 122° 30’ 1,400 Finegrained volcanic rock 13,500

9° 37’ 124° 15’ 4,100 Yellow soil, quartz 5,600

8° 39’ 125° 27’ 1,900 Schist 15,000

* 9xxx numbers were Forest Research Institute, Canberra seed lot numbers; numbers in brackets were the assigned Department of Forests PNG seed batch numbers.

These were assigned PNG seed batch numbers at HQ. After some delay, quantities of each of these four batches were received by the Department of Forests, Bulolo, and receipt acknowledged by letter drafted by N H S Howcroft and signed by K J Hart, Acting Officer in Charge on behalf of J L R Godlee. Apparently, Neville Howcroft took charge of the seed intending to establish a provenance trial. He arranged for the sowing of 23 trays from 1 to 11 September 1970. Germination took place from 5 to 17 September. On 16 September a letter was sent to HQ, requesting instructions on the design, area of plots and spacing to be used. Kevin White, then Assistant Director, Silviculture, wrote back 29 September directing the proposal to be reduced to a single planting on a rainforest site, planted in blocks of four rows, one row each provenance. Another exchange took place on 21 October and 30 October about spacing and area to be planted for each provenance. The outcome was for a spacing of 9 x 9 feet (about 2.75 x 2.75 m) and general block planting by provenance after stock had been allocated to the line plots, each of about 20 trees (8 line plots, 2 for each provenance were actually planted).

55 The small-fruited E. deglupta was used as the female parent, fertilized by pollen from the large-fruited E. “decaisneana”. The other way around, the inheritantly short pollen tube development from the pollen of E. deglupta that is adapted to travel down a relatively short style would probably not be able reach the ovary down the relatively longer style of E. “decaisneana”. An emasculation technique that involved simultaneous decapitation of the upper part of the style of the large fruited eucalypts was developed later.

By the end of October all the seedlings had been tubed. On 14 January 1971, Neville Howcroft submitted a progress report to HQ over Rod Holesgrove’s A/OIC signature, with the following results:

Batch Number and Locality Surviving tubed stock (number) Mean Minimum Height (cm) Mean Maximum Height (cm)

336 Dili, Portuguese Timor 337 Flores, Indonesia 338 Portuguese Timor 339 Indonesian Timor 1,531

1,060 876 395 1.6

0.7 0.5 1.2 10.6

12.7 10.1 13.7

Neville carried out a study of leaf shapes when the seedlings were 3 – 6 inches (7.5 – 15 cm) in height (two leaves per seedling, being the third last whorl). Provenance 336 had the best germination result and was the most vigorous in the germination trays. 336 had predominantly narrow lanceolate and broad lanceolate leaves. Provenances 337 and 338 had mainly narrow lanceolate leaves while provenance 339 had similar leaf shapes to 336. Provenance 338 alone had a high number of leaves described by Neville as “peculiar” in shape, this was “more or less very narrow linear with undulate edges, and sometimes with the lamina interrupted by a gap down to the mid-rib”. Most of these “peculiar” seedlings died or were culled before they reached the field. My later interpretation of these unusually shaped leaves was that Provenance 338 might have contained a high proportion of inbred individuals arising from selfed seed. Lignotubers were developing in all batches.

The chosen planting area was Nauti LA Compartment 1A off Road 53, near the Watut River. The lines were planted in July 1971, and given an initial measurement by Bob Johns and Toni on 27 July 1971. Provenance 337 Mean height 41 cm Provenance 338 Mean height 38 cm

The “peculiar” leaf shapes Neville observed in E. “decaisneana” seemed to me similar to rare individuals I had observed with E. deglupta at Keravat in 1968 (left, compared alongside a normal seedling, shown on the right). This was not pest damage, for example from cutworms consuming all but the central main vein, since the narrow leaf laminae still had all the features of normal leaves in miniature including intact intramarginal veins. This was more likely a genetic mutation of some kind.

Provenance 339 Mean height 33 cm Provenance 336 Mean height 29 cm

Planting of the blocks at Bulolo took place from October 1971. The whole planting (the 8 lines of 20 trees each, plus the four blocks) originally occupied about 12.7 acres (about 5 ha).

Meanwhile, Professor Lindsay Pryor made a memorable trip to Portuguese and Indonesian parts of the island of Timor and to the Indonesian island of Flores with John Turnbull and Jerry Cole of the Forestry and Timber Bureau, Canberra in August 1971, primarily to collect botanical specimens of Eucalyptus alba and E. “decaisneana”. With the help of tiny overburdened ponies and Lindsay’s provisioning and catering (sardines for breakfast, lunch and dinner), the party reached peaks nearing 3,000 m above sea level. In addition to the botanical specimens about 20 more seedlots were collected and later distributed to several countries including Papua and New Guinea (see later) where the seed was used in some of the first formal provenance trials of E. “decaisneana”. Botanical material from this trip much later was included in extensive cooperative analyses of the Timor eucalypts and allied species published by Australian scientists in 1993 and 1995.56

Jeff Fairlamb remeasured the line plots on 5 December 1972. They had been severely affected by a lack of weeding and many stems were dead or missing especially near the road (Road 53). Results were:

EUCALYPTUS “DECAISNEANA” PROVENANCES, LINE PLOTS AT ONE YEAR

Provenance Mean Height (cm) Survival (%)

338 149 90

337 336 339 131 157 152 53 43 33

It was decided to establish a (temporary) growth plot near the middle of each of the provenance blocks where growth and survival seemed to be better than in the line plots. These were 1 chain by 2 chains with the long dimension along the rows. About 7 rows were included in each of the plots, about 100 potential tree locations per plot.

56 Pinyopusarerk K, Gunn B V, Williams E R and Pryor L D 1993 Comparative geographical variation in seedling morphology of three closely related red mahoganies, Eucalyptus urophylla, E. pellita and E. scias, Australian Journal of Botany 41:23-24 and, Pryor L D, Williams E R and Gunn B V 1995 A morphometric analysis of Eucalyptus urophylla and related taxa with descriptions of two new species, Australian Systematic Botany 8:57-70.