Tree Breeding

Tree breeding seeks to improve yield and quality through controlled science — building genetic improvements that pay back over generations of forest.

Programme Objectives

Eight ways we improve the trees

From controlled pollination to the introduction of new species — eight clear objectives drive the Tree Breeding Unit’s work.

01Controlled pollination

02Selective breeding

03Extensive provenance & progeny testing

04Reduction in rotation period

05Improvement in stem form

06Increased profitability for forest industries

07Introduction of new species

08Latest propagation technologies

Part II

Contribution to Climate Change Mitigation

How tree breeding is adapting to a changing climate.

Softwood Pines

Fast-growing species adapting to a changing climate.

Climate change presents new challenges for tree improvement. The Tree Breeding Unit focuses on fast-growing species that can adapt to changing environments — primarily exotic softwoods (pines) and hardwoods (eucalypts).

Pinus maximinoii and Pinus tecunumanii (high and low elevation populations) outperform P. taeda, P. elliottii and P. oocarpa. To mitigate monoculture risks in high altitudes, P. greggii and P. maximinoii are also introduced. In low-rainfall areas, P. roxburghii is under evaluation from 3 provenances.

Top performers

Recommended pine species

Pinus maximinoii High altitude · outperforms taeda/elliottii

Pinus tecunumanii High & low elevation populations

Pinus greggii Monoculture-risk mitigation

Pinus roxburghii Low rainfall · under evaluation (3 provenances)

Hardwood Hybrids

Eucalyptus hybrids for climate adaptation

For tobacco-growing regions, eucalyptus hybrids offer fast growth and adaptability — providing sustainable fuelwood alternatives.

E. grandis × E. camaldulensis

Drought Frost resistance

E. grandis × E. tereticornis

Drought Disease resistance

E. grandis × E. saligna

Fast growth

E. grandis × E. europhylla

Disease resistance

E. grandis × E. pellita

Fast growth Disease resistance

Clonal Hedge at FRC

Vegetative propagation addresses poor seeding performance

The Forest Research Centre has established a clonal hedge with selected hybrid individuals:

21 E. grandis × E. tereticornis Individuals

24 E. grandis × E. camaldulensis Individuals

Field Data

Vegetative Propagation at JMFRS

Cutting trials at the John Meikle Forest Research Station — comparing performance with and without Seradix root hormone treatment.

Species	Growth Medium	With Seradix	Without Seradix
P. caribaea × P. tecunumanii	Pine bark / Sand	220	348
P. caribaea × P. tecunumanii	Pine bark / Sand	52	96
P. tecunumanii	Pine bark / Sand	59	96
P. patula	Pine bark / Sand	711	7,519
P. taeda	Pine bark / Sand	48	35
P. elliottii	Pine bark / Sand	16	303
P. maximinoii	Pine bark / Sand	—	1,211
Total cuttings		14,290

Dry-Zone Research

Dry-zone research trials

12 active trials across Matabeleland and Manicaland — testing provenance, progeny and breeding orchard performance under low-rainfall conditions.

Trial No.	Type	Species	Location
`EV133A`	Provenance	Azadirachta indica	Matopos
`EV133B`	Provenance	Azadirachta indica	Ntabazinduna
`EV133C`	Provenance	Azadirachta indica	Gwanda
`EV133D`	Provenance	Azadirachta indica	Forest Hill
`EX132`	Progeny / Provenance	Faidherbia albida	Matopos
`EV128C`	Provenance	Acacia aneura	Ntabazinduna
`EV131`	Provenance	Acacia erioloba	Matopos
`EV136B`	Provenance	Acacia auriculiformis	Kosi
`EV138`	Provenance	Sesbania sesban	Matopos
`EV139`	Provenance	Sesbania goetzii	Matopos
`EB45`	Breeding Orchard	E. tereticornis	Forest Hill
`EB46`	Breeding Orchard	E. tereticornis	Forest Hill

National Tree Improvement Programme

F. albida & primary research sites

F. albida progeny / provenance trials are established at seven sites across Zimbabwe.

Matopos Chesa Chibhero Makaholi Middle Sabi Kadoma Chesa

Primary Research Station

Chesa Forest Station

Primary research on E. camaldulensis and E. tereticornis

Altitude1,460 m

RegionV

Annual rainfall546 mm

Breeding Strategies

Genetic improvement & gene conservation, across 23 species

Our programme balances yield improvement with the long-term conservation of genetic diversity — the foundation of resilience.

13 Pine species Under active breeding and conservation

10 Eucalyptus species Under active breeding and conservation

2 Programme arms Genetic improvement & gene conservation

Seed Orchards Database

165 orchards across 321.6 hectares

The complete national seed-orchards inventory — species, number of orchards, breeding generation and total area.

Species	Orchards	Generation	Area (ha)
E. grandis	6	2^nd, 4^th	15
E. camaldulensis	17	1^st–4^th	33
E. tereticornis	9	2^nd, 3^rd	10
E. citriodora	1	1^st	0.6

P. patula	26	1^st, 2^nd	46
P. taeda	24	1^st, 2^nd	33
P. elliottii	28	1^st, 2^nd	61
P. kesiya	17	1^st, 2^nd	53
P. oocarpa	7	1^st	22
P. pseudostrobus	1	1^st	0.7
P. maximinoii	4	1^st	19
P. tecunumanii	14	1^st	18
P. caribaea var. hondurensis	1	1^st	0.6
P. caribaea var. bahamensis	1	1^st	0.6
P. caribaea var. caribaea	1	1^st	0.6
P. palustris	1	1^st	0.5
P. chiapensis	4	1^st	6

Pinus spp. hybrids	2	—	1.4
Cupressus lusitanica	1	—	0.6
Total	165	orchards	321.6