- The choice of eucalyptus species to produce commercially will depend on the target market or the intended purpose.
- For timber, transmission and construction poles, go for species such as E. grandis, E. saligna, E. globulus, E. hybrids, E. paniculata or E. camandulensis.
- However, all species of eucalyptus can be used as a source of fuel wood, charcoal, fibre and for apiculture.
- Routine scouting for pests and diseases and effective control should also be conducted primarily during the first two years, writes Lominda Afedraru.
Forests and trees are crucial to the lives of many Ugandans, especially the rural communities who rely on them for food, employment and as an income earning initiative.
This is achieved through increased resilience of human made and natural growing of tree species for both wood and provision of fuel energy, including other wood products.
As such scientists at Food and Agricultural Organisation (FAO) in partnership with other stakeholders including the Ministry of Agriculture have been carrying out initiatives with rural communities across the country in a bid to increase the forest cover to sustain people’s needs. Seeds of Gold caught up with Leonidas Hitimana, the projects coordinator of Sawlog production grant scheme at FAO and below he explains the best practices of tree farming.
What FAO is doing
Hitimana explains that the way forward taken by FAO team in promoting commercial forest plantation is by establishing private sector and local communities through provision of grants and technical assistance throughout the country.
The target is to establish 31,500 hectares of plantation by 2020 including 23,000 hectares by private individuals and companies, 4,000 hectares by small scale farmers and 2,500 by fuel wood public plantation growers.
Already FAO has certified 92 private nursery operators dealing in various tree species namely hybrid eucalyptus, pine as well as hard wood species such as grivalian, gmelina arborea, musizi and mahogany among others by July 2018 up from 66 in 2017. The team is looking at establishment of trees such as shea nut butter tree species where farmers can reap both from processing its seed for oil and the tree for timber.
Hitimana says for this initiative to benefit the rural farming communities engaged in establishment of forest plantations, it is pertinent for them to follow best practices as highlighted below.
Farmers are advised to choose a suitable site in terms of soil factors, climate, rainfall and topography.
In a 2004/2005 a report by National Environment Management Authority (Nema), stated that on average the country receives between 1000mm – 1500mm per annum and temperatures ranging from 20°C to 30°C which is favourable for forest plantation. Prevalence of pests and disease is a key determinant of site suitability for a particular species and planned plantation area should be subdivided into recognizable management units.
The recommended compartment sizes for uniform species is 25-30 hectares for small and medium size plantations and up to 100 hectares for larger forest areas.
Growers are advised to avoid wetland and swampy areas, river line areas, steep slopes and highly erodible soils.
Residual remnants should be lower than 20 centimetres and all trash should be moved at least six metres away from roads.
Large woody material should be de-branched a maximum of one meter length and in contact with the ground. Tilling the land is not a necessity.
Lining out and pitting
Correct spacing of three by three metres for pines and eucalyptus species grown for saw logs or transmission poles but closer spacing may be used for fuel wood plantations.
The pits must be in straight line dug in 25 centimetres deep and 25 centimetres wide. After pitting all soil should be returned into the pit to avoid loss of moisture.
Planting seedlings should be raised from approved and certified nursery seed sources.
Seedlings should be healthy to provide the right shoot root ratio of 2:1 millimetres. Root collar diameter for eucalyptus seedlings is two millimetres and three millimetres for pines to provide stable root ball growth. Diseased, dead, dying and pest infested seedlings are not allowed since they will cause root distortion as well as over-mature planting seedlings.
Planting and blanking
Seedlings should be planted upright in the centre of the pit and the planting pit should be clear of weeds within one metre diameter.
Plants should be planted two centimetres above the cutting point to ensure at least 80 per cent survival and stocking rate.
Blanking should be done within one month of planting for eucalyptus and two to three months for pine using the same planting stock as planted.
Do not plant with the polythene pot, ensure there are no rocks and stones around the plant and weeds must be kept around 50 centimetres radius from the plant.
All weeds within one metre diameter from the tree should be removed. Inter-row weeds should be less than 50 centimetres in height. There should be no disturbance of the soil around the tree and damaged trees must be removed.
Post- plant chemical weeding
Farmers must ensure to use the recommended and endorsed herbicides and selective herbicide is recommended depending on the tree species. Agronomists recommend Roundup ProBio measured in five litres per hectare for perennial weeds and three litres per hectare for annual weeds
For Roundup ProVantage herbicide 3.75 litres per hectare is required for perennial weeds and 2.25 litres for annual weeds.
Maintain basal area per hectare of from 13-22 square meters and it is important to follow recommended thinning methods for different tree species. The basal area can be greater than 22 square meters or below 20 in one cutting cycle. Farmers should allow early or delayed thinning and the stumps should be higher than 15 centimetres from ground level.
Those growing eucalyptus can start pruning when the trees are three years but for traditional hardwood trees the duration is more.
Pest and disease
There are various pests which attack trees species. The most common and important insect pests include blue gum chalcid, aphids, snout beetles, and termites. Blue gum chalcid is a severe eucalyptus insect pest that results in galls on the foliage and tender growing points, thus affecting growth. The pests can be controlled using insecticides. Diseases can be controlled by spraying using appropriate chemicals.
Farmers are advised to contact forest officials for pest and disease management.
Thinning and pruning waste should be stacked six metres from the compartment boundary and fire breaks should be clear of combustible material.
Internal fire breaks between blocks should be more than five metres wide and external fire breaks should be more than 10 metres wide.
Farmers are advised to install water pipes and fire fighting equipment for precautionary measures.
Maturity and ideal harvesting age are dependent on the intended purpose or market.
The harvesting age significantly varies from three to four years (construction poles), six to 12 years (transmission poles) to as late as 15-20 years for timber production.
Age at which the trees can be harvested is significantly dependent on the intended purpose and the market demand. The time the tree takes to reach harvestable maturity should, therefore, not scare potential eucalyptus tree producers from the investment.
Currently a mature eucalyptus pole cost between Shs150,000 and Shs200,000 depending on its height.