NCT field day provides foresters with valuable insights

NCT Forestry held a highly successful field day at their Enon forestry farm near Richmond in the KZN midlands recently. Foresters and tree farmers came from far and wide to attend the field day and pick up a few useful tips from the experienced NCT team, happy to blow away the cobwebs and engage with colleagues in the real world after months of COVID lockdown.

There were a number of interesting indoor presentations, field stops and equipment demonstrations, finishing off with a delicious braai around the Enon dam.

Prof Keith Little of Nelson Mandela University provided info on the trials he has been conducting in an effort to find a suitable replacement for Paraquat which has been used by foresters for decades to prepare tracer belts to facilitate the safer burning of fire breaks. Paraquat worked brilliantly but has been outlawed by FSC due to the risks associated with handling the chemical. The key thing that made Paraquat so effective was that it rapidly dessicates and kills the above ground vegetation, making it easier and safer to proceed with burning the firebreak in between the tracer belts – but it does not harm the below ground roots. Thus the grass on the tracer belts grows back readily in spring and protects the soil from subsequent erosion and invasion by weeds.

Keith presented some encouraging results that he has had in trials using pelargonic acid (PA) in varying conditions and sites. It seems that it is a good substitute for Paraquat but it is a bit more costly and must be applied at the correct rate and solution to be effective. In other words it is not as ‘bullet-proof’ as Paraquat.

Roger Poole of the Timber Industry Pesticide Working Group says the industry has applied for registration of pelargonic acid for use in South Africa, and hopefully it will be registered in time for the 2023 fire season. In the meantime many foresters are using brush cutters very effectively to prepare tracer belts.

Jacob Kotze of NCT Tree Farming provided info on the best performing tree species in terms of their return and impact on the bottom line. Salient points from his presentation were as follows:-

• Wattle gives the best net profit return on all NCT farms.
• The cost of wattle rust resistant clones is worth the investment due to reduced silvicultural costs and improved MAI.
• Green wattle (Acacia decurrens) is a viable alternative to E. dunnii on certain sites.
E. grandis clones give a good net profit on good sites if a pole market is an option.
E. smithii remains a good option on the right sites.
• Plantation insurance costs are considerably less for acacia species vs eucalypts.
• TU period is generally shorter for eucalypts than it is for wattle.

The team from Andermatt Madumbi then delivered their presentation on the importance of looking after soil health for good, sustainable yields. They have developed various biological-based products to improve soil and root health which inevitably results in improved vigour and growth of the plants – whether they be trees or agricultural crops. They have had a lot of success with improving crop yields after their soil treatments, and have recently been doing trials in tree nurseries with their root health programme. According to Andrew Keller the programme resulted in improved root health and growth of the cuttings. He said this would lead to improved survival, better pest and disease tolerance and the trees would be quicker to canopy.

Andrew said that there is increasing pressure on farmers all over the world to reduce chemical use in their fields due to declining soil health and productivity over successive rotations, hence the value of using quality biologicals to boost soil health.

He said that tree farmers need more fungi and less bacteria in the soil which will build up the carbon content and lead to healthier crops. At just 3% organic matter in the soil you get “massive growth improvement”, he said. As the fungi to bacteria ratio increases, so too the growth of the plant accelerates.

Tree improvement programme

After the indoor presentations we took a drive around Enon to view some of NCT’s tree improvement trials, from rust-tolerant wattle trees, black and green wattle hybrids and a raft of Eucalyptus hybrids that are producing ever improving results with better growth, improved pest and disease tolerance, wood quality and stem form.

For over 20 years a hybrid breeding consortium has been funding research and testing clones for independent timber growers in the forestry industry. Recently, NCT together with TWK and affiliated clonal nurseries - CPS Seedlings, Ezigro Seedlings, Sunshine Seedlings, Sutherland Seedlings and Top Crop - have formed a non-profit company known as the Hybrid Clone Consortium (HCC) to continue managing this programme.

Highlights of the programme include the development of GN 2107, one of the most widely and successfully grown GxN clones in the industry today; the development of GU 400 and 412 at the height of the L. invasa infestations to help growers combat this pest; and the release of the first South African black wattle clones to the market.

There are now well over 100 hybrid trials planted across a wide range of South African forestry sites which are contributing crucial info that is steadily building an understanding of which clones to plant on which sites for desired results.

At the same time nursery practises have evolved and clones are now produced through mini-cuttings, which form a tap-root like root system which more closely resembles the root architecture of a seedling. The introduction of paper pots over the past few years has also improved the quality of the root plug and ease of handling of clonal cuttings which are the future of forestry.

We were then treated to a demo of the use of drones to spray the tree canopy from above, the use of a highly effective blower to manage and extinguish a fire by the STIHL team; and various spray and planting rigs from Midlands Spraychem.

Thanks to the NCT team for organising a highly informative field day.

Drone-mounted tool for sampling tree canopies

A University of Sherbrooke research team specialising in aerial robotics has developed a self-powered, drone-mounted tool that is able to collect foliage samples from high up in tree canopies, according to a report from Friday Offcuts.

The DeLeaves canopy sampling tool is suspended beneath a drone, is equipped with an HD camera, and has two robotic arms to collect foliage samples from trees.

The tool was first used by a group of horticulturists to sample foliage from tropical forests in Vietnam.It has been deployed by the Canadian Airborne Biodiversity Observatory to study the spectral and functional trait differences within tree crowns; and has been used to sample Douglas Fir, Silver Firs, and Western Hemlocks by the National Ecological Observatory Network team.

Since then it has been used to collect samples of tree canopies in North America and Europe. It has further potential for crop sampling in agriculture. The DeLeaves canopy sampling tool will be showcased at the ForestTECH 2021 event being run in Rotorua, New Zealand in November.

Source: Friday Offcuts
Visit: www.foresttech.com