The influence of sugar feeding on transplanted tree establishment offers "a multitude of benefits", University of Reading Bartlett Tree Research Laboratory researcher Dr Glynn Percival has found.
He said his studies using root-pruned containerized stock of Betula pendula, Quercus rubra, Prunus avium and Sorbus aucuparia show a positive increase in root vigour following the application of sugar as a root drench.
Based on experimental data of 12 tree species, it is recommended that sugars should be applied at 30-50g per litre of water per square metre of ground from the trunk base to 1m beyond the canopy drip line.
Percival said his experiments show pure mulchon European beech derived from high-sugar hawthorn and cherry increase survival rates from 10 to 70 per cent.
Further field experiments using apple (Malus cv. Gala), and pear (Pyrus communis 'Concorde') following field transplanting found crown volume and fruit yield could be increased by 53 and 100 per cent respectively by application of hawthorn and cherry pure mulches.
Percival is now testing sugar-based vegetable fertilizers Fulcrum CV and Fulcrum Blade on trees. He said: "Results indicate applications of sugars offer a multitude of benefits for professionals involved in tree management.
"This is an area worthy of consideration given the fact that sugars are water soluble, non-toxic, environmentally safe and inexpensive to purchase."
Percival is also looking at plant defence activators such as salicylic acid, phosphites and willow mulches in experiments to find quick solutions to tree health issues. He added that 2012 HortScience paper Biochar Amendment Increases Resistance to Stem Lesions Caused by Phytophthora spp. in Tree Seedlings prompted him to work with a biochar/phosphite mix supplied by Carbon Gold at a five per cent rate to protect against disease.
"It is something we add to soil that will protect trees against disease. We'd love to use a fungicide against Chalara but we would be arrested. By the time the Government has found something and registered it, it will be too late. We know fungicides work so why re-invent the wheel?"
He said unscrupulous tree surgeons are telling homeowners there is no cure to Chalara. "How many thousands of ash are being taken down unnecessarily? We have fungicides we know work so why not register one or two to let people do something? It's going to be a Dutch elm disease scenario.
"Spread was so rapid last year and nothing really was done so it's going to get even worse. Climatic conditions have been ideal - overcast and wet. We'll start to see it from mid to late June."
Sugar application - enhanced root growth
- Gene expression alteration in favour of root over shoot growth (University of Florida)
- Sugar-induced changes in soil microbial and fungal rhizosphere populations alter plant nutrient uptake patterns in favour of root growth.
- Recovery following root severance is dependent on the ability of a tree to manufacture carbohydrates such as sucrose.
- Carbohydrate loading.