The efficacy of Chondrostereum purpureum in sprout control of birch during mechanized pre-commercial thinning

Appl Microbiol Biotechnol

Saarinen

Rantala

et al. 2020

Self Cite

In forest regeneration areas, alongside roads and railways, under electric power lines and above gas pipe lines, there is a need for regular sprout control. A biocontrol method against broadleaved sprouting with formulations including the decay fungus Chondrostereum purpureum (Pers. Ex Fr.) Pouzar has been shown to be effective. Yet, heavy rain during spreading of this fungal inoculum on freshly cut stumps may affect the efficacy of the treatment, i.e., stump mortality during the following years. Thus, we performed an experiment where freshly cut birch stump surfaces (Betula pendula Roth and Betula pubescens Ehrh.) were treated with fungal inoculum under heavy irrigation and without it. Furthermore, two different adjuvants which aimed to fix the fungal inoculum to freshly cut stumps during irrigation and to protect against solar radiation were tested. Our results revealed that the artificial rainstorm treatment caused a delay in the efficacy of C. purpureum, but after three growing seasons, there was no significant difference in the mortality of birch stumps treated under irrigation or without it (stump mortalities 74 and 86%, respectively). Adjuvants did not improve the efficacy in stumps treated under irrigation nor in those treated without irrigation. Key Points • Heavy rain delayed the sprout control efficacy of a fungus Chondrostereum purpureum. • Final efficacy of formulations was the same in wet and dry conditions. • No additional adjuvants are needed to improve formulations.

Section: Discussionsupporting

confidence: 55%

Rainstorm effects on the biocontrol efficacy of the decay fungus Chondrostereum purpureum against birch sprouting in boreal forests

Appl Microbiol Biotechnol

Saarinen

Rantala

et al. 2020

Self Cite

“…In recent years, some practical scale experiments for spreading inoculum with clearing saws and devices installed on forest machines have been conducted (Laine et al 2019(Laine et al , 2020a. In motor-manual work, different kinds of nozzle solutions connected to clearing saw blades have been tested (Laine et al 2020b), and in mechanized PCT-work, a UW40cleaning head installed on a Tehojätkä mini-harvester (Usewood Forest Tec LTD) and Mense cutting head installed on a normal harvester have been tested (Laine et al 2019(Laine et al , 2020a. According to these studies, the efficacy of the biological control was not as high as in manual application experiments.…”

Section: Devices In Biological Sprout Controlmentioning

confidence: 99%

“…Seasonal effects on the sprout control efficacy of C. purpureum have been found in several tree species. In birch ( Betula pendula and B. pubescens ), the sprout control efficacy of C. purpureum is good when the treatment is performed in spring or summer but it seems to decrease towards the end of the growing season (Hamberg et al 2015 , 2017 ; Laine et al 2020a ; Vartiamäki et al 2009a ). The reason for decreasing efficacy towards the end of a growing season is not fully understood.…”

Section: Introductionmentioning

confidence: 99%

Role and function of Chondrostereum purpureum in biocontrol of trees

Appl Microbiol Biotechnol

Saksa

Hantula

2020

Self Cite

A decay fungus, Chondrostereum purpureum (Pers. Ex Fr.) Pouzar, has been investigated in Europe, Northern America and New Zealand for its ability to decay hardwood stumps and thus prevent sprouting. The aim of these investigations has been to find an alternative to mechanical (cutting only) and chemical sprout control (cutting and applying chemicals to stumps in order to prevent sprouting). Mechanical sprout control is not an efficient option due to hardwood tree species’ ability to re-sprout efficiently after cutting, and therefore management costs are high. Chemicals would be efficient but due to their harmful effects on the environment, alternatives are needed. The fungal treatment, i.e., cutting accompanied with C. purpureum inoculum is an environmentally friendly and efficient option for sprout control. This mini-review comprises the role and function of C. purpureum in biocontrol of trees: the ecology of C. purpureum, its sprout control efficacy, factors affecting sprout control efficacy, devices in biological sprout control, potential risks, and the future perspectives of biological sprout control. Key points • A fungus Chondrostereum purpureum is efficient in preventing sprouting of hardwoods • C. purpureum is not sensitive to environmental conditions • Devices should be developed for cost-efficient biological sprout control

“…Several investigations have been performed to investigate the efficacy of C. purpureum as biological sprout control agent (Spiers and Hopcroft 1988, de Jong 2000, Dumas et al 1997, Becker et al 2005, Vartiamäki et al 2008a, Roy et al 2010, Lygis et al 2012, Bellgard et al 2014, but in most of them, spreading of fungal inoculum has been applied manually, although in practice it is almost impossible to treat all saplings without motor manual or mechanized spreading devices. Some investigations have been performed with clearing saws able to spread fungal inoculum on freshly cut stump surfaces (Roy et al 2010, Laine et al 2020b, and with fully mechanized devices (Laine et al 2019(Laine et al , 2020a. Especially, fully mechanized devices with a spreading feature would need to be attached to a harvester that can carry the weight of inoculum medium, cut saplings, and apply fungal inoculum immediately on freshly cut stump surfaces, a feature that is important in efficient sprout control (Hamberg and Hantula 2020).…”

Section: Introductionmentioning

confidence: 99%

“…Especially, fully mechanized devices with a spreading feature would need to be attached to a harvester that can carry the weight of inoculum medium, cut saplings, and apply fungal inoculum immediately on freshly cut stump surfaces, a feature that is important in efficient sprout control (Hamberg and Hantula 2020). However, the sprout control efficacy of fully mechanized devices has been rather low so far (Laine et al 2019(Laine et al , 2020a, and therefore new alternatives are needed.…”

Section: Introductionmentioning

confidence: 99%

Cutlink Cleaning Head with a Spreading Feature for Biological Sprout Control

Croat. j. for. eng. (Online)

Strandström

Saksa

2021

Self Cite

The ability of deciduous trees to sprout efficiently after cutting is problematic in young forests where the target is to cultivate coniferous trees for industry. Since the use of chemicals has been restricted, new alternatives are needed. One potential and environmentally friendly option is biological sprout control that is based on the use of a white-rot fungus, Chondrostereum purpureum (Pers. Ex Fr.) Pouzar. This method has been efficient in earlier investigations when performed manually, but efficient, fully mechanized devices which are able to cut and treat stumps with a fungus are still unavailable. Therefore, the efficacy of biological sprout control conducted with a Cutlink cleaning head equipped with a spreading feature was studied in two young Norway spruce (Picea abies (L.) H. Karst.) forests in central Finland.Sample plots for the control (cutting deciduous saplings only) and fungal treatment (cutting and spreading fungal inoculum on fresh stump surfaces) were established, and the ability of the Cutlink cleaning head in preventing sprouting of silver and downy birch (Betula pendula Roth and B. pubescens Ehrh., respectively) in the sample plots was investigated for two years.In the near vicinity of cultivated Norway spruce, the proportion of cut deciduous saplings varied from 50–60% after the Cutlink operation. The average mortality of silver and downy birch stumps in the fungal treatment plots was ca. 40%, while stump mortality in the control, i.e., cutting only, was only ca. 13%, after two years. Stump mortality increased up to 73% if the stumps did not include old branches, i.e., the stump was cut to a low enough height.These results confirmed that the Cutlink cleaning head is a potential tool in young stand management operation but further development will be needed in working methods in order to achieve lower stump heights (no branches on the stump) and also to increase the proportion of cut saplings.