Understand soil resilience to improve tree health
Lead Research Organisation:
Cranfield University
Department Name: School of Water, Energy and Environment
Abstract
Apple replant disease (ARD) causes significant economic losses across all major apple growing regions worldwide. The disease etiology is not well defined and expresses as the poor growth of newly planted trees. This problem is exacerbated in Europe by the removal of several effective chemical soil fumigants and many modern cultivars lacking resistance to other pathogens such as European Canker (Neonectria ditissima). Recent results at NIAB EMR suggested that ARD is likely to be caused by several organisms: lack of specific beneficial microbes (particularly bacteria), fungal and oomycetes pathogens, and exacerbated by nematodes. Thus, in absence of broad-spectrum fumigants, reducing ARD requires careful soil management to improve soil structure (particularly microbiota), especially in nurseries where young trees are grown in a high density. Furthermore, empirical evidence on the rapid development of apple canker symptoms at specific planting sites also suggested that certain soil conditions are likely to affect canker development in new plantings.
Objective
This project aims to understand how various soil management practices (including amending soils with specific microbes) will impact soil quality in terms of ARD and canker development.
Approach
We will investigate temporal dynamics of the soil microbial community, changes in specific beneficial microbes (e.g. arbuscular mycorrhizal fungi, known biocontrol microbes of plant diseases, and plant growth promoting rhizobacteria) and candidate ARD pathogens in response to soil amendments. Such microbial dynamics will also be studied under a few climate change scenarios: combination of elevated CO2x temperature x water potential stress. Both traditional and modern DNA sequencing technologies will be used to quantify microbial changes. Short and medium term experiments under several climate change scenarios will be conducted at the newly purpose-built AgriTech Centre (CHAP) at Cranfield University. The central hypothesis is that by improving tree health in nurseries we can improve tree establishment when planted in conjunction with appropriate management (irrigation, soil amendment etc.).
Objective
This project aims to understand how various soil management practices (including amending soils with specific microbes) will impact soil quality in terms of ARD and canker development.
Approach
We will investigate temporal dynamics of the soil microbial community, changes in specific beneficial microbes (e.g. arbuscular mycorrhizal fungi, known biocontrol microbes of plant diseases, and plant growth promoting rhizobacteria) and candidate ARD pathogens in response to soil amendments. Such microbial dynamics will also be studied under a few climate change scenarios: combination of elevated CO2x temperature x water potential stress. Both traditional and modern DNA sequencing technologies will be used to quantify microbial changes. Short and medium term experiments under several climate change scenarios will be conducted at the newly purpose-built AgriTech Centre (CHAP) at Cranfield University. The central hypothesis is that by improving tree health in nurseries we can improve tree establishment when planted in conjunction with appropriate management (irrigation, soil amendment etc.).
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| BB/S507167/1 | 01/10/2018 | 30/09/2022 | |||
| 2146486 | Studentship | BB/S507167/1 | 01/10/2018 | 30/09/2022 | Chris Cook |
| Description | We have shown a limited effect on the above-ground establishment in field and semi-field conditions due to each of the biological amendments we applied. Effect of the amendments if any also appeared to be cultivar specific ie. Pseudomonas fluorescens was only correlated with increased girth expansion in Gala trees and not for Braeburn trees. We also did not find any benefit in applying amendments in consortia rather than individually. We suggest that planting trees in the inter-rows (alleyways) between successive generations can be an effective strategy to manage apple replant disease and also noted rootstocks closer related to the previous generation were more severely affected by replant in the previous tree stations. Short-term exposure of apple orchard bulk soil to climate change conditions was most influenced by the management system (organic vs conventional) but it was noted that there was a marked (but not significant) impact of the two climate conditions investigated on bacterial and fungal diversity. It is therefore unlikely from the results of the work that substantial shifts in the rhizosphere community would occur due to short-term exposure to elevated CO2 and temperature alone (for example, during a hot summer in the UK). |
| Exploitation Route | Growers can make decisions on the best cultural practices to adopt (such as rootstock genotype selection and planting position) as a low economic impact management strategy for apple replant disease. More research needs to be conducted to optimise the strains, application and efficacy of biological soil amendments for apple replant disease management. Additional trials using the cultural practices alongside amendment are being conducted at NIAB, East Malling to see the combined effect of both management strategies. |
| Sectors | Agriculture, Food and Drink |