scholarly journals Assessment of Agro-Ecological Apple Replant Disease (ARD) Management Strategies: Organic Fertilisation and Inoculation with Mycorrhizal Fungi and Bacteria

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 272
Author(s):  
Ulrike Cavael ◽  
Peter Lentzsch ◽  
Hilmar Schwärzel ◽  
Frank Eulenstein ◽  
Marion Tauschke ◽  
...  

Apple replant disease (ARD) impacts the economic yield of orchards by physiological and morphological suppression of apple trees on replanted soils. The complexity of replant disease caused by a plethora of biological interactions and physical properties of the soil requires complex management strategies to mitigate these effects. Based on expert recommendations, we selected two management strategies linked to agroecological principles of (a) organic fertilisation with a specific mulch composition (MDK) and (b) biofertilisation with arbuscular mycorrhizal and bacterial strains (AMFbac), applied by a composition of existing products. For both management strategies we provide a proof-of-concept, by pot and field experiments. Both treatments have the potential to mitigate ARD effects on plant vigour. ARD effect was fully mitigated by MDK treatment in the short-term (one year) and was mitigated by up to 29% after seven years of MDK treatment (long-term). MDK provides an additional substrate for root growth. AMFbac has the potential to mitigate ARD effects on plant vigour but with non-replicable plant-beneficial effects in its current form of application. Thereby our results show a principal potential to mitigate economic effects but not to overcome replant disease inducing effects. While the MDK treatment is found resource intensive but reliable, the AMFbac treatment was found more user-friendly.

Plant Disease ◽  
2005 ◽  
Vol 89 (11) ◽  
pp. 1207-1213 ◽  
Author(s):  
Mark Mazzola ◽  
Kent Mullinix

Alternative management strategies to the use of preplant soil fumigation for the control of apple replant disease (ARD), including cover crops and strategies incorporating Brassica napus seed meal (rape seed meal [RSM]) amendment as the central component, were evaluated in the orchard. A 1-year wheat cover crop consisting of three short-term cropping periods with plant material removed at the end of each growth period and a 3-year B. napus green manure significantly enhanced vegetative growth and yield of Gala/M26. However, in each instance, the resulting disease control and growth response were inferior to that achieved through preplant methyl bromide soil fumigation. A 3-year bare fallow and 1- or 2-year B. napus green manure neither suppressed disease development nor enhanced tree growth. Preplant RSM amendment in conjunction with a postplant mefenoxam soil drench provided effective suppression of ARD, and the resulting tree growth and yield were comparable with that attained in response to 1,3- dichloropropene-chloropicrin fumigation in one orchard. At a second orchard, the growth response attained with the alternative treatment was inferior to preplant soil fumigation, which was associated with an apparent re-infestation of RSM-treated soils and tree roots by Pratylenchus spp. Application of RSM after wheat cropping or in conjunction with soil solarization provided an intermediate level of disease control and a corresponding reduction in growth and yield of apple relative to preplant fumigation at both sites.


2019 ◽  
Vol 3 (4) ◽  
pp. 273-285 ◽  
Author(s):  
Greg Deakin ◽  
Felicidad Fernández-Fernández ◽  
Julie Bennett ◽  
Tom Passey ◽  
Nicola Harrison ◽  
...  

Continuous plantation of apple trees (Malus pumila) at the same sites where the same or a closely related species were grown previously leads to poor establishment, reduced growth vigor, and subsequent crop losses; this phenomenon is termed apple replant disease (ARD). Management of ARD is a continual challenge due to (i) restrictions on the use of broad-spectrum soil fumigants, (ii) putative causal agents of ARD can be site-specific, and (iii) more than one causal agent can be present at a site. We conducted an experimental study at two orchard sites to investigate the succession effect of rootstock genotypes on apple tree establishment with three specific objectives: (i) whether ARD in newly planted apple trees is more severe if the same rootstock as the previous one is replanted, (ii) whether trees develop better in the aisle than in original tree stations, and (iii) the extent of association of rootstock genotypes with rhizosphere microbiome in relation to ARD. Tree growth and rhizosphere microbiome were assessed within 30 months of replanting. In one orchard, replanting trees with a rootstock genotype different from the previous one can be effective in reducing ARD development, susceptibility to ARD is likely to be genetically controlled, and replanting trees in the previous grass aisle can reduce ARD development. However, the opposite results were obtained in the other orchard, possibly due to the lack of weed management in the grass aisle affecting tree establishment in the grass aisle. Rhizosphere microbiota associated with specific rootstock genotypes reached a stable state within 7 months of replanting. An arbuscular mycorrhizal fungi operational taxonomic unit (OTU) had reduced abundance with ARD trees; however many other OTUs associated with ARD cannot be identified to low taxonomic ranks and hence their roles cannot be easily interpreted. In conclusion, replanting trees with rootstocks that are genetically differently from the previous one can reduce ARD development. However, in adopting this strategy, the extent of genetic relationships among rootstock genotypes needs to be considered.


2020 ◽  
Author(s):  
Tengteng Gao ◽  
Yusong Liu ◽  
Xiaomin Liu ◽  
Kai Zhao ◽  
Lei Shan ◽  
...  

Abstract Apple replant disease (ARD) is a soil-borne disease that leads to economic losses due to reduced plant growth and diminished fruit yields. Dopamine is involved in interactions between plants and pathogens. However, it remains unclear whether dopamine can directly stimulate defense responses to ARD. In this study, an exogenous dopamine treatment and dopamine synthetase MdTYDC (tyrosine decarboxylase) transgenic plants were used to verify the role of dopamine in treating ARD. First, two-year-old trees of Malus domestica cv. Fuji apple, grafted onto rootstock M.26, were grown in replant soils. The addition of dopamine (100 μM) to the soil promoted seedling growth and changed the accumulation of mineral elements in plants in replant soils. Such supplementation improved the activity of invertase, urease, proteinase, and phosphatase under replant conditions. Sequencing analysis of 16S rDNA and ITS rDNA revealed that dopamine had a slight influence on bacterial diversity, but had an obvious effect on fungal diversity in replant soils. The application of dopamine to replant soil changed the composition of bacterial and fungal communities. Second, overexpression of MdTYDC in apple plants alleviated the effects of ARD. MdTYDC transgenic lines exhibited mitigated ARD through inhibited degradation of photosynthetic pigment, maintaining the stability of photosystem I and II, and improving the antioxidant system. Furthermore, overexpression of MdTYDC improved arbuscular mycorrhizal fungi colonization by improving the accumulation of soluble sugars under replant conditions. Together these results demonstrated that dopamine enhances the tolerance of apples to ARD.


2018 ◽  
Vol 2 (4) ◽  
pp. 261-274 ◽  
Author(s):  
Emma L. Tilston ◽  
Greg Deakin ◽  
Julie Bennett ◽  
Tom Passey ◽  
Nicola Harrison ◽  
...  

Continuous planting of apple in the same area leads to reduced growth vigor and subsequent crop losses, i.e., apple replant disease (ARD) syndrome. Several soilborne plant pathogens including Pythium, Fusarium, and Cylindrocarpon spp. are often proposed as candidate causal organisms for ARD. In addition, the presence of root lesion nematodes and the lack of beneficial groups of bacteria are believed to exacerbate or ameliorate the effects of the plant pathogens. The importance of these proposed causal and auxiliary agents seems to vary with site. Using a spatially explicit sampling strategy to minimize spatial variability we collected rhizosphere soil samples from neighboring pairs of healthy and putative ARD trees to identify candidate causal organisms of ARD. Amplicon-based metabarcoding was used to obtain community-level profiles of the bacteria, fungi, oomycetes and nematodes in the soil samples. Total bacterial and fungal biomass in each sample was estimated using qPCR to adjust the raw sequence reads data. The results suggested that ARD is not ameliorated by enhanced rhizosphere biodiversity per se. We identified 25 bacterial operational taxonomic units (OTUs), 16 fungal OTUs, 18 oomycetes OTUs, and one nematode OTU group with differential abundance between healthy and putative ARD trees. All 25 bacterial OTUs had lower abundance in samples from ARD symptomatic trees than from healthy trees. One AMF OTU had lower abundance in samples from ARD symptomatic trees. None of 13 fungal OTUs that had higher abundance in samples from ARD symptomatic trees is a known plant pathogen; but at least one Pythium OTU (probably Pythium intermedium) is a candidate for causing ARD. The abundance of one nematode OTU was much higher in samples from ARD symptomatic trees than in healthy trees. The results suggest that, apart from the use of broad spectrum fumigants, the complexity of ARD may necessitate the combined use of multiple management strategies with the success of these measures expected to vary considerably between sites because of the varying importance of ARD causal agents among sites.


2008 ◽  
Vol 61 ◽  
pp. 48-53
Author(s):  
H.J. Ridgway ◽  
J. Kandula ◽  
A. Stewart

Specific apple replant disease (SARD) impairs the growth and establishment of trees in replanted apple orchards Apple roots are normally colonised by arbuscular mycorrhizal fungi (AMF) which may have beneficial effects on plant growth Four AMF inoculation treatments (three species of AMF Glomus mosseae Acaulospora laevis and Scutellospora calospora and an uninoculated control) were applied to M26 apple rootstock seedlings in SARD and nonSARD soil Of the fungi inoculated S calospora had the greatest beneficial effect in improving shoot and root dry weight and shoot length in SARD soil More disease symptoms occurred on main and feeder roots in SARD soil and none of the inoculated AMF fungi reduced these Both A laevis and S calospora significantly increased shoot length and gave a higher percentage of AMFcolonised roots in nonSARD soil These results showed that AMF improve tolerance of apple to SARD and indicate that the beneficial effect is species specific Characterisation of endogenous mycorrhizae in the soil identified S pellucida This is a new species record for New Zealand and provides the opportunity to determine whether the beneficial effect is specific to the genus Scutellospora


Author(s):  
Alicia Balbín-Suárez ◽  
Samuel Jacquiod ◽  
Annmarie-Deetja Rohr ◽  
Benye Liu ◽  
Henryk Flachowsky ◽  
...  

Abstract A soil column split-root experiment was designed to investigate the ability of apple replant disease (ARD) causing agents to spread in soil. ‘M26’ apple rootstocks grew into a top layer of Control soil, followed by a barrier-free split-soil layer (Control soil/ARD soil). We observed a severely reduced root growth, concomitant with enhanced gene expression of phytoalexin biosynthetic genes and phytoalexin content in roots from ARD soil, indicating a pronounced local plant defense response. Amplicon sequencing (bacteria, archaea, fungi) revealed local shifts in diversity and composition of microorganisms in the rhizoplane of roots from ARD soil. An enrichment of OTUs affiliated to potential ARD fungal pathogens (Ilyonectria and Nectria sp.) and bacteria frequently associated with ARD (Streptomyces, Variovorax) was noted. In conclusion, our integrated study supports the idea of ARD being local and not spreading into surrounding soil, as only the roots in ARD soil were affected in terms of growth, phytoalexin biosynthetic gene expression, phytoalexin production, and altered microbiome structure. This study further reinforces the microbiological nature of ARD, being likely triggered by a disturbed soil microbiome enriched with low mobility ARD-causing agents that induce a strong plant defense and rhizoplane microbiome dysbiosis, concurring with root damage.


Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 402
Author(s):  
Rama Kant Dubey ◽  
Pradeep Kumar Dubey ◽  
Rajan Chaurasia ◽  
Ch Srinivasa Rao ◽  
Purushothaman Chirakkuzhyil Abhilash

Global agricultural production is accountable for the emission of ~30% of greenhouse gases. Therefore, the wide-scale adoptions of low-input, soil-friendly, and resource-conserving agronomic practices are imperative for the ‘planet healthy food production’ and also for reducing the carbon emissions from agricultural soil. In this context, the present study aimed to analyze the impacts of integrated agronomic interventions i.e., the application of arbuscular mycorrhizal fungi (AMF) + reduced tillage (RT), biochar + RT, and AMF + biochar + RT, on spatiotemporal variations in soil-quality and soil-sustainability indicators, including microbial and soil respiration, in the Indo-Gangetic Plain (IGP) of North India. For this, field experiments on the above-mentioned agronomic interventions were employed using three different staple crops (Zea mays, Vigna mungo, and Brassica juncea) growing in three different agro-climatic zones of IGP (Varanasi, Sultanpur, and Gorakhpur) in a randomized block design. Periodic data collection was done to analyze the changes in physiochemical, biological, and biochemical properties of the soil, and statistical analyses were done accordingly. Irrespective of the sites, the experimental results proved that the integrated application of AMF + biochar + RT in V. mungo resulted in the highest soil organic carbon (i.e., 135% increment over the control) and microbial biomass carbon (24%), whereas the same application (i.e., AMF + biochar + RT) in Z. mays had the maximum reduction in microbial (32%) and soil (44%) respiration. On the other hand, enhanced occurrence of glomalin activity (98%) was noted in Z. mays cropping for all the sites. Significant negative correlation between soil respiration and glomalin activity under AMF + biochar + RT (−0.85), AMF + RT (−0.82), and biochar + RT (−0.62) was an indication of glomalin’s role in the reduced rate of soil respiration. The research results proved that the combined application of AMF + biochar + RT was the best practice for enhancing soil quality while reducing respiration. Therefore, the development of suitable packages of integrated agronomic practices is essential for agricultural sustainability.


Author(s):  
Yingmei Tang ◽  
Huifang Cai ◽  
Rongmao Liu

AbstractIn the absence of formal risk management strategies, agricultural production in China is highly vulnerable to climate change. In this study, field experiments were conducted with 344 households in Heilongjiang (Northeast China) and Jiangsu (East China) Provinces. Probit and logistic models and independent sample T-test were used to explore farmers’ demand for weather index insurance, in contrast to informal risk management strategies, and the main factors that affect demand. The results show that the farmers prefer weather index insurance to informal risk management strategies, and farmers’ characteristics have significant impacts on their adoption of risk management strategies. The variables non-agricultural labor ratio, farmers’ risk perception, education, and agricultural insurance purchase experience significantly affect farmers’ weather index insurance demand. The regression results show that the farmers’ weather index insurance demand and the influencing factors in the two provinces are different. Farmers in Heilongjiang Province have a higher participation rate than those in Jiangsu Province. The government should conduct more weather index insurance pilot programs to help farmers understand the mechanism, and insurance companies should provide more types of weather index insurance to meet farmers’ diversified needs.


Sign in / Sign up

Export Citation Format

Share Document