scholarly journals Efficacy of Anaerobic Soil Disinfestation for Control of Prunus Replant Disease

Plant Disease ◽  
2018 ◽  
Vol 102 (1) ◽  
pp. 209-219 ◽  
Author(s):  
G. Browne ◽  
N. Ott ◽  
A. Poret-Peterson ◽  
H. Gouran ◽  
B. Lampinen

Prunus replant disease (PRD) is an important soilborne complex that suppresses growth and productivity of replanted stone fruit and nut orchards. It is effectively managed with preplant soil fumigation but, due to regulatory challenges, nonfumigant-based control strategies for PRD and other soilborne disease problems may become increasingly important, especially in California. We examined the potential of preplant anaerobic soil disinfestation (ASD) for control of PRD in four repeated orchard replant trials on sandy loam soil near Parlier, CA. After removal of the old orchard trees, alternative ASD treatments, all using rice bran as the main carbon source, were implemented, starting in late September. The alternative treatments incorporated rice bran at (i) 20 t ha−1, alone, in 3.0-m-wide row strips; (ii) 20 t ha−1, preceded by incorporation of a sudangrass cover crop and followed by drip application of molasses (10 t ha−1), in 3.0-m-wide row strips; (iii) 20 t ha−1, alone, in 1.8-m-wide strips; or (iv) 12 t ha−1, alone, in 1.8-m-wide strips. All ASD-treated areas were covered with clear tarp and drip irrigated with 25 cm of water. Tarps remained for 6 weeks, during which the soil moisture level was kept at or above field capacity by drip irrigation. All trials included nontreated control and fumigated standard treatments. ASD raised temperature and reduced redox potential in soil at 15- and 46-cm depths for 6 weeks. Fumigation and ASD treatments both nearly eradicated bioassay inoculum of Pythium ultimum in the soil before almond trees were replanted and significantly affected almond tree root communities of fungi and oomycetes after planting. Fumigation treatments and ASD treatments with rice bran at 20 t ha−1 in 3.0-m strips increased tree growth significantly and by similar magnitudes. Among repeated experiments, mean increases in trunk cross-sectional area growth due to fumigation ranged from 137 to 264%, while the increases due to ASD at 20 t ha−1 in 3.0-m strips ranged from 148 to 214%, compared with controls. ASD offers effective control of PRD and is worthy of further optimization and testing for management of PRD and additional orchard replant problems.

2019 ◽  
Vol 80 (1) ◽  
pp. 191-201 ◽  
Author(s):  
Amisha T. Poret-Peterson ◽  
Nada Sayed ◽  
Nathaniel Glyzewski ◽  
Holly Forbes ◽  
Enid T. González-Orta ◽  
...  

AbstractAnaerobic soil disinfestation (ASD) is an organic amendment-based management tool for controlling soil-borne plant diseases and is increasingly used in a variety of crops. ASD results in a marked decrease in soil redox potential and other physicochemical changes, and a turnover in the composition of the soil microbiome. Mechanisms of ASD-mediated pathogen control are not fully understood, but appear to depend on the carbon source used to initiate the process and involve a combination of biological (i.e., release of volatile organic compounds) and abiotic (i.e., lowered pH, release of metal ions) factors. In this study, we examined how the soil microbiome changes over time in response to ASD initiated with rice bran, tomato pomace, or red grape pomace as amendments using growth chamber mesocosms that replicate ASD-induced field soil redox conditions. Within 2 days, the soil microbiome rapidly shifted from a diverse assemblage of taxa to being dominated by members of the Firmicutes for all ASD treatments, whereas control mesocosms maintained diverse and more evenly distributed communities. Rice bran and tomato pomace amendments resulted in microbial communities with similar compositions and trajectories that were different from red grape pomace communities. Quantitative PCR showed nitrogenase gene abundances were higher in ASD communities and tended to increase over time, suggesting the potential for altering soil nitrogen availability. These results highlight the need for temporal and functional studies to understand how pathogen suppressive microbial communities assemble and function in ASD-treated soils.


2020 ◽  
Author(s):  
Anna Louise Testen ◽  
Marlia Bosques Martinez ◽  
Alejandra Jimenez Madrid ◽  
Loic Deblais ◽  
Christopher Taylor ◽  
...  

Tomato production in Ohio protected culture systems is hindered by a soilborne disease complex consisting of corky root rot (Pyrenochaeta lycopersici), black dot root rot (Colletotrichum coccodes), Verticillium wilt (Verticillium dahliae), and root-knot (Meloidogyne hapla and M. incognita). In a survey of 71 high tunnels, C. coccodes was detected in 90% of high tunnels, while P. lycopersici (46%), V. dahliae (48%) and Meloidogyne spp. (45%) were found in nearly half of high tunnels. Anaerobic soil disinfestation (ASD) with wheat bran (20.2 Mg/ha) plus molasses (10.1 Mg/ha) and grafting onto ‘Maxifort’ or ‘Estamino’ rootstocks were evaluated in high tunnels on five farms. In post-ASD bioassays using trial soils, root and taproot rot severity were significantly reduced following ASD, and root-knot galling was also reduced by ASD. Soilborne pathogenic fungi were isolated less frequently from bioassay plants grown in ASD-treated soils than control soils. Similar results were observed in tomato plants grown in high tunnels. Root rot was significantly reduced by ASD in nearly all trials. Corky root rot severity was highest in non-grafted plants grown in non-treated soils, while the lowest levels of corky root rot were observed in Maxifort-grafted plants. Black dot root rot severity was higher or equivalent in grafted plants compared to non-grafted plants. Root-knot severity was lower in plants grown in ASD-treated soils in high tunnels compared to plants grown in control soils, but grafting did not significantly decrease root-knot severity. However, soil treatment did not significantly impact yield, and grafting led to inconsistent impacts on yield.


Author(s):  
Oleg Daugovish ◽  
Joji Muramoto ◽  
Carol Shennan ◽  
Margherita Zavatta

Anaerobic soil disinfestation (ASD) has been optimized and adopted as an organic alternative to chemical fumigation by strawberry growers in California. The ASD process relies on mixing labile carbon sources into the soil to generate chemical, physical, and microbiological changes aiding suppression of the soil-borne pathogens and enhancing fruit production. Continued ASD adoption is hindered by the increasing cost of rice bran, currently the most widely used carbon source. To address this need and to find suitable and economical alternative carbon sources, we conducted field evaluations of locally produced or sourced plant-based products. ASD with incorporated grass-sod clippings spent grain and coffee grounds from one supplier provided a 47% to 83% increase in fruit yields compared to untreated soil, but coffee grounds from a different supplier decreased strawberry yields. Carbon, nitrogen, and their ratios had important impacts on the efficacy of ASD with coffee grounds and grape pomace. ASD with wheat midds at 20 t/ha provided strawberry yields similar to chloropicrin-fumigated soil while substituting 30% of rice bran carbon rate with on-site grown cereal cover crop biomass resulted in yields similar to the full rate of rice bran but at a reduced cost. As we continue exploring cost-effective methods of soil disinfestation, we utilize ASD integrated with other pest management tools, such as the use of resistant cultivars and crop rotation for sustainable production.


2021 ◽  
Vol 9 (8) ◽  
pp. 1638
Author(s):  
Shashika S. Hewavitharana ◽  
Emmi Klarer ◽  
Joji Muramoto ◽  
Carol Shennan ◽  
Mark Mazzola

Charcoal rot and Fusarium wilt, caused by Macrophomina phaseolina and Fusarium oxysporum f. sp. fragariae, respectively, are major soil-borne diseases of strawberry that have caused significant crop losses in California. Anaerobic soil disinfestation has been studied as an industry-level option to replace soil fumigants to manage these serious diseases. Studies were conducted to discern whether Gramineae carbon input type, incubation temperature, or incubation duration influences the efficacy of this disease control tactic. In experiments conducted using ‘low rate’ amendment applications at moderate day/night temperatures (24/18 °C), and carbon inputs (orchard grass, wheat, and rice bran) induced an initial proliferation and subsequent decline in soil density of the Fusarium wilt pathogen. This trend coincided with the onset of anaerobic conditions and a corresponding generation of various anti-fungal compounds, including volatile organic acids, hydrocarbons, and sulfur compounds. Generation of these metabolites was associated with increases in populations of Clostridium spp. Overall, carbon input and incubation temperature, but not incubation duration, significantly influenced disease suppression. All Gramineae carbon inputs altered the soil microbiome and metabolome in a similar fashion, though the timing and maximum yield of specific metabolites varied with input type. Fusarium wilt and charcoal rot suppression were superior when anaerobic soil disinfestation was conducted using standard amendment rates of 20 t ha−1 at elevated temperatures combined with a 3-week incubation period. Findings indicate that anaerobic soil disinfestation can be further optimized by modulating carbon source and incubation temperature, allowing the maximum generation of antifungal toxic volatile compounds. Outcomes also indicate that carbon input and environmental variables may influence treatment efficacy in a target pathogen-dependent manner which will require pathogen-specific optimization of treatment protocols.


2017 ◽  
Vol 218 ◽  
pp. 105-116 ◽  
Author(s):  
Haichao Guo ◽  
Francesco Di Gioia ◽  
Xin Zhao ◽  
Monica Ozores-Hampton ◽  
Marilyn E. Swisher ◽  
...  

2021 ◽  
Vol 25 (3) ◽  
pp. 401-406
Author(s):  
A. Saleh ◽  
M.L. Suleiman

Weed control is one of the major problems in crop and vegetable production in Nigeria. Most of the peasant farmers use manual weeders in their cultivation, a process that is costly, labour intensive and time consuming. The process does not also give the farmer adequate returns to enable him breakeven. It is, therefore, necessary to design a weeding equipment which minimize the human effort and provide efficient work output for the peasant farmer. This study focus on designing, construction and evaluation of a hand-pushed weed control machine that would eliminate the challenges being faced by the farmer in weeding. Materials selected to suit the construction of the weeder are durable and locally available, easily replaced if damaged and at affordable cost. They include mild steel (3mm, 5mm), 30 mm circular (hollow) pipes, 10 mm diameter steel rod, and 40 cm pneumatic tyre. The developed weeding machine was evaluated in the experimental farm of IAR with impressive results. It works well in sandy loam soil of about 25.65% moisture content and requires less labour force compared to the manual hoe. It has about 84.7% weeding efficiency, 0.0129ha/hr effectivefield capacity, 0.019ha/hr theoretical field capacity and 68% field efficiency. The average cost of the weeding is N21, 000:00. Keywords: Manual weeding, hand-pushed weeder, weeding efficiency, field efficiency


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