The influence of time, soil moisture and exogenous factors on the survival potential of oospores and chlamydospores of Phytophthora cinnamomi

2020 ◽  
Vol 51 (1) ◽  
Author(s):  
Jamba Gyeltshen ◽  
William A. Dunstan ◽  
Andrew H. Grigg ◽  
Treena I. Burgess ◽  
Giles E. St. J. Hardy
Keyword(s):  
Soil Moisture ◽  
Phytophthora Cinnamomi ◽  
Exogenous Factors ◽  
Survival Potential

scholarly journals Association of Phytophthora cinnamomi with White Oak Decline in Southern Ohio

Plant Disease ◽  
2010 ◽  
Vol 94 (8) ◽  
pp. 1026-1034 ◽  
Author(s):  
Annemarie M. Nagle ◽  
Robert P. Long ◽  
Laurence V. Madden ◽  
Pierluigi Bonello
Keyword(s):  
Soil Moisture ◽  
Phytophthora Cinnamomi ◽  
Clay Content ◽  
Environmental Drivers ◽  
Quercus Alba ◽  
Oak Decline ◽  
White Oak ◽  
Population Densities ◽  
Exponential Relationship ◽  
Root Health

A decline syndrome and widespread mortality of mature white oak tree (Quercus alba) associated with wet and low-lying areas has been recently observed in southern Ohio forests. Previous studies have isolated Phytophthora cinnamomi from white oak rhizospheres. In 2008 and 2009, P. cinnamomi population densities in two healthy and two declining white oak stands at Scioto Trail State Forest were quantified and potential roles of three environmental drivers of Phytophthora spp.–induced decline were assessed: soil texture, soil moisture, and topography. Significantly higher P. cinnamomi propagule densities were found in declining stands in both years but propagule densities were not associated with soil moisture content. Trends in population densities were not correlated with soil moisture or topographic position within field sites. There was a positive, exponential relationship between overall P. cinnamomi population levels and soil moisture on a seasonal scale in 2008 but not 2009. Sites with greater soil clay content were associated with greater decline. Effects of P. cinnamomi inoculum and periodic flooding on root health of 1-year-old potted white oak trees grown in native soil mixes in the greenhouse were examined. Root systems of potted oak were significantly damaged by soil inoculation with P. cinnamomi, especially under flooding conditions. Results of these studies support the hypothesis that P. cinnamomi is a contributing agent to white oak decline in southern Ohio.

Association of Phytophthora cinnamomi With Pinus radiata in South Australia

1981 ◽  
Vol 29 (1) ◽  
pp. 11 ◽  
Author(s):  
M Bumbieris
Keyword(s):  
Soil Moisture ◽  
Population Density ◽  
Pinus Radiata ◽  
Phytophthora Cinnamomi ◽  
South Australia ◽  
Pine Forest ◽  
Forest Plantation ◽  
Root Zones ◽  
High Soil Moisture ◽  
High Soil

In a pine forest plantation, P. cinnamomi was rarely isolated from the root zones, and never from the roots, of established P. radiata growing at P. cinnamomi sites. When a P. cinnamomi site was replanted with P. radiata, a third of the young pines died during the first 9 months, about 50% of them yielding P. cinnamomi from roots. Death of the trees followed an increase in the soil population density of P. cinnamomi which appeared to be correlated with increasing soil temp. and high soil moisture.

Survival of Chlamydospores of Phytophthora cinnamomi in Several Non-Sterile, Host-Free Forest Soils and Gravels at Different Soil Water Potentials

1979 ◽  
Vol 27 (1) ◽  
pp. 1 ◽  
Author(s):  
G Weste ◽  
K Vithanage
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Phytophthora Cinnamomi ◽  
Matter Content ◽  
Soil Types ◽  
Native Forest ◽  
Sterile Soil ◽  
Water Potentials ◽  
Chlamydospore Formation ◽  
Disease Free

Chlamydospore survival was investigated for six soil types, collected from disease-free areas of native forest in Victoria, in 50-g packs of non-sterile, unamended soils and gravels at five different matric soil water potentials ( ψ ). No chlamydospores survived in gravel free from OM, and only one chlamydospore survived at ψ -3000 kPa. In other packs the numbers of chlamydospores declined for 2 months then increased markedly at 4-6 months. Many chlamydospores remained viable for 8 months and some for 10 months despite the use of non-sterile soil and the absence of hosts. Maximum numbers survived in gravel from the Brisbane Ranges 6 and 8 months after inoculation at ψ -500 kPa. Decreasing soil moisture appeared to stimulate chlamydospore formation while a low rganic matter content and small numbers of microorganisms increased survival.

Phenology of Eucalyptus marginata on Sites Infested With Phytophthora cinnamomi

1989 ◽  
Vol 37 (3) ◽  
pp. 193 ◽  
Author(s):  
EM Davison ◽  
FCS Tay
Keyword(s):  
Soil Moisture ◽  
Phytophthora Cinnamomi ◽  
Pathogenic Fungus ◽  
High Surface ◽  
Summer Rainfall ◽  
Cambial Activity ◽  
Eucalyptus Marginata ◽  
Young Leaves ◽  
Healthy Area ◽  
Leaf Flush

The phenology of Eucalyptus marginata (jarrah) was followed at three sites, Churchmans, Karnet and Ross, in the high rainfall zone of the jarrah forest for a minimum of 3 years. On each site, trees growing in an area infested with the soil-borne, pathogenic fungus Phytophthora cinnamomi (dieback area) were compared with trees of similar diameter in the adjacent, uninfested forest (healthy area). Phenology of jarrah on these dieback sites did not follow a consistent pattern. In the dieback area at Churchmans, the cambium was active more often, and trees had young leaves in their crown more frequently than trees in the healthy area, while at Karnet the reverse occurred. This is consistent with growth measurements. At Ross, in the dieback area, the cambium was active less often but young leaves were seen more frequently than in trees in the healthy area. The trees did not flower every year. At Ross flowering started in early October while at Karnet and Churchmans it started at least 1 month later. New leaves were produced intermittently during autumn and winter while the main leaf flush occurred in spring and summer. Data from all years showed that the leaf flush started earlier at Ross than at Karnet and Churchmans. The cambium was intermittently active throughout the year with most trees growing in late autumn, winter and spring. Observations of stem growth following unseasonable summer rainfall suggest that cambial activity is triggered by high, surface soil moisture, but only if soil aeration is adequate. It is unlikely that timing of the main leaf flush and flowering are determined solely by temperature, soil moisture or photoperiod.

PROTOTIPE APLIKASI PENYIRAMAN TANAMAN MENGGUNAKAN SENSOR KELEMBABAN TANAH BERBASIS MICRO CONTOLLER ATMEGA 328

2019 ◽  
Vol 5 (1) ◽  
pp. 97-106
Author(s):  
Rudi Budi Agung ◽  
Muhammad Nur ◽  
Didi Sukayadi
Keyword(s):  
Soil Moisture ◽  
Growth And Development ◽  
Large Scale ◽  
Simple Method ◽  
Moisture Sensor ◽  
Sensor Development ◽  
Soil Moisture Sensor ◽  
Application Systems ◽  
Harvesting Systems ◽  
Working Principle

The Indonesian country which is famous for its tropical climate has now experienced a shift in two seasons (dry season and rainy season). This has an impact on cropping and harvesting systems among farmers. In large scale this is very influential considering that farmers in Indonesia are stilldependent on rainfall which results in soil moisture. Some types of plants that are very dependent on soil moisture will greatly require rainfall or water for growth and development. Through this research, researchers tried to make a prototype application for watering plants using ATMEGA328 microcontroller based soil moisture sensor. Development of application systems using the prototype method as a simple method which is the first step and can be developed again for large scale. The working principle of this prototype is simply that when soil moisture reaches a certainthreshold (above 56%) then the system will work by activating the watering system, if it is below 56% the system does not work or in other words soil moisture is considered sufficient for certain plant needs.

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