Incidence of root and hypocotyl diseases in lupin crops in Western Australia between 1986 and 2005

2010 ◽  
Vol 61 (3) ◽  
pp. 241 ◽  
Author(s):  
G. J. Thomas ◽  
W. J. MacLeod ◽  
M. W. Sweetingham
Keyword(s):  
Crop Rotation ◽  
Western Australia ◽  
Root Rot ◽  
Plant Density ◽  
Management Systems ◽  
Sowing Depth ◽  
Root Rots ◽  
The Past ◽  
Predominant Pathogen ◽  
Growing Region

Three separate surveys were carried out in commercial lupin crops in the major lupin growing region of Western Australia in 1986, 1990, and 2004–05. In total, 333 sites were sampled and plants assessed for the incidence and cause of root and hypocotyl rots. Measurements were made of plant density and sowing depth at all sites. In all surveys, root rot was more common than hypocotyl rot. Root rot occurred in more than 95% of sites in each survey; however, a greater proportion of sites had high levels of root rot in early surveys. The incidence of root rot within sites decreased from an average of 34.9% in 1986 to 10.2% in 2004–05. Hypocotyl rot incidence varied among surveys, incidence of infected paddocks, and within-paddock incidence was greatest in the 1990 survey. Hypocotyl rot incidence was lowest in the 2004–05 survey. Rhizoctonia solani and Pleiochaeta setosa were commonly isolated from root lesions and R. solani was the predominant pathogen isolated from hypocotyl lesions. Analysis of the R. solani isolates by pectic zymogram showed that the ZG3 strain was most regularly isolated from roots and hypocotyls. This series of surveys indicates that the incidence of root rots in commercial lupin paddocks in Western Australia has decreased dramatically over the past 20 years; however, root rot still occurs in most paddocks regardless of soil type, location, crop rotation, and management systems.

Influence of Weed Management Practices and Crop Rotation on Glyphosate-Resistant Horseweed (Conyza canadensis) Population Dynamics and Crop Yield-Years III and IV

Weed Science ◽  
2009 ◽  
Vol 57 (4) ◽  
pp. 417-426 ◽  
Author(s):  
Vince M. Davis ◽  
Kevin D. Gibson ◽  
Thomas T. Bauman ◽  
Stephen C. Weller ◽  
William G. Johnson
Keyword(s):  
Population Dynamics ◽  
Crop Rotation ◽  
Crop Yield ◽  
Cover Crops ◽  
Weed Management ◽  
Management Practices ◽  
Plant Density ◽  
Crop Yields ◽  
Management Systems ◽  
No Till

Horseweed is an increasingly common and problematic weed in no-till soybean production in the eastern cornbelt due to the frequent occurrence of biotypes resistant to glyphosate. The objective of this study was to determine the influence of crop rotation, winter wheat cover crops (WWCC), residual non-glyphosate herbicides, and preplant application timing on the population dynamics of glyphosate-resistant (GR) horseweed and crop yield. A field study was conducted from 2003 to 2007 in a no-till field located at a site that contained a moderate infestation of GR horseweed (approximately 1 plant m−2). The experiment was a split-plot design with crop rotation (soybean–corn or soybean–soybean) as main plots and management systems as subplots. Management systems were evaluated by quantifying in-field horseweed plant density, seedbank density, and crop yield. Horseweed densities were collected at the time of postemergence applications, 1 mo after postemergence (MAP) applications, and at the time of crop harvest or 4 MAP. Viable seedbank densities were also evaluated from soil samples collected in the fall following seed rain. Soybean–corn crop rotation reduced in-field and seedbank horseweed densities vs. continuous soybean in the third and fourth yr of this experiment. Preplant herbicides applied in the spring were more effective at reducing horseweed plant densities than when applied in the previous fall. Spring-applied, residual herbicide systems were the most effective at reducing season-long in-field horseweed densities and protecting crop yields since the growth habit of horseweed in this region is primarily as a summer annual. Management systems also influenced the GR and glyphosate-susceptible (GS) biotype population structure after 4 yr of management. The most dramatic shift was from the initial GR : GS ratio of 3 : 1 to a ratio of 1 : 6 after 4 yr of residual preplant herbicide use followed by non-glyphosate postemergence herbicides.

Influence of Weed Management Practices and Crop Rotation on Glyphosate-Resistant Horseweed Population Dynamics and Crop Yield

Weed Science ◽  
2007 ◽  
Vol 55 (5) ◽  
pp. 508-516 ◽  
Author(s):  
Vince M. Davis ◽  
Kevin D. Gibson ◽  
Thomas T. Bauman ◽  
Stephen C. Weller ◽  
William G. Johnson
Keyword(s):  
Population Dynamics ◽  
Crop Rotation ◽  
Crop Yield ◽  
Cover Crops ◽  
Weed Management ◽  
Management Practices ◽  
Plant Density ◽  
Management Systems ◽  
Integrated Weed Management ◽  
Rapid Decline

Horseweed is an increasingly problematic weed in soybean because of the frequent occurrence of glyphosate-resistant (GR) biotypes. The objective of this study was to determine the influence of crop rotation, winter wheat cover crops (WWCC), residual nonglyphosate herbicides, and preplant herbicide application timing on the population dynamics of GR horseweed and crop yield. A field study was conducted at a site with a moderate infestation of GR horseweed (approximately 1 plant m−2) with crop rotation (soybean–corn or soybean–soybean) as main plots and management systems as subplots. Management systems were evaluated by quantifying horseweed plant density, seedbank density, and crop yield. Crop rotation did not influence in-field horseweed or seedbank densities at any data census timing. Preplant herbicides applied in the spring were more effective at reducing horseweed plant densities than when applied in the previous fall. Spring-applied, residual herbicide systems were the most effective at reducing season long horseweed densities and protecting crop yield because horseweed in this region behaves primarily as a summer annual weed. Horseweed seedbank densities declined rapidly in the soil by an average of 76% for all systems over the first 10 mo before new seed rain. Despite rapid decline in total seedbank density, seed for GR biotypes remained in the seedbank for at least 2 yr. Therefore, to reduce the presence of GR horseweed biotypes in a local no-till weed flora, integrated weed management (IWM) systems should be developed to reduce total horseweed populations based on the knowledge that seed for GR biotypes are as persistent in the seed bank as glyphosate-sensitive (GS) biotypes.

scholarly journals Distribution of root rot in grain crop rotation depending on the elements of cultivation technology

2020 ◽  
Author(s):  
T.B. Permyakova ◽  
Keyword(s):  
Species Composition ◽  
Winter Wheat ◽  
Crop Rotation ◽  
Root Rot ◽  
Tillage Systems ◽  
Root Rots ◽  
Grain Crop ◽  
Cultivation Technology

Species composition and pathogenicity of winter wheat rot in the grain crop rotation is given. The influence of the main tillage systems and preceding crops on the level of accumulation and spread of the root rots is given. The advantages of traditional cultivation technology are demonstrated.

Emergence, survival and seed production of Enteropogon ramosus in a pasture - wheat rotation or continuous pasture rotation in the wheatbelt of Western Australia

2010 ◽  
Vol 61 (8) ◽  
pp. 601 ◽  
Author(s):  
C. P. D. Borger ◽  
G. P. Riethmuller ◽  
A. Hashem
Keyword(s):  
Seed Production ◽  
Crop Rotation ◽  
Western Australia ◽  
Plant Density ◽  
Cropping System ◽  
Soil Disturbance ◽  
Grass Species ◽  
Competitive Effect ◽  
Minimum Tillage ◽  
C4 Grass

Enteropogon ramosus is a native, perennial, C4 grass species found within the wheatbelt of Western Australia. Emergence, survival, seed production and seed dormancy of E. ramosus was investigated in a continuous pasture rotation, a pasture–minimum tillage wheat rotation, and a pasture–minimum tillage wheat rotation where a cultivation event at the beginning of the pasture year was used to kill all E. ramosus plants. The results indicated that E. ramosus could germinate throughout the year, although plant density (ranging annually from 0 to 17 plants m−2) was lowest in conditions of low rainfall (summer–autumn drought). Seed production (estimated from seed head production, r = 91.7, P < 0.001) ranged from 0 to 2274 m–2 and was greatest in spring, in the continuous pasture rotation. Seed germinability reached 80–89%, following an initial 3 months of dormancy directly after seed production. Cultivation at the beginning of the pasture-crop rotation killed all plants, reduced emergence and prevented seed production for the 2-year period of the experiment. Soil disturbance from minimum tillage crop sowing reduced but did not eliminate E. ramosus plants. As a result, E. ramosus grew throughout the year in the minimum tillage cropping system. Further research is required to determine the competitive effect of E. ramosus on crop growth.

The effect of inoculum distribution and sowing depth on Pleiochaeta root rot of lupins

1991 ◽  
Vol 42 (1) ◽  
pp. 121 ◽  
Author(s):  
MW Sweetingham
Keyword(s):  
Grain Yield ◽  
Western Australia ◽  
Root Rot ◽  
Surface Soil ◽  
Field Trials ◽  
Sowing Depth ◽  
History Of

In paddocks with a history of previous lupin cultivation, propagules of the fungus Pleiochaeta setosa are most concentrated in the top 2 cm of soil and rapidly decline to zero at the base of the tillage layer (10-14 cm). The severity of Pleiochaeta root rot is greatly reduced as sowing depth increases, due to avoidance of the concentrated surface soil borne inoculum. Hypocotyls are not infected by P. setosa, enabling disease escape. In four field trials over three seasons, optimum establishment and grain yield occurred at sowing depths close to 5 cm, deeper than previously recommended for lupins in Western Australia.

scholarly journals Our New Cathedrals: Spirituality and Old-Growth Forests in Western Australia

2006 ◽  
Vol 3 (1) ◽  
Author(s):  
David Worth
Keyword(s):  
Social Movements ◽  
Western Australia ◽  
The State ◽  
The South ◽  
Old Growth ◽  
The Past ◽  
South West ◽  
Old Growth Forests ◽  
Heated Debate ◽  
Policy Proposals

Over the past 30 years in Western Australia (WA), there has been heated debate about the future use of the remaining karri and jarrah forests in the south-west of the State. This debate revolves around policy proposals from two social movements: one wants to preserve as much of the remaining old-growth forests as possible, and an opposing movement supports a continued

scholarly journals First Report of Phytophthora megasperma and Pythium irregulare As Olive Tree Root Pathogens

Plant Disease ◽  
1997 ◽  
Vol 81 (10) ◽  
pp. 1216-1216 ◽  
Author(s):  
M. E. Sánchez-Hernández ◽  
A. Ruiz-Dávila ◽  
A. Trapero-Casas
Keyword(s):  
Root Rot ◽  
Olive Tree ◽  
The United States ◽  
Damping Off ◽  
Phytophthora Megasperma ◽  
Root Rots ◽  
Foliar Symptoms ◽  
Root Pathogens ◽  
Root Necrosis ◽  
Olive Trees

Several species of the genus Phytophthora are associated with root rot and trunk cankers in olive trees (Olea europaea L.). Among them, Phytophthora megasperma has been cited as being associated with olive root rots in Greece (1). Unidentified species of Pythium and Phytophthora have also been associated with olive tree root rots in the United States. However, the status of P. megasperma and Pythium spp. as olive tree root pathogens has remained unclear. Following a 5-year period of severe drought in southern Spain, autumn-winter rainfall rates in 1996 to 1997 steadily increased in both quantity and frequency. Under these unusually wet conditions, olive trees remained waterlogged for several months. During this period, we observed foliar wilting, dieback, and death of young trees, and later found extensive root necrosis. In 46 of 49 affected plantations surveyed, P. megasperma was consistently isolated from the rotted rootlets, particularly in young (<1- to 10-year-old trees) plantations. This fungus was not detected on plant material affected by damping-off from several Spanish olive tree nurseries. The opposite situation occurred with P. irregulare. This species was not associated with rotted rootlets in the field. In contrast, it was consistently isolated from necrotic rootlets from young olive plants affected by damping-off. These plants were grown in a sand-lime-peat soil mixture under greenhouse conditions and showed foliar wilting and extensive necrosis of the root systems. Pathogenicity tests were conducted with several isolates of P. megasperma and P. irregulare on 6-month-old rooted cuttings of olive, under both weekly watering and waterlogged conditions. Under waterlogged conditions, both fungal species produced extensive root necrosis 2 weeks after inoculation that resulted in wilting of the aerial parts and rapid plant death. Waterlogged control plants remained without foliar symptoms but a low degree of root necrosis was recorded. In addition, under weekly watering conditions, plants inoculated with either species showed some degree of root rot but foliar symptoms were not evident. No differences in pathogenicity were observed within the Phytophthora or Pythium isolates. Reference: (1) H. Kouyeas and A. Chitzanidis. Ann. Inst. Phytopathol. Benaki 8:175, 1968.

The ecology of a graveyard

1975 ◽  
Vol 23 (5) ◽  
pp. 803 ◽  
Author(s):  
WA Loneragan
Keyword(s):  
Western Australia ◽  
Information Analysis ◽  
Ecological Conditions ◽  
The Past ◽  
Characteristic Species ◽  
Severe Disturbance

The present-day vegetation of a cemetery at Gingin, Western Australia, is described by means of normal and inverse information analysis. In spite of severe disturbance during the past 10 years through annual burning and slashing, a well-defined floristic pattern is identifiable, even in the absence from the analysis of the two most characteristic species, Anigozanthos manglesii and A. humilis. It is suggested that whereas, in the past, parts of the cemetery were ecologically distinct and characterized by different groups of species, regular disturbance is altering these ecological conditions and causing changes in the distribution and behaviour of the species present. This changing ecology appears to be most sensitively demonstrated by the behaviour of A. manglesii and A. humilis.

Effect of long-term crop rotation and fertilisation management on soil humus dynamics in organic and sustainable agricultural management systems

Soil Research ◽  
2021 ◽  
Author(s):  
Laura Masilionytė ◽  
Zita Kriaučiūnienė ◽  
Egidijus Šarauskis ◽  
Aušra Arlauskienė ◽  
Ričardas Krikštolaitis ◽  
...  
Keyword(s):  
Crop Rotation ◽  
Agricultural Management ◽  
Management Systems ◽  
Soil Humus
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