scholarly journals Analysis of Patterns of Pineapple Mealybug Wilt Disease in Sri Lanka

Plant Disease ◽  
1998 ◽  
Vol 82 (8) ◽  
pp. 885-890 ◽  
Author(s):  
G. Hughes ◽  
S. Samita
Keyword(s):  
Sri Lanka ◽  
Probability Distributions ◽  
Disease Incidence ◽  
Wilt Disease ◽  
Statistical Probability ◽  
Factors Affecting ◽  
Mealybug Wilt ◽  
Field Experimentation ◽  
Pineapple Mealybug Wilt ◽  
Made In

Mealybug wilt disease of pineapple has a complicated etiology, which is not yet fully understood. As a result, assessments of the disease in the field, such as those that are made in the context of evaluation of disease control methods, are usually based on symptomatology. Field assessments, based on symptoms of mealybug wilt disease, were made in the Kurunegala and Gampaha districts of Sri Lanka. These data were fitted to statistical probability distributions as a method of summarizing the spatial pattern of disease incidence. Most plots showed aggregated patterns of diseased plants, but there were some exceptions. Summarizing patterns of disease incidence by means of fitting statistical probability distributions provides a basis for significance testing in cases where factors affecting disease incidence are the subject of field experimentation. Some examples of this methodology are given.

scholarly journals First report of Pineapple mealybug wilt‐associated virus‐1 and ‐2 associated with mealybug wilt disease of pineapple in Mauritius

2021 ◽  
Vol 44 (1) ◽  
Author(s):  
A. Gungoosingh‐Bunwaree ◽  
F. Maudarbaccus ◽  
D. Knierim ◽  
P. Margaria ◽  
S. Winter ◽  
...  
Keyword(s):  
Wilt Disease ◽  
First Report ◽  
Mealybug Wilt ◽  
Pineapple Mealybug Wilt ◽  
Pineapple Mealybug

scholarly journals Comparative Evaluation of Sri Lanka Tall and Dwarf x Tall Coconut Hybrids for Tolerance to Weligama Coconut Leaf Wilt Disease in Sri Lanka

CORD ◽  
2016 ◽  
Vol 32 (2) ◽  
pp. 8
Author(s):  
S.A.C.N. Perera
Keyword(s):  
Sri Lanka ◽  
Disease Incidence ◽  
Severity Index ◽  
Wilt Disease ◽  
Lower Percentage ◽  
Close Proximity ◽  
Leaf Yellowing ◽  
Mixed Plantation ◽  
Index Value ◽  
Disease Pressure

Weligama Coconut Leaf Wilt Disease (WCLWD) is a phytoplasma disease found in Southern Sri Lanka. It is an incurable, debilitating disease resulting in yield loss and ultimate death of the palm and over 250,000 palms have been identified to be infected. Breeding coconuts for resistance is a viable option in managing incurable diseases and for this WCLWD resistant germplasm is needed. Accordingly, the objective of the current research was to investigate the comparable levels of WCLWD resistance of Sri Lanka tall and CRIC65 coconut cultivars which are favoured in Sri Lanka.          Eight coconut estates which were planted with Sri Lanka tall (SLT) and CRIC65 hybrids as a mixed plantation or in close proximity were observed. Out of them an extent of about 04 acres of one estate was selected for detailed analysis using the disease severity index developed based on the WCLWD symptoms; flaccidity, leaf yellowing and marginal necrosis of leaflets.          General observations indicated the presence of WCLWD in both SLT and the hybrid CRIC65. Marginal necrosis was at a minimal level in both the cultivars, while the other symptoms; flaccidity and yellowing scored higher values at all levels in the spiral in SLT than in hybrid CRIC65. Moreover, the hybrid coconut CRIC65 displayed lower percentage of disease incidence and significant reduction in the levels of the main symptom flaccidity.  As a result, the hybrid palms recorded significantly low disease index value than SLT. Moreover, disease incidence was observed to be low in properly managed estates irrespective of the cultivar. With the findings of the current study, coconut varieties SLGD and selected SLT which remain healthy under the same disease pressure can be recommended as parents in a breeding programme aiming at resistance/tolerance to WCLWD.

scholarly journals Bromelia pinguin (wild pineapple).

2020 ◽  
Author(s):  
Shruti Dube
Keyword(s):  
Sri Lanka ◽  
Neotropical Region ◽  
Native Vegetation ◽  
Alternative Host ◽  
Caribbean Islands ◽  
Invasive Mammals ◽  
Mealybug Wilt ◽  
Pineapple Mealybug Wilt ◽  
Pineapple Mealybug

Abstract Bromelia pinguin is a large, perennial bromeliad with spikey fronds that grow up to two metres long. It often grows in dense colonies. It is native to the Neotropical Region but has been introduced as an ornamental to Florida, Hawaii and other Caribbean islands as well as India and Sri Lanka. Though some sources consider it native to Cuba, it is also recorded as invasive, where it is invading forests and savannahs, displacing native vegetation and providing a niche for small invasive mammals. It is also an alternative host to Pineapple mealybug wilt-associated virus 2 (PMWaV-2), which threatens commercial pineapple farming in Cuba.

scholarly journals Host density dependence and environmental factors affecting laurel wilt disease incidence

2020 ◽  
Author(s):  
Robin A. Choudhury ◽  
Hong Ling Er ◽  
Marc A. Hughes ◽  
Jason A. Smith ◽  
Gretchen E. Pruett ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Density Dependence ◽  
Disease Incidence ◽  
Host Density ◽  
Wilt Disease ◽  
Laurel Wilt ◽  
Factors Affecting ◽  
Laurel Wilt Disease

scholarly journals Spatial and Temporal Incidences of Pineapple mealybug wilt-associated viruses in Pineapple Planting Blocks

Plant Disease ◽  
2010 ◽  
Vol 94 (2) ◽  
pp. 196-200 ◽  
Author(s):  
D. M. Sether ◽  
W. B. Borth ◽  
M. J. Melzer ◽  
J. Hu
Keyword(s):  
Ananas Comosus ◽  
Ratoon Crop ◽  
Virus Incidence ◽  
Central Regions ◽  
Mealybug Wilt ◽  
Pineapple Mealybug Wilt ◽  
Pineapple Mealybug ◽  
Fruit Harvest ◽  
Propagation Material

A complex of Pineapple mealybug wilt-associated viruses (PMWaVs) that can infect pineapple (Ananas comosus) is correlated with reduced yields and mealybug wilt of pineapple. The incidences of PMWaV-1 and PMWaV-2 at planting, fruit harvest, the beginning of the ratoon crop, and ratoon fruit harvest were determined for end, side, and central regions of planting blocks in eight commercial fields. Differences in virus incidence for the three regions at ratoon harvest were highly significant (P = 0.0018). Central regions of planting blocks had lower virus incidences at the time of ratoon fruit harvest. Collection of propagation material from the central regions of planting blocks will help to minimize PMWaV incidence in fields planted with this material.

STUDIES ON THE SEEDLING DISEASE OF BARLEY CAUSED BY HELMINTHOSPORIUM SATIVUM P.K. & B.

1956 ◽  
Vol 34 (4) ◽  
pp. 653-673 ◽  
Author(s):  
R. A. Ludwig ◽  
R. V. Clark ◽  
J. B. Julien ◽  
D. B. Robinson
Keyword(s):  
Disease Incidence ◽  
Infested Soil ◽  
Disease Development ◽  
Toxic Activity ◽  
Factors Affecting ◽  
Seedling Disease ◽  
Nutrient Salt ◽  
Helminthosporium Sativum ◽  
Treatment Comparisons

A standard sand – cornmeal – nutrient salt medium, for use in the production of artificial inoculum of Helminthosporium sativum, is described. This inoculum induces uniform plant disease development when thoroughly incorporated with the planting soil. The results presented clearly demonstrate the necessity of using a series of infestation levels in studies of factors affecting disease development in artificially infested soil. It is shown that considerable reliance can be placed on treatment comparisons within an experiment but that comparisons between experiments are much less accurate. The role of a toxin (or toxins) in disease development in barley seedlings has been demonstrated. The toxic activity was found to be distinct from that frequently encountered on addition of organic matter to soil. Results obtained suggest that toxin adsorption by the soil may play an important role in reducing disease incidence and severity.

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