Marbling disease of 'Nanas Johor' Peninsular Malaysia

Lim W.H., . Marbling disease of 'Nanas Johor' Peninsular Malaysia. pp. 25-32. ISSN 0127-7944

Some research findings on marbling disease of 'Nanas Johor' were presented. Disease incidence was observed to range from 0 percent to 48 percent. Yellow and white bacteria were consistently isolated from diseased fruitlets. The yellow bacteria were identified as Erwinia herbicola var. ananas. Inoculation studies confirmed that both types could reproduce marbling symptoms. Large fruits weighing 2-3 kg had higher disease levels (e.g. severity of 5-12 infected fruitlets per fruit) than smaller fruits weighing 0.8-1.4 kg (e.g. severity of 0.2-2.3 infected fruitlets per fruit). Increasing the planting density from 35 880 plants/ha to 95 990 plants/ha resulted in significantly smaller fruits and significantly less marbling. The use of high urea levels (e.g. 4 percent) in ethephon for flower induction resulted in significantly higher marbling disease incidence. This was probably due to the damage of the protective trichome layer thus paving the way for bacterial entry. Attempts to control marbling by liquid fertilizer sprays on the fruit and by increasing potash application to the plants were unsuccessful. However applying certain plant growth regulators (e.g. ethephon) on the fruit increased fruit acidity and reduced marbling severity. The stage of fruit ripeness influenced disease severity - unripe fruits (pink bract stage) had significantly less disease than ripe fruits. Recommendations for the control of marbling disease on 'Nanas Johor' were discussed.

Full text available from:

Abstract

Some research findings on marbling disease of 'Nanas Johor' were presented. Disease incidence was observed to range from 0 percent to 48 percent. Yellow and white bacteria were consistently isolated from diseased fruitlets. The yellow bacteria were identified as Erwinia herbicola var. ananas. Inoculation studies confirmed that both types could reproduce marbling symptoms. Large fruits weighing 2-3 kg had higher disease levels (e.g. severity of 5-12 infected fruitlets per fruit) than smaller fruits weighing 0.8-1.4 kg (e.g. severity of 0.2-2.3 infected fruitlets per fruit). Increasing the planting density from 35 880 plants/ha to 95 990 plants/ha resulted in significantly smaller fruits and significantly less marbling. The use of high urea levels (e.g. 4 percent) in ethephon for flower induction resulted in significantly higher marbling disease incidence. This was probably due to the damage of the protective trichome layer thus paving the way for bacterial entry. Attempts to control marbling by liquid fertilizer sprays on the fruit and by increasing potash application to the plants were unsuccessful. However applying certain plant growth regulators (e.g. ethephon) on the fruit increased fruit acidity and reduced marbling severity. The stage of fruit ripeness influenced disease severity - unripe fruits (pink bract stage) had significantly less disease than ripe fruits. Recommendations for the control of marbling disease on 'Nanas Johor' were discussed.

[error in script]

Item Type:	Article
Additional Information:	1 col. plate; 5 tables; 15 ref. Summary (En Ms)
AGROVOC Term:	ANANAS COMOSUS
AGROVOC Term:	ERWINIA
AGROVOC Term:	FRUTAS
AGROVOC Term:	MALASIA PENINSULAR/ SINTOMAS
AGROVOC Term:	MEDICION
AGROVOC Term:	ETEFON
AGROVOC Term:	ESPACIAMIENTO
AGROVOC Term:	ACIDEZ
Depositing User:	Ms. Norfaezah Khomsan
Last Modified:	24 Apr 2025 05:56
URI:	http://webagris.upm.edu.my/id/eprint/20242

Actions (login required)

View Item