Mango malformation disease: presence and identification of the casual organism Fusarium subglutinans in main branches of mature trees and saplings grafted with infected scions, and importance of sanitation treatments in orchards.
Lahav C., Sztejnberg A., Maymon M., Danisov Y., Freeman S.
Author Affiliation: Extension Service, Ministry of Agriculture and Rural Development, Israel.
Alon Hanotea 55 : 301-304
Abstract : The presence of F. subglutinans [Gibberella fujikuroi var. subglutinans] causing mango malformation in several orchards in Israel was determined by PCR analysis using samples from infected portions of the main branches of mango trees. In a related experiment to determine the direction of the growth of the fungal mycelium, saplings grafted with infected scion material were tested using PCR. The efficiency of sanitation treatments to control the fungal pathogen was determined in a 3-year (1998-2001) survey conducted in Ginnosar Orchard in Israel. The pathogen was detected in all samples throughout the length of the branches up to the main trunk. The majority of the fungal pathogen was observed in the grafted scions, while a few instances of fungal movement was observed below the graft union. Yearly sanitation treatments were effective in reducing the presence, spread and severity of the disease. The initial number of infected trees and trees with 2 or more flowers were 86 and 38%, respectively. In 1999, the number of infected trees rose to 97%, while the percentage of infected trees with 2 or more flowers dropped to 20%. In 2000, the number of infected trees was reduced to 34%, while the number of infected trees with 2 or more flowers decreased to ~3%.