Pathogenic fungi and soil conditions causing root rot and wilt disease complex during acclimatization of tissue culture-derived banana plantlets [electronic resource].

Includes references.

Rhizoctonia solani and Fusarium oxysporum were isolated from banana plantlets produced via tissue culture technique showing root rot-wilt complex disease. Isolation from culture soil mixture under banana plantlets resulted in fungal isolates identical to those isolated from diseased plantlets. These isolates proved to be pathogenic to banana plants causing complex disease symptoms. In vitro test, Rizolex-T and Topsin-M at 200 ppm have completely inhibited the growth of R. solani and F. oxysporum, respectively. Recorded results proved that the main source of R. solani and F. oxysporum, the causal pathogens of root rot and wilt complex disease, was the used soil culture medium in some surveyed nurseries. In addition, measures of soil pH and water holding capacity (WHC) of cultivated soil under banana plants revealed the records of pH 3.4 and 99.3% WHC. These unfavourable growth conditions affected negatively the plant which became more susceptible to attack by the soilborne pathogens. It could be suggested that application of irrigation scheme with Rizolex-T and Topsin-M alternatively for five days each at the rate of 2 g/l irrigation water and minimizing the irrigation time to 2 hr/day at the emergence of disease symptoms could successfully be used as a control measure for root rot and wilt complex disease of banana plants in production nurseries. Key words: Banana, disease complex, F. oxysporum, R. solani, root rot, tissue culture and wilt.

Summary in Arabic.

1