ISSN:
0268-2605
Keywords:
Organotins
;
fungitoxicity
;
Phytophthora
;
pepper
;
cocoa
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Several triorganotin(IV) compounds and Terrazole® 35 WP were screened for their in vitro antifungal activity against three isolates of Phytophthora palmivora. Two isolates (isolates Phy. 2 and Phy. 334) were obtained from black pepper (Piper nigrum L.) and one isolate (isolate Phy. 56) from cocoa leaves (Cacao theobromae). ED50 values for radial growth of the isolates ranged from 0.09 to 1,700 μg cm-3 for the triorganotin(IV) compounds and from 3.46 to 1 227 000 μg cm-3 for Terrazole®. Diphenylbutyltin bromide exhibited the highest antifungal activity against the three isolates of P. palmivora with ED50 values ranging from 0.30 to 0.73 μg cm-3.Diphenylbutyltin bromide was equally effective against a freshly isolated virulent culture of P. palmivora (isolate Phy. 346) from black pepper leaves in Sarawak, East Malaysia, yielding an ED50 value for radial growth of 0.87 μg cm-3 and a probit-log concentration regression line slope value of 1.04. In vitro efficacy of diphenylbutyltin bromide against isolate Phy. 346 using detached healthy pepper leaves showed 40-75% infection of leaves at 100 μg cm-3 and no infection at 500 μg cm-3. Diphenylbutyltin bromide at 100 μg cm-3, however, inhibited the diameter of lesion by 43.3-73.7% compared with the untreated controls. Black pepper leaves treated with Terrazole® at 778 μg cm-3 exhibited 5.3-33.3% inhibition of lesion diameter compared with the untreated controls, where 90-100% of the leaves were infected. Concentrations of diphenylbutyltin bromide of 1000-2500 μg cm-3 caused some injury lesions on the leaves. From the results obtained, it appears that diphenylbutyltin bromide could be used as a protective spray or drench against P. palmivora infection of black pepper at 100-500 μg cm-3.
Additional Material:
6 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/aoc.590030307
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