Cost reduction of powdery mildew control in mango with mono potassium phosphate.
Oosthuyse S. A.
Author Affiliation: HortResearch SA, P.O. Box 3849, Tzaneen 0850, South Africa.
Yearbook - South African Mango Growers' Association 18 : 40-42
Abstract : The effect of using monopotassium phosphate [potassium dihydrogen phosphate] (KH2PO4 or MKP), a potassium-phosphate fertilizer, in suppressing powdery mildew in mango (caused by Oidium mangiferae) was investigated in 1997. MKP was applied in a spray to flowering Kent and Tommy Atkins mango trees, either alone or with conventionally used curative fungicides (Punch C [carbendazim + flusilazole], Benlate [benomyl], Folicur [tebuconazole], prochloraz, or wettable sulfur) generally at quarter strength. Unsprayed trees served as controls, and certain trees were sprayed with Bayfidan [triadimenol] at full strength. In Kent, the fungicide/MKP mixes were almost as effective as Bayfidan at full strength in reducing tree percentage of diseased inflorescences. MKP applied alone was less effective than Bayfidan in this regard. In Tommy Atkins, the fungicide/MKP mixes were as effective as Bayfidan at full strength in reducing tree percentage of diseased inflorescences. MKP applied alone was apparently slightly less effective than Bayfidan in this regard. In Kent and Tommy Atkins, the extent of mildew inflorescence colonisation was reduced by every spray. In Kent, the reduction was most marked following Bayfidan application. The results clearly show that MKP is effective in retarding the development of powdery mildew on mango inflorescences, and can thus be used to reduce the cost of powdery mildew control in mango.