South African Avocado Growers ’ Association Yearbook 1994. 17:49-52 CONTROL OF BLACK SPOT OF AVOCADO BY ORGANIC AND INORGANIC FUNGICIDES

Several organic and inorganic fungicides and different methods of application were evaluated for control of black spot and sooty blotch in an attempt to decrease visible spray deposits on avocado fruit at harvest. Treatments were applied on two dates, i.e. during November 1992, and January 1993. Applications of copper oxychloride (255g a.i./100 ℓ) at the first date, followed by either copper oxychloride (170g a.i. /100 ℓ), copper ammonium carbonate, or cyproconazole at the second date, controlled black spot and sooty blotch effectively, and caused less visible spray deposits when compared to coppe roxychloride (255g a.i./100 ℓ) applied at both dates. Application of triadimenol EC stem injections at both dates also controlled black spot and sooty blotch effectively while causing less visible spray deposits when compared to application of copper oxychloride (255g a.i. / 100 ℓ) at both dates. UITTREKSEL Sekere organlese en anorganiese swamdoders en verskillende toedieningsmetodes is geëvalueer vir beheer van swartvlek en roetvlek in 'n poging om sigbare spuitneerslag op avokadovrugte met oes te verminder. Behandelings is toegedien op twee datums; gedurende November 1992, en Januarie 1993. Toedienings van koperoksichloried (255g a.b. / 1001) tydens die eerste datum, gevolg deur koperoksichloried (170g a.b. / 100 I), koperammoniumkarbonaat, of cyproconazole tydens die tweede datum, het swartvlek en roetvlek effektief beheer, en minder sigbare spuitneerslag veroorsaak wanneer vergelyk met koperoksichloried (255g a.b. /1001) toegedien tydens beide datums. Toediening van triadimenol EC staminspuitings tydens beide datums het ook swartvlek en roetvlek effektief beheer terwyl minder sigbare spuitneerslag veroorsaak iswanneer vergelyk met toediening van koperoksichloried (255g a.b. / 1001) tydens beide datums