The effect of avocado sunblotch disease (ASBD) on tree morphology, fruit maturity, yield and quality of ‘Hass’ avocado in South Africa

Abstract Avocado sunblotch viroid (ASBVd) is found in many avocado-growing regions of the world, where it affects fruit yield and quality. The trees develop two types infections: symptomatic symptomless infections. Symptoms are most obvious as yellow streaks on leaves, green stems carrier do not display any such symptoms. Symptomless considered primary source disease transmission orchards. Hence, this study investigated impact ASBVd-infected tree morphology, maturity, quality ‘Hass’ avocado from 2019 until 2021. Differences were observed orchard between infected healthy trees; with medium high concentrations excessively produced flowers, lost leaves during flowering ultimately bore few to no at end season. dry matter content results showed that ASBVd did affect rate maturity fruit, matured same time. Yield counts indicated highly 83 96% lower yields compared trees. Postharvest studies significantly firmness coloured up more rapidly than fruit. Infected, non-stored also developed external rots shrivels, however, these disorders reduced stored 5 °C for 28 days. Therefore, flower overbearing shedding can be used indicators infection orchards but confirmation molecular testing required. These observations incorporated into an ASBD management strategy