Effects of irrigation, 1-methylcyclopropene (1-MCP) and cold storage temperature on quality of 'hass' avocado fruit

Thesis (M.Sc. (Horticulture)) -- University of Limpopo, 2020

The South African Agricultural Sector has a mandate to reduce water use so that water can be available for other economic sectors. Thus, various water saving techniques must be continuously investigated in agricultural production to find efficient water use technique that saves water without compromising fresh fruit quality. Therefore, combined effect of irrigation method, 1-methylcyclopropene (1-MCP) and cold storage temperature on postharvest quality of ‘Hass’ avocado fruit was evaluated. Postharvest attributes of fruit colour, flesh firmness, ripening percentage, respiration, weight loss, body rot, stem end-rot, vascular browning, chilling injury and electrolyte leakage were assessed for 2 x irrigation methods [Full irrigation (FI) and Partial root-zone drying (PRD)], 2 x 1-methylcyclopropene (300 ng/L 1-MCP and untreated) and 2 x storage temperature (2.0 and 5.5°C) treatments. An interaction between the three treatments did not significantly (P > 0.05) influence fruit colour, flesh firmness, ripening percentage, fruit weight loss, body rot, stem end-rot, vascular browning, chilling injury and electrolyte leakage. Their combined effect was only significant (P = 0.019) on ‘Hass’ fruit respiration rate. The combination of full and PRD irrigation, 1-MCP and low storage temperature (2.0°C) did not negatively affect fruit quality. However, fruit stored at 2.0°C without 1-MCP treatment were affected by chilling injury when compared with fruit stored at 5.5°C. In conclusion, due to the inconclusiveness of results obtained, further studies, on the effect of these treatments especially under 5.5°C storage temperature should be carried out prior recommending the combination treatment for export markets.

Agricultural Research Council-Tropical and Subtropical Crops (ARC-TSC) and Agricultural Sector Education Training Authority (AgriSeta)