Abstract:
Effects of 1- methylcyclopropene (1-MCP) and gibberellic acid (GA3) on chlorophyll degradation oflime fruit cv. Paan (Citrus aurantifolia Swingle) were investigated. The experiment was divided into 3trials. In the first part, lime fruits were treated with 1-MCP at concentrations of 0, 125, 250, 500 and 1,000 ppb for 6 and 12 hrs. The fruit was stored at 20 ?C for 12 days. The results revealed that lime fruit treated with 500 ppb of 1-MCP for 6 hrs had the best appearance due to its low chlorophyll a, chlorophyll b, total chlorophyll degradation and low carotenoids and peel color as L, a, b and color index value. Although respiration rate of 1-MCP limes was reduced, ethylene production wasincreased. In the second part, GA3 was applied to the limes at concentrations of at 0, 200, 400 and 800 ppm after treatment fruits were stored at 20 ?C. The results showed that all concentration of GA3retarded chlorophyll degradation, with very small changes of carotenoids and peel color. In the thirdpart, the combination of 1-MCP at 500 ppb for 6 hrs and GA3 at 200 ppm on chlorophyll degradationwas studied. The experiment was observed at 10 oC 90+5 % RH for 70 days. It was found that 1-MCPbefore or after treated with GA3 could store the lime fruits for 70 days with a small degradation ofchlorophyll. Treated fruits with GA3, 1-MCP and the control (no chemical application) retardingchlorophyll degradation within 63, 49 and 35 days, respectively. In addition, 1-MCP, GA3 and thecombination of 1-MCP and GA3 could reduce respiration rate and chlorophyllase and peroxidase activity of the lime fruit.