Effect of ethephon, benomyl, thiabendazole and wax on colour and shelf-life of Coorg mandarins (Citrus reticulata Blanco).

Postharvest treatments of (i) untreated control; (ii) 500 p.p.m. ethephon for 2 min; (iii) as (ii) dried + 1000 p.p.m. thiabendazole for 2 min; (iv) as (ii) dried + 1000 p.p.m. thiabendazole in 6% wax emulsion for 2 min; (v) as (ii) dried + 250 p.p.m. benomyl for 2 min; (vi) as (ii) dried + 250 p.p.m. benomyl in 6% wax emulsion for 2 min; and (vii) 6% wax emulsion for 1 min, were used on Coorg mandarins to improve colour and control spoilage. (ii) was most effective for degreening, giving 0.90 mg chlorophyll/100 g peel after 15 days vs. 2.45 in (i). Max. control of spoilage (mainly caused by Penicillium and Geotrichum), reduced wt. loss and increased % marketable fruit was obtained by (iv) and (vi) which both showed 74% marketable fruit after 15 days vs. 38% in (i). Total acidity was lowest (0.75% as citric acid) in (ii) vs. 0.90% in (i).