The synthetic triazole derivative 14C-labeled BAS111 (14C-BAS111) was readily translocated throughout 8-week-old apple seedlings (Malus domestica Borkh.) within 3 days of application to roots in hydroponic nutrient solution. The majority of labeled BAS111 and total 14C activity was recovered from middle leaves and root tissues. Two metabolites of labeled BAS111 were found. Both 14C-BAS111 and metabolite 1 were recovered predominantly from leaf and root tissue and from nutrient solution. Metabolite 2, however, was found almost exclusively in root tissue. The rapid degradation of 14C-BAS111 accounts for its low efficacy in comparison with other triazole growth retardants. Chemical name used: [1-phenoxy-5,5-dimethyl-3-(1,2,4-triazol-1yl)-hexan-4-ol] (BAS111).
A. Nathan Reed and David A. Buchanan
Don C. Elfving, Stephen R. Drake, A. Nathan Reed and Dwayne B. Visser
A sprayable formulation of 1-methylcyclopropene (1-MCP; AgroFresh, Spring House, PA) was applied to ‘Scarletspur Delicious’ and ‘Cameo’ apples in the orchard 1 to 3 weeks before harvest and compared in different postharvest studies with the commercial postharvest 1-MCP fruit treatment (SmartFresh; AgroFresh) and with aminoethoxyvinylglycine (AVG; ReTain; Valent BioSciences, Walnut Creek, CA). Treated apples were held in air storage for 50 to 60 d or in controlled-atmosphere storage for 120 to 125 or 215 to 225 d. With increased concentration, sprayable 1-MCP treatments were effective at controlling flesh firmness loss and internal ethylene concentration (IEC) up to 225 d of storage as well as during a 7-d poststorage shelf life simulation at room temperature. Application closer to harvest improved the effect of sprayable 1-MCP on control of flesh firmness loss and IEC. Concentrations of sprayable 1-MCP above 90 mg a.i./L produced similar fruit effects to 1-MCP. Treatment with 1-MCP showed little effect on soluble solids concentration (SSC), titratable acidity (TA), or skin or flesh color in ‘Delicious’ but slightly increased SSC and TA in ‘Cameo’ apples. AVG applied 4 weeks before commercial harvest controlled IEC nearly as well as either sprayable 1-MCP or 1-MCP during storage, but AVG-treated fruit allowed to ripen for 7 d at room temperature after storage lost much more flesh firmness regardless of storage regime. Sprayable 1-MCP also reduced starch hydrolysis, IEC and fruit drop at harvest. Sprayable 1-MCP may offer new opportunities for effective preharvest management of apple fruit condition, storability, and poststorage fruit quality.