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  • Author or Editor: G. S. Howell Jr. x
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Abstract

Environmental and phenological factors considered potential components of flower bud hardiness of highbush blueberry (Vaccinium australe Small) were regressed against hardiness (T50). Three multiple regression equations were derived from 1 year’s hardiness and component data on 7 commercial highbush cultivars. Factors considered in the models were air temperature, photoperiod, bud dry weight, bud moisture content, bark color, date of leaf drop and pollen tetrad formation in the field and time to 50% flowering. The standard deviations of the estimated T50 values from the actual T50’s were 1°C or less.

Open Access

Abstract

The reliability and convenience of 5 viability tests were evaluated. Growth and tissue browning were the most reliable tests, but they required considerable time and were qualitative. Triphenyl tetrazolium chloride (TTC) reduction and specific conductivity were satisfactory for grape, but TTC was not as reliable as specific conductivity for cherry and raspberry. Neither test proved satisfactory for strawberry.

A second exotherm always indicated living stems and the absence of a second exotherm accurately predicted stem death. Freezing curves for raspberry showed the stems to be 5 degrees hardier than the control growth tests indicated.

Open Access

Abstract

Application of (2-chloroethyl)phosphonic acid (ethephon) reduced fruit removal force (FRF) as much as 50% depending on concentration and time of application. Reduction in FRF allowed reduced mechanical harvesting vibration frequency which reduced damage to berries during harvest and thus increased shelf-life. Mechanical harvest was further facilitated by ethephon-induced color development and hastening of abscission which reduced the number of machine harvests required.

Open Access