INCREASING PRODUCTIVITY OF ALTERNATE YEAR CROPPING SYSTEMS FOR ZESPRI® GOLD KIWIFRUIT ('HORT16A')

T.G. Thorp, A.M. Barnett
Alternate Year Cropping (AYC) is a string-assisted growing system that is used to crop a single row of vines over the combined pergola area of two rows, in every second year. Non-cropping vines are required only to grow replacement fruiting canes trained onto strings extended high above the fruiting canopy of adjacent cropping vines. In the following year, the roles are reversed; the fruiting canopy of the previously cropped vines is totally removed and the replacement cane canopy produced on the non-cropping vines is tied down, once again to extend across two rows. For ZESPRI® GOLD kiwifruit (‘Hort16A’) in New Zealand, yields of up to 18,000 Class 1 trays/ha (59.4 t/ha) have been achieved with AYC. Projects were established in 2006 to see if yields of AYC vines could be further increased by using: reflective ground covers, applying minimal pruning to retain more leaf area and closer cane spacing to give more canes and thus more fruit per vine. Reflective ground covers used for the whole growing season increased the number of flowers and fruit per cane and subsequently increased vine yields by 2,330 trays (13%) to 19,896 trays/ha (65.7 t/ha) of Class 1 fruit. Fruit weight (FW) was not affected, even with the higher crop, yet fruit also had higher dry matter concentration (DM) than fruit from control vines. Increased leaf area per vine had no apparent effect: vines with intensive summer pruning and thus low leaf area produced fruit with similar FW and DM to fruit from vines with minimal summer pruning and high leaf area. Increasing yield potential crop load by increasing the number of canes per vine reduced average FW from 108 to 100 g, so there was no net gain in yield of Class 1 trays. In conclusion, better irradiance in the existing canopy through use of reflective ground covers induced a 13% increase in yield; whereas neither increased canopy leaf area nor increased numbers of fruit per vine resulted in higher commercial yields.
Thorp, T.G. and Barnett, A.M. (2011). INCREASING PRODUCTIVITY OF ALTERNATE YEAR CROPPING SYSTEMS FOR ZESPRI® GOLD KIWIFRUIT ('HORT16A'). Acta Hortic. 913, 321-326
DOI: 10.17660/ActaHortic.2011.913.42
https://doi.org/10.17660/ActaHortic.2011.913.42
Actinidia chinensis, training systems, reflective ground covers
English

Acta Horticulturae