R.M. Silva, M.I. Ferreira
As part of a comprehensive study to develop a support system for irrigation scheduling in perennial woody crops (ISIS – Integrated System for Irrigation Scheduling), a search for an appropriate microdendrometric index was performed. The studies on stress indicators were conducted on Actinidia deliciosa plants, in an automatic weighing lysimeter and in a kiwifruit orchard, in the northwest of Portugal, during 2005 and 2006. LVDT sensors were used for measuring variations in plant organ dimensions associated with plant water status, testing supporting frames and positions (trunk and branches). Comparison with predawn plant water potential and midday stem water potential showed a better performance of the microdendrometric indexes when in branches than in the trunk. Conventional indexes such as MDS (maximum daily shrinkage) and OGR (organ growth rate), showed a poor performance in independently quantifying plant water status. An analysis of the performance of the indices led to the combined index MDS (1-OGR), with good results when compared with Ψst for the lysimeter and in the orchard. Although the index MDS (1-OGR) has not been tested in other woody species, in kiwifruit it revealed to be reliable and stable, allowing to estimate continuously crop water status, with enough precision for irrigation scheduling.
Silva, R.M. and Ferreira, M.I. (2014). A NEW MICRODENDROMETRIC INDEX TO QUANTIFY WATER STATUS IN KIWIFRUIT. Acta Hortic. 1038, 43-50
DOI: 10.17660/ActaHortic.2014.1038.3
plant water status, LVDT sensor, Actinidia deliciosa

Acta Horticulturae