Articles
CROP LOAD AND IRRIGATION MANAGEMENT DURING THE LATTER STAGES OF RIPENING: EFFECTS ON VINE WATER STATUS, FRUIT DEHYDRATION AND FRUIT COMPOSITION OF ‘MERLOT’ GRAPEVINES
Article number
889_5
Pages
67 – 74
Language
English
Abstract
A field trial was carried out during the 2007 and 2008 seasons in a commercial Merlot vineyard in the Central Valley of California.
The goal was to study the effects of late season water deficit and crop load on vine water status and fruit composition.
All vines in the study were deficit irrigated replacing 70% of the estimated crop evapotranspiration (ETc) until fruit reached approximately a total soluble solids level of 20°Brix.
Thereafter, irrigation was increased to 120% of ETc only in one set of vines.
Within each irrigation treatment, two crop load treatments were imposed.
At veraison, vines were either unthinned or thinned to one cluster per shoot.
Irrigation during the latter part of the season significantly decreased yield losses, specially in the unthinned vines.
Vines receiving 120% ETc during the final stages of ripening had greater levels of leaf chlorophyll and reduced mid-day leaf water potential compared to vines irrigated at 70% of ETc.
However, these differences were smaller in the unthinnned vines compared to the thinned ones.
Overall, irrigation levels during the latter stages of ripening had little impact on fruit composition.
However, high crop load had a significant and negative effect on fruit color and aroma precursors.
The results of the study indicate that vine water status and yield losses due to berry dehydration during ripening are influenced by irrigation and crop load.
The goal was to study the effects of late season water deficit and crop load on vine water status and fruit composition.
All vines in the study were deficit irrigated replacing 70% of the estimated crop evapotranspiration (ETc) until fruit reached approximately a total soluble solids level of 20°Brix.
Thereafter, irrigation was increased to 120% of ETc only in one set of vines.
Within each irrigation treatment, two crop load treatments were imposed.
At veraison, vines were either unthinned or thinned to one cluster per shoot.
Irrigation during the latter part of the season significantly decreased yield losses, specially in the unthinned vines.
Vines receiving 120% ETc during the final stages of ripening had greater levels of leaf chlorophyll and reduced mid-day leaf water potential compared to vines irrigated at 70% of ETc.
However, these differences were smaller in the unthinnned vines compared to the thinned ones.
Overall, irrigation levels during the latter stages of ripening had little impact on fruit composition.
However, high crop load had a significant and negative effect on fruit color and aroma precursors.
The results of the study indicate that vine water status and yield losses due to berry dehydration during ripening are influenced by irrigation and crop load.
Authors
M.P. Mendez, L. Sanchez, N. Dokoozlian
Keywords
berry weight, cluster thinning, fruit composition, stomatal conductance, Vitis vinifera
Online Articles (79)