Mediterranean Basin is characterized by high evapotraspirative demand of the orchards. In semi-arid conditions, where water availability is limiting, the efficient water management is an issue. This purpose can be reached reducing water supply and water consumption, thus increasing water use efficiency. The use of hail nets is a common practice for high revenue orchards. Covering materials could be multipurpose if they were used to modify the orchard microclimate according to the plant needs. The aim of this study was to investigate the effect of light intensity modulation on microclimate, plant functionality, productivity and water use on a late ripening nectarine (cv. California). Two different shading hail-nets with neutral transmissivity, high diffusivity and a shading capacity of 10 (H) and 30% (S) were evaluated. In 2017 and 2018, leaf net photosynthesis (Pn), stomatal conductance (gs), transpiration (Tr), stem water potential (Ψs), fruit growth, shoot length, productivity and fruit quality were measured. The moderate reduction of solar radiation decreased temperature and VPD increasing Ψs and Pn. Fruit growth was strictly dependent by skin transpiration and photo-assimilates downloaded in the fruit. During fruit cell expansion, fruit Absolute Growth Rate (AGR) increased with VPD till its maximum. The excessive VPD reduced AGR because of the high water imbalance in the fruit (water-in vs. water transpired) and the reduced photo-assimilation. The moderate light reduction decreased temperature and VPD within an optimum range for plant functioning and fruit growth. Productivity was 20% higher in S than in H and the opposite was observed for water consumption. Fruit size was higher in S than in H, however sugar content and the over-color were slightly affected. The use of covering nets seems to be promising. Further research should be performed to better define the degree of light reduction as well as the quality of light.
Effects of two covering nets on water use efficiency and production in California nectarine cultivar. 9th International Symposium on Irrigation of Horticultural Crops
P. Losciale;L. Gaeta;
2019-01-01
Abstract
Mediterranean Basin is characterized by high evapotraspirative demand of the orchards. In semi-arid conditions, where water availability is limiting, the efficient water management is an issue. This purpose can be reached reducing water supply and water consumption, thus increasing water use efficiency. The use of hail nets is a common practice for high revenue orchards. Covering materials could be multipurpose if they were used to modify the orchard microclimate according to the plant needs. The aim of this study was to investigate the effect of light intensity modulation on microclimate, plant functionality, productivity and water use on a late ripening nectarine (cv. California). Two different shading hail-nets with neutral transmissivity, high diffusivity and a shading capacity of 10 (H) and 30% (S) were evaluated. In 2017 and 2018, leaf net photosynthesis (Pn), stomatal conductance (gs), transpiration (Tr), stem water potential (Ψs), fruit growth, shoot length, productivity and fruit quality were measured. The moderate reduction of solar radiation decreased temperature and VPD increasing Ψs and Pn. Fruit growth was strictly dependent by skin transpiration and photo-assimilates downloaded in the fruit. During fruit cell expansion, fruit Absolute Growth Rate (AGR) increased with VPD till its maximum. The excessive VPD reduced AGR because of the high water imbalance in the fruit (water-in vs. water transpired) and the reduced photo-assimilation. The moderate light reduction decreased temperature and VPD within an optimum range for plant functioning and fruit growth. Productivity was 20% higher in S than in H and the opposite was observed for water consumption. Fruit size was higher in S than in H, however sugar content and the over-color were slightly affected. The use of covering nets seems to be promising. Further research should be performed to better define the degree of light reduction as well as the quality of light.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
