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Tecniche di irrigazione controllata (Prd) per la coltivazione del melo in aree a bassa disponibilità idrica
No full textEffects of partial rootzone drying and rootstock vigour on dry matter partitioning of apple trees (Malus domestica cvar Pink lady).
No full textThe effects of partial rootzone drying (PRD) and rootstock vigour on dry matter accumulation and partitioning
among leaves, shoots, fruits, frame and roots of apple trees (Malus domestica Borkh. cvar Pink Lady) were
investigated in 2005 near Caltavuturo, in Sicily. In a first field trial, trees on MM.106 rootstock were subjected
to: conventional irrigation (CI), maintaining soil moisture above 0·80 of field capacity; PRD irrigation, where
alternating sides of the rootzone received 0·50 of the CI irrigation water; and continuous deficit irrigation (DI),
where 0·50 of the CI water was equally applied to both sides of the rootzone. In a second trial, trees on M.9
or MM.106 were subjected to CI and PRD irrigation. In trial 1, dry matter accumulation was markedly reduced
by DI irrigation and to a lesser extent by PRD; PRD trees partitioned 20% less to leaves, 31% less to fruits and 24%
more to woody components than CI trees; DI trees partitioned 14% less to current shoots and 18% more to fruits
than CI and had the highest fruit:leaf ratio. In trial 2, there was no interaction between rootstock and irrigation
treatments. MM.106 induced greater leaf, shoot, frame and root dry weights (DWs) than M.9, resulting in more
vegetative growth and larger trees. PRD reduced leaf, shoot, frame and fruit DWs, while root DWs were similar to
CI, and thus PRD trees were 18% smaller than CI trees. Neither rootstock nor irrigation affected dry matter
partitioning among organs or root:canopy ratio, whereas PRD trees or trees on MM.106 showed better water
use efficiency than CI and M.9, respectively. The results show that PRD trees did not activate drought tolerance
strategies in terms of dry matter allocation that could improve acquisition of water resources, regardless of
rootstock. PRD irrigation increased above-ground dry matter partitioning towards woody components at the expense of leaves and fruits
Growth, fruit yield and quality of ‘Golden Delicious’ apple trees under fixed partial rootzone drying
No full textVegetative and productive responses of ‘Conference’ and ‘Williams’ pear trees planted at different in-row spacing
No full textThe effect of in-row spacing on the vegetative and productive performance of 4-year-old ‘Conference’ (CON) and ‘Williams’ (WIL) pear trees was studied. Analysis of digital images was used to estimate canopy growth and conformation. Fruit quality was determined by measuring fruit weight, flesh firmness, peel color, soluble solid content, and titratable acidity. WIL produced more and more efficiently than CON, especially at closer spacings. WIL canopies were generally bigger than CON canopies, and reduced spacing penalized stem growth and influenced canopy conformation. Root growth and conformation was similar for both cultivars, whereas decreasing in-row spacing reduced root dry weight, length, volume, and spread area only in WIL. Also, WIL trees partitioned more to fruit and leaves compared to CON, and increasing spacing resulted in a relative shift toward vegetative growth. CON fruit was smaller but sweeter and less acidic than WIL fruit. Increasing spacing influenced negatively WIL fruit quality parameters, with the only exception of fruit weight, which was increased. For the range of in-row spacing considered, our results indicate that WIL may represent a more efficient and competitive option than CON for high-density plantings, at least in the early stages of orchard life
Growth and biomass partitioning of Arbutus unedo, Laurus nobilis, Phillyrea angustifolia and Rhamnus alaternus seedlings under water deficit
No full textWater scarcity in the Mediterranean areas is very common and the selection of drought tolerant species is a priority for landscaping purposes in the Mediterranean areas. The objective of this study was to evaluate the effect of water deficit on growth and biomass partitioning of Arbutus unedo, Laurus nobilis, Phillyrea angustifolia and Rhamnus alaternus. Seventy-two seedlings per species were grown in the greenhouse in 4-liter pots and three water regimes were imposed starting on 6 April and until 9 June, 2010. One-third of the plants was well irrigated to maintain soil water content in the 25-35% range (CTR); a second group of plants was deficit-irrigated to maintain soil water content in the 15-25% range (MD); a third group was irrigated with a minimum amount of water to keep soil water content in the 5-15% range (SD). Toward the end of the deficit period, photosynthetic rates and stomatal conductances of all species were significantly reduced, especially under SD. By the end of April, reductions in stem elongation rate were evident in all species under SD, while stem diameter growth was affected only after mid May. By the end of the experiment, plant dry weight of all species was significantly reduced in both MD and SD treatments, with R. alaternus and L. nobilis showing greater reductions (61 and 57%, respectively) than P. angustifolia (36%) and A. unedo (21%). Water deficit generally reduced shoot:root ratios in P. angustifolia, whereas SD plants of A. unedo showed a reversed tendency mainly due to reduced allocation to roots. P. angustifolia seedlings generally exhibited the best performances even under SD, while R. alaternus and L. nobilis were severely affected by water deficit. A. unedo resulted relatively tolerant to water deficit (minor growth reductions) mainly due to its constitutional slow growth and small size
Variazioni Giornaliere Dello Stato Idrico E Del Contenuto Di Mannitolo E Acido Malico In Alberi Di Olivo Delle Cvs 'Biancolilla' E 'Cerasuola'
No full textEffects of partial rootzone drying and rootstock vigour on growth and fruit quality of 'Pink Lady' apple trees in Mediterranean environments
Full text linkWe investigated the effects of partial rootzone drying (PRD) and rootstock vigor on water relations, vegetative and productive performance of ‘Pink Lady’ apple (Malus domestica Borkh.) trees in central Sicily. In a first field trial, trees on MM.106 rootstock were subjected to: Conventional irrigation (CI), maintaining soil moisture above 80% of field capacity; PRD irrigation, where only one alternated side of the rootzone received 50% of the CI irrigation water; and continuous deficit irrigation (DI), where 50% of the CI water was equally applied to both sides of the rootzone. In a second trial, trees on M.9 or MM.106 were subjected to CI and PRD irrigation. PRD reduced stomatal conductance (gs) more consistently in trees on MM.106 than in trees on M.9, but maintained relative water content (RWC) to the levels of CI. DI induced greater gs reductions than PRD and lower RWC than CI and PRD. Rootstock vigor did not influence plant response to irrigation strategy. PRD induced some reduction in fruit number but no change in yields and fruit quality compared to CI, whereas DI reduced fruit size and marketable yields. Significant reductions in shoot and leaf growth were induced by DI, whereas only leaf growth was affected by PRD. Our observations indicate that responses induced by PRD are due to a combination of the amount and way of applying water, and not just to reductions in irrigation volumes, suggesting a possible use of PRD for increasing apple water use efficiency in Mediterranean environments
Performance vegeto-produttiva di alberi di melo 'Pink Lady' innestati su M.9 e MM.106 e sottoposti ad irrigazione di una porzione dell'apparato radicale
No full textProductive and vegetative responses of 'Gala' and 'Fuji' apple trees under controlled irrigation strategies
No full textWe investigated the productive and vegetative responses of ‘Gala’ and 'Fuji' apple (Malus domestica Borkh.) trees to deficit irrigation and partial rootzone drying under the dry climate of central Sicily. Soil water tension (SWT), stomatal conductance, yield, fruit quality, fruit growth, and shoot extension of conventionally irrigated trees (CI), where drip emitters on both sides of each tree were left open, were compared to that of partial rootzone drying (PRD) trees, where only one side of the rootzone was irrigated for the entire season (receiving 50% of the CI irrigation water), and to that of deficit irrigated (DI) trees, where drip emitters on both sides of the rootzone were delivering 50% of the CI irrigation water for the entire season. The irrigation season started on 21 June and ended on 4 Sep, 2006. In CI trees and on the wet side of PRD trees, SWT remained generally above -50 kPa (about 80% field capacity) and followed oscillations due to irrigation cycles. In DI and the dry side of PRD trees, SWT progressively decreased to values around -200 kPa. In PRD trees, wet and dry sides were alternated at intervals of about 20 days. In both 'Gala' and 'Fuji', gs of DI trees was significantly lower than that of CI trees (52% reductions) during the entire irrigation period, while gs of PRD trees exhibited intermediate levels (24% reductions). Fruit size and fruit and shoot growth rate was similar for all treatments and in both cultivars, although 'Gala' fruits of PRD trees tended to be larger than those of CI and DI, and 'Fuji' shoots stopped growing earlier than 'Gala' shoots. In both cultivars, trees of the three treatments had similar yields, number of fruits, yield efficiency, although 'Gala' trees under PRD tended to produce less than those of the other treatments. In 'Gala', fruit quality was similar for all treatments, whereas PRD and DI fruit of 'Fuji' were firmer and better colored than CI ones. This first year of observations suggests similar potential water savings without loss of yield and fruit quality using both PRD and DI irrigation strategies in 'Gala' and 'Fuji' apple orchards, although cumulative effects of deficit irrigation could preferentially penalize yields of 'Gala' trees under the climate of central Sicily
The effect of saline water on Phillyrea angustifolia L. seedlings
No full textWater limitations in the Mediterranean areas are very common and the use of saline water for plant irrigation is becoming a necessity. Salinity generally affects plant growth and physiological processes, and can eventually lead to leaf injuries and plant death. For these reasons, the selection of salt tolerant species is a priority for landscaping purposes in the Mediterranean areas. The objective of this study was to evaluate the effect of saline water on Phillyrea angustifolia plant performance. Seventy-five rooted cuttings were grown in the greenhouse in 4-liter pots and irrigated for 5 months with saline water at different NaCl concentrations for two consecutive years. In 2010, 45 plants were irrigated with 0, 40 and 80 mM NaCl water; in 2011, 30 plants were irrigated with 0, 100 and 120 mM NaCl water. No signs of leaf injury were observed in any of the two years or at any NaCl concentration. On the other hand, photosynthetic rates and stomatal conductances were reduced at all NaCl concentra¬tions. Reductions in shoot elongation were significant in both years, while shoot diameter growth and dry weights were affected only by high NaCl concentrations in the second year. In 2011, plant dry weight was reduced by 52% at 100 mM NaCl and 55% at 120 mM NaCl. Roots were highly susceptible to NaCl with a biomass reduc¬tion of 64 and 66% at 100 and 120 mM NaCl, respectively. Both leaf area and dry weight were influenced by NaCl with a reduction of over 50% at 120 mM NaCl. No significant effect was observed in biomass partitioning with the exception of a decrease of partitioning to roots at the highest salt concentrations. Phillyrea angustifolia plants were able to survive to all ranges of NaCl tested but CO2 fixation and shoot elongation rates were already reduced by moderate salt concentrations
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