Evaluation and
use of organic fertilizers from agro-food related industrial
process and domestic waste to ameliorate soil fertility and tree
nutrient uptake. Architecture, morphology and physiology of tree
root system. Root growth turnover and life span. Biochemical
aspects of lime-induced iron chlorosis. Sustainable strategies to
prevent Fe-deficiencies of fruit trees. Evaluation of natural
extract in fruit tree management. In vivo researches on biological
activity of plant derivatives (Meliaceae, Brassicaceae, Amaranthus,
etc.). Nitrogen partitioning within the tree as affected by the
timing of N application, with special emphasis on fruit quality and
storage suitability. Nitrogen uptake under root stress conditions.
Nitrogen and carbon partitioning within the fruit tree (using
environmentally friendly stable isotopes such as 15N and 13C). Time
of application for the highest fruit quality, and the lowest risk
of N losses into the ground water. The use of soil salinity and
calcium supply as a tool to increase pear tolerance to disease such
as brown spot. Agronomical and chemical evaluation of pomegranate
as a source of nutraceutic juice. Use of biochar in orchard
fertility management
Compost from municipal solid waste represents an excellent
organic fertilizer. It is cheap largely available with a potential
of promoting soil fertility and tree nutritional status. At the
same time compost allows to reach two important goals: 1) it can
replace successfully other, more expensive, mineral and organic
fertilizers such as cow manure, 2) it can increase the volume of
waste recycling as required by the Italian legislation. However it
is not completely known yet the effect of long term application of
compost on environment contamination, soil chemical and physical
properties and tree nutritional status. In particular the regular
application of organic material can increase the availability of
soluble nutrients in soil to promote a higher rate of root uptake,
with consequent improvement of vegetative growth, tree yield, and
fruit mineral concentration.
The roots system has diverse function including nutrient and
water absorption, anchorage and storage. Fine laterals roots
associated with the absorptive portion of the root system may be
replaced once or several times per year. Typically, only the finest
two orders of roots have an important role in nutrient absorption
and represent the most dynamic portion of the root system. The
application of organic matter and the consequent microbial
decomposition lead to heterogeneity distribution of nutrients in
the soil this is mainly due to the variations of release and
diffusion of inorganic ion deriving from organic matter degradation
and can be considerably high. The effect of OM on root
proliferation is not only due to the increase of inorganic
ions in the soil but it can also be associated to the presence of
humic substances released by organic matter. The addition of
organic matter to the soil can stimulate the microbial biomass and
the release of N and C, following the response named ‘priming
effect'. This response is studied in relation to soil addition of
neem cake and melia leaf derivatives.
Armillaria root rot, which can be caused by several members of
the basidiomycete genus Armillaria, occurs all over the
world on a wide variety of forest ( e.g. Abies,
Picea, Pinus, Pseudotsuga)and fruit trees
(e.g. Citrus, Juglans, Malus, Prunus,
Vitis) in a range of climates. The infection causes a
general state of suffering, with poor terminal growth and
undersized, curled leaves on major limbs. Infected peaches may
collapse suddenly during summer with most of the leaves still
attached at the plant. In peach orchards in the Po valley, where
the disease is caused primarily by Armillaria mellea (Vahl.)
P. Kumm., there is an extensive tree mortality during replanting of
orchards resulting in considerable economic losses to producers.
Since none of the available rootstock is immune and all fumigants
are scheduled for imminent phasing out, biological control of
Armillaria root rot seems to be one of the best way to go
and has been pursued for a number of years. If dead or dying roots
could be colonized by an effective competitor of A. mellea
before their removal, the extent of root colonization by A.
mellea could be reduced, thereby decreasing the threat to
adjacent trees and/or subsequent plantings. Such competitors may be
found among species of Trichoderma, arbuscolar mycorrhizal
fungi (AMF) and actinobacteria. Another strategy involve the use of
plant derivatives of Brassicaceae such as B. Juncea
or B. nigra, rich in glucosinolates that in presence of soil
moisture and the enzyme mirosinase produce isothiocianates
that are toxic for a number of pathogens, nemathodes and insects.
The aim of the following study is to evaluate the effect of
commercial products with Trichoderma and AMF and some
derivatives of Brassicaceae on root growth and A.
mellea infection in peach tree.
Lime-induced iron (Fe) chlorosis represents the most important
nutritional disorder of susceptible fruit crops especially when
cultivated on alkaline-calcareous soils which represent
approximately 39% of world soils. Fe chlorosis in crops occurs
mainly as a consequence of a scarce solubility of mineral Fe
sources in the soil and of a reduced Fe uptake by the symplast,
induced by the soil active lime fraction. Fe-deficiency decreases
leaf photosynthetic pigment concentrations, especially chlorophyll.
Recent findings pointed out physiological alterations of leaf
morphology, stomatal control, xylem vessel morphology, leaf
hydraulic conductance and leaf water potentials of chlorotic peach
leaves, indicating that Fe deficiency implies pronounced
disturbances in leaf water relations. Fe chlorosis depresses yield
and fruit quality, decreases tree vigor and shortens orchard
productive lifetime. In alkaline-calcareous soils, when quince
(Cydonia oblonga Mill.) is adopted as rootstock, pear is one of the
species most susceptible to Fe chlorosis. Although synthetic
Fe-containing compounds such as Fe-chelate (e.g., Fe-EDDHA) are
usually effective in overcoming Fe-deficiency disorder, they induce
a short-lasting re-greening effect, are expensive and represent a
risk of water table contamination. Current agriculture requires
sustainable and costeffective alternative strategies to overcome
lime-induced Fe chlorosis on susceptible crops. Preliminary reports
indicate that soil-applied aqueous extracts of some herbaceous
species (e.g., Urtica dioica L., Amaranthus retroflexus L.) may
prevent Fe chlorosis symptoms in potted pear trees also improving,
at low concentrations, the nutritional status and vegetative
growth. In addition, Amaranthus spp. (commonly pigweed) residues
mixed with exogenous iron sulphate (FeSO4) were more effective than
Fe-EDDHA in reducing Fe chlorosis and increasing plant dry matter
and grain yields in sorghum plants grown on severely Fe-deficient
soil. The aim of this study is to test the hypothesis that
soil-applied aqueous extract of A. retroflexus can be effective in
preventing Fe chlorosis of fruit trees.
Brown spot (Stemphylium vesicarium) is one of the most
important diseases affecting two of the main varieties (Abbé Fetel
and Conference) of the Italian pear industry causing heavy yield
losses. The ineffectiveness of chemical control, the increasing
resistance of the fungus to the most recent synthetic molecules
(e.g. strobirulin) along with the demand for sustainable orchard
management drive research toward integrated control strategies.
Recently, soil applied calcium chloride (CaCl2) has shown a
positive effect on the control of symptoms of brown spot in pear
leaves. This response was related to an increase in leaf calcium
(Ca) concentration. Chemical forms of Ca, such as that bound as
pectate in the middle lamella is involved in the organization of
cell wall and potentially confers strength against fungal and
bacterial infections. The objectives of this study are to evaluate
the effectiveness of soil- and leaf-applied CaCl2 on: 1) the
incidence of brown spot in pear leaves and fruits; 2) the
involvement of the fractions of Ca in the host tissues in the
relationship between host and pathogen.
Walnut and pomegranate may represent a suitable alternative to
the traditional fruit species such as peach, apple, pear etc, that
are facing persisting market problem and low price. Both fruits are
reach in functional component that make them among the nutraceutic
food. The agronomical problem along with the composition of the
fruits are among the topic studied.
