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Osservazioni sullo stato della coltura del mirto
Full text linkL'esigenza di elaborare modelli di coltivazione del mirto deriva dal successo commerciale
dei prodotti industriali ottenibili da questa pianta, ma anche dalla contemporanea necessità di
tutelare le formazioni vegetali spontanee che costituiscono oggi il serbatoio, quasi esclusivo,
dei frutti e biomassa fogliare che le industrie utilizzano come materia prima.
In assenza di una normativa che regolamenti in modo chiaro il prelievo di biomassa dalle
piante spontanee, e la loro gestione in termini di sostenibilità ecologica, senza trascurare
l'esigenza di applicare le norme ed effettuare i necessari controlli sul territorio, la coltivazione
più o meno intensiva del mirto può contribuire a creare un volano di sostenibilità nel rapporto
tra raccoglitori e industrie
Risultati preliminari di una prova di concimazione nell'arancio «Washington navel»
No full textIn this paper are reported the results of 4-year research on the effects of differential N, P, K
treatments on young «Washington navel» orange trees.
The following treatments were compared:
A - Control;
B - Nitrogen fertilization at rate of 60 Kg/ha per year (N);
C - Nitrogen and phosphorus fertilization at rates, respectively, of 60 Kg/ha and 120 Kg/ha
per year (NP);
D - Nitrogen and potassium fertilization at rates, respectively, of 60 Kg/ha and 90 Kg/ha
per year (NK);
E - Nitrogen, phosphorus, and potassium fertilization at rates, respectively, of 60 kg/ha, 120 kg/ha,
and 90 Kg/ha per year (NPK).
The results evidenced that 4 year later the start of the research the different treatments did
not influence tree growth, while N and Mn content of the leaves was increased by NP and NPK
treatments.
No difference was found between N, NK, and NPK treatments on the average yield, that was
reduced in NP treatment and in the control trees.
As for as the fruit quality is concerned, a higher juice percentage was found in fruits from the
control trees, while total soluble solids were increased by treatments NP and NPK
A Progress report on citrus rootstocks studies in Sardinia
Full text linkThis paper reports further results of long-term research on citrus
rootstocks in Sardinia started in 1969. Two rootstocks (sour orange and
« Troyer » citrange) have been compared for « Hamlin » and « Frost Navel »
sweet oranges, and «Frost Eureka» lemon. Five rootstocks (sour orange,
« Troyer» citrange, «Rubidoux» trifoliate orange, « Orlando» tangelo, and
« Palestine» sweet lime) were also compared for « Frost Marsh» grapefruit.
The growth and productivity for all of the stock/scion combinations were
evaluated from 1973 to 1977. The results showed that both growth and
productivity of «Frost Navel» orange were better on «Troyer» citrange
than on sour orange. «Hamlin» orange productivity was also improved by
« Troyer» citrange, while sour orange increased the tree-growth. In « Frost
Eureka» lemon both growth and productivity were increased by sour orange.
The fruit quality was normally improved by «Troyer» citrange in comparison
with sour orange. The growth and fruit production of «Frost Marsh»
grapefruit were mainly increased by «Orlando» tangelo and «Palestine» sweet lime. Intermediate growth and productivity were found on sour orange
and «Troyer» citrange. The lowest growth and yield were recorded on
« Rubidoux» trifoliate orange, but it and « Troyer» citrange improved fruit
quality
A Factorial experiment onCitrusstock/scion combinations in Sardinia
Full text linkFiveCitrusvarieties ("Washington navel", "Tarocco", "Biondo comune", "Valencia" sweet
oranges, and "Avana" mandarin) on different rootstocks (sour orange, "Troyer" citrange, citremon 1449,Poncirus trifoliata"Rubidoux", "Orlando" tangelo), and at two planting distances (4x4 m, 5x5 m) were evaluated for 3 years in a factorial experiment, with a completely randomized design. Observations were made on growth, productivity and fruit quality.
Tree growth, productivity and fruit quality were affected both by variety and by rootstock and
planting distance. "Valencia" and "Biondo comune" showed the best growth and yield, and "Avana" mandarin the poorest. Several differences in fruit quality were observed in the different varieties, mostly concerning fruit weight, rind thickness, juice, TSS and T A. The
rootstock also affected growth, yield and fruit characteristics. The growth was decreased by
"Rubidoux" trifoliate orange, while the yield was slightly increased by "Troyer", "Rubidoux" and "Orlando". "Rubidoux" and citremon improved several fruit characteristics, such as rind thickness, juice, and TSS content. As the trees were still young, planting distance did not affect growth, but some small differences were found in fruit quality. The yield/tree and the
efficiency were increased by 5x5 m treatment, while the yield/ha was, on the contrary, higher in 4x4 m treatment. Finally, some interactions were found between variety and rootstock
Some factors influencing flowering and fruit-set of clementine mandarin
Full text linkA four-year research study conducted in center Sardinia on clementine
mandarin has evidenced that flowering and subsequent fruit-set can be
affected by several factors, i.e., growth substances, light intensity and temperature
before flowering. Particularly it has been shown that gibberellic
acid sprayed during flower differentiation reduced the number of flowers/
square meter of canopy,but increased the number of leafy inflorescences
and the fruit-set percentage. Alar sprayed in the same conditions increased
the number of flower/square meter and reduced the number of leafy inflorescences
and the fruit-set percentage. Low light intensity obtained by
shading trees with large cages covered with nets of black nylon decreased
the number of flowers and leafy inflorescences, but no clear effects were
found on the fruit-set percentage. Warm temperatures before flowering
increased the number of flowers/square meter, but decreased the fruit-set
percentage
Ricerche sui portinnesti degli agrumi: influenza sullo stato nutrizionale delle foglie
Full text linkThis paper reports some results concerning the influence of different
citrus rootstocks on leaf nutritional status of the scion varieties. Two
rootstocks (sour orange and «Troyer» citrange) have been compared for
« Hamlin » and «Frost Navel» sweet oranges, and «Frost Eureka» lemon.
Five rootstocks (sour orange, «Troyer» citrange, «Rubidoux») trifoliate
orange, «Orlando» tangelo, and «Palestine» sweet lime) were
also compared for «Marsh seedless» grapefruit.
The results showed that rootstocks appear to exert a strong influence on
the leaf mineral levels of the grafted varieties. Particularly it has been
observed that sour orange decreases N, P, K and Mg uptake, while increases
leaf Ca content.
« Troyer» citrange induces higher Mg and Cu levels, and reduces leaf
Ca content.
« Rubidoux » trifoliate orange, on the other hand, exerts a positive
influence on N and Mg uptake, and a negative influence on Ca, Na, Zn, and
Cu leaf content. «Orlando» tangelo shows a marked aptitude in increasing
N, P, K, Ca and Na leaf levels, while decreases Cu leaf content.
Finally, «Palestine» sweet lime induces on the scion leaves higher
contents of N, K, Ca, Na, and Mn, and lower Mg and Cu levels
Colturain vitrodi apici vegetativi diQuercus suberL
Full text linkThe agamic propagation ofQuercus suberL. could be useful for the genetic improvement of
the species and could have noticeable advantages in forest nursery practices.
For this purpose we have tried some experiments of in vitro cultures of tips obtained from
vigorous new shoots collected from a cork-oak grove which had been affected by fire.
The developmental stage ended with the sprouting of 25% of the tips. The two following
subcultures showed an average rate of multiplication of 3.6:1. The 82.5% of the shoots that
had been cultured gave off roots, but produced very small plants due to the poor growth of
the shoots during the previous elongation stage
Study of myrtle (Myrtus communis L.) genetic resources to promote extensive crop as integration of spontaneous harvests
No full textUses of myrtle as aromatic plant are related to essential oil extraction from leaves (for perfume and food industry) and to liqueur production by cold infusion of fruit. Myrtle uses are largely dependent on harvest from wild plants, although this seems not sufficient to support a further increase of liqueur production. To develop myrtle cultivation as an aromatic crop, investigations on germplasm variability were made. Morphological and biometric characters of ecotypes selected from spontaneous populations have been recorded to obtain a preliminary database for a further clone selection. Useful characters for the selection of good clones may be indicated in fruit mean weight, peduncle length and pulp/seed ratio
Influenza della posizione degli erogatori sulle componenti dello sviluppo e della produzione nell'arancio «Valencia»: risultati preliminari
No full textIn this study two irrigation systems (drip and microjet) and different positions of emitters were
compared in a young «Frost Valencia» orange grove.
The following irrigation treatments were set out:
- two drippers (4 l/h each) per tree at apposite distance of 1 m trom the trunk:
- two drippers (4 l/h each) per tree at apposite distance of 0.5 m from the trunk;
- two microjets (65 l/h) per tree at apposite distance of 0.2 m from the trunk.
Both the irrigation systems were able to wet a 3 m strip of soil along the rows, while thc central
part of interrows was kept dry.
Among the wet area drip irrigation induced different soil moisture pattern, since the soil moisture
percentage was greater near the emitters (more than the «field capacity») and particularly at
50 cm depth; and decreased as the distance trom the drippers increased.
The water distribution under the microjets resulted more uniform and the soil moisture reached
the highest values at 25 cm soil depth, alwais close to the emitters.
Leaf water potential and leat diffusive resistance measured at different times did not show any
symptom af water-stress, while trunk growth resulted not affected by different irrigation treatments
Light distribution oncitrus canopyaffects physiological parameters and fruiting pattern
Full text linkLight interception by the orange tree canopy during flower bud differentiation and subsequent
flowering and fruit setting has been monitored by continuous data recording from 48 silicon
cells distributed in different canopy zones. Two experimental conditions have been tested:
trees artificially shaded by a black nylon net cage, and non-shaded trees. Observations were
made on the total radiation accumulated in the different canopy zones, and they were related
to photosynthetic activity, stomatal conductance) flowering and fruiting pattern, and fruit
quality. The different light distribution affected both photosyntesis and stomatal conductance:
in fact, they were both drastically reduced in shaded trees, and a significant decrease was also
found in both shaded and unshaded trees in relation to different canopy zones. A significant
decrease of flowering and fruit setting was found from the top of the canopy to the bottom
and from outside to inside, in relation to the different amount of radiant energy availability.
Finally significant differences were found on fruit quality
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