Influenza dell'intervento irriguo sul ciclo produttivo dell'olivo: nota 2.: influenza del regime idrico sulla biologia floreale e sui caratteri morfo-qualitativi dei frutti

An irrigation trial was carried out on the Ascolana tenera table-olive variety to test the possible effects of high water volumes. The following treatments were compared: A: 20 m3/tree/season at weekly intervals; B: Il m3/tree/season at biweekly intervals; C: 8 m3 /tree/season at triweekly intervals. Percentage of aborted flowers and total yield per tree, resulted positively affected by frequent irrigations. Fruit characteristics like fresh weight, volume, fruit length and mesocarp thickness, instead were better on trees watered once every three weeks because of fruits from less yielding trees produced bigger fruits. No substantial difference was found between the first two treatments. Though the frequent watering, alternate bearing and statistically significant differences on flowering and fruit characteristics were found among the three years of experiments

Indagine conoscitiva sulla mandorlicoltura sarda

Il presente articolo illustra una breve analisi della coltura del mandorlo in Sardegna: l'isola possiede un patrimonio varietale estremamente eterogeneo, ricco di vari cultivars, oltretutto anche di un certo pregio. Le tecniche colturali impiegate nella mandorlicoltura sarda restano ancorate ad un concetto tradizionale che fa considerare il mandorlo come specie marginale. Ciò comporta una produttività estremamente scarsa ed è la causa maggiore del continuo abbandono che investe questo settore. Gli inconvenienti indicati possono trovare una valida soluzione nell'impiego di cultivars o cloni più pregiati e produttivi, allevati con tecniche agronomiche più oculate e razionalmente valide

Ricerche sullo stato nutrizionale di dodici cultivar di mandarino e mandarino-simili: nota I: variazioni di alcuni micro e macroelementi nei primi cinque anni di osservazioni

In this study leaf mineral content of twelve mandarin, mandarin hybrids, and mandarin-like varieties was determined at the beginning and at the and of the growing season for a 5 year period. The following varieties - all grafted on sour orange - were tested: clementine «Comune» - ICS/OL 1, «Carvalhal», «Page», «Nova», «Fremont», «Ponkan», «Malvasio», «Murcott», «Minneola», «Ortanique», «Fortune» and «Sampson». N, P, K, Ca. Mg, Na, Cu. Zn, Fe and Mn, were determined in mature leaves collected from non fruiting terminals. The results showed that all the varieties tend to accumulate nutritional etements in autumn rather than in spring as the trees begin to bear fruits. Significant differences were also observed among all the varieties in relation to N. P, K, Ca, Cu, and Mn leaf content

Ricerche sui portinnesti degli agrumi: influenza sullo stato nutrizionale delle foglie

This 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

Influenza dell'intervento irriguo sul ciclo produttivo dell' olivo: nota 3.: effetti del turno d'irrigazione sull'attività vegetativa e produttiva della cv «Ascolana tenera»

An irrigation trial was carried out during three years on «Ascolana tenera» olive tree variety. The following treatments were compared: A - irrigation at weekly intervals; B - irrigation at biweekly intervals; C - irrigation at triweekly intervals; D - irrigations at montly intervals; E - irrigation at intervals of five weeks. Observation on vegetative growth and on some aspects of floral biology were made. Fruit characteristics like volume, weight, thickness, lengh and width were also determined. Furthermore, mesocarp and stone thickness and the ratio mesocarpfstone were recorded. A distinct variability of the resu1ts regarding the growth and the productive behaviour of the trees was observed, though the different irrigation intervals did not always effect them. In the other hand, frequent irrigation intervals affected sto ne thickness and the ratio mesocarpfstone in a positive way

Some factors influencing flowering and fruit-set of clementine mandarin

A 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 su alcuni sistemi di allevamento del vitigno "Vernaccia": nota 1.: osservazioni sulla colatura

A 3 year research has been conducted on grapevine « Vernaccia » variety to evaluate the influence of some training systems on the flower failure percentage. Four training systems were compared: spur pruning, horizontal cordon, bilatera1 Guyot, and Sylvoz. Observations were made each year on the flower number per inflorescence, and on the flower failure percentage. The resu1ts showed a great influence of the training system on the flower failure percentage, while the number of flowers per inflorescence was mainly related to the different seasons. The highest flower failure percentage was found in spur pruned trees, the lowest in Sylvoz trained trees, and the intermediate in horinzontal cordon and bilateral Guyot trained trees

Test morfoqualitativi e chimici applicabili ai frutti di agrumi frigoconservati

A preliminary bibliographical research provided the methods to be followed for a morpho-qualitative control of refrigerated citrus fruit. The different methods were then checked in order to determine the procedures through which the qualitative aspects and their changes in refrigerated citrus fruit are best shown. The methods which can be suggested to those in charge for this type of control are then described

"San Giovanni", "San Giovanni Arrubia" e "Di Luglio": tre cultivar precocissime di melo del germoplasma autoctono

San Giovanni, San Giovanni Arrubia and Di Luglio, are three very early ripening apple cultivars from the local germplasm which can be harvested since the second half of June. Fruits of San Giovanni and San Giovanni Arrubia were harvested the 20th of June, while those of Di Luglio the 2nd of July. Fruits were stored at 20De and 75% RH for a 15-days period. Respiration activity and ethylene production rate, together with chemical and sensory characteristics are reported. Data analysis showed a very high metabolic activity common to the three cultivars and the occurrence of water core, especially in San Giovanni and Di Luglio. Amongst the three cultivars San Giovanni Arrubia is the only one that, for physiological and sensory characteristics, could have commercial interest. La San Giovanni, la San Giovanni Arrubia e la Di Luglio, sono tre cultivar di melo del germoplasma autoctono della Sardegna a maturazione precocissima, che possono essere raccolte tra la seconda e la prima decade di luglio. In questa nota sono descritti gli aspetti metabolici (attività respiratoria e produzione di etilene) e le caratteristiche chimiche e sensoriali alla raccolta, avvenuta il 20 giugno 1998 per la S. Giovanni e la S. Giovanni Arrubia, ed il due di luglio 1998 per la Di Luglio e nel corso di un periodo di shelf-life di 15 giorni a 20°C e 70% di UR. L'analisi dei dati ha reso evidente un'elevata attività metabolica di tutte e tre le cultivar ed un'accentuata predisposizione alla vitrescenza della San Giovanni e della Di Luglio. La San Giovanni Arrubia è l'unica che, per le caratteristiche fisiologiche ed organolettiche, potrebbe avere un certo interesse commerciale

Osservazioni sulle variazioni stagionali del contenuto di micro e macroelementi negli organi epigei delle pomacee: nota l.: melo « Golden Delicious »

In this study, some observations on «Golden Delicious» apple tree variety are reported in order to evaluate annual changes of macroelements (N, P, K, Na, Mg) and microelements (Fe, Zn, Cu, Mg) in various tree organs such as flower-buds, flowers, fruits, leaves and shoots. In flower-buds, flowers and fruits, N, P, K total amount increased during growth season; while, the percentage of such mineral elements steadily increased until full-bloom and it decreased from fruit-setting till fruit-ripening. In flower-buds Ca totai amount was nearly constant, while in flowers and fruits higher levels were reached. On the contrary Ca percentage in the same organs decreased up to fruit ripening althougth higher levels were reached during flowering. Total N and P content in leaves increased, where in mature leaves the levels rcached a steady state. Potassium behaved similarly, but it reached the constant state with lower levels. On the contrary N, P and K concentration, as percentage of dry matter, decreased; then, in mature leaves N, P, K percentage resuited almost constant until leaf-fall. In the leaves an initial increase of Ca content, both as totale amount and percentage of dry matter was recorded, followed later by a steady state. The new shoots, at the beginning of their development weer rich in N, P, K; where in mature shoots significant changes were not observed. Traces of microelcments were recorded in all tree organs