Un nuovo ospite di Sclerotium bataticola: La Lavanda

Summary

The existence of the Macrophomina Phaseoli was noticed on the roots of Lavander plants in the cultures at Cel di Nava (Riviera Ligure). The patogenicity of this microrganism in the ctiology of the Lavander decay was examined and discussed.     

Contributo alla conoscenza della Flora dei pascoli erbosi e boschivi di Monterotondo (Roma)

Summary

After having summarly described the ecological conditions of the area of the Roman Province which are studied by the author, he lists the plants collected and adds some critical remarks on the taxonomy. He gives a list of a few taxa, which must be regarded as having been found for the first time in Lazio, or are infrequent in this Province.

The author describes the vegetation of some pastures and woods by means of statistical investigations. Finaly he takes into consideration the reciprocal influence exerted by the various plant-communities.     

Prove DI Degemmazione Nel Pesco E Loro Effetti Sulla Istogenesi della Cerchia Legnosa

Summary

Tests on disbudding and their effects on the histogenesis of the wood ring. In this work the effects of hormonic character which appear during the histogenesis of the wood ring have been studied testing disbudding effects on the peach tree.

Some observations on the consequences due to defoliation are also included.

By removal of the buds, the annual ring shows a greater depth and a more marked uniformity of structure, due to an increased frequency of the vascular elements.

By removal of the leaves, the cambial activity is completely inhibited. These results are attributed to the fact that the leaves, according to the more recent hypotheses, produce the substance which stimulates the formation of the wood elements and the differentiation of the newly formed elements.

This inactive substance, produced by the leaf, would exert its action only when the buds, towards which it is directed, transform it into its active form. The removal of the buds would eliminate the centres of diffusion of the inactive substance and also its centres of activation and concentration for the coming rest period, in view of a new vegetative cycle.

As a conseguence the circulation of the inactive substance is more marked, as it is probably activated by the cambium, and its activity lasts longer, producing in the annual ring those characters peculiar to the spring wood, that is of a season in which the circulation of this substance is at its utmost.     

Studio Del Ritmo Vegetativo Di Olea Europaea L. in Messina Negli Anni 1952–54

Summary

The vegetative growth of the olive tree in Messina is described. The growth period begins at the end of March and prosecutes without interruption as late as November. The secondary wood tissue producted during summer time (from Yuly to August) is abnormal being of a parenchimatoide type. During winter there is a well defined rest period.

The cambium produces secondary wood and bark with an alternate rythm, so that in spring the wood production prevails on the liber and in autumn the opposite condition is realized.

Each phase of production of secondary conducting tissues (wood as well as bark) is followed by a phase of starch storing.

In the stem several false wood rings are produced during one year, while in the young branches each wood ring corresponds to one year.

The longitudinal growth and cork formation on the branches of the year are particularly pronounced during spring (March-May).

Cambium cells swell in a characteristic way before they start dividing and collapse during the resting periods, thickening evidently their walls, so that in winter it is difficult to distinguish a cambial cell from a parenchimatic one.

The behaviour of the vegetative growth of the olive tree in Messina is discussed on the base of the climatic characters of the region.     

Long-Time Respiration of Contaminated Soil Samples during Laboratory Storage under Different Conditions

Soil samples have to be stored during transportation and investigation in the laboratory if they are not analyzed directly at the site. Existing standards and investigations give no recommendations on handling and storage of soil materials for (eco-)toxicological investigations. The objective of this investigation was to determine if microbial turnovers and losses of volatile organic compounds mainly cause storage-dependent changes in soil samples. Furthermore, recommendations are given for storage of soil reserve samples for toxicological investigations. During 18 months of storage, the microbial respiration of six highly contaminated soil samples was determined. Physicochemical characteristics, such as contaminant and nutrient content, were analyzed before and after storage. From the investigations it can be concluded that the oxygen consumption depends on the storage temperature, organic matter content, nutrient content, and total content of toxic substances. Based on the results, a flow scheme was derived that could be a useful tool for a sequential approach to determine the storage capacity of contaminated soil samples and sites for toxicological investigations.