Ricerche sulla flora infestante delle colture in Italia

Summary

Studies on the weeds of cultivated land in Italy. IV: Weeds of a small farm near Montecatini Terme.

In the first part of this researche, the author gives the chief climatic data of the Montecatini Terme zone together with pedological informations about the stations offered by a small farm on which biological and statistical investigations are conducted.

All weeds (241 species) found on the area of the small farm are listed. For each species is indicated Raunhiaer's biological form, its occurence in cultivated fields or in path lanes, graves and fences.

The most of them are Therophytes (55%) and Hemicriptophytes (30%). Scarcely represented are the Geophytes (8,33%), Chamaephytes (3,75%), Phanerophytes (2,92%). Therophytes increase very much (till 78%) if only are considered the species which occur in cultivated ground.

In the second part of the work is conducted a bio-statistical study on the weeds behaviour in eight fields. Once a month, on thiese fields, statistical relieves have been made after Raunkiaer's method. The results are condensed in graphics in which, besides the percent frequences of the various weeds, are also reported the various biological stages, the types of root-system and the influence of the tillages.

Follows an examination of the weeds which have been found in the various cultivations (wheat, patatoes, corn, legumes ecc). The most important weeds (36 species) are, then, biologically and phyto-geografically classified in accordance with Korsmo's and Eig's systems, respectively. Of these weeds 81% are «seed plants» and 19% are «wandering plant» 52,7% belong to «liason group», 36,1% are polychorous or adventicious, 11,2% belong to mediterranean Element. «Stationary plants» are missing, it depends upon the fact that there are only annual crops.

At last, for the most important weeds, details are given about germination, blossoming and dissemination time, their relations with crops, their occurrence in the low or in the high part of the farm.

For a resume, conclusions are as follow:

1^°) The slope of the ground influences weed distribution on the fields of the farm; many of them (specially the winter-spring species) prefer cool fields of the low part of the farm, so that the high one is infested by a relatively small number of weeds;

2^°) the greatest number of weeds is found in the fields in spring time;

3^°) annual plants are prevailing over perennial ones;

4^°) the most infested crop is weat, the least is potatoes;

5^°) Variations of winter precipitations and, sometimes, of the sowing time may influence gravity of infestation by weeds.