[Agrometeorological considerations on arid and semi-arid countries]

anglais. In the different phases of their cycle the plants have specific requirements that can be met to a major or lesser extent by environment conditions. In the case such requirements are fully satisfied, the plants will grow normally; otherwise they will exhibit changes in their development and finally give lower yields. By means of meteorological investigations we can reconstruct, day by day, which have been the needs of a given plant during its cycle. This is possible in that the yield depends on weather conditions, as expressed by the formula: R = f(e, t, b...) f(T); i e. the yield (R) is a function of various edaphic (e), biotic (b), technical (t) and other factors, which in their turn are directly or indirectly conditioned by the meteorological weather (T). Once the requirements of the plants in the different phases of their cycle are known, thanks to the above formula it will be possible to determine what are the upper and lower limits which mean respectively excess or deficiency of a given environment factor. Within the range of such limits the production of the plants will be abundant; beyond them it will be scarce because of excess or deficiency of one or more factors. The knowledge of such limits will allow to determine in each area what are the probabilities that conditions favourable to the crops take place.

italien. La pianta in ogni momento del suo ciclo manifesta dei bisogni i quali possono essere o non essere soddisfatti dall'ambiente. Nel primo caso, la pianta non manifestera esigenze; nel secondo caso, manifestera delle esigenze. Mediate l'indagine meteorologica - in quanto il redimento di una pianta e una funzione composta dal tempo meteoroligico esprimibile con la seguente espressione R