| Abstract: | On the relationship between the vegetative growth of vines and pedohydrological and climatic factors Results of a study comparing 12 test sites situated in the vine-growing area of Südbaden (SW-Germany)During the growing periods of 1972 and 1973, investigations in twelve test sites were carried out, each having vines of the ‘Ruländer’ variety and were situated in the viticultural areas of Breisgau, Kaiserstuhl-Tuniberg and Markgräflerland (Südbaden). In order to obtain a broad variation in the soil moisture content as well as in climatic differentiation, the test sites were chosen on 1) loess, which had been consolidated and terraced to a large extent (Kaiserstuhl, Tuniberg, Vorbergzone), 2) limestone and marl mixed with loess (Markgräflerland), 3) volcanic weathering material (Kaiserstuhl) and 4) a mixture of sand and gravel from the lower terrace (Oberrheinebene). Each experimental site had 30 genetically homogenous vines of the ‘Ruländer’ variety (Pinotgris). During the growing periods (hydrological summer half-years 1972 and 1973), topoclimatic and pedohydrological factors, (atmospheric and soil temperature, evaporation of a ceramic disk according to CZERATZKI, total soil water and the actual available soil moisture in the profile of the main root zone) were measured either continuously, or at weekly and fortnightly intervals. The following vegetative factors in vine development were ascertained: weight of pruning wood and topping foliage (from which the vegetative production is determined) as well as the length of three internodes. Grain size and pore space distribution were plotted for characteristic sites. In order to ascertain the soil water actually available to the plants, the total soil moisture content, measured by means of a neutron probe, was reduced by subtracting the amount of bound water, which had been diverted, according to the methods developed by HARTGE (1969) and RENGER (1972). The air capacity of soil was derived from the pore space distribution.By means of statistical evaluation, multiple linear regression and correlation calculations are discussed, taking into consideration the most significant dependent variables for ‘vegetative growth’ (weight of pruning wood and topping foliage, length of the 3 internodes of segment no. 6, and the vegetative production) in biological and hydrological relation to the abovementioned climatic and pedohydrological factors. The following relations were detected:1) Evaporation of the ceramic disk according to CZERATZKI has, generally, the most influence; therefore, with increased evaporation, the weight of pruning wood and topping foliage and consequently vegetative growth is reduced, and the length of the three internodes of segment no. 6 is shortened. 2) In both experimental years, the effectiveness of soil water proved to be the second most important influence. Increased soil water content available to plants produced an increased vegetative growth of the vines. In the relatively dry year of 1972, a greater significance in the effectiveness of soil water was noticed. With the increased soil moisture in th year 1973, the soil water was of less significance. Therefore, the effect of the air capacity of the soil on vine is indicated. Attention is drawn to further coherence between vegetative growth strength and yield development and consequently the wine quality. |
