Regrowth of Shrubs of Elderberry Interspecific Hybrids Cut to the Ground

Vsakoletno mulčenje bezgov bi lahko nadomestilo obrezovanje, poenostavilo obiranje plodov in socvetij ter povečalo produktivnost. V raziskavi smo spremljali sposobnost obraščanja 46 različnih medvrstnih hibridov bezga (skupno 159 rastlin), ki smo jih na začetku aprila 2018 porezali do tal. Želeli smo predvideti odziv medvrstnih križancev na spomladansko mulčenje. V treh terminih smo obravnavali različne morfološke parametre, ki bi skupaj opredelili sposobnost obraščanja. V prvem terminu smo merili premer grma pri bazi, dolžino najkrajšega in najdaljšega poganjka, določali smo število poganjkov, število listov in nodijev na najdaljšem in najkrajšem poganjku ter dolžino in premer 3. internodija na najkrajšem in najdaljšem poganjku. Dolžino najdaljšega poganjka smo merili v drugem in tudi v tretjem terminu, ko smo ponovno določali število nodijev najdaljšega poganjka, spremljali prisotnost cvetenja in zalistnikov ter merili dolžino vršnega, 2. in 3. internodija pod vrhom najdaljšega poganjka pri križancih, ki so takrat že cveteli. Medvrstni križanci so se med seboj zelo razlikovali po času cvetenja, številu in dolžini poganjkov, razlike so bile prisotne tudi znotraj posameznih analiziranih križancev. Raziskava je pokazala, da nekateri medvrstni križanci ne prenesejo ali pa slabo prenesejo rez do tal. To so predvsem tisti, ki imajo le en sam poganjek. Najboljši za gojenje v kombinaciji s spomladanskim mulčenjem do tal bi bili križanci, ki imajo veliko število poganjkov, so nižje rasti in zacvetijo do polovice julija.The annual mulching of elderberry plants could replace pruning, simplify the harvesting of fruits and inflorescences, and increase productivity. For this reason, we monitored the regrowth of 46 different interspecific hybrids (a total of 159 plants), which were cut at the ground level, at the beginning of April, 2018. We wanted to predict the response of different interspecific hybrids to the spring mulching. In three different terms, we monitored various morphological parameters, which were assumed to be closely associated with the regrowth. In the first term, we determined the diameter of each shrub at the base, the length of the shortest and longest shoot (stem), the number of shoots, the number of leaves and nodes on the longest and the shortest shoots, and the length and diameter of the 3rd internode on the shortest and the longest shoots. The length of the longest shoot was also measured in the second and the third term, when we re-determined the number of nodes of the longest shoot and documented the presence of inflorescences and stipules, and measured the length of the first, second and third internode below the inflorescence base of the longest shoot, at the time of flowering. Interspecific hybrids differed from each other regarding the flowering time, and the number and length of the shortest and longest shoots. In some of the traits, there were also big differences within the analyzed crosses. Our study has shown that some interspecific hybrids do not tolerate or poorly tolerate the cut to the ground. These are, in particular, the plants with a single stem (single shoot). For cultivation based on spring mulching, the most appropriate are hybrids which have a large number of small shoots and start flowering before mid-July