Variation of plant growth and macronutrient uptake in grafted tomatoes and eggplant on three different rootstocks

Grafting, even for tomatoes and eggplants, can be considered a useful tool for tackling the problems ofsoil borne diseases. However, marked variations in plant vigour in relation to scion rootstock combinations are observed in field conditions. Among the mechanisms causing such variations, are those connected to plant nutrition; however, information on this is incomplete and limited mainly to the cucurbits species. Bearing this in mind, the purpose of thisstudy was to verify in which ways grafting combinationsin tomato and eggplant determine variations in plant assimilation and macronutrient uptake. Thestudy was carried out on tomato (‘Rita’ F1) and eggplant(‘Mission Bell’ F1) grafted with three rootstocks(Energy, PG3 and Beaufort) and self-grafted (Control).Self-grafted tomato plants and those grafted on intraspecific rootstocks (PG3 and Energy) were less vigorousand produced less dry epigeous biomass than plants grafted on interspecific rootstock (Beaufort).However, the converse was found in eggplant whenBeaufort was used, proving the interaction betweenscion and rootstock. Nutrient uptake per hectare differedgreatly in relation to grafting combinations, particularly with regard to phosphorous, calcium and sulphur for which the variations ranged between 100 and 300%. This variability seems related to a differing degree of nutrient absorption, expressed by varying concentrationsof these in the plant tissues, as well as tothe different plant vigour expressed by the biomassproduction.The results have allowed highlighting how, scion/rootstock combinations in tomato and eggplant can considerably affect plant growth and the content of different macronutrients; therefore, fertilizationshould take account of the different uptakes in relationto grafting combinations when grafted plants are used.

L’innesto erbaceo in orticoltura rappresenta sempre più un utile strumento al fine di far fronte alle condizioni di stress biotico e abiotico cui la coltura è frequentemente sottoposta. Il modificato assetto biologico conseguente all’uso di genotipi differenti come portinnesto rende opportuno quantificare le mutate esigenze nutritive della coltura anche al fine di migliorare l’efficienza agronomica e ambientale degli elementi nutritivi. Il numero di citazioni è espressione del contributo che tale ricerca può fornire per migliorare le conoscenze su colture altamente rappresentative dell’orticoltura in ambiente protetto.