Agronomic performance and characteristics of traditional tomato varieties grown with low input conditions

The adaptation to local agro-climatic conditions of traditional varieties renders them a valuable resource for low-input agriculture. This study evaluates the effects of fertilisation (100 % and 50 %) and irrigation (100 % and 75 %) doses on the agronomic performance and fruit quality of traditional tomato varieties. Flor de Baladre (FB), Muchamiel (MC), Pera Pinatar (PP), and Negro de Nerpio (NN) varieties were studied, along with two F1 hybrids (H1 and H2) obtained by crossing NN with other traditional varieties. Mongo (MO) was used as a commercial reference. All traditional cultivars exhibited superior sensory quality and achieved yields similar to MO in the control treatment (7.4 kg plant⁻¹), except for NN (lower number of fruits) and PP (smaller fruit size). FB and MC showed reduced agronomic performance in the treatment combining high fertiliser dose with low irrigation rate (100F+75I), while fruit quality improved due to concentration effects. Despite this, both varieties maintained their yield under reduced fertilisation, with FB further enhancing phenolic compound concentration (17 %). NN and H1 and H2 hybrids showed higher mineral requirements, as their yield was negatively affected by fertiliser reduction. H1 excelled under reduced irrigation treatments, maintaining its yield and improving fructose and phenolic concentration (10 and 11 %, respectively). PP showed tolerance to low in-puts, retaining its yield in all of the treatments and increasing glucose, fructose and vitamin C concentration under reduced fertilisation (12, 8 and 9 %, respectively). The variability of the response of this collection of traditional Spanish varieties represents a valuable resource for sustainable production, being each of the varieties adapted to specific low-input conditions.