Physiological efficiency during the vegetative stage of tomato crops developed from magnetically treated seeds

The study of the effects of magnetic seed treatment (MST) has garnered significant attention from scientists due to its positive results in seed germination and seedling establishment. Few studies have comprehensively evaluated developmental parameters during the plant's vegetative stage. This study aimed to analyze tomato plants developed from magnetically treated seeds during the vegetative stage in terms of i) physiological responses, ii) growth dynamics, iii) correlation between physiological variables, and iv) the contribution of the technique compared with the performance of a highly commercial cultivar. There were 225 experimental units and three experimental groups with 75 plants each. Treatment one (T₁) included plants developed from magnetically treated low-cost seeds; control 1 (C₁) included plants developed from the same low-cost seeds without magnetic treatment (MT), and a secondary control (C₂) was included with plants developed from high-cost seeds without MT to contrast the effect of MT on a low-cost seed with the performance of a high-cost one. Each plant was measured twice a week for leaf area, stem diameter, height, number of leaves, and chlorophyll content. A longitudinal study, using a repeated-measures design over time, was complemented by a correlational cross-sectional study through principal component analysis. A longitudinal study showed that magnetic treatment continuously modified the structure and biomass accumulation of plants throughout the vegetative stage. Plant height, stem diameter, and leaf number were directly and independently correlated with time, whereas chlorophyll content and leaf area were time-dependent. The effect of MST persists and improves the physiological responses of tomato plants up to the vegetative development stage. MST changes the growth dynamics of T₁ compared to C₁. Lastly, the physiological performance of plants generated from magnetically treated low-cost seeds was superior to that of plants generated from seeds without MST, and it closely followed the trend of the highly commercial cultivar, C₂. To ensure the viability of MST as a biotechnological tool applicable to agriculture, future work should include the analysis of the subsequent phenological stages of the plants and determination of crop yield.