Morpho-physiological adaptations in grafted tomato plant under concomitant infestation of Fusarium oxysporum and Meloidogyne incognita

This study evaluated the impact of rootstocks, scions, and their interactions on tomato growth, physiology, yield, fruit quality, and disease resistance under Fusarium-nematode infested conditions. At early stages, nongrafted scions (R0) showed higher plant height (up to 28.56 cm at 60 DAT), but at final harvest, grafted plants with RB5 rootstock reached the greatest height (146.25 cm) compared to RB3 (144.79 cm) and R0 (142.42 cm). RB5 also significantly increased leaf area (33.70 sq. cm with polyhouse LC scion) and leaf relative water content (71.25%), outperforming RB3 and non-grafted plants. Carotenoid content peaked at 1.35 mg/g in RB5 × Pusa Ruby, and chlorophyll content reached 2.95 mg/g in RB5 × Polyhouse LC. Yield attributes were highest with RB5: 6.76 trusses per plant, 45.73 fruits per plant, average fruit weight of 50.67 g, and total fruit yield of 257.66 q/ha, surpassing RB3 and R0. Fruit quality improved with RB5, showing highest total soluble solids (5.80 °Brix) and ascorbic acid (20.25 mg/100g), while acidity remained stable (~0.31%). Disease parameters revealed RB5 strong resistance, with the lowest root galls (12.50), egg masses (7.17), soil nematode population (41.85/200 cc), and fusarium wilt incidence (27.50%), compared to high susceptibility in R0 (galls 124.42, egg masses 104.25, nematodes 284.55, wilt 91.67%). Scion effects were less marked and interactions mostly nonsignificant, indicating rootstock RB5 as the key factor for enhanced growth, yield, quality, and disease tolerance in nematode-infested conditions.