Combined Effects of Grafting and Vermicompost on Nutrient Composition in Eggplant under Drought Stress and Its Correlation with Yield

Abstract

Drought poses an increasing threat to global food production, necessitating sustainable agricultural practices to reduce yield and quality losses. In this study, the synergistic effects of grafted seedlings and vermicompost-V on the nutrient content of eggplant plants and their relationship with yield were investigated. The study was carried out with eggplant seedlings (grafted-G) and non-grafted-NG) in pots containing vermicompost-V (V₀: 0%, V₁: 1%, V₂: 2%, V₃: 3%) under three different drought levels (100% irrigation-, 70% irrigation, mild drought stress -MS) and 30% irrigation, severe drought stress-SS) as irrigation. The findings showed that the interaction of ‘grafting x vermicompost x drought’ created statistically significant differences in terms of N, P, K, Mg, Fe, Cu and Mn contents. Higher increases were observed in grafted plants under stress compared to the control due to vermicompost application. The most striking increases were 50.56% and 45.67% for N; 110.08% and 96.59% in G x V₃  under SS conditions. In terms of P content, under SS had a 116.50% increase in G x V₃. There was an increase. In terms of K content, 115.69% and 111.16% increases were evident in MS and SS in G x V₂. However, positive correlations were observed between K and N, P and Mg; Mn and Fe and Cu; Fe and Cu. On the other hand, weak and negative correlations were determined between yield and N and K; and high positive correlations were determined between Mn, Fe and Cu. The polar heatmap with dendrogram revealed that macro (N, P, K, Mg) and micro (Fe, Mn, Cu) nutrients were clustered in different groups. While a direct relationship was observed between yield and Fe, Mn and Cu, an indirect relationship was determined with N, P, K and Mg. The findings showed that grafting and vermicompost applications increased nutrient uptake under drought stress conditions and there was a close relationship between yield and nutrient elements. The results are important in terms of revealing the positive effects of sustainable agricultural practices on plant nutrition and yield in drought.