Stimulation of Static Electric Field and Exposure Time on Germination and Stem Tissues of Hybrid Philippine Zea mays Genotypes

The Philippines has a tropical and maritime climate that inhibits the agricultural lands from continuous production. Because industrial crops are sensitive to electrotropism, stimulating them may break the germination dormancy and improve the growth and quality but the amount of effective electric field depends on each genotype. In this study, three hybrid Philippine maize genotypes namely, NSIC CN 282, IPB VAR6, and PSB CN 97-97, were cultivated in three replicates in an electroculture system with 0.4 V/cm electric fields. Four treatments were employed: 5 minutes daily (T5), 10 minutes (T10), 15 minutes (T15), and control. Germination rate of each genotype was modeled using 5-gene genetic programming. To verify the impact of the electric field to plant tissue, morpho-anatomical microscopy was performed. Longer exposure time to a static electric field (T10-T15) resulted in more basal roots, longer and heavier root and shoot systems. T15-treated seedlings exhibited an advanced proliferation in stem and parenchymal tissue thickness. Also, T15-treated seedlings were observed to have more dominant and thicker xylem and phloem vessels that biologically allow the ease of water transport and sugar mobilization from leaves to other parts of the plant system, thus, accelerating growth. NSIC CN 282 and PSB CN 97-92 are more sensitive to electric field stimulation than the IPB VAR6. Based on the findings, the germination is not completely and directly relational to the growth after two weeks of cultivation but having high germination score revealed to be a relatively good determinant of root and shoot quality.