Analysis of physical resistance of black grape (vitis vinivera) exposed to extremely low frequency (ELF) magnetic field with intensity of 300µT and 500µT.

Exposure to ELF magnetic field intensity more than 700 µT was proven to be able to suppress the proliferation of pathogenic bacteria, and was able to increase the resistance of tomatoes and grapes. However, it is not yet known the lowest threshold intensity of the ELF magnetic field that can increase the resistance of grapes.This study aimed to analyze the black grapes' (Vitis Vinivera) resistance exposed to a magnetic field of Extremely Low Frequency (ELF) with intensity of 300 µT and 500 µT. The research design used a completely randomized design with a sample of 5 kg of black grapes that had been stored for 10 days from harvest. Extremely Low Frequency (ELF) magnetic field exposure is generated by the Current Transformer. Samples were divided into 5 groups of 1 kg each. Control group (K), two groups exposed to an ELF magnetic field intensity of 300 µT for 60 minutes (E300.60) and for 120 minutes (E300.120), two the group exposed to an ELF magnetic field of intensity 500 µT for 60 minutes (E500.60) and for 120 minutes (E500.120).The variables studied included the physical resistance of grapes with indicators of the number of grapes that had spots, density, and pH value of the grapes. The data was analyzed by using analysis of Mann Whitney and Kruskal Wallis, data on physical conditions were analyzed descriptively. The results showed that the number of grapes that had spots in the sample group exposed to the ELF magnetic field with an intensity of 300 µT and 500 µT was higher than the control group. However, the number of grapes that had spots in the group exposed to the 500 µT ELF magnetic field was still lower than the group exposed to the 300 µT ELF magnetic field. Conclusion: exposure to the ELF magnetic field with intensity of 300 µT - 500 µT for 60 minutes and 120 minutes was still not able to increase the resistance of grapes [ABSTRACT FROM AUTHOR]