Increasing thickness of lineplot with ggplot2

Question

I created the following line plot using ggpubr and would like to increase the thickness of the three colored lines, but cannot seem to figure it out. Could anyone please advise on how to change the thickness of lines? Please find a subset of the data and the code for the plot. Thank you.

structure(list(Irrigation = c("Reduced", "Reduced", "Reduced", 
"Normal", "Normal", "Normal", "Reduced", "Reduced", "Reduced", 
"Normal", "Normal", "Normal", "Reduced", "Reduced", "Reduced", 
"Normal", "Normal", "Normal", "Reduced", "Reduced", "Reduced", 
"Normal", "Normal", "Normal", "Reduced", "Reduced", "Reduced", 
"Normal", "Normal", "Normal", "Reduced", "Reduced", "Reduced", 
"Normal", "Normal", "Normal", "Reduced", "Reduced", "Reduced", 
"Normal", "Normal", "Normal", "Reduced", "Reduced", "Reduced", 
"Normal", "Normal", "Normal", "Reduced", "Reduced", "Reduced", 
"Normal", "Normal", "Normal", "Reduced", "Reduced", "Reduced", 
"Normal", "Normal", "Normal"), Graft = c("B", "C", "S", "B", 
"C", "S", "B", "C", "S", "B", "C", "S", "B", "C", "S", "B", "C", 
"S", "B", "C", "S", "B", "C", "S", "B", "C", "S", "B", "C", "S", 
"B", "C", "S", "B", "C", "S", "B", "C", "S", "B", "C", "S", "B", 
"C", "S", "B", "C", "S", "B", "C", "S", "B", "C", "S", "B", "C", 
"S", "B", "C", "S"), Lfarea = c(412.65, 531.47, 498.32, 1052.09, 
865.87, 1007.27, 586.32, 457.35, 416.85, 995.63, 1189.53, 714.32, 
490.21, 504.43, 484.88, 1017.22, 847.26, 811.33, 457.03, 657.6, 
414.11, 1087.13, 926.38, 819.73, 508.07, 421.35, 502.89, 1139.59, 
969.15, 814.56, 815.18, 643.94, 708.38, 939.63, 725.23, 630.88, 
774.63, 637.85, 569.9, 939.61, 700.09, 930.13, 621.35, 549.07, 
515.87, 1251.75, 953.75, 751.64, 679.42, 580.09, 620.78, 770.68, 
807.01, 739.67, 741.88, 644.48, 535.71, 810.74, 1148.67, 612.91
)), .Names = c("Irrigation", "Graft", "Lfarea"), row.names = c(NA, 
-60L), class = c("tbl_df", "tbl", "data.frame"))

CODE:

  library(ggpubr)
  Leafarea<-ggline(newdata,x="Irrigation", 
 y="Lfarea",linetype="Graft",shape="Graft",color="Graft",palette=c("#1F78B4","#33A02C","#E31A1C"),
   add = c("mean_se"))
LF<-ggpar(Leafarea,
      main = "Leaf Area",
      font.main = c(24,"bold.italic", "black"),
      font.x = c(20, "bold", "black"),
      font.tickslab = c(14),
      ylab="Leaf area \n (cm2)",
      font.y = c(20, "bold", "black"))
LF <- LF + scale_x_discrete(limits=c("Normal", "Reduced"))