Error bars for barplot only in one direction

Is it possible to adjust errorbars in ggplot2 so that they are plotted only in one direction (e.g. only upwards but not downwards)?

df <- data.frame(trt = factor(c(1, 1, 2, 2)), resp = c(1, 5, 3, 4),
                 group = factor(c(1, 2, 1, 2)), se = c(0.1, 0.3, 0.3, 0.2))
df2 <- df[c(1,3), ]

limits <- aes(ymax = resp + se, ymin = resp - se)
dodge <- position_dodge(width = 0.9)

p <- ggplot(df, aes(fill = group, y = resp, x = trt))
p + geom_bar(position = dodge, stat = "identity") +
    geom_errorbar(limits, position = dodge, width = 0.25)

An easy work-around would be to plot the error bars first:

p +
  geom_errorbar(limits, position = dodge, width=0.25) +
  geom_bar(position = dodge, stat = "identity")