extracting max row from data matrix

dear group, 
i have a data matrix with some replicate items with different values. I want to extract the row with max value. 

for example:

x

fruit weight
1  apple    1.3
2  apple    1.5
3  apple    1.6
4 orange    1.4
5 orange    1.6


x is a data frame. 
I want to extract unique items from fruits that has max weight. 

that is:

3  apple    1.6
5 orange    1.6

I want to be able to use apply functions. Could some one lend some help please. 

Thanks
srini