Verse 62 clarifies that these events are related to the last days. This is the last time that the Lord will attempt to gather the righteous, for after this final gathering will come the destruction of the wicked.
To assist in this great final task, the Lord sees that both the magnitude of the task and the time available will require more labor that that of the servant, and so verse 61 calls in other servants to assist in the task of this final gathering together. These are the missionaries on the latter day, both those called formally and those whose efforts effect missionary work without the formal calling.
These verses also refer to the "natural fruit." In other parts of the allegory, the fruit may be good or useful, but is not described as "natural." Similarly, the use of "natural has been as a contrast between good and evil. While the "natural" fruit is certainly good, there appears to be a greater meaning here, as this natural fruit is better than any other. In this context, it is the gospel truly understood and lived. The ability of the children of man to be good is greater under the gospel than any other way. although mankind may certainly be good when the gospel is not present. It is this superior "goodness," this perfection through the gospel, that is the focus in this verse.