Explanation:

- Option 1: director - This word is a noun typically associated with a person leading or managing an organization, not suitable here.

- Option 2: directing - This is a verb form, suggesting ongoing management or guidance action, not applicable to the context.

- Option 3: directed - This past participle indicates action being guided, but doesn't fit the sentence contextually as it suggests passive direction.

- Option 4: directly - This adverb fits perfectly, implying the lemon crop goes straight to factories without intermediary steps.