Perhaps you should try some spelling variations:
"horticulturalist" » "horticulturalists", "horticulturist", "horticulturists", "multiculturalist"
"multiculturalist" » "multiculturalism", "multiculturalisme", "multiculturalismo"
"agriculturalist" » "agriculturalists", "agriculturist", "agriculturists", "agricultureist"
"horticultural" » "multicultural"
"agricultural" » "agriculture"
"horticulture" » "agriculture"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("horticulturalist" OR "multiculturalist") OR "multiculturalist") OR "agriculturalist") OR (("horticultural" OR "agricultural") OR "horticulture")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"horticulturalist\" or \"multiculturalist\") or \"multiculturalist\") or \"agriculturalist\") or ((\"horticultural\" OR \"agricultural\") or \"horticulture\"))".
• Removing quotes may allow a broader search: (((( horticulturalist or multiculturalist ) or multiculturalist ) or agriculturalist ) or (( horticultural OR agricultural ) or horticulture )).
• Adding a wildcard symbol may retrieve word variants: (((("horticulturalist" or "multiculturalist") or "multiculturalist") or "agriculturalist") or (("horticultural" OR "agricultural") or "horticulture"))*.