Tropius

Chlorophyll
Speed doubles in sun.
Type Tier
Grass / Flying NU
Statistics
Min- Min Max Max+
HP
99
- 339 402 -
Atk
68
154 172 235 258
Def
83
181 202 265 291
SpA
72
162 180 243 267
SpD
87
189 210 273 300
Spe
51
124 138 201 221
Name Item Nature

Sunnybeamer

Leftovers / Petaya Berry Modest
Moveset EVs
~ Sunny Day
~ Solarbeam
~ Synthesis
~ Hidden Power Fire / Hidden Power Ice
68 HP / 204 SpA / 232 Spe

Sunny Day makes Synthesis recover two-thirds of your HP as well as Solarbeam only takes one turn. Hidden Power Fire is also upped, and it is needed to stop Steel types like Skarmory from ruining your fun. Add in the fact that Tropius' ability is Chlorophyll, this makes it the best moveset, but Tropius is still a lot worse than Exeggutor. Since Tropius' Special Attack is no where near that of Exeggutor's, lower Special Defense Pokémon like Skarmory would sit and take Solarbeams like nothing. Petaya Berry is an option because Tropius could use all the Special Attack boosts it can get, and with Synthesis recovering 66.7% in the Sun, there's little need for Leftovers. Hidden Power Ice does less to Steels and Grass-types (as it doesn't get the weather boost), but Salamence is probably the safest switch into Tropius, so why not get it with Hidden Power Ice? It also hits other Fliers harder than Solarbeam / Hidden Power Fire would.

Name Item Nature

SDer

Leftovers / Salac Berry Adamant
Moveset EVs
~ Swords Dance
~ Hidden Power Flying
~ Earthquake
~ Substitute / Synthesis
196 HP / 188 Atk / 124 SpD

A physical Tropius version. Tropius will have trouble sweeping anything without the Speed boost from Chlorophyll, because Tropius is pretty damn slow. This is also why Salac Berry is an option. For the last slot, Substitute would be good if perhaps Tropius was faster, and Synthesis isn't going to do too much good with Tropius's many weaknesses and the fact that there is no Sun to boost it. There are definitely better Pokémon to Swords Dance with than Tropius.

Other Options

Growth. You could try and raise Tropius' pathetic Special Attack with that, but honestly, it'll still be slow and the set up is too much with Tropius's lacking stats. You can use Leech Seed to help support Tropius, but the low Speed and mediocre defenses combined with high HP is the exact opposite of what you want in a Subseeder.

EVs

The Sunny Day versions will need Speed and Special Attack. The Swords Dancer will need Attack and HP / Defenses instead of Speed, because it'll be slow as hell anyways. Tropius' ultimate max on HP is 402, so it gets shafted for not being able to produce 101 HP Substitutes.

Opinion

Tropius is basically a poor version of Exeggutor. It cannot use Swords Dance well either. If, perchance, it had 2 more Max HP possible, it could produce 101 HP Substitutes and then have a use, but unfortunately it doesn't. 99 Base HP is very odd. Seriously, use Exeggutor for Sunny Day + Chlorophyll movesets. Tropius can have a shot in ubers at switching into Groudon Earthquake and Solarbeaming it to death or Swords Dancing up, though it stands no chance at all, and is still inferior to Jumpluff thanks to Sleep Powder, Encore, and a myriad other special condition moves.

Counters

Anything carrying Ice Beam. Even Suicune, which will be dealt a Solarbeam under Sunny Day, can survive its attacks due to Tropius' poor Special Attack and then OHKO it with Ice Beam. The Pokémon Tropius could counter with its top movesets, Water Pokémon, can easily OHKO with a non-STAB move. Pathetic. Blissey, Snorlax and other special wall Pokémon, especially Regice, can easily defeat any Tropius moveset. Any semi-decent Physical tank such as Weezing or Skarmory can and will laugh at Swords Dancing Tropius.