I heard that using HSG as an Agriculturist to get a sweet gem berry is more valuable than other fruits or vegetables.

If you __disagree__, prove me with math.

Okay, here we go...

Sweet Gem Berry, grow time: 24 days, base value: 3000, investment cost: 1000

HSG, costliest ingredient is radioactive ore which is 300g value each so additional 300 investment cost (1 ore = 1 fertilizer)

DF costliest ingredient is iridium bar which is 1000g value each so an additional 200 investment cost (1 bar = 5 fertilizer)

Point #1: HSG+Agriculturalist: 13 day grow time, so 2 harvests using the same fertilizer (and this is the only way to get 2 harvests in season). For each tile used to grow sweet gem berries, you've now doubled your harvest. So for each tile you've now increased your total investment to 2300g for a base return of 6000g, without quality taken into account... but with it being 2 harvests, that is reduced to a 1150 investment, 3000 return per berry before quality.

Point #2: DF: 24 day grow time, so only 1 harvest in season. Since you only get 1 harvest, you are using 1 fertilizer/berry for 1200 total investment per berry and tile, and again this is before quality is taken into account.

At this point, the investment per berry is roughly the same, yes? The only thing that will change our equation is the quality of the berry... and only 1 of the 2 got any fertilizer to increase the quality, so that one's going to win out, per berry, every time. DF is the way to go. In fact,

*ANY* fertilizer that increases quality will get a better return per berry every time.

However, you might be not be looking at the per berry return... you might be looking at the return per tile, and getting double the harvest, no matter the quality, is more valuable than increasing the quality, because the absolute

*best* that quality can do is double your return (edit to add: and that can't happen unless you're using DF, but here we're already using HSG), and you've already done that. Quality is gravy at this point... but that's only on a per tile basis.

The specifics of the math don't actually matter. If you have limited space and are only growing in season, Agri+HSG is the way to go... but by the time you have HSG... you already have the Greenhouse and Ginger Island, which means you shouldn't have limited space. If you have the Greenhouse and Ginger Island, your best return for Sweet Gem Berries can be nothing other than Deluxe Fertilizer.