A Chinese seller is guaranteeing me that GA3 20% Tablet, water soluble at about $1.5 will increase yield and health if sprayed every 2 weeks on folia (on the condition that the other elements are enough - N P K water and sunshine).

He says I should buy a few and try, if I'm not convinced, I should not buy anymore. He is that confident

But I also read somewhere that such PGRs makes your plants inorganic.

Fortunately for you, an overdose of GA produces outstanding, albeit bad, effects on most plants (an exception is aroids). These effects include a lengthening of stems and petioles, so much that the plant topples over under its own weight. I said "fortunately" because you can use an overdose to test whether your product is real.

Unfortunately for me, PGRs such as Diethyl aminoethyl hexanoate, Sodium Nitrophenolate, 2-(3,4-dichlorophenoxy) triethylamine and brassinolide do not produce outstanding effects when overdosed on the vast majority of plants therefore I cannot easily test whether I got what I paid for.

Since originally posting, DA-6, 25 ppm, sprayed tomato plants had the first ripe fruit. DA-6, 25 ppm, soil drenched lemon seedlings are larger. And, DA-6, 250 ppm (an overdose), sprayed canna 'Pink Sunburst' produced tiny leaves. Same effect for 0.5 ppm brassinolide. Canna 'Pink Sunburst' is the only sensitive canna, For my four other canna varieties, there is no effect at any concentration.

Well, I read some university research which showed that GA3 increases Tomato yield. That was what prompted my research that landed me on the site of the Chinese seller.

Google:

1. Effect of Gibberellic Acid Spray on Performance of Tomato

2. Effect of Different Plant Growth Regulators on Growth and Yield of Tomato

3. OUTCOME OF GA3 IN SHADY AREA ON PLANT GROWTH, YIELD AND

QUALITY ATTRIBUTES OF TOMATO

Yes, also GA in combination with 4-CPA:

http://www.banglajol.info/index.php/PA/article/viewFile/24512/16632