I don't know that it necessarily is a problem. I certainly don't think of it as one. To be clear to anyone who reads this, I am commenting on the use of Plant Growth Regulators in commercially-produced tomato or pepper transplants for home gardeners. The use of PGRs in tomato crop field or greenhouse production is a separate issue.

For a long time, there weren't any PGRs labeled for use on edible vegetable transplants so it wasn't a real concern for any of us. (I'm not saying that maybe some growers weren't, perhaps, using PGRs off-label on vegetable transplants.... just that they shouldn't have been.) Ever since Sumagic was allowed to issued a supplemenental label that included the use of the PGR on some vegetable transplants, which was 3 or 4 years ago, the possibility has existed that anyone who purchases tomato transplants might be buying some that were sprayed with this PGR. And it probably isn't just applied by spraying nowadays, I imagine it may be applied as a drench or through a fertigation type system if one is use. I don't know of any way to know for sure if anyone is using a PGR on tomato or pepper transplants.

Oddly, research shows differing effects. Sometimes when tomato plants, for example, were sprayed with a PGR they did produce small fruit or less fruit or later fruit. However, in other research they actually showed less transplant shock and also produced earlier. So.....is the use of PGRs in veggie transplants something to worry about? I don't really think so. That is, of course, assuming the products are used appropriately and at precise dosages. If the plants get too much of a PGR product applied to them or if it is applied too often, it could have adverse effects on the plant---like a failure to set fruit early enough here in our heat, or maybe the plant would set fruit but then it wouldn't enlarge and grow well.

How worried am I about this? Pretty much not at all. The large commercial growers have the production of tomato and pepper transplants down to an exact art. They can use precisely timed applications of water and fertilizer to control growth, and they also can use specific light levels or temperatures to control the rate at which their plants grow as well. With all those methods available to them, I don't know why they'd bother using a PGR on a tomato or pepper transplant if the plant is intended to produce fruit. There's no point in increasing your input costs unnecessarily. Also, the use could have a negative effect on sales. Most home gardeners buy a transplant take it home and put it in the ground. Then, they want to watch it grow. The retail plant industry would be hurting themselves and their future sales if gardeners noticed that their plants weren't growing. If they are new to gardening, they'd be likely to blame themselves and decide they lack a green thumb and give up gardening. Why run the risk of alienating gardeners by selling them plants that had too much PGR and won't grow?

Now, I can understand why they might use these PGRs on ornamental peppers or flowering kale or something....because those are sold more as inedible/flowering bedding plants and the sellers like for them to be all pretty and precise in their sizing when they are for sale in the stores.

There have been times when people have purchased a tomato or pepper transplant that simply would not enlarge and take off and grow for weeks or even months after it was transplanted. I know we've discussed it here and wondered about it and wondered if maybe the plant was given an overdose of a plant growth regulator, but there's just no way we ever could know that for sure.

One way to avoid the issue is to purchase locally-grown, organically-grown transplants. I don't think they could or would spray a PGR on an organically-grown transplant. Most locally grown transplants are grown on a small-enough scale that they don't have to spend extra money to keep the plants short and uniform until they go to the retail stores. Why take on the expense?

If you were talking about the use of PGRs in commercial tomato crop production, then there are ways they can use the PGRs to manipulate blooming and fruit set. For a commercial grower, this could be beneficial. For example, if they could make all the fruit set at the same time and be ready to pick at the same time, then they get a bigger yield when those gigantic tomato harvesting machines pull up the plants and harvest the fruit from them. That could increase profits. I don't know if the PGRs are used that way, but I can understand why they might be.

As far as the safety of the PGRs themselves, you'd have to locate and read the MSDS for each product to see if it is classified as a possible or known carcinogen or if it is known to have other effects in animal testing. Still, to me, that would be more of a worry for the people applying the PGRs than for a casual gardener picking up and handling a few transplants.

Dawn

Dawn, thank you for your response. I enjoy your writings. I should have remembered that my tomatoes are growing fine when the weather turns good in the spring

Oldokie,

You're welcome and I am glad you enjoy my writings. I could just ramble on and on about gardening forever...and sometimes I do.

Dawn

I have purchased some tomato seedlings at Atwoods over the years that I am near certain were treated. Yet others seemed to not be treated.

Carmichaels in Bixby definitely has not treated any of the ones I have purchased there.

I hate to buy ones that are treated without knowing it. I usually get mine the first week of Mmarch and pot them up and keep them under lights for a few weeks with the goal of lots of early June fruit. This doesn't work well with treated ones.

On the other hand, the ones that I would guess are treated are still very strong and healthy looking on the Atwoods racks after even a few weeks there. By mid-April the un-treated ones are not strong and do not do as well compared to the treated ones which seem to take off but not until a few weeks after they initially show up for sale. Yet, all this is just a guess when it comes to which ones are really treated.

Scott, I bet they were treated. You can usually tell when they are just too uniformly the same size. Of course, the dead giveaway is when they don't grow.

I hardly purchase any transplants any more unless I stumble across a variety that I haven't raised from seed....like last year I stumbled across Merced at Mike's Garden Center in the D-FW Metroplex.

I wish they were required to label whether the plants are sprayed or not. I don't even see many labeled organic unless I am in a nursery that carries a lot of organic transplants.

Dawn