Zucchini in new AP system

[Gary Wong]

I planted zucchini in my new AP system (2 mos old now).  I also planted zucchini in the ground about the same time.  Ground zucchini producing nice zucchini, both male and female flowers.  AP zucchini leaves are not as dark green, some turning brown, only male flowers, no female flowers.  5 tilipia and 2 comet goldfish in 50 gal tank, two 25 gal growbeds, one loop siphon and one constant flood.

Just wondering if there is something I can do to get female flowers to show up in the AP zucchini.

Thanks.

[TCLynx]

Have you given the system a dose of seaweed extract?  That can help with flowering sometimes.  But the yellowing leaves could be a few things.  Do you have results of your water tests and can you share pictures?

[Scott Westhoff]

You are most likely missing nutrients in your AP system.  You can add minerals by adding sun dried sea salt.

[TCLynx]

sea salt can add some trace elements but you have to be careful not to add so much that you make the water too salty since that can be hard on some types of plants.

[Scott Westhoff]

So seaweed extract is a better choice?  

TCLynx said:

sea salt can add some trace elements but you have to be careful not to add so much that you make the water too salty since that can be hard on some types of plants.

[TCLynx]

Not necessarily.  They are both options and if the sea salt is from a clean source and dried in a location with little/no precipitation to leach away the nutrients then it will probably be a very good choice.  But Seaweed extract is fairly easy to get too and I know it generally contains a good amount of potassium along with the trace elements and stuff good for plants.

In a new system or when I'm worried about fish health or I know I will be subjecting the fish to some excess stress (like getting new fish or having to harvest and handle fish extra) I will salt my system to between 1-2 ppt and the solar dehydrated sea salt is good for that (solar water softener or pool salt.)

If I'm just trying to boost potassium and trace elements for the plants, I'm probably more likely to use a splash of seaweed extract for each grow bed.

Scott Westhoff said:

So seaweed extract is a better choice?  

TCLynx said:

sea salt can add some trace elements but you have to be careful not to add so much that you make the water too salty since that can be hard on some types of plants.

[Gary Wong]

No seaweed extract ever.  Have added salt, but not sea salt.  I recently added a little bit of chelated iron to both grow beds.  4 tilipia and two small comet goldfish in the pot (which is in a 55 gal barrel).  I kept them separate as I was worried the tilipia would attack the gold fish.  Gold fish eating duckweed well.  Tilipia being fed tetramin that I had laying around for my guppies.  Also pictures of a darker green zuc plant, yielding great zuc's vs the AP zuc plant, no female flowers (planted same time).  Also photo of my wicking bed trial, with bok choy in it.  Oh and one more photo, of an experiment with guppies and a 5 gal bucket.  Not sure what a ton of guppies can support, but I was thinking of either 1-2 bok choy or 1 tomato plant.  I also wanted to try a sump, just to see how that goes.  Sorry, went a little crazy with the photos I guess ;)

http://s1198.photobucket.com/albums/aa454/pthawaii/AP%202-18-2012/

[Vlad Jovanovic]

Hi Gary, just about any environmental stress (high temps, crowding, water stress, lighting etc)... can affect the male to female ratios of many monoecious plants (including zucchini...usually resulting in more, or even all male flowers unfortunately...Even many uni-sex species of plants will actually morph from being a  female, to being a male if it gets bad enough. It seems to be a survival mechanism that kicks in when conditions are not too good.

I'm just guessing here (and judging from the yellowing, and necrotic leaf margins in your photos) that it is at least nutrient related. Since 1).your system is new and many new systems seem to be notoriously lacking in K. Which would also explain the necrotic margins and lesions, and 2).those are some pretty darn heavy feeders you got going on for a real new system. 3).You haven't added any MaxiCrop type 'booster' to help out a bit.