Hi all,
Anyone know what this problem is with my tomatoes, and how to treat it? Seems to affect the lower leaves more than the upper.... But accompanied by systemic yellowing and discoloration, as seen in photos.
All my plants are well fertilised with Yates tomato thrive, according to instructions, and grown in good soil mix with slow release fertiliser added.
Many thanks for your advice.
Purple spots on leaves?
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It may be one of two things: Spotted wilt or bacterial spot. Wilt is a virus vectored by thrips or other disease caring bugs. Prevention is to do a very good clean-up of the garden from the year before and to keep the area weed free. Mulching under and around the plants help greatly. Bacterial spot is the result of wetness on the leaves allowing the bacteria to thrive. Refrain from overhead watering. Lots of rain or heavy dew will also be a factor that nothing can be done about. Again, mulching is key. Also keep the leaves from being in contact with bare soil. There are fungicides but they don't cure or fix the problems but keep the diseases from spreading.
As a side note, too much fertilizer often reduces production by encouraging foliar growth at the expense of fruit numbers and size. Too much fertilizer also increases stress on a plant by increasing foliar growth so quickly it is more susceptible to disease.
As a side note, too much fertilizer often reduces production by encouraging foliar growth at the expense of fruit numbers and size. Too much fertilizer also increases stress on a plant by increasing foliar growth so quickly it is more susceptible to disease.
Thanks Paul. Based on your description, I'm guessing bacterial spot, as we've had a lot of humidity and rain. Plants are not overfertilised, and are seeing fruit relatively well, although a lot of flowers withering, again in assuming to heat and humidity.
I been quite vicious removing all the leaves like this on the whole lot of them. Is there anything else I can do, organically, to deal with this? You say mulching is the key, but these plants are all in large containers, with a thick layer of eggshells on top of the soil...should I be doing anything else? Thanks for the advice. I'm only a novice!
I been quite vicious removing all the leaves like this on the whole lot of them. Is there anything else I can do, organically, to deal with this? You say mulching is the key, but these plants are all in large containers, with a thick layer of eggshells on top of the soil...should I be doing anything else? Thanks for the advice. I'm only a novice!
Mulch for containers would be anything to keep the leaves from contact with the soil. Grass trimmings that have not been chemically treated, straw, even newsprint. My experience with container tomatoes is that the plants are smaller with smaller and less fruit, but really handy to have on a deck, porch or patio. Heat and humidity will cause blossom drop, so if during the hottest part of the day the plants may need to be shaded if possible. With lots of rain it is suggested the fertilizer be replenished every ten days or two weeks with a liquid plant food that contains little nitrogen...like a 'bloom booster' type with a formula of 8-20-20 or similar. The plant food will wash out in a container with rain or watering after a while.
These are being grown in containers?. It looks like a nutrient deficiency like Magnesium which will cause yellowing and necrotic spots on the lower leaves first and then they usually fall off.
I would try planting in potting mix, not soil. A mix made with peat moss and perlite with no more than 20% compost or at most only a couple of handfuls of vermicompost. Use a different fertilizer. I use 9-12-12 plus micros from Expert but any slow N complete fertilizer will do. I put 1/2 cup of fertilizer in the pot mixed with the potting mix. I plant tomato seedlings deep. Fertilize with 1 tbl of the same fertilizer at first flowering, when the tomatoe starts forming fruits, and monthly thereafter. Determinate tomatoes need at least a 5 gallon container, and indeterminate tomato at least 15 gallons. Organic needs a pot that is at least 26 gallons to have a large enough soil community to feed the plant. Otherwise you will need to supplement weekly with fish emulsion and probably some micros as well.
I would try planting in potting mix, not soil. A mix made with peat moss and perlite with no more than 20% compost or at most only a couple of handfuls of vermicompost. Use a different fertilizer. I use 9-12-12 plus micros from Expert but any slow N complete fertilizer will do. I put 1/2 cup of fertilizer in the pot mixed with the potting mix. I plant tomato seedlings deep. Fertilize with 1 tbl of the same fertilizer at first flowering, when the tomatoe starts forming fruits, and monthly thereafter. Determinate tomatoes need at least a 5 gallon container, and indeterminate tomato at least 15 gallons. Organic needs a pot that is at least 26 gallons to have a large enough soil community to feed the plant. Otherwise you will need to supplement weekly with fish emulsion and probably some micros as well.