Auckland
November
Q.
Hi, I had a bumper crop of Oxheart tomatoes last year from seeds I purchased from Kings. This year I had more seeds left so have another 24 for summer. In last 10 days they look very sick and I’ve actually pulled a couple out. I have attached photos, have you any idea what has happened and what the treatment is for yellow curling leaves. I would appreciate any advice you can give me I used Tui Tomato mix and Tomato food as I did last year.
Mike Gould
A.
Hi Mike, that looks like chlorosis which is a lack of chlorophyll production and the plant telling you all is not well. Chlorosis can be caused by a number of things - sudden changes in temperature from hot to cold (or frost), poor drainage, damaged or compacted roots, high alkalinity (too much lime), disease or a nutrient deficiency - underfeeding or over application of fertiliser. It will be a process of elimination to find a solution. As your plants are planted into Tui Tomato mix and you have applied fertiliser, it is unlikely to be nutrient deficiency, but could it possibly be over application of fertiliser? There is fertiliser in the tomato mix, have plants had a double fertiliser dose? If you suspect this then put the hose onto the tomatoes for 10-15 minutes to try and flush excess nutrients out of the soil. Have you or anyone around you done any weed spraying in the vicinity of your plants? Tomatoes are very sensitive to herbicides and it can show up as distorted foliage and yellowing of the leaves. Also a possibility is Mosaic virus which is usually spread by sucking insects such as aphids and can cause similar symptoms, check the leaves for signs of insects, if you suspect virus then the plants are not able to recover from this and will need to be pulled out and thrown away so it doesn't spread to other plants. Have the plants dried out at any stage and then had copious amounts of water applied which causes plant roots to burst allowing soil pathogens to enter, it if was a root disorder the whole plant would start showing signs of collapse. Has your water source changed from last year - are you using grey water, bore water or tank? Are you spraying with any insecticides natural or synthetic?
My solution for now is to apply Tui Organic Seaweed Plant Tonic at a rate of 100ml per 9L watering can every 7 days and hope that the plants start to show signs of recovery soon. Make sure plants are regularly watered, feed every 4-6 weeks following the application rates on the pack and with weekly applications of Tui Seaweed Plant Tonic hopefully the plants will recover. The Tui Team.
Post a comment
My tomatoes have started curling up and leaves are turning yellow, can you help? Comments
Battling with Blight both in and out of glasshouse. I cleaned up last season both outside and in the glass house, l washed down all surfaces and sprayed with Jayes Fluid, including soil and left over winter. Rotary hoed, added fertiliser and left 3 weeks then planted Tomatoes, watered every 2 to 3 days, not on leaves after 3 weeks looking good then bang Blight struck both in and out of glass house, stripped and burnt all effected leaves, but will have to pull out. What should I be doing differently? Could plants have been exposed to blight before purchasing them. Cheers Pat. Note no Blight for 5 years.
Pat and Jeanette Bishop
Hi Pat, how disappointing when you have put so much work and effort in to preventing blight. I don’t know which region you are in, but the wet start to spring and into early summer isn’t helping tomato crops, as well as a lack of sunshine hours. Good air circulation around plants is key to helping prevent blight, ensure the glasshouse is ventilated or leave the door open during the day to make sure air circulates around the plants. It sounds like you have collected up infected plant material from the previous season, before planting dig into the soil fresh compost, tomato mix or potting mix to replenish it. Regular protectant sprays with a copper based fungicide may be helpful, there are natural fungicide sprays that are copper and sulphur based. Some tomato varieties have a natural resistance to blight such as the heirloom varieties – Moneymaker, Brandywine and Roma to name a few. Also by planting grafted tomatoes you increase plant vigour and so less chance of pests and diseases affecting the plants, this is not as cost effective as raising your own seed as grafted tomatoes are around $8-$9 per plant. Try drip irrigation if you don’t already run this system rather than watering with a hose that potentially wets the foliage and raises the humidity around the plants, and leads to blight. Some gardeners use apple cider vinegar sprays to help prevent disease. Mix 1 cup of apple cider vinegar to 5 litres of water and spray the foliage, you can do this weekly in the growing season. Take care not to spray in the heat of the day in a glasshouse as this can burn the foliage. Regular applications of Tui Seaweed plant tonic might be beneficial as well to help improve overall plant health and stimulate root growth. Hopefully some of these ideas will work for you and you end up with a bumper crop of tomatoes.
Lianne