How do you get rid of rust mites without using pesticides?

Question

I work in a tomato greenhouse, and we have a problem with rust mites right now. About a fifth of the plants are affected, but they are all grouped together among about 30% of the plants. Can i get rid of them using beneficial insects or something or is my best option to tear the affected plants out and hope they don't spread?

Answer 1

If you are sure you have mites, a suggestion by Rodale is to blast the mites with a strong water flow 3 times skiping a day between blasts. You can also use insecticidal soap (follow directions on labels especially where it concerns harvest timing but they suggest 3 sprayings 5-7 days between each). From having spent a lot of time doing greenhouse production there are some mechanical tricks and some techniques you can check out. I don't know where you are so I don't know what you can make work, but...

Keep your facility super clean. Haul as far away as possible all debris and trash and never compost any greenhouse material that you plan to use in or near your greenhouse. Employees need to be clean in that they can't wander the fields and countryside before work or on breaks. That keeps contaminates like mud and clinging bugs out (one pregnant aphid can put you out of business in short order). Seal up your greenhouse and keep it clean and well maintained. Ventilation systems should attempt to keep the greenhouse in a positive air pressure when compared with the outside and incoming air for venting and cooling should be filtered when possible. That means fine insect netting even when considering that some flow will be lost (sorry). Take a look at your fertilizer formula and consider a lower comparative nitrogen so that plants are tougher and less likely to be enjoyed. Find a trap crop (potted) to attract what is in the greenhouse at present and when it is picking up mites as a sacrifice, toss it way way out and replace it. That plant chosen should be one to attract the problem (even another tomato) and can even be over dosed with higher nitrogen to make it more succulent. That one can be sprayed with chemicals as you don't harvest from it. You can, if careful, use non-organic chemicals with care "around" but not on your crop, and still keep to the organic way. I am not familiar with a rust on tomato so take time to double-check. If you want try a different variety brought in over time; Campbell135 and Kewalo were mentioned. If you are doing hydroponics and/ or recycling solutions, you may want to replace them at a shorter interval to keep them properly balanced as a plant/ crop will not use materials in the solution at equal rates and they will become unbalanced. You may want to insure that your fertilizer components are reaching your plants as you expect them to in the right amounts. Sometimes just to mix things changes them, causes the plant stress, and then they become susceptible to problems. Yes, a whole lot to consider, but everything needs to be looked at closely. I have seen people lose big money over a simple thing and I have seen people resort to "questionable", unsafe tactics (with legal implications) to keep going, and utterly fail for want of the use of good advice from qualified people. Talk to your extension agent and have them over for coffee. That's what they do. Give me a hollar at my email for more info if needed.

Answer 2

You may try

1. Soluble potasium silicate spray ( not categorized under pesticides)

2. Dip some cotton in 30% alcohol and rub over infested portion

3. Neem oil, nimbicidine, Azhadiractin etc as spray (natural pesticide)

4. You will get natural enimies from mite infetsted area, then culture them abd release.

5. Increased temperature may be a reason. So keep temperature between 23-26 oC.

Answer 3

Spraying the plants with water several times a day should control the mites but tomatoes will not like that and you could open up a whole 'nother can of worms. plus it sounds like way too many plants for this to work effectively unless you can devote one employee to doing nothing put spraying water.

i would certainly try beneficial insects. they work very well in greenhouse situations. Peaceful valley Seeds sells a wide variety of beneficial insects http://www.groworganic.com as does Buglogical http://www.buglogical.com. I have used both place and both do a great job and have knowledgable staff that can tell you what beneficial will work best for your problem.

Buglogical is the eastern USA. Peaceful Valley is on the west coast.

Answer 4

Neem oil is an all natural insecticide/miticide/fungicide

I start spraying my stuff right away and spray every couple weeks right up to harvest time. In a greenhouse you will need to treat everything because what you describe is going to hit everything soon.

Answer 5

It would be effective to use horticultural oil or insecticidal soap, predatory mites or mycopesticide which can create disease in mites naturally and spread to the subsequent population. These kind of biopesticides are species specific. I am well aware of the facts because I have developed a formulation which is working well against mites in poly house. This product is been commercialised in India

Answer 6

Mites are difficult.

Isolate the infected plants and spray with very dilute soapy water, to which you have added olive oil.

1qt. water, 1/4 tsp dish washing liquid, 1 tsp olive oil.

Be very thorough.

You may have to bite the bullet and use this:

in a blender:     1T Dish-washing liquid

                          2T  Hot pepper sauce

                          2T  Coleman's dry mustard

                          1/4 cup of olive oil

                           2 cloves of Garlic

                           1/2 tsp of borax

                           1 cup of tomato leaves (large, not new leaves)

                           12 oz beer (cheap beer!)

Blend and strain.

Add  to two full quarts of water and spray.

Test on  a couple plants before using.

You may have to destroy all the plants and really clean up the space.

I hate mites.