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Millville, UT

my season is now over. Pumpkins have stopped growing and it looks like I have been a victim of a mosaic virus. I have taken a leaf sample to the local university for confirmation. My research has indicated that this is caused by aphids transmitting the disease from which it probably originated from some weed nearby. I just hope this is something not in my soil that would cause me not to be able to grow pumpkins. What I would like to know is suggestions for next year. Some things I have come up with is: better weed control, start spraying for bugs early and often, maybe us a reemay row cover to prevent any insects from coming in contact. Suggestions?????

8/7/2014 12:00:37 PM

Torrance, Ca.

Me too:( Taken out my whole big patch................ Sounds like your on the right path but would also like to hear others opinions on this topic.

8/7/2014 12:43:13 PM

Central NY

Test your soil .. Weekly fungicide, weekly bugaside..weekly milk and water (starting in July).. Maybe look into systemic early for better protection

8/7/2014 2:01:34 PM

Springfield, VT

It seems to be a big issue this year. Depending on the virus it may be in the soil also. Probably not but your tissue test should tell you which one. Look at Matt D's diary from this and previous years.

8/7/2014 2:41:42 PM

Millville, UT

I read through Matt's diary and wow even he has had a tough year with the virus. I just wish either of my pumpkins would have kept growing longer after infection like his. I also read his piece from the Oct issue of the OVGPG on the virus. I see he is even killing the neighbors weeds. I don't have pokeweed here but there are several of the other weeds listed. My pumpkins stopped at 300# and other at 350#. Both plants have been the strongest plants I have ever had, then I noticed at almost the same time on both plants one of the secodaries started looking funny and shortly after that it was all over. I have read that some gardeners and even commercial folks use reemay covers. I am curious if anyone else had tried that.

8/7/2014 3:54:02 PM

Torrance, Ca.

Lots and lots of weed control and stay on top of the bugs before the plants are even in the ground is what I am hearing.....

I'd rather have mosaic then what I have at my house patch,,,, that's for sure.

Keep the info coming! Matt, develop a mosaic resistant seed for us,,,,,,,, please:)

8/7/2014 5:22:45 PM

Colorado

Get the pumpkin plants out of there. Keep the weeds down and don't let them go to seed.Spray safari on any vegetation that may be a possible safe harbor. Ive got watermelon mosaic potyvirus in the city garden next door and its a tough foe.

8/7/2014 5:43:51 PM

Connecticut

Background about my patch (and virus experiences) for those that are not a Matt D. "Groupie";-)

2012= My patch was a total loss due to ZYMV (Zucchini Yellow Mosaic Virus)

2013= Was a very good year for me with a new personal best and State record

2014= Patch is infected with what I believe is WMV-2 (Watermelon mosaic-2 virus). What is interesting is that the screen did not indicate any ZYMV. I have three plants growing and while their growth is not great, they are growing better than I would expect considering how bad the plants look.

Now, let me try state some facts about mosaic virus in general...

1.) Mosaic virus is a board term that covers many different types of viruses as they all produce the same visual symptoms. Most labs screen for potyviruses which are the most common are are aphid vectored so they have the greatest economical impact. Essentially you need to get a scientific screen preformed on the plant material to know for sure what you may have (or not have) in your plants. This is a link to the lab that I have used:
http://www.agdia.com/testing-services/Cucurbit-Cucumber--Melon.cfm

2.) Once you determine what you have a plan can be better prepared. TMV (Tobacco mosaic) is probably the worst as it has the longest residual. Most common that I have heard from pumpkin growers are the low residual viruses that hit hard this year but do not over winter in the patch. (Note: Typically dagger nematods are the soil vector.)

8/7/2014 8:40:32 PM

Connecticut

Yet another one of my posts that goes over the 2,000 character post limit;-)

3.) To get at your main question of what to do next year the reply is simple... PREVENT APHIDS
*Physical barrier is the most effective and while insecticides would seem logical they do little good as the aphid needs only to penetrate its stylet into the plant for only 6 seconds to transmit the virus. So killing the insects does little good, fungicides are a waste (for virus) and milk applied to the plants will not prevent the virus, but it is a good practice to wash your hands in milk after touching infected plants as the proteins bind to the virus to prevent it from attaching to other plant material.

4.) Weeds are the most likely place that is the overwintering host for virus. There are a few select species but odds are there are more than a few of the weeds in your local area. Also, most infected weeds do not show visual symptoms that they are infected so this is a challenge to have conformation that you found an infected weed.

5.) So.Cal = there is actual ZYMV (Zuccini Yellow Mosaic Virus) resistant germplasm out there, and there is even Powdery Mildew resistance, they may just not be the giant size you were hoping for...
https://www.harrisseeds.com/storefront/p-13900-pumpkin-magician-farmore.aspx

6.) I have found the name of a great research scientist that I am working on getting in touch with to try and prevent aphids/virus. I have spoken with them briefly and I am working on tweaking the system for what we do as giant pumpkin growers and then will get in touch with them again to finalize a plan. This season is what it is, but I working on plan for next year.

Any other questions let me know but in short, I am working on an anti aphid/virus system for 2015.

8/7/2014 8:40:48 PM

Torrance, Ca.

Just what I was looking for!


Thanks Matt and keep us posted:)

8/7/2014 10:17:01 PM

Millville, UT

I am a Matt D. "Groupie" by-the-way and I have read a lot of your articles - great stuff. Some day I hope to meet you. I always have question but for now just a couple:

- From what you have said about the pumpkin having all the cells it is going to have at 20 days does that mean the seeds are OK to use if the plant does have the virus and the fruit doesn't show signs of it?
- maybe using some sort of insect repellant like pyrethrum - or planting Tanacetum cinerariifolium flowers around the patch?
- use of some sort of cover cloth maybe in conjunction with a repellant?

I only have about 900 ft2 and I can't rotate my patch from year to year. I have thought about only planting every other year but that is no fun.

8/8/2014 11:42:01 AM

Connecticut

Hi cachekin- Always nice to know I have followers (stalkers;-)

Getting to your questions…

-Virus in Seeds?
Short answer is most likely not.
Longer answer is, read over these links to previous posts I have done on the topic…
http://www.bigpumpkins.com/MsgBoard/ViewThread.asp?b=6&p=487469
http://www.bigpumpkins.com/MsgBoard/ViewThread.asp?b=6&p=406259

-Insect Repellent for aphids?
Ideally this is the best and only option. I have used Garlic Barrier in the past and it does seem to help but apparently I need to use it more often. I am also looking into other plant species that may be more favored by aphids that will essentially distract them from the pumpkins. The key is to find species that will not become infected with the virus which will allow me time to target the insects.
I am also looking into reflective mulches/screens that may help confuse the aphids and limit their entry to the field. Since I really do not have very many (insect pressure is low) this may be another way to put the odds in my favor.

-Physical Barrier?
This is also something I have considered, but the challenge is with aphids they are very small and to cover the entire area that I have (6,000sq.ft.) I can see a tear developing and creating a weak point for the aphids to enter

-You should not have to rotate because of virus if you can control the aphids and not have a heavy source of local inoculum. I plan on screening the plant material at the end of the season again to see if my plants picked up and additional viral strains. Looking at the leaves I have and due to my experience I feel I am getting better at picking out slight differences I feel that I now have more than one viral strain in my pumpkin patch, but I need the diagnostic test to prove this.

Any other questions just let me know.

8/8/2014 9:37:58 PM

East Jordan, MI

garlic repels them
spray patch and surroundings with garlic once a week

Silver repels them
I've read about people using aluminum foil on the ground to reflect the sun up under the leaves (where the prefer to go)

The combination of Aluminet shade cloth (http://www.ecologictechnologiesinc.com/shade_cloth_films_screens_greenhouse_shade_cloth_aluminet.html) as a wind fence and spraying garlic once a week seems to work for us

8/8/2014 9:45:32 PM

Millville, UT

These little aphids are sounding more like little vampire:
- they suck the plants blood
- they are repelled by garlic
- silver repels them
- little wooded stakes to their hearts????

I sure am going to give some of this a try. All out war next year.
- better weed control in the patch and surrounding area
- early and often insect control
- garlic spray - I will also be growing my own garlic next year
- plant Pyrethrum daisy or Tanacetum cinerariifolium around the patch. I hear it is a good insect repellant due to it produces pyrethrum.
- maybe some tin foil. I want to test to make sure it doesn't burn the plant.

8/11/2014 11:19:39 AM

Almeria Spain

I have carefully read every detail about the problem of viruses in plant giant pumpkin, my experience is two years running with this problem, the first infection after an analysis had shown that two different virus potyvirus family
potiviridae exactly WMV-2 strain CABYV and Morocco and in 2014-I had Tomato leaf curl New Delhi virus (ToLCNDV)
the 2014 did everything better than 2013 was having a better result when using a natural predator native Nesidiocoris worked very well keeping the plants free from mirzus persicae aphid and whitefly are the main vectors of transmission of viruses in cucurbits, in exchange for some minor leaf damage aesthetic unimportant since when the population increases Nesidiocoris damage the host plant pumpkin here but this also can be easily controlled, along with the use of sticky yellow color traps for aphid blue and white fly traps for thrips.

10/31/2014 5:14:08 PM

Almeria Spain

All this complemented with some innovative products falsely called
fitovacunas, are but triggers defenses phytoalexins jasmonates plants and put them on guard against attacks, this really helps but is not enough, when the temperature is high increases the population of aphids and whiteflies and impossible to control, insecticides are worthless because you have described as pink sheet once already inoculated virus but die aphid
my opinion is that there is nothing definitive but if the sum of all results can be sorted in that area because it is becoming more widespread if your neighbor does nothing you infectaras your plants in a few days so if you can recommend something for my experience 90% is the most effective antivirus maya smallest size, light water moves through and do a bit of shade, that some color to match the leaves traps and a double door if it is possible to enter the plant in addition to keep the area weed are the reservoir of clean infected aphids
until a variety of giant pumpkin resistant difficult short term thing is achieved because too many viruses out there today, I hope I have clarified a little more to this problem and am having to use the translator of google for not knowing your language, my 2015 project to make a greenhouse of 100m2 with maya antivirus if I want to grow up to end of season.
best regards from southern Spain.

10/31/2014 5:15:07 PM