Bean Golden Mosaic Virus

 

This is the leaf canopy for the Musica pole beans. The trellis is 8 foot tall and the vines are over the top and loaded with beans. The top of the canopy looks dark green and healthy but look at the bottom. The leaves are starting to yellow and are mottled. Since taking this photo last week, the yellowing is now half way up the vines, so it spreads fast.

 

 

Here is a closer look. The leaf at the top is showing the top surface and the lower leaf is flipped over to show the underside. The leaves are yellow with a mottled pattern.

 

 

From what I can gather, this looks like Bean Golden Mosaic virus, something I have never encountered before. It is fatal and all you can do is remove the plants and destroy them. It is not a seed-borne disease, which makes sense because these plants came from the same seed packet I used successfully last year. The disease is spread by insects, most likely aphids or whiteflies. That is puzzling because I generally never see an aphid in my garden. I have Japanese Beetles taking up their favorite dining spot at the top of the vines, but no aphids.

 

BGM is apparently a major problem in South America, Mexico, and parts of southern US and limits production of bean crops in those areas. Any legume plant can host the disease, including all the clover and vetch I have growing as weeds in the paths in the garden. Serves me right for not keeping up with my weeding. I hope to be able to at least harvest the pods now on the vines, but it does affect pods and I am starting to see signs of that. My Gold Marie  bean plants did poorly right from the start but their leaves don’t look this. I don’t know what their problem is but that crop is mostly lost.

 

Soil Drench for Tomatoes

This year I decided to try a new (to me) technique to prevent or reduce the chance of soil-borne diseases affecting my tomatoes and peppers. In catalogs I have read about natural products like Actinovate (containing the bacteria Streptomycin lydicus) that can populate the rhizosphere and attack fungal infections such as Fusarium and Pythium in the soil before they infect the plant.  It sounded like an interesting idea, maybe worth trying.

A little searching on the internet showed these types of biological products are considered safe and effective and are used by commercial growers. Actinovate is used by landscapers to treat fungal infections in lawns such as brown patch and dollar spot. Actinovate is also OMRI-listed and is being used by gardeners to treat vegetable crops. Renee of Renee’s Garden uses Actinovate as a preventive spray on her garlic fields to ward off garlic rust. There is a lot of discussion on the Tomatoville garden forum worth reading and one of the more interesting threads describes the use of a mix of Actinovate and other products to create a soil drench to be used before planting out tomatoes and peppers. I decided to try my own slight variation of Ami Deutch’s formula from the Tomatoville forum.

The basic idea is to create a soil drench solution in which the beneficial organisms are dissolved. The tomatoes, still in their pots, will be soaked in the solution and then drained before planting in soil. This inoculates the root zone with the beneficial organisms. They colonize the area and promote healthy plant growth and help the plant resist attacks by fungal diseases. You could use just a single product/organism such as Actinovate, but why not make a comprehensive soil drench, since the biggest effort here is in mixing the solution and drenching the plants.

 
The three components of Ami’s mix are Actinovate, Biota Max, and Myco-Grow (for which I substituted Great White). What are these? Actinovate identifies itself as a fungicide for organic gardening. Since it gets used for lawn problems, it is widely available at garden centers as well as from online sellers and Amazon. If  you buy locally, be sure to check the use by date sticker. The stuff at my garden center was 18 months past the use by date. Actinovate contains a single ingredient, a patented strain of the bacteria Streptomyces lydicus, strain WYEC 108. It colonizes the root zone of the plant, setting up a symbiotic relationship with the plant. It feeds off exudates of the plant while excreting by-products beneficial to and protective of the plant and attacking some disease organisms. Soil diseases suppressed include the soil borne fungi Fusarium, Verticillium, Rhizoctonia, Pythium, and Phytophthora. Actinovate can also be used as a foliar spray and is effective against powdery and downy mildew, grey mold, fire blight, rust, and black spot.

The next major component of the mix is the Myco-Grow or Great White. These are water soluble mycorrhizae inoculants and contain roughly equivalent organisms, both fungal and bacterial. Rather than include the whole list, you can view a comparison I did of the composition of several products here. Both are a bit pricey and you want to get the smallest size, about an ounce, so you can use it up in one season. Myco-Grow has to be bought from the supplier while Great White is widely available from hydroponics stores and from mail-order suppliers and Amazon.

The third component is Biota-Max,  which is described as a Soil Probiotic. I consider it optional if you have trouble obtaining it since it adds just a few new microbes to the mix, but I chose to use it. You have to source it online direct from Custom Biologicals. What you get in your package is a single lozenge, somewhat like an Alka-Seltzer tablet. Ami calls for it to be cut in quarters, with one quarter used in each gallon batch of drench.

To make the drench, dissolve one quarter tablet of Biota-Max in a gallon of pure (chlorine-free) water. Be careful using city water if it is treated because it will kill all your expensive microbes. Then add 2 teaspoons (10 cc) of Actinovate and 2 teaspoons (10 cc) of Great White to the water and mix thoroughly. I used a gallon milk jug to mix and carry the water to the garden. For the dipping container, I cut an opening in an empty gallon cider jug.

After I prepared the planting hole and added all the supplements, I submerged the plant in the drench in its container so the soil mass did not dissolve in the drench. After about 5 seconds when the bubbling stopped, I lifted the plant and let the excess drench drain back into the container and then planted it. The gallon was more than enough to treat 14 tomatoes in Solo cups plus a couple in packs. The left over solution can be poured around the base of the plants. I would like to be able to say that the plants are exuberant and rapidly growing today, but shortly after being planted we started three days of rain with daytime temperatures in the 50s and nighttime temps in the 40s, so the plants are actually looking a little shell shocked. The inoculant is not going to be active at these temperatures, but I am looking at long term results and disease resistance, so it will be awhile before I can decide if this was successful.

Grafted Tomato plants in your future?

The new 2013 seed catalogs have been arriving and I noticed, for the first time, that some catalogs are offering grafted tomato plants this year. Well, it turns out they have been available to home gardeners in the US for several years now, while they have been extensively used in Europe and Japan, and in US greenhouse agriculture, for years. The concept of grafting is a very old horticultural practice. Roses and fruit trees (members of the Rose family) are routinely grafted onto rootstock because they do not run true from seed. And of course, we all know the European wine industry was saved when an entomologist in Missouri developed a method of grafting Vitis vinifera scions onto phylloxera-resistant American root stock.

 

What is new to me is the concept of grafting non-woody annuals like tomatoes, cucumbers, peppers and eggplants. What advantage can be obtained? Grafted tomato plants in the catalogs are priced $8-10 each, so what would make that price worth the benefits? Japan was one of the early adopters of grafted plants, a country where space is at a premium. Then Europe. In the US, greenhouse growers are the economic driver behind grafted plants and the economics are simple. Greenhouses are a large capital investment and have a finite capacity for plants. If the productivity of a given plant could be improved for whatever reasons (vigorousness, soil disease resistance, etc.), say 40-50%, that would be a huge payback for the additional cost of grafted plants. Even for field-grown tomatoes, a significant yield per acre is money in the bank.

 

Do grafted plants have any benefits for the average home gardener? I think that remains to be seen, but the potential is intriguing. A number of benefits are claimed for grafted plants. Among them are increased vigor, extended harvest and disease resistance. Suppose you take a vigorous, disease tolerant rootstock and graft it with a desirable heirloom tomato such as Brandywine. If the grafted plant can produce even 50% more fruit for the one spot I can devote to a Brandywine plant, it would be worth it to me.

Here are some of the claimed benefits of grafting:

More vigorous rootstock that can pump more nutrients into the grafted scion. There are claims that the root mass of the rootstock may be 4-5 times larger than usual. The rootstock is capable of delivering far more nutrients to the scion, yielding more and larger fruit, thus increasing productivity. There is of course an art to pairing rootstock  to scion. Too much vigor and you may overwhelm the scion and  just get rampant vegetative growth. My concern comes from growing in raised beds, where I have constrained volume for each plant, both root mass and foliage. The growers recommend pruning to two leaders to spread the vigor, which was my practice for in-ground plants trained up a pole. In raised beds, I prune to a single leader trained up a trellis cord. At the end of this season I pulled tomato plants with large root systems that consumed their own square plus most of the adjacent square. Do I really want a plant with 4-5 times the root system?

Improved disease resistance, primarily from soil-borne diseases. The root stock varieties are selected for their resistance to some soil-borne diseases and nematodes. For example, Estamino, an organic rootstock bred by Enza Zaden in the Netherlands is grown by King Seeds in the US and retailed by Johnny’s and High Mowing Seeds. Estamino has strong resistance to Verticillium and Fusarium wilts, tomato mosaic virus and leaf mold. It has intermediate resistance to root knot nematodes and tomato spotted wilt virus. The airborne diseases like late and early blight aren’t mentioned, but I have seen blight resistant varieties like Defiant grafted onto rootstock, giving you the best of both. Unfortunately, Defiant is a determinate variety not suited to trellis training. Still, the soil disease resistance is a definite plus for situations like hoop houses, greenhouses and raised beds where there is limited to no opportunity to practice crop rotation. Graft an heirloom with no disease resistance onto rootstock and you get the disease resistance of an hybrid.

Extended production of fruit. The combination of disease resistance with a vigorous rootstock means that plants will keep growing and producing fruit. For a greenhouse with a controlled environment, that is an obvious advantage. If it proves true in the home garden, that would also be a plus. My tomatoes tend to tire out in late summer. This year they only got about 4 feet up a 6 foot trellis. I am no disease expert but I suspect diseases may play a role in this. Usually I am hoping the couple of fruits still on the vine will mature before cold weather. I think that instead, wondering what to do with the bushels of green tomatoes still on the vine would be a pleasant problem to have.

 

\If you want to see how grafting is done (and why retail grafted plants are expensive), there is a great video produced by the University of Vermont here. And just a WARNING: While grafting is not GMO, it is a high-tech process used in agribusiness and Monsanto is heavily involved. The Dutch company De  Ruiter, a Monsanto company, is the source of seed for the Maxifort, Multifort and Beaufort rootstock which are widely used. Seminis has its own rootstock, Cheong Gang. Johnny’s and others do offer rootstock seed not produced by Monsanto but retail growers don’t always volunteer what rootstock they are using. It looks like Log Cabin Plants sold by Territorial in 2011 used Emperador rootstock from Syngenta in the Netherlands, a non-Monsanto product. For 2013, they are using a rootstock branded “SuperNaturals” and it isn’t clear if this is Emperador re-branded or a new rootstock. If you are concerned about avoiding Monsanto products, you should probably ask what rootstock is used.

 

I am definitely intrigued by the concept of grafting tomatoes and will probably try a few plants in 2013. Right now I would have to mail order plants, since I haven’t seen grafted plants at any of the garden centers around here in New England (although Home Depot has trialed selling the Mighty ‘Mato grafted plants, but only online). In the US (outside of the greenhouse industry), most home garden activity seems to have started in the Pacific Northwest, with Log Cabin Plants and retailers like Territorial Seeds. Log Cabin in conjunction with Garden Life developed the Might ‘Mato brand and they seem to be the major grower/promoter for now. Retailers like Home Depot, Territorial, Jung, Totally Tomatoes (and allied Vermont Bean Seed), White Flower Farms, and others are reselling selected Mighty ‘Mato plants. The widest selection seems to be offered by Garden Life itself. Plants will also be available from some garden centers (primarily in western US but hopefully in the NE as well). Expect to pay an average of $8 per plant plus shipping (and usually a 3-plant minimum order). And you probably should order early if you are serious because production is limited.

 

So, do you have any plans to plant grafted tomatoes in 2013? Have you done so before/? I am thinking of trying a grafted Cherokee Purple, because I am such a fan of it and last year was disappointing. Garden Life also offer Paul Robeson, a Russian heirloom that is supposed to be great tasting and early. Then what about Juliet? It is already vigorous and productive, but if I could get 50-100% more fruit from one vine, I only need to plant one of them. I am not ready to try eggplant or pepper yet. I doubt an 8 US$ eggplant is going to be any less susceptible to flea beetle attacks than my 50 cent transplants.

Harvest Monday–30 July 2012

Not much to show this week. Tuesday was busy and by Wednesday I had some stomach bug that put me out of action for three days. First got to the garden on Saturday and found a few things overgrown, but everything is edible assuming my appetite comes back. We also have said several days of rain so I did not have to worry about watering.

I picked two pounds of beans, some of them a little large. Actually I welcome larger beans because it is a reason to make stewed beans with tomatoes. That’s comfort food to me and they freeze well, so a good way to use up the older beans and excess tomatoes.

An assortment of small tomatoes, Juliet, Sun Gold, and Black Cherry. The cherries are very tasty but I’m not sure I like Juliet. Kind of tough and dry, not very flavorful. Fortunately none of the tomatoes split from the sudden rainstorms. I left a medium sized Cherokee Purple on the vine to sun-ripen for a few more days. Hope it’s still there. Yesterday I got an email from a fellow gardener who had surprised a poacher at the garden. This person drove their minivan right up to the gate of the community garden, got out with a shopping bag, and proceeded to do her produce shopping among the various plots. Most items I have plenty of at this point, but I have special plans for that tomato.

Some of the squash got away, which happens. They are actually larger than they look in this photo. I think these two types of squash are still edible when fairly large, but I really did not need more squash right now. I think I might try stuffing the zucchini and turning it into a main dish. The cucumbers are two pickling cukes.

I got some bad news while picking the beans. I noticed some small discolorations on some of the beans, like a wet spot. As I got down the bed, I found the reason. In the picture below you can see black lesions on the beans, sure sign of halo bean blight, a bacterial bean disease from infected seed (see an earlier post). The wet looking spots are the early stage of the infection. As it progresses, a lesion appears with a cream-colored center. You can see that on the bottom bean on the right. As the infection proceeds, you get the sunken lesions you see on the top, which turn black from secondary infection. I was surprised because usually the leaves are affected first, with brown lesions surrounded by a yellow halo, but this hit the beans first.

This is a bit disappointing. I cleaned up the garden debris last year and the disease is not supposed to overwinter in New England. I rotated the beds and made sure I had seed from reputable sources. And it is supposed to be less likely to infect bush beans. All I can do is remove infected plants and hope it doesn’t spread further (wet, windy weather like we had the past few days will do it).

That is all from here. To see what other gardeners around the world are harvesting from their gardens, head to Daphne’s Dandelions and join the fun.

Harvest Monday–16 July 2012

Well, it is definitely summer now! The past few days’ highs have been in the 90s and we are looking at another week of 90+ weather, with occasional thunderstorms. Plus all the bugs and disease. At least we are now getting some summer crops which makes up for it. Powdery Mildew has arrived in the garden, affecting some summer and winter squash plants (but thankfully none of mine). Last year I had a lot of trouble with PM, which killed my zucchini after just a few fruits. It turns out there is a simple, organic spray based on milk that helps prevent PM infection. You can find the recipe in my post on the BCG blog here. A follow-up inspection showed the plants in the photos there had significantly improved and were showing only a few spots of mildew after spraying with the milk solution, so it seems to be pretty effective as well as easy and cheap.

I had my last two endive plants bolt but the escarole has been hanging in there. This is one of my last two heads, weighing in at about a pound.



Some more chard and the last of the mustard, which has now bolted. I pulled the mustard and will replant at the end of August.



While pulling a large weed that I found after I removed the row cover from my squash, I disturbed the roots of this red onion, so I decided it was better to pull it. The garlic scapes were given to me by another gardener. I found the entire scape except for the bulb at the top to be woody and inedible. So what is the deal with scapes, I thought they were edible? These had not formed a coil so I assume they were not cut too late.



My first peppers, two Hungarian wax peppers. And more snow and snap peas, close to the last of them. The heat is getting to them.



So I lied when I said the lettuce was finished. These were volunteers from the compost applied to the raised beds. The red lettuce was found growing in the beets. Good thing I’m a casual weeder. You get gifts like this from being lazy.



I decided to cut the last head of escarole, figuring it would last longer in the refrigerator than in the garden given the heat we are experiencing. At the bottom is my first squash, a Costata Romanesco.




The squash are now starting to produce. The yellow patty pans are Sunbust, a great squash with a creamy texture and nutty flavor. Below them is my second Costata Romanesco. Broccoli sprouts to the left and snow/snap peas to the right. At the bottom of the photo are my first tomatoes, four Sungold and a couple of Black Cherry. Note that a pair of the Sunburst squash seem to have fused together.





This week I should be picking beans from the Provider bush beans, with the Fresh Pick beans probably a week later. There will more squash and a few tomatoes. The cucumbers seem to be taking their time getting going. You would think they would like the hot weather. Well, hopefully that means they will have a long, productive life and not succumb to disease right away.

That’s all from my garden last week. To see what others around the world are harvesting from their gardens, head over to Daphne’s Dandelions.

UMass Extension Vegetable Program

The Agricultural Extension Program at UMass Amherst has a Vegetable Program for growers of vegetables. While the Program is aimed at commercial growers of vegetables and herbs in Massachusetts, their web site has lots of useful information of value to home gardeners throughout New England. For example, they have a page on the halo bean blight that hit my pole beans after TS Irene.

In addition, they have an email newsletter called Vegetable Notes that is well worth subscribing to. It provides an update on disease and insect prevalence in New England and suggests what measures can be taken to protect your garden. The advice is oriented toward commercial growers and is not necessarily suited for organic growers, but is still useful to us home gardeners.

The September 8 newsletter provided a lot of useful information on how to deal with the effects of storms Irene and Lee, which included flooding followed by outbreaks of disease and insect infestations. Certainly in our community garden, we have seen many of the problems described in the newsletter. Fortunately for us, flood water in the garden was only a few inches deep and was clear and not full of mud, but we still got the mildew and rot that followed.

Halo Bacterial Bean Blight

I reported on my discovery of this bean problem in my Harvest Monday post. Unfortunately, I was not able to identify the problem plaguing my pole beans (picture above) using the nifty Visual Diagnostic Aid I posted here. So I turned to “teh google” to find what appears to be my problem: a bacterial bean blight called Halo Bean Blight. I have documented what I found below.