2019 NOVIC Tomato Field Trial

Finally, the summer weather has arrived to our little corner of the Pacific Northwest. Temperatures in the mid 80s all week and low humidity have given the tomatoes a much needed rest from fungal/moisture stress. During this weather, a few of the plants that were showing signs of heavy stress have made some slight recovery and nearly all of the plants have fruit of varying size on their branches (all except for a the LB 21-7-4 variety) that continue to get slightly bigger every week.

Some JTO 1021 fruit!

That being said, there are still some plants that are not recovering as gracefully as I would hope. Here I will go over the plants that have shown little improvement, or have shown a regression in health:

• The Crimson Sprinter plants, #2 and #4 of plot 2 still appear to be struggling heavily with what I think could be Bacterial Wilt. These plants haven’t shown any vigor for weeks and the few fruit that are on plants have remained small and stunted, similarly to the plant they sit upon. C.S. #1 of plot 2 looks much healthier than the others but still much smaller when compared to the other plants. (I must remember that this is the only semi-determinate variety in the trial and may behave differently when compared to the others.)
• Pilu KS, plot 1 #1, and #2, are both thin and weak and aren’t producing a lot of fruit but have continued growing and don’t look as notably wilted as they have in the past. While these may produce a few ripe fruit, I expect the yield to suffer because of it’s ailment.
• Frederick, plot 1, #1 is looking quite unhealthy. The plant is not only a full foot shorter than the others of it’s variety, it is also heavily wilted and has yellowed leaves at it’s base that were removed from the plant and the plot. The plant looks very similar to the two sick Crimson Sprinters in plot 2. There is a nice comparison to be made between the unhealthy and healthy plants of the same variety standing right next to each other, there is a clear distinction between what a sick plant should look like when healthy. (The photo I took was blurry and will need to be retaken)
• LB 21-7-4, *all plants in both plots* – This variety has struggled through the entirety of the trial. While the plants in plot 2 look slightly healthier (bigger) than those of plot 1, all of them are small and spindly. Rather than producing many leaves and leaflets, this variety seems to focus on growing large ‘Burdock-style leaves’ that needed to be pruned once the leaves showed signs of Early Blight, leaving few photosynthetic sites for the plant. This mixed with a cloudy and wet summer, and perhaps some plant genetics has left the LB 21-7-4 behind the other varieties, at least this is my hypothesis as to why this variety could be smaller and weaker than the other varieties.   (Below you can compare the LB 21-7-4 to a Frederick, both are indeterminate)

LB 21-7-4

Frederick

I want to also briefly catch you all up on the plants that had been showing some strange new symptoms of a new disease. I had written about how the stem of 4 different plants had been infected and looked necrotic, from those observations I have guessed that the plants suffer from what is called Pith Necrosis, Pseudomonas corrugata. The truth of this disease will hopefully be identified once the pathology results return from the plant that I sent to the lab. I observed today that the disease has not continued to spread to surrounding branches of the tomato plants. The stems that were afflicted were removed, but the remaining stems still look healthy and vigorous. (Good news!) I will continue keeping a close eye on the plants showing signs of this necrosis.

Aside from these observations, I did some plot maintenance that included weeding and trellising the ever growing  tomatoes and took another round of leaf curl observations. The plot is looking full and it is only a matter of weeks until the first ripe fruit will be in my hands.

Have a great week and I will do the same.

Since I posted last week about the first fatalities in the field, I have watched as disease has spread through the field, targeting certain plants and avoiding many others. It has been a tumultuous week in my world and that of the tomatoes. The weather has heated up and begun to look more like our normal summers, with temperatures in the mid 80s and getting hotter, making for some nice growing conditions for the healthy plants. The plants with the compromised vascular systems have begun to suffer in the heat of the direct sunlight, unable to transport enough water to keep from drying out.

I am still waiting for the results of the pathology report from the dead tomato plants that I sent to WSU, I plan to dedicate this post to what diseases frequent a Pacific North West (PNW) tomato patch and my thoughts on what is afflicting my tomatoes in this 2019 trial.

Rotted pith, common with Verticillium Wilt

Plant off to the pathology lab

New Disease in the field, unknown

A majority of the diseases that you will find in your PNW tomato plants will be fungal, and many of the fungal pathogens found in the Solanaceae family have similar symptoms with a few key distinguishing factors. A few common fungal pathogens are:

Verticillium Wilt (Verticillium albo-atrum): Yellowing or brown lesions on the leaves and/or the stem, often in a ‘V’ shape, are symptoms of the Verticillium. Verticillium often only affects one side of the plant, and because is can affect the stem, it will also affect the vascular system of the plant, causing it to wilt and often one will find a brown, rotted pith in the stem of the plant. (Verticillium, 2014)

Fusarium Wilt (Fusarium oxysporum sp.): Very similar to Verticillium, but rather than browning at the pith, the Fusarium Wilt attacks the outer edge of the pith in the vascular cambium. (Maryland, 2019)

Early Blight (Alternaria solani): The tell tale sign of this fungal pathogen is found in the yellowing, necrotic leaves. In the dead necrotic parts of the leaves (and sometimes the stems) are concentric circles that spread through the leaves. Early blight isn’t always detrimental and if the leaves are pruned and removed from the area, it shouldn’t effect your plant too heavily. (Ontario Crop IPM, 2009)

Late Blight (Phytophthora infestans): Irregular stem and leaf lesions that will spread through out the plant. When late blight sporulates, the brown/black lesions will be tinged with the white fruiting bodies that produce the spores. A sure sign of late blight is the brown necrotic lesions that are tinged with white. This fungal pathogen is a common end to most PNW tomato crops. (NC State, 2011)

Septoria Leaf Spot: Leaf and stem spots are all much smaller than with late blight and often have a characteristic tan center. Fruit are not affected, can be confused with flea beetle damage. (Cornell, 2019)

Field Observations: 

Wilt:   Between now and last Monday the 15th (where I observed 3 sick plants in the field), I have been observing as plants from 4 different varieties showed signs of a common disease. The varieties affected were the Pilu KS, Crimson Sprinter, Frederick, and Damsel.  On the 16th my observations went from 3 effected plants to 8 plants showing varied severity of the disease that I have hypothesized to be Bacterial Wilt (Pseudomonas solanacearum). On the 18th and the 20th, I counted 11 sick plants that were the same on both dates. Now today (7/22), after a weekend of nice, warm weather, I counted only 6 plants showing signs of this common wilt. Of those 6 plants, only 4 looked to be quite unhealthy. Based off of my observations, this means that some of these plants were able to fight through whatever it was afflicting them. (Observations should be taken at mid day when the plants are at their worst) This does not mean that they are necessarily cured but that the plants are fighting through the disease. The two varieties that are being hit the hardest by this wilt are the Crimson Sprinter and the Pilu KS.

Something new:   Aside from the plants that are wilting, I observed something new in the field today. It appears to be effecting the stems of 4 different plants. The disease looks like long, deep and black scars that move up the stem and into some branches. The stems that are afflicted the worst show no more green, living tissue and are completely hollow. While some branches have survived, I don’t expect any of the branches that are currently infected to survive much longer. A Galahad, two separated Red Racers, and a JTO 1007 are of the infected varieties. I am unsure of what this is and will be asking for assistance in diagnosing this disease as well. Here a few photos of the new disease:

A branch that I removed showing one side of branches sickly and the other healthy (Verticillium?)

Multiple branches infected, white substance at node

With every passing week I become more and more attached to the plants that I care for. I find myself thinking about their well being and wondering if the rainy days are too wet and humid, or if the heat of summer is too hot; I have allowed myself to become connected to each one of these plants. —  Groucho Marx says: “Outside of a dog, a book can be a man’s best friend. Inside of a dog, it’s too dark to read.” — All of this is on my mind because we had our first fatalities of the tomato trial. I am sad (yet oddly excited) to inform you that two of the plants have succumbed to a disease that I am in the process of identifying. I have been observing the two plants in question (Pilu KS, plot 1) over the last 3 weeks, watching them slowly lose their structural integrity while showing no signs of leaf discoloration. While, the lack of turgor pressure is only a symptom of an unknown disease, I have researched some of the possible diseases that could have caused this full-plant wilt. There is a bacterial pathogen that enters the plant through the roots, eventually clogging the vascular system, halting the flow of water and nutrients to the rest of the plant. This pathogen is known as Bacterial Wilt (Pseudomonas solanacearum) and can be soil borne or transmitted by a few different insect vectors.

Early observation of the wilted plants

Last moments before being pulled from the plot.

It is important to note that this diagnosis is only speculation. To ensure that I get the definitive culprit I have sent a specimen (an entire plant) into the plant pathology lab at Washington State University where I will get results within a month that will include a wide array of information about exactly what was found on/in the plant. In the mean time there are some in-home tests that I can perform to either confirm or deny that it is a bacterial pathogen, information on that can be found here.

Seeing as I still have some seedings of each variety in a flat in the green house, I considered replacing the plants that were removed but decided that it would skew the plant-yield results while adding another variable to the project. While a farmer for profit would plant the back-ups and be happy with any future yield, I am more concerned with comprehensive data. It is for these reasons that I will continue the project with only 6 Pilu KS plants, instead of 8.

Wilting Crimson Sprinter observed today in plot 2

I am slightly perplexed as to why these two individuals were ‘attacked’ while the surrounding plants, including plants from the same variety, look happy and healthy. To further my confusion, I observed one other plant (of a different variety) showing the early signs of this full plant wilt, yet this plant (Crimson Sprinter, plot 2) is separated by about 30 row feet of healthy tomatoes. This leads me to believe that an insect carrier could be responsible for this distribution pattern. Answers to these questions will have to wait until we find out exactly what killed the plants.

Aside from dealing with the afflicted plants, I took the observational leaf curl assessments for each individual and then proceeded to prune the plants that have began to get overcrowded. In hopes of opening up space for air flow I did a bit of light pruning to the lower branches and at the same time, removing any leaves that showed signs fungal pressure. The weather for the entire last week was rather dismal (and the forecast to come doesn’t look to be much better), heavy rains and high humidity have me concerned that the spread of fungal diseases will only get worse for the time being. This weather is a good reminder of why tomatoes don’t always thrive in our region.

I have continued to observe what I believe to be Early blight on some of the older leaves of various plants throughout the tomato bed. As is expected, these leaves are removed from the plant and field to slow the spread of spores. *Note has been taken of which varieties have shown signs of fungal pressure. Along with Early Blight, I continue to see small populations of aphids on various plants, sometimes as few as one or two on an entire plant, rarely do I see any eggs or young aphids. This past week I went out with a backpack sprayer, filled with nothing but water, and proceeded to spray and aphids I saw off of the plant. With a slight amount of water pressure, the aphids are washed off of the plant and usually die before making it back onto the plant. (Aphid eggs are harder to remove and it may be easier to simply remove the leaf/leaflet that they inhabit.)

To close the week with some good news: the tomatoes have began setting fruit, or at least there are a few varieties that have a few tiny, green pearls hidden in their foliage. I can almost taste them! We will see how this coming week of rain and humidity will affect the plants.

Happy Growing!

I always like to start arranging my thoughts by looking at what the weather was like for the day. Just as it is with the plants of this world, our bodies (and our minds!) are closely connected to the weather patterns of our area. Todays weather, much like most of the previous week, it was indecisive and spontaneous. The day would go from being overcast with a slight chill to blazing sunlight for a time and then on to a slight drizzle that would last only a few minutes; what nice weather it was.

The tomatoes are very much in tune with the weather and have benefitted from the warmer temps and the sporadic, light rains. A lot of new growth was added this week and it made for some busy days of pruning and observing the changes that are taking place with the plants. As is it stated in my NOVIC Tomato Variety Trial Protocol, I began my leaf curl observations that should be done on a weekly basis as the plants begin putting on vegetative growth. There were a few varieties that distinctly stood out from the others: the Damsel,  PILU KS, JTO 1021 and 1007, as well as LB 21-7-4 the varieties that showed any signs of leaf curl, the rest of the varieties showed little to no signs of leaf curl.

I did some pruning and weeding within the lower areas of the plant to allow for more air circulation, and while doing this I saw a fair amount of aphids and Flea Beetles on ≈70% of the plants. I also observed signs of a fungal disease that I believe to either be Early Blight (Alternaria solani) or Septoria Leaf Spot (Lycopersicon) on two separate individuals of the PILU KS variety. I plan to ask someone that knows more about fungal diseases than myself and will report back to you. The afflicted leaves were removed and destroyed so that the spores cannot spread any further.

Here are a few photos of what I observed:

In the photo of the leaf you can see small concentric circles within the brown areas, it is these concentric circles that make me think that it could be Early Blight rather that the Leaf Spot; we should, however, be able to see the same concentric circles on the stem lesion but I don’t and this is why I want to get a second opinion.

From here I will be adding another line of trellising for the tomatoes and keeping a close eye out for any changes that may happen, especially with regard to the fungal pathogens and the aphids. Enjoy the week!

Can you smell that? That is the hand of a tomato pruner hard at work, pruning the indeterminate varieties of the trial: JTO 1007, JTO 1021, PILU KS, Frederick, and Damsel. The difference between and indeterminate and determinate tomato variety is found in their growth habit; indeterminate varieties have vine like growth and will produce fruit in multiple successions in a growing season, where determinate varieties grow more bushy and set all of their fruit at once. The indeterminate varieties are pruned to promote the vertical and vine-like growth, as well as promoting a healthier setting of fruit. The theory behind this is that when less photosynthetic energy is being spent to grow many lateral branches, the plant can reinvest that energy into 2-3 leaders (branches with apical dominance) that will be producing the majority of the fruit.

While I was pruning the plants, that have now grown to reach the second line of trellising, I was able to be up close and personal with all of them, keeping my eyes open for insects and insect damage. The flea beetles and flea beetle damage that I had observed on a majority of the plants last week remains isolated to the older leaves, and while I still saw flea beetles on some of the plants (far fewer than last week) the extent of the damage is of little concern to the overall health of the plant, in my opinion. Also seen today were two small populations of aphids (≈10 aphids) on two different plants, one population on a PILU KS plant in plot 2 and the other on a Crimson Sprinter plant also in plot 2. I will keep my eye on these.

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I want to encourage you to visit the NOVIC website and read about their mission and about some of the exciting projects that they are a part of, there is a link to their website in the Who We Are menu.

NOVIC collaborates with The Organic Seed Alliance who was just highlighted in a piece by The New York Times about the importance of healthy and Organic seed. You should read the piece here.

An important part of the NOVIC goal is the merging of the culinary arts with the plant breeders and farmers that are producing the food that we all love to eat. You can learn more about this at The Culinary Breeding Network. Here is a link to their upcoming events.