 So that brings us to Susie Thompson. She is an associate professor and plant breeder at NDSU. She develops new potato cultivars for growers, the industry, and also consumers. She grew up on a seed farm here in the Red River Valley and she loves anything out in the field. And according to Susie, the best part of her job is working with potato growers, gardeners, and students. So with that, thanks for being with us today Susie. Thank you Julie for that nice introduction and happy first day of spring to everyone. I hope that everybody is in the gardening mood since it's finally bright, sunny, and fairly warm out today. I just came from the greenhouse where I was crossing so I had my North Dakota Caribbean escape for the day and I can't help but be excited for the upcoming planting season whether it's in the field or out in our own yards or even pots on our sidewalks. I wanted to remind everybody that you can type in questions and then as Julie indicated when I'm finished with my presentation then I will go ahead and try to answer those questions that you've submitted. The title of my presentation today is one potato, two potato, three potato, four best management practices to produce more. And of course I was reminded or came up with this title because of an old nursery rhyme that many of us probably remember. I can't, the part I can't remember is if we used to sing it while we jump roped or when it was that we used it but anyway potatoes are near and dear to my heart so I chose that as a way to talk about production and and how we might optimize production in our gardens. Please advance the slide. So potato as a kind of a background, potato is a member of the Nightshade family or the Solanaceae. In that family are about 2,000 species. Only 160 of them are tuber bearing. There are 20 cultivated species that we would consider to be potato or wild potato relatives. And of course the botanical name for the common potato that we raise or what some people might refer to as the white potato or Irish potato is Solanum tuberosum. Please advance the slide. And a little bit more in relationship to the botany. So being a member of the Solanaceae potato is a relative of tomato, eggplant, pepper, tobacco, petunias and of course one of our favorite, not really, favorite weeds, the Nightshades. We grow potato tubers for their or potatoes for their underground tubers and kind of to help put everybody into perspective, potato tubers are really modified stems. So things that can go on in potato foliage can go on in potato tubers too. And I'll try to come back to this or I definitely will come back to it when we talk about potato storage, but also when we talk a little bit about some physiological disorders that might impact potato. Potato would be what we would consider to be an herbaceous dicot. So dicot means that it would have two cotyledons. It's not a grass. And herbaceous of course means that it's succulent. And potatoes are annuals. Potato has its origin in the South American Andean region. And it stretches all the way from that backbone of the Andes all the way up through Central America, Mexico, into the Four Corners region of the US. So the people from the Gene Bank in Sturgeon Bay, Wisconsin, they actually do collection expeditions in the Four Corners region of Arizona, Colorado, Utah, and look for some wild species that are growing in the wild and important and native to that particular region. In terms of production, the potato industry is more than a $4 billion industry. North Dakota, as you can see on this table, ranks third in terms of the acreage harvested and but not always in turn and usually in terms of production. Sometimes we are eclipsed. And in this case, you'll see that Wisconsin in 2017 surpassed North Dakota in terms of their total production as well as the value then. But we oftentimes will flip flop between our two states. And they have the potential for a higher yield in Wisconsin. They have a little bit longer of a growing season. And of course, in North Dakota, our production is based on both non irrigated as well as irrigated production. In terms of certified seed potato production, North Dakota ranks second only after Idaho. And just for those of you that might be curious where Minnesota would rank, Minnesota in terms of production usually ranks about sixth. There are many cultivars, more than 200 cultivars of potato that are available to producers in the US or in North America. These are the on the list are the predominant cultivars in order of their production. But many of these are not necessarily the right choice for gardeners. You will recognize probably dark red, Norland and also Russet, North Dakota. Of course, Norland was released from NDSU in 1957 and Russet, North Dakota in the early or excuse me, late 1980s. And so those cultivars you can oftentimes find at your local gardening center or the grocery store that might be carrying some seed potatoes, etc. But these are the predominant varieties in terms of commercial production in the US. For market classes, this might be area where some of you will have a keen interest. There are basically four classes. The first would be our round whites. And in our growing area, the round whites that we grow are high in dry matter content. So they kind of have a mealy, dry texture. And of course, they're used to make potato chips out on the east coast, though, there is a market for round whites that would have a lower dry matter. So they would use them more similarly to how we use red potatoes here. The texture would be more creamy or more waxy. And so they would be using those for boiling and then home fries or making potato salad or things like that. The important features for making potato chips, of course, would be that high dry matter content as when we are doing the processing, the water content of the potato is replaced by oil in that frying process. And then the amount of sugar in the tuber is usually less when we have high dry matter potatoes in favor of starch and that results in a lighter chip or French fry color. So those are some features that would be important for that market class. The second market class, and hopefully everybody can find the kind of brown colored tubers on the left hand side of the photos there, is the long rusted in whites. And some of these are used for processing. And many of them are also used for table stock or for fresh use. So some important characteristics for these are, again, if they're going to be used for French fry processing that they have that high specific gravity or that high dry matter. So potato variety like Russet Burbank is number one for making French fries all across the globe. And of course, they need that elongate shape with the Russets for the table stock industry, something like Russet Narcota. These will tend to have a lower specific gravity. So again, that more waxy or creamy texture, they tend to be higher in sugars. And and and so they don't make good French fries, they would fry too dark, they would be caramely and probably even smell a little bit burnt when when we would cook them. Not not necessarily right after you harvest them, but certainly after you would store them, particularly at temperatures that we store table stock potatoes at. On the bottom are some red selections from a field day that NDSU was a part of. And these are showing reds for the table stock industry or for fresh use. And these of course are very popular in our area. The Red River Valley is quite famous for its red potato production. They tend to again have that creamy or waxy texture. They make excellent additions to soup to stew. They make great mashed potatoes. And of course, these are really the potatoes that we're looking for when we are going to be making the traditional potato salad. And then lastly on the middle right is a picture of what I would consider to be our heirlooms or our specialties. Probably everyone is pretty familiar with Yukon Gold. And of course that has a soft yellow flesh interior of the tuber. And some people also might maybe will have heard of a variety called all blue. It's an old variety from Europe that came across with our ancestors. There's also all red. And now some of the breeding programs around the US are starting to release others. Some with additional cultivars that have red flesh or blue flesh. Adirondack blue, for example, comes out of Cornell. So the heirlooms and specialties with the exception of Yukon Gold are probably not found routinely in most grocery stores, at least in our area. However, they tend to be more frequently found at farmers markets during the summer or during the fall. In terms of utilization, about 88% of the potato production in the US is used for human consumption. About 61% of that is used for processing and 26% of the production is used for the fresh market potatoes. 7% of our production is used for seed potatoes. 6% would be shrink or those losses that a potato grower might suffer in storage. And then less than 1% is now used for livestock feed. When we would go across the pond to Europe, they feed a significantly higher portion of their livestock with potatoes than we do here in the US. In terms of nutritional attributes, I think that potato oftentimes gets a bad rap in the media. But really, potato should be considered a little powerhouse. Our average potato that we would be baking or maybe we have multiple potatoes, little b-sized tubers, small ones, totaling about five ounces, it would be equal as serving. And that single serving only has 100 calories. Potatoes have no fat, they have no cholesterol and no sodium. However, potatoes actually have higher amounts of potassium than banana. And of course, in the media and with some nutrition folks, banana has kind of been the poster child for high potassium foods. Potato does have high total carbohydrates. And sometimes in the literature, we hear that potato is bad because it has a high glycemic index. I think that more and more research is showing that it really depends upon what foods you're consuming with the potatoes. Yes, if you're just eating chip after chip out of a bag, that probably is going to impact your blood sugar quite rapidly. But if you're having mashed potatoes with a bit of salmon or some other type of lean meat elk or beef, that is going to impact how quickly the carbohydrates are broken down and shuttled into your blood stream. And potato is high in dietary fiber, it provides about three grams. And of course, obviously, if we eat the potato skins or include them if we're making mashed potatoes or if we're eating our baked potato, that would help us reach that fiber level. And for potatoes are actually pretty high in protein when compared with other vegetables or fruits. And another area where potato really shines, even the white flesh cultivars, one serving of potato provides about 45% of the US RDA for vitamin C. That's even higher than an orange or a serving of oranges. So I hope that everyone will reconsider the nutritional attributes that potato can provide and how it can be a part of a healthy lifestyle. Since we're talking about potatoes, I thought it would be a good idea to maybe share just a little bit of background about our potato breeding program at NDSU. It was begun in 1930. So we have more than 85 year history now. During that time, 26 cultivars have been released or varieties. I use the two terms interchangeably, but usually here talk about cultivars. The major goal or objective of our breeding program is to release exceptional, multi purpose cultivars that meet the needs of potato producers and the industry in North Dakota, Minnesota, the Northern Plains, and beyond. And for some of you guys, as I had mentioned, the Norland and Russet, North Dakota, but the picture I have there on the bottom is of the famous potato breeder, Dr. Bob Johansson. And obviously nowadays, we grow red Norland and dark red Norland, but he released Norland in 1957. And to think that we're still growing line selections from that is is pretty impressive and pretty exciting. And this is just a listing of the cultivar releases coming from NDSU all the way from Nordak, Norglim and Norland that were released in 1957. I don't know why I have read Norland on that list, but it seemed to have a spare one there. And then all the way through Dakota Ruby, which was released in 2014. We have a lot of different lines coming along in our pipeline here at NDSU. So I'm hoping that in the next few months, we'll be releasing a new chip variety and or a new very early Russet variety that would be great for people's gardens in a short growing season. In terms of climate and soil, potato is a cool season crop. And the optimum temperatures that potatoes like to thrive under would be in that temperature range of 55 to 70 degrees Fahrenheit, even up to 75. Potatoes do not really like hot temperatures at all. And at temperatures above 87 to 90 degrees Fahrenheit, photosynthesis will decrease or actually stop. And of course, that photosynthetic production during the daytime is turned into starches and shuttle down and deposited it as the into our tubers at nighttime during the our summer months after we've had tuberization. So production of the photosynthes is very important. Potatoes have a high water requirement. And this is predominantly due to them having a shallow root system. So the roots of potato are primarily in the 18 top 18 inches of our soil. And this is much more shallow root system than our agronomic crops like wheat or barley, alfalfa goes down about six feet deep is more similar to many of our vegetable crops. And so most of us are familiar that we need to be able to provide a consistent and uniform irrigation or have timely rainfall in order to get adequate production. Potatoes prefer well drained and slightly acid soils. But they are really widely adapted and potatoes will grow from sea level all the way to high mountains. They obviously like the sandy or sandy loam type of soils, but they also do very well in things like muck soils or in peat based soils like we have near gonvic or clear broken in Minnesota. In terms of pH, they will grow on a wide variety of pH is out East, there are soils that they grow potatoes on that would have a pH in that 4.5 to five range. And I have been working in breeding programs and cultivar development programs all around the Intermountain West. And many producers are growing potatoes on soils where the pH is 7.8 or eight. The reason why we talk about soil pH is that sometimes we say or and we see it there happens to be more common scab and I'll show you some pictures of what or a picture of what common scab is on an upcoming slide. But I think that it really depends upon what biotypes of the streptomyces you might have in your soil. And then what beneficial flora and fauna you might have in your soil that would help protect the developing tubers. And and that pH isn't the the complete answer shall we say my next bullet I have day length written down and day length is important because of the wild species particularly many of our wild potato species will not tuberized under long day conditions. But as all of you are familiar with we have very long days during our summer times here when we're producing potatoes. So our our potatoes are usually setting tubers right around that June 21 the longest day of the year the first day of summer and and then rapidly bulking after that. But when I try to use wild potato species that came from places like Peru or Ecuador or or even Central America or Mexico. A lot of them will not start tuberizing until the days get to be quite short like we have in September. And so it's hard for me to maybe maintain tubers of those those particular clones. And I would be using those as a way to intergress late bite resistance for example or maybe resistance to Colorado potato beetles or things like that. And and I'm doing my crossing in the greenhouse but I like to be able to to grow the potatoes out in the field. And so lots of times those will be just little itty bitty tiny things when we go to harvest them. Whereas our selenium tuberosum that had its origins in the area of southern Chile near Chilauea Island. They tuberized under long day conditions. So not something that's so important maybe for you gardeners to think about but it is important for for the potato industry to be aware of. So let's talk a little bit more about our prepping our potatoes for production. So we'll talk about propagation. There are two types of propagation that we do or can use for potato production. The primary one of course is asexual reproduction and that's where we use either a small hole tuber or we use a piece of a tuber. It's also referred to as clonal propagation and when we are doing potato seed certification we will utilize plantlets that we grow in test tubes that would be free from diseases. This would be the start of the seed certification system. But each one of those plantlets or each one of those pieces of potato would be a clone of the same variety. And so it's also referred to as clonal propagation. In terms of our seed potatoes in Europe they tend to plant the small potatoes whole. In the US we generally will our seed will be bigger. So we will be cutting it either in half so that we wind up with two pieces that are about two to three and a half ounces or or we might be cutting eight ounce tuber into four pieces that would make that that optimum range of a two to three and a half ounce seed piece. The important feature of course is that each seed piece needs to have an eye because that's where the new stem will develop from. And we breeders however and I have a couple of pictures on the bottom of this slide. We create and use what is called true potato seed. And so if any of you have seen what some people will call those little tomatoes on top of the potato plant. Those are our potato berries or potato fruits. They can contain up to 250 individual seeds because of the highly heterozygous nature meaning we have a lot of genes and there's a lot of diversity in those genes. Each one of those brother and sister seeds in one of those fruits will be genetically different from or can be genetically different from all of the other brothers and sisters. So when I make a cross and plant out the seed in the greenhouse so and then take the tubers that I grow in the greenhouse from those the and plant them in the field it will kind of look like a patchwork quilt. I can have different flower colors. I can have different maturities. We can have different skin colors. We can have different flesh colors. Just a myriad of traits. It's really fun and and so if anyone's interested in you know either harvesting the berries and extracting the seed or doing a little crossing on your own cross pollinating the and growing them out that can be a real fun project with your kids or or just as an adult see the diversity that you can attain. In the wild the primary pollinator is the bumblebee but that's not important for our potato production in the garden. We're using clonal propagation so we are trying to produce all potatoes that look alike and of you know probably one variety. I guess a couple of other points that I should make in terms of prepping for planting and propagating. We can cut our tubers. It's a good idea to use a sharp knife. We don't want to use a serrated knife. The potato seed will heal better if it's a nice clean cut or sharp cut. We would need about 15 pounds of seed potatoes to plant a 100 foot row and we'll talk a little bit more about spacing in a subsequent slide. When we are searching for seed potatoes obviously garden catalogs are a typical source or a lot of our local grocery stores will carry seed potatoes in their produce section. You should not choose the potatoes from their produce display however because more than likely those potatoes have been treated with a sprout inhibitor to prevent them from sprouting and because of that if you tried to cut them and plant them in your garden you might not get any of the eyes to sprout and grow a new plant. We recommend that you purchase your seed potatoes either from a reputable seed grower or from a reputable garden catalog or from one of your local garden centers or perhaps grocery stores. I'm going to diverge from my slides here just for one second so please you can go ahead and leave it on this one. I didn't talk much about cultivars when I showed the slide about what cultivars were are being grown by the commercial potato farmers but the typical cultivars that you'd probably find in the in your seed catalogs are some of the older varieties. You might find Kennebec or Irish Cobbler, obviously red Norland, red Pontiac, sometimes red Lasotas. Many people like to grow a few Russets so I think a typical one that you would find would be Gold Rush. I do not recommend trying to grow Russet Burbank in your gardens. Russet Burbank is quite temperamental and it doesn't do particularly well in our heavy soils like we have in the Fargo Moorhead area and it also is very temperamental when it comes to water. It has to have very uniform water in order to produce nice smooth attractive looking tubers so I don't recommend that you purchase Russet Burbank or look for that. In our area you might find some Russet Norcodas and some Vikings at your local seed retailers and of course Yukon Gold. Yukon Gold is a great variety to grow in your garden. It's quite upright. It doesn't produce a lot of tubers per plant though so you may want to plant them a little bit closer and plant a few more hills. The tubers when they get big for Yukon Gold oftentimes will have hollow heart if the moisture hasn't been quite uniform or if you let them get to be too large. But they are a good you know quite early maturing potato and they are really have so many uses. They're kind of my go-to in terms of multi-use when I'm cooking. Here at NDSU we've released some great varieties that are probably a little bit harder to track down but if you know a seed potato grower and you want to get something into or talk to your local grocery store produce manager or your garden center manager and they can talk to the certified seed potato growers but it takes about three years to get geared up to produce potatoes for a new market. So if somebody wanted to grow our beautiful Dakota Ruby for example it produces a high set of beautiful bright red skin round like apples potatoes very high yielding but in order to you know you probably aren't going to find it in the marketplace and so you might have to ask and then it might take them a year or two to be able to get them in but I would like to hope that some people would be adventures and try to maybe explore some different potato varieties than the old standards. Okay we can advance to planting. So when we are going to be planting in our gardens we're not going to be using a fancy machine like we have here for planting our research plots but I thought that it was kind of a good picture because it shows the hills that oftentimes we will use and as gardeners you might want to be forming as well and you have the opportunity to form those hills before you plant and then plant into them or you can plant into flat ground and then create a hill as part of your cultivation, weed control whatever you want to call it in the garden and I'll talk more about healing I believe in the next slide. So for spacing in our gardens most of us will plant our potatoes and rows that range from 30 to 36 inches wide or the distance from the top of the hill or the the row from the distance between the two rows would be 30 to 36 inches. Some potato growers will also use 38 inch rows but it just depends upon what equipment they own so you are welcome to do what you might what might work best for you within the row most of us will plant 10 to 12 inches apart or you know somewhere around a foot between plants or between seed pieces if we want to produce a high volume of very small tubers then we might want to put our seed pieces closer together within the row so maybe put plant them at eight inches if that is the desired tuber size profile that we would be after and then I have the word beds on my little bullet points here some people are starting to grow potatoes in what would I would call a raised bed it would be like a hill except that it would be three feet wide so you would you would build it up and then it would be three feet wide and some people will plant basically three rows of potatoes but they will be offset so they're more in a diamond shape and and again you can use whatever seed or within row spacing that you want depending upon what you're going to be doing with the potatoes or what size of potatoes you want and when we plant we usually plant our potatoes so that they are about four inches deep so if we've already formed our hill then we will poke them down to about four inches below if we are going to plant our potatoes and then form the hill we might just want to poke them in a couple of inches and then build up that hill as I mentioned when we're doing our weed control in terms of fertilization most of us would base our fertility management on a soil test and even we gardeners should probably be testing our soil every few years you know we're rotating our different vegetable crops around we are maybe adding some compost that we're making in a barrel on our patio sometimes there is you know backyard flooding so we are getting a mixture of soil from new construction you know in our neighborhood or or varying things so doing a soil test is a good idea and here at North Dakota State University we do have a soil testing lab and so you can get a little bag from them or just pull a few cores from your soil and put them in a paper bag and mail them or bring them in and they can run a little soil test report I would recommend going down to 12 inches in your garden and like I said do it every five years or three to five years or three to eight years just so that you kind of have an idea when it comes to actual fertilizers we can use commercial fertilizers like we would get at any of the big box stores or at our gardening centers but we can also use manure or other types of organic sorts of fertilizers and and it doesn't really matter what we are shooting for is we want to supply our potato plants with the proper amount of fertilizer so that we can attain a high yield with our commercial growers we have a little chart and we say that you know depending upon your soil test and your yield goal this is what you should be providing in terms of NP and K nitrogen phosphorus and potassium for we gardeners I guess I use more of a rule of thumb that we need to apply about one third of a pound of nitrogen for every 100 square feet of potato production we have going on some of us might have those beds or some of us might have rows and so I'll let you kind of do your own math but but that would be kind of a general rule of thumb for when we don't necessarily have a recent soil test when we are placing our fertilizer whether it be commercial fertilizer or manure we can work it into the soil pre-plant or if we want to we can when we're using commercial fertilizers like granular fertilizers we can place it two inches to the side and two inches below our seed piece the reason why we don't want to put it right with our seed piece is that we can um the the salts and commercial fertilizers can cause burning to the developing roots and develop developing shoots so that's a reason why we might avoid putting at least any type of volume of commercial fertilizer in close proximity to our seed pieces a typical fertilizer that I recommend for potato production we use it on the farm I use it in my research plots and it's a good one that home gardeners can usually access would be something like 15 30 15 and just to refresh everybody's memory that first 15 stands for N the 30 stands for I said N and didn't say nitrogen um the 30 stands for P for phosphorus and the last 15 stands for K for potassium potatoes are a high user of phosphorus and especially with some of the pHs that our soil pHs that we have in this area our phosphorus might not be as readily available as some areas where they have a lower pH of soil so it's important that we select a fertilizer that has a high phosphorus content or that we add supplemental phosphorus because it's very important for tuber production and for high quality tubers um let me see then a comment about manure we should use well aged manure um typically I would recommend that you apply manure to your garden in the fall before you're going to be planting whatever vegetables but especially potatoes and the part of the reason for this is that if the manure is not you know somewhat composted already it um has been implicated and causing common scab on potatoes but it also is more likely to be harboring things like weed seeds or even some insect pests and things like that so we like to say to incorporate well aged manure and to do that in the fall prior to our growing season now we can advance the slides to the culture okay so i talked a little bit about healing and hopefully um this picture you can see the hills and how the potatoes are coming up in the middle of those hills um healing is important for potato production for two reasons number one is it helps with water management so if we get a heavy rain or if we're using an overhead sprinkler in our garden the water will stay in the furrow part hopefully and um our potato plants will not have to wet the feet hopefully um that's one reason for the healing and of course the other reason for the healing is to help prevent greening of our developing tubers even sometimes as we're approaching fall and we maybe have had some dry soils we maybe have a really great potato crop coming up as our vines start to senesce or our plants start to die there might be some cracks in our soil and sometimes we'll find that our tubers have little um green lines or green splotches on them because they have been exposed to the light remember i said that the tuber was a modified stem so anything that happens to the foliage can happen to the tubers and greening is one of those things the tuber will develop chlorophyll just like our stems um so irrigation a reminder the potato plant is shallow rooted they're primarily in the top 18 inches when we have water stress we might see our potato plants wilting we might see a blue green gray color to our foliage and when we go to harvest our potatoes we might start to see some misshapen tubers they might be pointy on one end they might be shaped like a dumbbell there might be some external defects things like growth cracks or what i call knobs that are second growth and when we go to cook them and cut it into them we might see some internal problems things i call a heart so potatoes don't like water stress but they also don't like being over watered and that's the reason why i have our bullet late season watering as we start to see our potato plants start to senesce or die that you'll see yellow chlorosis and the plants probably will have kind of started to crouch down um or lay down in the rows they're not being hugely photosynthetically active probably we don't want to over water at this point because we can create problems where our tubers are struggling to breathe you might see some little white freckles on the potatoes when you dig them out of wet soil um those are the breathing pores and when the potatoes are struggling to breathe in the soil they will the those breathing pores will kind of expand and they almost look fuzzy those white freckles but because those breathing pores are wide open we can have some pathogens enter and then this can limit the shelf life or the storage life of our potatoes in our root cellar or in our potato storages so we need to be cognizant of late season watering we don't really have a bullet point in here indicating how much water we should be using or how much irrigation we should be doing but typically we um want to keep the top 12 inches of soil damp and we would be thinking about supplying about one inch of water per week a potato crop will use between 18 and 36 inches of water depending upon our soil type for a whole growing season you know for 100 to 120 day growing season so um so I you know certain soils are going to like hot dry sands are going to require heavier watering than if we're growing potatoes on our loams or certainly on our clay soils like we have here in the Red River Valley now on the next couple of slides we're going to talk about pest control and we'll start out talking about weed control first my first comment would be if you want to change slides would be that we do not use a herbicide in the garden now if we're growing potatoes for uh farmer's market scenario you're probably going to have larger areas but when we're gardening we tend to have a lot of different species and very close proximity to one another so I don't really recommend using herbicides in our home gardens instead that should be what I tell my mom is it's therapy after work you know at the end of the day it's a nice fun way to go out and you know do a little puttering around after supper weeding and tending to your garden it's a very peaceful enjoyable time of the day to listen to the birds talk to your backyard neighbors just uh you know just a better way to to handle weeds but there are some weeds that particularly seem to be problematic in in potatoes some of them like the nightshade like the picture that i'm showing here they're related to potatoes and so the two seem to come hand in hand but we might see things like fox tails or wild oats um in our farm fields a lot of times we'll see volunteer cereal grains so we might wind up with oats or wheat or barley depending what the previous crop here was oftentimes in our gardens we'll see things like wild mustard I definitely find a lot of pigweeds in lamb's quarters in my garden uh buckwheat is becoming a problem in some areas um certainly canada thistle can be problematic if we have it in our our yards or in a row ditch that it can easily move and the more tillage we do the more canada thistle spreads and then of course in my garden I oftentimes will find kosher and it depends on where you're growing your gardens or where you might be growing potatoes for the for a farmer's market or or a field but um the complexion of weed species might change depending where you are on the globe for insect pests um the major insect pest a potato is Colorado potato beetle and oddly I worked in Colorado for six years in the San Luis Valley we didn't have Colorado potato beetles but the original um naming of the beetles came because they identified these beetles that once they started producing potatoes in Colorado came off of the buffalo per which again is related related species to potato and um and so that was in the northeastern corner kind of near that Greeley area so so that's how Colorado potato beetle got its name but it doesn't mean that beetles grow everywhere in Colorado so the top three photos that I have the top photo shows you the the adult and they do some defoliation the middle photo shows you a potato plant that was defoliated by beetles and then if you look very very closely on that that very bottom of the top three but actually turns out to be the middle photo on the the slide you'll see some little larvae that sort of look like fat little slugs and um some people refer to these as pigs because they're kind of pink and they start out tiny in red um the eggs would be found on the undersides of the leaves and they usually are a yellowy orange color and then the closer they get to hatching they they kind of start to become this orangey yellow or orangey red color um but these little larvae then when they hatch they start eating and so the the size of these ones would have quite voracious appetites and they can consume a lot of potato foliage in just a day or two again in your garden i'm not sure if you really need to be using an insecticide um for control a lot of people will hand pick them or you can shake them into a little coffee can of something like turpentine or you can just collect them into a container and put them into your trash you know if you are uncomfortable with killing them but we i think in our home gardens controlling them is using insecticides is not as important as controlling them using another method like hand picking the bottom right hand picture is a picture of green peach aphids and they are literally covering the potato foliage in in that particular photo aphids you'll sometimes find in your garden they vector viruses or they can transmit potato viruses in your garden it's probably not a big deal but it's a huge issue for our certified seed potato growers so they like to control aphids many of them as a sustainable practice will release ladybird beetles because they're a natural predator of aphids that's something that you can purchase i know in some of the garden catalogs you can purchase a little tub of ladybird beetles and let them go free in your garden but for the most part growers have commercial growers have a hard time using any kind of insecticide because the aphids move and and they fly and so they struggle with that so they have to you know do other things which is number one try not to have potatoes with viruses in close proximity to your seed fields if you do have the aphids in your crop you might see some honeydew or you might see some crinkling of leaves like our and kind of some rolling like we see in this photo that could be a symptom of their their activity leafhoppers can be a problem in our area these little insects are quite tiny they do hop they sort of look like a teeny teeny teeny tiny grasshopper if you look at them closely they have wings they blow up on the winds from southern states and so sometimes if they've had a lot of them in southern states on other crops and they blow up will have a few leafhoppers around early in the summer generally not something that we need to control usually the predator insects get them flea beetles are another one that occasionally we'll see it will get that shot holding effect i my go-to plant if i am wondering if i have flea beetles i look at my radish plants because flea beetles seem to like radishes better than everything so that's the the story on insects the bottom picture is of wireworms and particularly if we're taking our or putting a garden in where we have just taken it out of sod or out of alfalfa we might see wireworms very rarely do we have grubs potato diseases in your garden hopefully you're not going to see too many the upper left hand picture is a picture of common scab again it's caused by fungus in the soil called streptomyces you may or may not have it it's a good reason to rotate spots in your garden and we can certainly peel it away it's not harmful it just doesn't look appetizing early blight is the picture in the middle and if you have a chance to come back and review this you'll see that those little lesions look like a bullseye the funny thing about early blight is early blight tends to come in late when our potatoes maybe have some kind of stress and late blight tends to come in earlier in the growing season late blight is in the lower left hand bottom picture and if we tip those leaves over we might see some mycelial growth around that kind of chlorotic yellow halo pink rot is the picture in the middle on the bottom and we would not notice this until we went to cut open the potato and it is a problem because your soil was too wet and particularly as the plants were maturing and then sometimes we'll see some scurfs the bottom right hand picture is a picture of black scur for rhizactonia some of us call it the dirt that won't wash off and there's another one that kind of gives our tubers a bronzy sort of sheen again neither of these are anything that you need to be scared of the the scurfs we can just peel them away they just don't look pretty they're kind of cosmetic but the other one we call silver scurf because of that kind of silvery bronzy sheen that we might see on some red potatoes for physiological disorders the upper picture is a picture with many growth cracks the middle picture shows you secondary growth or what we call knobs both of these are caused by as well as hollow heart which is the bottom left hand photo all of these are caused by our potatoes being under some kind of a stress usually heat stress and or water stress then we have an alleviation of that stress by either cooling of temperature or by supplying some irrigation or or getting a rain and then our potatoes decide that they're going to grow really really fast all of a sudden their fertilizer is available the temperature is nice so they grow really fast sometimes they manifest themselves in a crack on the outside of the potato sometimes it causes the dormancy basically to have been broken in some of those eyes so they form knobs or it causes a physical tearing on the inside of the tuber when we have very rapid growth because the potato can't keep up and and so we get that hollow heart or brown center we also might see some different misshapen tubers you might get the baseball gloves or we might get these pointy tubers like we have in the hollow heart picture and then the right hand picture is bruising this is a picture of black spot bruising and this is what happens when we maybe handle our potatoes roughly we're picking them up into plastic buckets and dumping them into something else or we are touching them hard with our potato digging fork so when we peel it we might see that black spot then for harvest we're already thinking about harvest i have new potatoes here because a lot of us if we plant early in the season i know some people like to plant on good friday we probably while even if we plant in may we might have new potatoes for the fourth of july for example if we want to harvest a couple of plants i recommend only harvesting what you can eat for that meal because they are small they have very thin skins they desiccate easily so i would just harvest a plant or two enough to get a pot of potatoes to have with peas and and call that good if we're going to be digging our potatoes to store then we want to have more moist soil but not wet but moist because again that kind of provides a cushion and then we need to be cognizant of temperatures growers do not harvest below soil temperatures of 45 degrees fahrenheit and they do not harvest when the temperature is above 65 degrees fahrenheit we have a little bit more leeway in our home gardens but really ideally we'd stay in that 20 degree range of 45 to 65 degrees and then lastly in terms of storage if we have a root cell or something we should be storing our potatoes at 90 to 95 percent relative humidity we don't want to have free moisture but we want to provide humidity because during the curing part that initial 10 days to two weeks we are allowing our potatoes to heal up any wounds that they might have and also to allow for the skins to set if need be we want to keep the initial temperature in that 50 to 60 degree range if we're going to be storing our potatoes over the winter then we gradually lower about one degree a day down to 38 to 40 degrees if we can and then I have light and light is really key again because if we forget to leave the light on in our root cellar or we have an open window in our basement and our you know an uncurtained window in our basement and that's where we're storing our potatoes they're going to be exposed to light and we're going to develop some greening some people are actually allergic to that green area and we can peel it away but if we don't and someone eats that they can develop a tummy ache or develop some flu-like symptoms and this is due to a natural insecticide called glycoalkaloids in the foliage and so that same thing happens in our tubers because our tubers are modified stems. Okay I think I've covered a lot of ground I didn't talk quite as fast maybe as I thought I was going to but I'm game to answer questions if people have them Susie there was one question so far from Diane what can we do for scab? Okay well scab is a soil-borne fungus so if people have it in their soil then if rotation is an option I would consider that you know to somewhere else in their garden maybe where they haven't grown potatoes or other solanaceous crops recently. There are very few fungicidal like seed piece or seed treatments or anything like that that we can use. There are some varieties that are a little less susceptible than others but this might be a good instance where the they maybe want to get a soil test and see what their soil pH is. Maybe there this would be an opportunity to do a little bit of soil amendment you know add lime if that if the pH is too high or add something else if they are growing potatoes on a more acidic soil because people also get common scab on acid acid soils it's called acid scab in those cases. We have time for one more question and we have one more here what cultivar do you recommend for a potato box? For a potato box I guess I don't I'm I'm not sure what they're referring to as a potato box maybe they can maybe I can answer the other question that popped up while they describe what a potato box is. Sure can you use your stored potatoes for seed potatoes? I do not recommend that people use their own potatoes as seed potatoes because you are not a seed grower and you know nobody's coming in and inspecting your crop during the growing season and inspecting it during the storage season like like rail certified seed potato growers do. I think that in many cases your yields are going to decline you're going to wind up with a lot smaller of tubers and you're going to have unthrifty plants. So here's a little more on the potato box question. She means growing potatoes in an elevated box where you add layers to the box as the potatoes grow. Okay this is a great question. I have not ever grown potatoes in in such a growing system but because they are are growing in a box like that I'm guessing that you're looking for something that is going to be putting on additional stolons and growing more tubers. You probably would want to pick a variety that would be more of a indeterminate variety. Something like red norland is is very determinant it's you know and also very early maturing so so I would not pick something like that. Out of our and I probably would not pick a Yukon Gold either because they they're not going to set more tubers. This is a little perplexing. A variety that might work would be redless soda if you could find it. I think that our Dakota Ruby could. There are some European varieties that you might find around. There's one called Molly. It produces a lot of little round tubers probably 20 per plant and they would have yellow flesh but again it's kind of going to depend what you're what's available at you know for your in terms of your source your garden supply store or your grocery store or or maybe you have a favorite seed catalog. So we have two more questions and then we're going to have to cut it off for the day from Linda. Can you use your stored potatoes for seed potatoes? Okay I answered that one previously and I indicated that I prefer that you not. I think that you're going to see a significant yield decline because if your potatoes have picked up viruses or other diseases they the tubers are not going to enlarge very much. Also your plants are not going to look healthy and your your crop is only as good as the quality of your seed. Okay and final question does the purple color or whatever color disappear after boiling? This is a great question. The purple if you're growing something or yes growing something like all blue or or say you bought it at the farmers market or there are some purple ones that have recently come out of Colorado and I can't say the name of it but if you leave the skins on the purple color will be retained in the flesh. If you peel them and put them into your salted water or whatever then yes the potato or that that purple color is going to dissipate and if you tried to mash them they would be gray. If you want to retain them one excellent preparation method is baking or microwaving and a lot of times in when I grow the purple ones and my girls were little or one of our school colors was purple we would make purple french fries and I actually would bake them on a baking stone after I peeled them and then the purple color was retained and of course they got a little gold and brown on the edges but but you could still tell that they were purple. That sounds like fun well I think I'll wrap it up for the day and I first want to thank Susie Thompson for a great talk. I think we all learned a lot and I also want to thank all of you for joining us and please join us again next week.