Plant Nutrition Sherlock Holmes Style

planned nutrition Sherlock Holmes style hopefully you're all here to learn a little bit more about plant nutrition and trying to take well hopefully take some of the mystery out of identifying plant nutrition problems specifically deficiencies and help you be a plant detective a plant nutrition detective on determining why you're having those deficiencies because identifying the deficiency is really only half of the problem so we're going to go through a number of different things we're going to follow this track triangle here the first thing is we're going to look at the symptoms what is caught or what the symptoms look like how to identify the nutrient deficiencies then we're going to look at the causes what are some of the causes that cause the symptoms and then I'm going to go over the process that I take when I'm trying to identify not only what the symptom is and what's causing it about how to diagnose the cause and what we can do to to remedy it and finally we're not going to do the practice today but practice is a big part of this this is not something that's going to come naturally after watching this webinar you're going to have to take these techniques and apply them on a regular basis to put them into your long-term memory so let's let's go back to symptoms and we're just going to talk about nutrient deficiency symptoms and identifying those deficiencies when we're doing this I'm going to go over just recognizing the actual symptoms broadly what I mean just going to go over some vocabulary then we're going to talk about the mobile elements the partial uhm partially mobile elements and then finally the immobilize wrong way sorry about that so some vocabulary I kind of stumbled over this up for a long time when when people talk to me about mobile elements and immobile elements and what we mean by mobile elements is not only do the elements get taken up by the plant because that's mobility but what we mean by mobility is can they be reallocated throughout the plants they move into the leaves and can the plant move those elements out of the out of those leaves and into different parts of the plant that mobile element notice that we have these two directional arrows on the leaves now when we talk about an immobile element once those elements get distributed to the plant to the leaves they're stuck there the plant cannot reallocate those two different parts of the plant as needed some more vocabulary chlorosis when we talk about chlorosis it's these this yellow in either a yellowing of the entire leaf or in our vinyl chlorosis that you see here on the right hand side but some type of yellowing to the leaf now that's converse to necrosis necrosis is some cell death some browning and it can be caused by a number of different things but necrosis refers to death or browning of leaf tissue just some examples of flower deformity this plant on the Left the flower it's kind of curled a little bit it also is discolored and then obviously the one on the right not all the petals are formed this isn't a case of the petals fell off these petals just never formed some leaf distortion some these petunias on the left you can see obviously these aren't what you would expect there's just some serious leaf distortion there or some leaf curling as we see here on the on the lily so we also have some speckling that can take take effect and here we see this in in these pansies that you see the spotting of some kind of a necrosis across the leaf blade so did it to move on we're going to use it kind of like a dichotomous key for the first part of this this presentation to be able to determine what the nutrient deficiencies what the symptoms are a lot of you probably use it economist key to identify flowers or trees or birds you know field guys that are dichotomous key to ask you a 2-part or a question with with two possible answers and depending on how you answer that question it takes you down one path or the other it's a very simple process of elimination so the first thing that we want to do is we want to start by asking the right questions and the first question that I always ask myself are are you really dealing with a nutrient deficiency and the way to determine that is to look for patterns or the lack of patterns within the green house or the flatter plants that you're looking at so usually if it's an insect or a disease what we call a biotic problem it's typically no pattern is involved but if it's a nutritional disorder or another environmental problem we consider that an abiotic problem there is a consistent pattern I'll show you some some examples of that so here's a just a line-drawing if we looked at that and if we folded this leaf in half is there any symmetry is there a pattern and we would generally say no because the spot up at the top and the spot down of the bottom and those spots in the middle they don't really line up when we when we fold that leaf in half so we don't have a pattern there which leads us to think that it's an a by a or it's a biotic problem like an insect or a disease now let's look at another line drawing and if we fold that leaf up it's not perfect perfect symmetry but it's a lot better than the one before we have the the necrosis or the lesions on the edges of this leaf and it's almost symmetrical so this was with this would be an abiotic disorder um here again is some some real plants in a greenhouse and you notice that it doesn't if we fold this picture in half it doesn't seem like their symmetry or or that there's a pattern but if I told you that there's two different irrigation lines here the one on the right with the lighter colored plants is on one irrigation zone and the one on the left is on another then you would say like aha there is a pattern here the entire crop is being affected so this would be an abiotic factor here's a pot of petunias and there doesn't seem to be any cemetery two of the plants in the pot are unaffected one plant is completely decimated in another plant we see some some effects of whatever problems afflicting this so there's no symmetry so this makes us think it must be a biotic factor and it was some type of a disease looking here there doesn't seem to be a huge or there is a little bit of a pattern but this this one can be tricky um this is actually just a genetic sport mutation so there's a little bit of a pattern that it's always running down kind of one side of the leaf or the other but it's not a biotic factor like an insect or a disease here's a real common one with poinsettias and you notice again we don't see a pattern there's a plant that's unaffected right next to a plant that's affected right next to another plant that's unaffected there's it's very random so this is a biotic factor a disease here on marigolds all these plants have the same symptoms in the same place there's lower leaf yellowing and if we look at the whole crop we would see that yellow with lower yellowing of the leaves across the whole crop it's not random at all there's a pattern so yes this would be an abiotic factor and in this case it's a nutrient deficiency so the next thing we want to ask ourselves is where do we see the symptoms on the plant and this is where the mobile and immobile part of the elements come into play if it's a mobile element we see the symptoms on the base of the plant because the plant is prioritizing the younger tissue that is needing those nutrients and it reallocates the nutrients that are in the lower leaves of the plant up to the top of the plant so those symptoms of nutrient deficiencies show up at the base of the plant when it's a mobile element and here you see problems in this cleome we're having the lower leaf yellowing it's a nitrogen deficiency and that plant is needing that nitrogen at the top plant and it's reallocating the nitrogen in the bottom leaves up to the top of a plant now conversely with an immobile element we're see the symptoms at the top of the plant we see them start at the top of the plant so they can't be reallocated from the lower leaves to the top of the plant where the plant needs it so we start to see the symptoms at the top of the plant and this is the classic iron deficiency with calibrachoa the iron is needed at the top of the plant the growing point but the lower leaves cannot reallocate the iron up to the top of the plant so the symptoms start at the top of the plant and then finally those elements there's a couple elements that are partially mobile they're not really efficient to being moved but they can be moved so you sometimes see those in the middle part of the plant or the whole plant now the important thing with this is that you really aren't honest with yourself of where did you see the symptom start not necessarily where did you see it now two weeks after the symptoms presented themselves in the first place because at that point is probably going to work its way through the whole plant but when did you first see those symptoms and where did they start that's the key so here's a question here's an example of a partially mobile element sulfur you can see on the right hand side this plant is has just an overall chloro chlorotic look to it and those symptoms all came together at the same time throughout the whole plant so now that comes to what are the symptoms that we're actually seeing so we're going to break that up by by the different mobility of the elements because now we're starting that process of elimination we're not just pulling these symptoms and these diagnosis out of the air it's a process of elimination so let's go with the mobile elements so at this point we've decided that it is certainly an abiotic factor we've asked ourselves is there a pattern to it is there any symmetry and we've said yes there's a pattern so that we know that it's an abiotic factor we're to assume that it's a nutrient deficiency here the next question that we've asked ourselves here is where did we start seeing the symptoms we see the symptoms at the top of the plant the middle of the plant or at the bottom of the plant and with the mobile elements we've answered that question that we first started seeing those symptoms at the bottom of the plant so just with those few questions we've narrowed it down to only four elements that can be a possibility nitrogen potassium phosphorus and magnesium so now we need to look at the symptoms and this is where it gets really tricky because when I was first introduced to nutrient deficiencies in the diagnosing knees and for years and years people would explain them to me and I would see the same symptoms recur over and over and it became overwhelming and that's why we're taking a systematic approach of pulling out questions and the process of elimination so we know that if on the bottom of the plant if the symptoms as we see are uniformed chlorosis now we have narrowed it down to either nitrogen or potassium or I'm sorry nitrogen or phosphorus and if we look at the the symptoms for nitrogen and phosphorus we see that we have uniform chlorosis stunting early flowering possible red color or leaf obsession with nitrogen and if we compare that to phosphorus a lot of those seem to be the same symptoms so what we're you see that there's a lot of the same symptoms here that are that are highlighted now if we disregard those ones and we look at the ones that are distant that are unique to each one of those those are the symptoms that we want to focus in on so early flowering in nitrogen and leaf incision along with these other symptoms and deeper green foliage initially and fewer and longer roots with with the phosphorus so let's look at nitrogen deficiency so we have this uniform chlorosis starting at the bottom of the plant and when it progresses to a certain extent we will get some necrosis but if you look at this here we see some severe stunting with the plant on the right that doesn't didn't have any nitrogen and you notice how far in a flower this the one on the right without any nitrogen is compared to the control plant those flowers are all open fully open compared to the other ones that there's are some buds starting to show color and just one or two that are beginning to open so we have that early flowering now looking at the the phosphorous we're looking at that deep green foliage and the fewer and longer roots the plant on the right this is the initial stage you see a little bit of darker green color to those plants on the right that have phosphorus deficiency you can also get that purple in color and that's a pretty distinct one but it's not always the smoking gun because there's several other deficiency symptoms that show some purple Ainur or red in color but if you take that plant out of the pot and it truly is phosphorus deficiency a lot of times you'll see fewer roots in the roots that you do see are very long and slender you don't have all those root hairs that you would expect to see now if the deficiency symptoms that we're seeing on the lower part of the leaf is in terminal chlorosis we've made it really easy it's magnesium it's the only one only element that has that type of interval chlorosis on the bottom of the plant so just to give you a look at that it's on the older leaves then eventually we will get some necrosis and again some possible red possible red coloration on the older leaves but we're really interested in that chloro interval chlorosis on the on the older leaves and this is these are the symptoms that we're looking at you can see these chrysanthemums on the right you know that the upper part of the plant live great but then again at the bottom we're starting to see that intervener chlorosis and then you see a close-up of another plant on the left you see that that kind of modeling the chlorosis is is not across the entire leaf but it's just the inner vinyl portions of it and again some some more looks at it here on the left is pretty classic you can see that the the veins are still pretty dark green and the tissue in between the veins are turning chlorotic and finally with our mobile elements we have potassium so if we have the first symptom that we see is some type of a necrosis on the lower parts of the leaves it's probably potassium you might see some chlorosis at the the tip or the margins of the leaves but it's going to happen very quickly it's going to rapidly turn to necrosis so that's the the portion that we're really looking at and here's some examples here like on this wax begonia up here in the upper left hand corner we never you can see a little bit of chlorosis on those upper leaves on the margins but it really went to a fast necrosis on those edges of the leaves and again here on on poinsettias you see that marginal necrosis really coming in and it really sticks to the to the margin there so that sums up our mobile element we're going to move on to our partially mobile element and the first one is is sulfur you're going to see a uniform chlorosis or the entire plant you might see some necrosis also some faded flower colors and the leaves are Internode's might develop some red pigmentation a lot of people with the music deficiencies really hone in on this red pigmentation because it's easy to identify but if you've noticed I've talked about two or three other elements that also can develop red pigmentation so it's not always the best one to go by so for stool for real look for that uniform chlorosis of the plant and the faded flower colors and here's another picture of sulfur sulfur deficiency we have stunted growth and that whole plant is just chlorotic it didn't necessarily start at the top or start at the bottom and all came across the entire plant at the same time and here's an example of it going to a very advanced stage and giving some necrosis on the leaf tip we also can see some some flower color fading and this is tough because you have to know what you should be expecting oh I'm sorry this is the the necrosis again of the leaves and down here is is the faded flower color you can see that the control on the left hand side of this photo is nice deep purple and then you get a nice lavender as you go off to the to the right and this is important to know what cultivar you're expecting and look at the other symptoms too because that that light lavender in the middle is not a bad color to look at it could be a very desirable color but if you're expecting the color that's a deep rich purple you know that something's not quite right now molybdenum is is pretty easy for the ornamental crops because the only ornamental crop that we have really seen molybdenum deficiency is in poinsettias so you can always be looking for that in poinsettias and don't really have to think about molybdenum too much in our other oriental crops and it's just a clear clear attic band around the leaf margin is the thing that we're really looking for and sometimes this can um excuse me be some mistaken for psycho cell damage because psycho cell damage looks very similar to this on poinsettias if you know you haven't applied any psycho cell in the last week or so and you're seeing this chlorotic band around the leaf margin you know that you're dealing with molybdenum alright that's wrapped up a little over half of our deficiency symptoms we're going to move on to our non-mobile deficiency symptoms so these are ones we're going to see the first symptoms show up at the top of the plant and if we see the top of the plant become chlorotic for the first symptoms we're going to be thinking about iron or manganese if we have a group necrosis and distortion at the top the plant it's going to be either calcium or boron and then finally if it's the most recently mature leaves so that second-ranked leaves up at the top of the plant is copper or zinc so let's look at iron and manganese first again if we look at these these symptoms are very similar so we're going to look at the things that are are unique to each one of those and that's the chlorosis that clears to yellow or white and then the Krause is for that iron and then the tan flaking firm for manganese so iron deficiency is probably the the most most the deficiency that we see the most in greenhouses it's pretty recognizable for most of us it's that that inner banal chlorosis of the young tissue oftentimes associated with with pH problems but you know if you've grown petunias or calibrachoa and gerber daisies most of us have probably seen iron deficiency at one time or another um with manganese deficiency you know we get this tan flaking of the of the young tissue so we see necrosis come in pretty quickly much like we see the necrosis come in with the potassium but this time it's at the top of the plant not at the bottom of the plant so you can see these photos here that we kind of get this necrosis on the leaf margins a little bit but really across the leaf the leaf blade I'm in this kind of random pattern here so calcium and boron if we see necrosis or m and leaf distortion at the top of the plant we're going to be thinking about these two elements and as we have seen with every element up until then here there's a lot of similarities between these two so we want to look at the differences with the boron we're also going to see in addition to the distortion and the incomplete flower form a flower formation in the short density branch roots we're going to see short Internode's thick leaves or Corky the boron deficiency and even growing tip abortion and excess branching to the plant almost looks like it was pinched but let's look at calcium first this one you know we see this leaf distortion a lot of times you see with these two photos on the left hand side it almost looks like there's a drawstring at the base of that leaf and somebody just pulled that drawstring up a little bit and curl the those margins of the leaf up and into each other and then as it progresses oftentimes we'll see that necrosis at the tip of the plant we see the incomplete flower formation and and really what this is is a symptom that we are very familiar with with tomato production and that's blossom end rot it's it's the flower form the flower which it was at the end of this tomato that the blossom end of the of the tomato it rots away because we don't have the calcium in there to help with the cell structure and we have that breakdown and that necrosis happening on the fruit or in our case we don't usually grow it all the way to fruit with our ornamentals with that incomplete flower formation and corks pot and apples is pretty common calcium deficiency will see those primary and secondary roots get are much shorter as you can see the plants here on the right have calcium deficiency associated with them roots are shorter and have quite a few more branches on them now if we look at the boron deficiency we see some of the same things but our again our incomplete flower formation the flower the pansy flower on the right has boron deficiency and it's obviously not forming into the flower that we would expect we have oftentimes collapse of the flower stem if you see here that in the tulips and here's a real kind of a smoking gun for boron deficiency here it is in pansies but it almost looks like somebody came and pinched the growing point out of this at and then we start to get some some lateral shoots coming in and in fact we did get to an abortion of the the growing tip it wasn't because somebody pinched it out is that the born wasn't there to complete that formation and it died out apical dominance has been lost and we get these pleura for a ssin of side shoots also the the leaves become very brutal and quirky if you feel in between your fingers they're just much thicker and more brutal than than what an uninfected plant would normally be with the blonde deficiency we get those thicker roots kind of club' roots is what we call them sometimes but fewer roots those secondary roots and just to pay attention to to looking at the bottom of the pot so that takes care of four of our immobile nutrients we have two more copper in sync these ones I don't really come across very often not something that we should be overly concerned about but something that we should be aware of still so we're looking at the young and recently matured leaves so not those newest ones that are still forming but those those ones are just expanded just below that so we have leaf curl variable chlorosis with both of them rapid necrosis of the fully expanded leaves so now we're looking at the difference between between the two and copper will gets smaller lighter colored flowers or no flowers at all um and that's very similar with sulfur we have that same scenario with sulfur but we showing up on the the most recently which are the most recently mature leaves with some of these other symptoms whereas with sulfur it's coming to the whole plant let's take a look at some examples we have this leaf roll here and then here's the the difference in the in the flower color the one here on the left is copper deficient and you can see that's it's much lighter purple to even pink but again you need to know what you're expecting because if this is the only symptom you see you might not notice it unless you know that this cultivar that you're growing should have a dark purple flower to it you know is here there's no flowering on the copper plants or the the copper deficient plants it's the same same cultivar grown at the same time but they're smaller and the flower is as the flowering just hasn't happened and here's something like with what I'm talking about with those recently matured leaves the growing tip here at the top of the plant isn't really affected but it's dropped all these leaves kind of in the middle of the stem and then the lower the stem again the leaves aren't affected finally let's look at sink we get the curling chlorosis of the young leaves a lot of times I hear people calling this kind of mouse earring if you can this is an apple tree and if you think about it it kind of looks like it's curled up and it looks like a little bit of like a mouse ear and again those small those most recently matured leaves the plant in the middle is is the control and the two plants on either side are deficient in zinc and you can see that middle section was most recently mature leaves are the ones that are affected so that sums up our kind of our key of our deficiencies nutrient deficiencies I haven't posted the the handout yet I apologize for that but I'll get that on my website shortly later today but you can download that along with that there'll be a one-page sheet that kind of goes through this dichotomous key for these nutrient deficiencies if you want to see more photos of a lot of different bedding plants there's this nutrient deficiency in bedding plants book that was written by a number of people at NC State you can buy this on amazon.com it has a whole bunch of float full-color photos of plants that were induced to have these different deficiencies so you can see but you can be expecting so right now before we're going to take a quick little break but before that I want to take any questions that any of you might have so go ahead there's a couple of questions here let me look at what we have okay nope no questions yeah don't give give you a couple of questions a couple of minutes to to get things typed in there if you have any questions about this so there's a couple questions early on that I didn't see about listening or being muted all of you are muted by the by me the organizer so we don't hear any background noise all right so it doesn't seem like there's any any questions at this point oh here we go now I got some so the the question is tell the difference in iron and manganese and iron is going to have the inner vein on chlorosis on the top part of the plant that's going to be the kind of the telltale sign for that and manganese is going to be on the top of the plant but will have that tan flaking some a little bit of necrosis it's throughout the band of the leaf blade I see there's a couple more questions so so the question is would someone need to do a soil test in order to determine which mineral is deficient and doing a soil test is one option to help you with the diagnosis and we'll go through that a little bit more the next part of the webinar but I usually look at the soil test as or substrate chest is kind of a look into the future of what is available for the plant to take up as opposed to what has been available and what the plant has or hasn't been able to take up because the depending on fertilizer fertilizer events and irrigation events you might have applied the right amount of nutrient to the plant it just hasn't been taken up to buy the plant from the substrate and that can be for a number of reasons and pH is one of them and it will we'll get into that a little bit in the next next part of the seminar let's see I'm not going to be talking about highlight aggravating magnesium deficiency I'm not going to get into that at all in this webinar so there is a common that just some of the symptoms look almost identical and I totally agree with you and that's why we use this systematic approach that you know iron deficiency and and and nitrogen deficiency have very similar symptoms but they just show up on different parts of the plant so there are some real key things that I've kind of underlined or highlighted throughout this webinar and it'll be in my hand out too if you look at these key symptoms on specific parts of the plant it starts to become much more clear and then the last question is why some why are some cations mobile and some immobile and and that's not an answer that I have off the top of my head right now I can look that up and try to email that out if you would like me to so that's all the questions we have now for this section it's my clock says 136 right now so how about we take about a four minute break so 140 in four minutes we'll start up with the second part of the webinar okay everybody my clock says 140 so as promised we're going to keep moving on so we finished up our first section with with symptoms and going through those symptoms and trying to identify those and just to to let those know who maybe showed up a little bit late um we are recording this so you will be able to watch this webinar in the future and also I do have a notes for this I have the slide handouts also a handoff to to help you with the keen of the symptoms I apologize for not getting that up on the the web prior to this webinar but I'll get it posted on my on my website that's NH floor culture calm I'll have that up on that website later this afternoon so we're going to continue on with the webinar and the next thing that I want to cover is the causes what can cause some of these symptoms obviously we know that it's probably some type of a nutrient deficiency but what's causing this this nutrient deficiencies is the next section that I want to go through so we talked a little bit about this earlier is trying to determine if it's an insect or disease or a nutrient deficiency and I just want to show you picture this Marigold that this does look a lot like a nutrient deficiency this could look be like a potassium deficiency with the necrosis on the edge of the leaves on the older leaves but in actuality this is an insect problem if we looked at this whole crop we would see that there's there's no real distinct pattern it starts in one place and it's very random so I just want to bring back this this message that just because it looks like a nutrient deficiency at the leaf level you need to look at the whole crop and decide is it really going to be a naturing deficiency or is an insect problem same goes with diseases here's some Mariga or some sorry some geraniums and they look very much like maybe a nitrogen deficiency but again you look and there's no real pattern to it you see plants that are affected and not affected right next to each other so we have a disease that's mimicking a nutrient deficiency symptom watering can cause nutrient deficiencies getting waterlogged substrate can can inhibit the uptake of nutrients and here's a case where we have some iron deficiency in this thinka and a lot of us know that vinca doesn't really like to be held wet for very long and when it is held wet we we slow down the metabolic processes that take up some of these elements and we get that deficiency even though the element is present in the substrate and this is where we're going with where i was going with the substrate testing of the soil testing is if we did a soil test on this we would see that there's enough iron in that substrate but the plants not taking it up so it might not have been the best diagnostic technique to figure this out so some of this up our watering techniques can induce nutrient deficiency symptoms when we look at the water itself we look at water alkalinity and water pH these can have effects on our on our nutrient deficiencies now we need to know what the difference between water alkalinity is and what water pH is and water alkalinity is the amount of carbonate and bicarbonate dissolved in the water and water pH is them is a measure of the hydrogen ions in your water and that we just to the to the concept that water pH has very little effect on substrate pH it might have a minor effect initially but you can have a very high water pH you can have a pH of of seven seven and a half and not have much an effect on your substrate pH depending on the fertilizer that you're using and depending on the amount of alkalinity that you have in your in your water so alkalinity is really what it is driving what's in our water which is driving the pH of our substrate up or down and it's important to check that water alkalinity on a regular basis the question that I get asked right after I say this is well what does it mean to check it regularly and I guess that depends on the type of operation that you are if you are a seasonal operation only producing the spring bedding plant crops if you do an aqua limit II test at the beginning of the the season that's probably good enough if you're a year round and you're producing through this the summer fall and winter probably every six months once in the winter once in the summer will give you an idea because alkalinity can change with the seasons depending on where your water source is coming from and the availability of water you know in in case of a well and if you're from a municipality if your water is coming from a municipality they might be pulling water from a number of different sources any given day and alkalinity can change but it's just a good idea to know that baseline of alkalinity and an alkalinity test you send it out to the lab is probably going to cost somewhere between thirty and forty dollars so it's not going to break the bank and it can save you from a whole lot of heartache and headache if you know what you're dealing with you're out and water alkalinity temperatures if you have improper temperatures with your with your crops in your greenhouse those can mimic some some nutrient deficiency symptoms here's a marigold crop this this crop is grown very cold and you see this purpling on the lower leaves it's it's one of those symptoms that most of us associate with phosphorus deficiency and in fact if you took a tissue sample of this it would be phosphorus deficiency but it probably isn't because there's no phosphorus in this in the substrate is because the temperatures on the greenhouse are too low the substrate then the physical and chemical properties of the substrate can have a huge effect on nutrient uptake and the um presentation of symptoms here in this point set a crop we we see some symptoms that look pretty pretty classic as a nitrogen deficiency but if I as I started to talk with this Brower I was realizing what was really happening if you notice the lip of that substrate I'm compared to the to the top of that pot it's then compressed quite a bit but the the plant the feather the physical properties in that substrate had been broken down due to improper handling of the substrate and it compacted down there's not enough air space in that pot for the for the roots to get enough oxygen so it decreases its ability to take up nitrogen and we're starting to see nitrogen deficiency even though there's adequate nitrogen in the substrate that substrate was compacted and there's low air volume in that substrate as opposed to the root ball on the right you see some nice pore space and some good healthy roots and that draining process is doing really well the fertilizer itself can be it can be a problem not all fertilizers are supplying all the elements it's they're not all complete fertilizer so we need to look and make sure that the symptom that we're seeing um doesn't coincide with the element that's missing from our fertilizer there can be antagonism some elements are competing for uptake by the plant with another element so if we have an excess amount of potassium calcium deficiency can can occur if we have an excess amount of nitrogen also calcium deficiency and if we have an excess amount of calcium we can have a deficiency in magnesium so we want to kind of look at a ratio of a potassium calcium magnesium ratio of four to two to one and our fertilizer mix to try to keep those in balance so we don't run into antagonism there's all fertilizers are either potentially acidic or potentially basic and this along with water alkalinity will drive the pH of our substrate up or down depending on if it's potentially acidic it has a potential to lower the pH and if it's potentially basic it has the potential to raise the pH of the crop and depending on the crop and and what it likes to throw and it can causes problems because we've we've all seen this chart where we see the pH is ranges and in what the element availability at these different pH ranges are and we usually try to recommend that growers keep their pH somewhere between like a 5 5 to 5 8 or 6.0 because that's kind of the sweet spot where the most of the elements are available at a maximum level or at least a an ideal level and we get outside of that we start to run into some problems one way or the other um checking the the pH and EC of our substrate is really key because of that also the EC or the electrical conductivity is the amount of dissolved salt in our in our water or in the soil solution and if the EC gets too high we might run into a problem that we see here with these mums this can be mistaken for a nutrient deficiency but in actuality it's just fertilizer berm that there's too much salt buildup in the substrate and the plants taking up and becoming necrotic where those salts build up we can use our pH and EC meter to calibrate our injector because if our injector is not working right we're not getting the fertilizer to the plants that we expect checking our substrate pH which I already covered so that we're falling in that 5.5 to 6.0 range for most of our crops and then the substrate pH like I mentioned with the with these mums here so um when it comes down to it usually the cause of our symptoms can usually be placing to one of these categories it's caused by an insect or disease not a nutrient deficiency at all I mean if it is a nutrient deficiency something to do with our water whether it's the pH or they are really the alkalinity of our water or the frequency of our watering um the temperature of our greenhouse or the temperature of our substrate in the that the roots are in the type of fertilizer that we're using does it have the right amount of fertilizer or one element versus the other element is it missing an element is it potentially acidic or basic and is that matched for our our water test with our alkalinity then what's the pH the EC of our of our substrate is that offers the the EC of our fertilizer water coming out of our injector correct as in our injector correctly calibrated so those are the causes now we need to have a systematic process because we have a systematic process of trying to figure out what deficiency we're working out with our symptoms we've looked at our causes now what's the process of troubleshooting which one of these causes is is making our symptoms present themselves and so that's our next part of our our presentation here and when I see a nutrient deficiency and I've decided which nutrient deficiency it is one of the first things that I ask and just about every time a grower calls me or emails me with a problem the first question I always ask myself or ask the grower is what's the pH and what's the EC if you don't know that as a grower and you call your extension specialist chances are good that that's the first thing that they're going to ask you and you're they're going to ask you to go back into the greenhouse and do a substrate test and it doesn't matter if you use a pour through or two-to-one method or a saturated media extract SME but you do need to let us know which method you use because that can skew the numbers one way or the other and my recommendation is to choose one of these methods and stick to it and always use it so that you be efficient at it and you get used to the numbers that you're obtaining from but the first process the first thing that I want to know within this process of diagnosing the cause of our nutrient deficiency is what what's the pH and eec of our substrate the next thing that I do that is all too often neglected is looking at the roots the roots can tell you so many things about what's going on with the top of the plant if I turn the plant over and I saw this root ball on these pansies and saw that as definitely there's not any problem with it with the substrate physical properties or watering or whatnot those roots look great there's something else causing this problem now if I look over on the right this happens to be a geranium plant I look at that and that root ball it's horrible if you look at it those roots are brown there's not a lot of roots on that substituting it's so wet so if there's a disease here - it's probably Pythium and now that root ball is just waterlogged so there's a number of different things that is causing the nutrient deficiency in this case the next thing if I haven't found my smoking gun yet I look at the fertilizer injector is it working properly and there's a really easy way to tell that on just about every fertilizer label you're going to see a table that looks like this table up on the right-hand upper right-hand corner of the slide and the first column says EC and if you have a hundred parts per million you should get an EC of 0.74 so you can use your EC meter to check the EC of the fertilizer water coming out of your injector to see if you have the if your injector is working properly there's a few nuances that you need to go through you need to it's a little bit more complicated than that but not much it takes about five minutes to do this test to see an in-depth process of this fertilizer injector calibration if you go to my website NH floor culture calm you can learn or you can find a video that goes through that injector calibration process we'd also just type into YouTube greenhouse fertilizer injector calibration and that that video of mine should come up and we also have on the e grow University website as well so the other thing with the fertilizer injector is is the fertilizer mixed up correctly I have worked at a greenhouse where we had the fertilizer recipe written in sharpie on the wall next to the injector but you know so many pounds of fertilizer and so many pounds of this fertilizer but our fertilizer has changed over the year nobody had changed the the Marquis recipe on the fertilizer or on the on the wall or we changed barrels we changed our different size of barrel that we were mixing our stock solution in so the recipes not being made correctly so there's two causes that I always go through with my process to eliminate those check their fertilizer injector calibration and make sure that the growers is mixing the fertilizer up the way they they intended to mix it up if you need a little bit of help with that brian wicker and i have come up with this program called fur cap it's also on my website NH flora culture com that will help you come up with the recipe to to mix up your fertilizer stock solution so you don't have to do the math the computer will do it for you paying attention to the weather are you seeing a deficiency symptom I'll go back and look at what the weather has been like has it been really sunny has it been really cloudy have the temperatures accidentally dropped in the greenhouse because the first went out or did somebody turn the thermostat down I'm too low for the night temperatures and and we're trying to grow those plants a too warm or too cold a scenario for that crop and then might delete late in it to have those deficiency symptoms the substrate how is the substrate handled many times I see this this example here on the lower right hand corner where when we have some downtime we'll fill our pots and our flats we'll stack them on the pallet so that they're ready for us when we need to transplant and our plants come in and there's nothing wrong with that but if you notice these plants or these pots are nested together and the close-up here on the right you see that they're compressed we're running in that same situation which I showed you earlier with that poinsettia is we've lost all the air holding capacity of that substrate and that plan is going to get waterlogged really fast and then you get on the upper hand or the top part of the slide you can see this played out um later in this season where we run into this endless process of spot watering because some of the plants are waterlogged because they we lost all but air holding capacity they don't dry out some aren't and we have this inconsistency so looking looking back to how the substrate was handled what the quality of the substrate was when it went into the pot can also be the cause and a question that I'm always asking myself as I'm going through this process of trying to determine why we're having this nutrient deficiency problem and that leads into our watering practices how are these plants being watered you know the plant here on the Left it just dried down somebody missed it and we're seeing the process on the edges of the leaves can be mistaken for a nutrient deficiency but if we think back to the the last few days or the last week we can remember oh we saw that wilting and now five days later we're seeing this necrosis as it's starting to grow back or I'm here with this geranium plant on the bottom right hand corner it didn't get fully water so it didn't get as much fertilizer in that pot is what we had anticipated we have half of the popping I'm saturated in half the pot not didn't get a full dose of fertilizer up here on the top right plants are really sensitive to cold water this plant had overhead irrigation applied to it and the water was really cold in that we had some damage from that cold water it's another nutrient deficiency it's just that cold water I'm having a prop having an effect on the leaves also with watering is the force that's being used from the hose breaker and here's a telltale sign that somebody was watering this with too much force all the pearlite is pushed to one side of the flat they were coming at one angle with a lot of pressure on that hose and making all the pearlite float and push off to the side and that pressure not only like made that pearlite move off to the side but over time you're going to compact that substrate and probably run into a problem with nutrient deficiencies because all that airspace is gone so um the the last thing though that I go that I have with the process that I lost my slide for that is a tissue test if I haven't figured out what the problem is to this point I will start going down the line of a tissue and a substrate test but those take you know probably a week at best to get those results back they can be expensive over time and they don't and they don't always give us the answers so it's always my last resort to go to the tissue and substrate test for nutrient analysis usually if I go through this process that I went just went through I can usually find the problem within one or more of those areas before I need the tissue test so the last part of this whole process is practice this is not something that you're just going to pick up today and just feel 100% confident after this webinar you have to put this in the process get this the systematic process in your head ed and run through it on it on a regular basis when I was before I was when I was a grower and when I first started grad school I'd see these extension specialists from around the country they would just click off these answers just so fast I mean it just boggled my mind because I thought they were just they were just that smart and they're pulling that answer just out of thin air and they just knew it right off the top of their head but as I spend more time through grad school and with with these specialists and picking their brain I realize that they're going through this process that I just explained whether it's the symptoms or the process of diagnosis of of what is causing the process or the the problem they're going through this but they've just done it so many times that it becomes very quick in their heads and it appears that they're just pulling out of thin air so don't let us fool you we're not as smart as we like to think we are we're going through this process very quickly because we do it on a very regular basis so that finishes up this second and last half of the of the webinar so happy to take some more some more questions there's a one question that came in about using sulfuric acid to control pH of in the high alkalinity in their water and they have a community if it looks like 270 parts per million can that cause a sulphur overload and it really shouldn't 200 parts per million alkalinity is is high but it's not abnormal depending on the part of the country that you're in and using sulfuric acid to to reduce your aqua linear trip to neutralize your alkalinity shouldn't cause the sulfur all overload and Brian wicker might be able to speak a little bit better to this with with nutrient toxicities but sulfur is not a toxicity that comes up very often so the other question was in regards to the picture of vinca that I showed that had the iron deficiency like asked if the roots were damaged or not necessarily damaged to cause that and no they're not necessarily damaged it's just because there is water log and it has too much water and that substrate and vinca doesn't appreciate that we just slows down the metabolic activity of those roots to be able to pull the the nutrients out of vote to substrate alright so how does pH how does the water pH have very little effect on the substrate pH can you explain this and I'll do my best without having any visuals here but the the water pH is just a very weak force on the on the substrate as compared to the potential acidity or put potential acidity of of your fertilizer or the alkalinity for all practical reasons alkalinity is really a lime application to your fertilizer or to your to your substrate so when you have a high alkalinity and you apply that over time what you're really doing is adding lime to your substrate every time that you're you're irrigating uh several questions about the printed guidelines for taking a tissue test I don't have any printed guidelines but I do have a video for that also you'll find it in the same places that you found the fertilizer injection calibration either on my website in each floor culture comm or will be on the ego University website Oh Brian whipper type Timmy said he's never seen sulphur toxicity ah then another question is how quick can you expect some of these nutrient deficiencies to correct themselves once the appropriate action is taken I don't think I have a really good guideline for for that if it's it's a it's really going to depend on the crop that you're growing the deficiency problem that you're having and how you correct it you know if it's something like a nitrogen deficiency and the plant is actively growing and it's just as simple as the plant wasn't getting enough nitrogen because the injector wasn't working you probably see a change in in it you know four or five days or or you know certainly within a week if it's something more dramatic than that it's really going to depend question about what is the most practical pH EC meter for a grower to carry with them I I've used a couple of different ones that I really like I like the the Hana 98 13 meter it's the meter that I showed a picture of there that's a really nice one that's what I like to use a lot it's not very handy to hold with you all the time it doesn't fit in your pocket um but spectrum meters makes a couple of really nice pH and EC meters that fit in your pocket really nice Hana does make a couple of small PVC meters that will fit in your pocket as well so yes the the website that I've been referencing is NH floor culture comm alright so there's a question about that is anything mimicked iron deficiency as far as another deficiency symptom you know something like a magnesium or nitrogen deficiency the symptoms look very similar but they show up on different parts of the plant and also as I showed you know that having plants that are kept too wet can often mimic iron deficiency even though it's not actually iron a deficiency in iron so I think that's all the time that we have unfortunately maybe some of you have heard that the daily leaf blowing from campus facilities is starting up again today outside my my office window so in lieu of keeping that noise to a minimum I think I'm going to stop the the webinar I want to thank you all for participating in the webinar today please email us with any questions be on the lookout for our webinars on the e grow website the recordings and we our plan is to have about one webinar a month through the spring and we're going to skip the December because of holidays but you will see more webinars from from ego comm so thank you all very much

Channel: e-GRO Webinars

Views: 90,624

Rating: 4.8596492 out of 5

Keywords: Plant Nutrition, egro, webinar

Id: AasjIXCkots

Length: 63min 58sec (3838 seconds)

Published: Tue Dec 03 2013