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Logo of 2019 Adventist Agricultural Association Conference: True Success

Plant Pathology - Part 1

Michael Trevizo


Farmer, Agricultural Reformer, Production Manager at Five College Farms, & Soil Scientist with a focus on Soil Science and Agronomy; Education: Bacherlor of Science in Crop and Soil Science, Oregon State University.


  • January 15, 2019
    9:15 AM
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My focus today is strictly on plant pathology that is a disease and as we're told it's my desire to teach you disease its cause its prevention and its cure because we are told by the Spirit of Prophecy that we need to become intelligent and disease its cause its prevention and its cure now she makes these statements was written with respect to disease in humans and disease in humans starts in the soil then it goes to the crops then it goes to the animals and the crops that are consumed by humans so let's go ahead and open with prayer Our Heavenly Father we thank you Lord for the opportunity to bring us all here this morning to. YOU THANK YOU for the opportunity for me to be able to share this information with everyone that is here and we pray Father that you would please. Be with everyone who is on their way who is traveling to come out to this convention we asked if you would bring them here safely that you give them Traveling Mercies father we also pray that you would be with everyone that's here that you would help me to convey this information in a way that would be most practical and useful for all those who have managed to maybe make it here this morning and Father we pray asking this and Jesus heavenly name Amen. Kids that I'd open up with some hope for those of you that perhaps have dealt with a lot of discouragement in agricultural lines but one of the statements that is made by Sister White ministry of healing page 127 she says and I think a lot of us are familiar with this the only hope for better things in this is in the education of the people and right principles because let physicians teach the people that restoration of power is not in drugs but in nature just like the medical industry and the agricultural industry we have largely turned to chemicals to seek for solutions to disease. And we are told that disease is an effort of nature to free the system from conditions that result from a by a lace and the laws of help this is about plant pathology this is about disease and plant so disease here that I'm focusing on is going to be plants and this particular statement Sister White was talking about disease and human however the principles are very much the same and case of sickness we're told 4 things were given for different councils the cause should be ascertained one to unhealthful conditions should be changed 3 wrong habits corrected and then finally for nature is to be assisted in her efforts. If we think about that now I think is adamant as we're used to thinking at this statement in health and we know that shortly after she made this statement she made us she said a few other things that led to what everybody now knows as the laws of health. However I really want you to take this and try to think about how you can apply this in an agricultural production system think of the diseases you're constantly bombarded with think about all the challenges you have on a daily basis trying to grow your crops and ask yourself the question if you were to take this approach where would you start to take a 2nd to reflect on that I hope that I can answer that question today but I'll go further on it now so education of the people and right principles is the 1st thing that we're told the only hope we have is education of the people in right principles I hope to bring that to you today. The only cure is what restoration of power is not in drugs chemicals patent nostrums which we can say patent chemicals patent plant genetics as well which has become very popular in the 21st century. Etc But in nature. Definition of disease. Now this is the definition that many ads in this use. Because it comes from Illinois the scientific community will not give you this verbiage that you see here in Illinois they'll tell you other things but it's surprisingly similar in the case of sickness we're told that the cause should be ascertained unhealthful conditions should be changed wrong habits corrected then nature is to be assisted in her efforts the main objective of this course of course is to ascertain the cause what is causing your crops to be diseased Secondly a job says I'm sorry the job said in. Chapter $2916.00 is the cause which I knew not I searched out. This is very important when it comes to your crops. He says in the case of sickness healthy condition should be changed from habits corrected nature supposed to be assisted and then we get to the definition of disease from a plant pathology a science textbook This is the definition we're given disease is that injures alteration of one or more physiological processes in a living system in our case a plant caused by the continuous irritation of a primary casual factor or factors so that's a lot of words right but what does that mean. Well. Pretty simply it means that you have in this particular picture you have leaf blights you have tankers you have Wilts you have. Sleeves spots stem Bly crown gals you can get root. Root rot you can get vascular we'll see the list goes on and on I mean there are so many diseases folks I mean I could just go on for days talking about diseases I'm not going to talk about every single disease out there what I'm going to try to do is take those diseases and categorize them into different from the different. Biological organisms so is it a fungus if so what type of fungus is it is that a bacteria of so then which bacteria is it is it an even toad is it is even a disease is it even a biological organism or is it a biological organism so I hope that you'll understand what that is in a minute for the 3 requirements for a disease is a pathogen agent this is again the scientific community a pathogenic agent must be present that means the pathogen. From fungus or bacteria viruses that are the host In other words if you have nothing you can have somebody sick and then of course the environment is conducive to the interaction of a pathogen and its host now I think I may have meant us in between these slides to put in the laws of health but I did not but. Anyhow this is commonly expressed of the disease triangle. And from a scientific standpoint what we're told is you need to have all 3 of those or you won't have a disease so if you don't have. A susceptible host then you will not have a disease if you do not have a pathogen then you will not have a disease if you do not have the favorable environment then you also will not have a disease so the from a scientific standpoint what they're telling us is that if you alter any one of those 3 you can get rid of the disease but again of course a pathogen suggests that it's another biopic living organism that is actually attacking your crops and that's actually a disease versus a condition of the host where maybe your have a mechanical damage or some other thing that is not actually a disease or I'm sorry a biological organism so then oh here it is I'm sorry the laws of health so we have we remember pure air sunlight temperance or also known as the stuff she says abstain Eunice I'm sorry that's a hard word for me sometimes rest exercise proper diet water trust in divine health etc If we take those 8 laws and we try to put them into the disease trying will say well the 1st but these 5 pertain to the host these 3 pertain to the environment so when we look at these 5 laws of health that pertain to the hostess nutrition of the host does not have proper nutrition Well the host been compromised therefore the host is now supple to a disease if the host doesn't get the proper exercise then it's compromised its health is compromised if it doesn't get proper rest it's compromise yes your crops do need rest some folks have tried to actually put grow lights on a crop around the clock guess what they don't like it they need rust to of stem in this temperance In other words you can't expect more than a certain amount of work out of your crop whatever it is good for that's all it's good for you try to push it harder than that you're not going to get it fine examples are when people don't properly prune flowers perhaps they put too big of a fruit load on their orchards or on their vineyards or etc etc You're expecting too much from your crop are not being temperate trust in divine power. You can't farm without trust in the vine power. And then of course there's the environment water pure air proper sunshine that is outside of the host it's the environment if you have the right environment it will be conducive to diseases so then of course there's the pathogens so which ones apply to the pathogens Well some of these have a double a double connotation because for the pathogen it too is a living organism so it's looking for the right nutrition it's looking for the right levels of like usually low light levels with most fungus it's looking for water and humidity most of the time if you have excessive levels of water or more sugar. It's favorable to pathogens to fungal development So these these laws the way that they're designed or at least the way that they're conveyed through a scientific standpoint very much falls in tune with what Ellen White was saying in fact she talks I think she goes further into it here they just kind of come to the surface and get real vague so I really like I prefer Ellen whites but all I'm really doing is I'm trying to take the prophet of the Lord and I'm trying to take the wisdom of the world and trying to take the truth of the both and mixing them together so you can see that what they're saying what the information that they're conveying is very much relative to what the prophet of the Lord has said so those same principles that we see in health reform for us it's also an agricultural reform for our crops we have to understand that we need to keep those 8 laws for our crops. That's the overwhelming point I want to get out of that so vocabulary for describing a disease now there's a lot of a cadre Larry you're going to have to learn simple Cabul or if you don't already know it turns out described a disease condition are called symptoms so we got to we really need to understand the difference between a sign and a symptom. Because when we start to this is more so especially true when you begin to read literature like I said I cannot go over everything that you need to learn in a 6 hour course there are tremendous amounts of information out there and a lot of times when you read that information it's overwhelming because we don't understand the vocabulary so what I was trying to what I'm trying to convey here is some of the words that we need to understand so there are symptoms and then there are signs so a pathogen of a pathogen can be seen in association with the symptom the observed pathogen structure is called a sign so you say look at the plants in their wilted you ask yourself why is it wilted So the wilting itself is not a sign the wilting is a symptom Now when you start to try to ascertain the cause as we are told by Sister White we start looking for the sign so when we see disease we see symptoms when we want to ascertain the cause we're looking for signs what are signs a sign could be perhaps. You didn't water it maybe irrigation is busted so if the irrigations busted you have a disease. You know. You you simply just don't have enough moisture but let's just say you have too much more so what if you're waterlogged What if your valve got stuck open and you're wilting what condition do you have then well you might develop fungus but you maybe you don't have the fungus yet you're just waterlogged because you can get to a point where your soil has too much water that it cannot transpire but either way that again would be the actual cause look so examples of signs fungal spores so now what to look for a sign is if we go into the soil and we start looking for perhaps you look at the root and you see that it's are the root crown and you see that it's a blighted really bad so you know again that's still a sign however. To find the sim I'm sorry that's still a symptom but the find the sign you actually have to take that route mask and start to look at it under a microscope and look for fruit for fungal fruiting bodies or fungal hifi or bacteria or something else that is attacking that root that it would actually tell you that sign that's telling you you have a certain disease if you don't find any of that you just have a will to plant then you know you have some other condition so in this particular case if we're looking for a sign read for spores fruiting body mycelium splitter to postulate cetera if it's bacterial then perhaps you're looking for bacteria bacteria in your vascular system that would give you bacteria wilt or maybe you have limited that could also all of these can cause a plant to wilt all of these will give you the same symptoms but are different diseases or different pathogens the signs versus versus symptoms examples of symptoms weakened or killed tissues necrosis chlorosis which of course necrosis for those of you that don't know more vocabulary that is. That is dead plant tissues so something that is usually black or brown that's going to be necrosis chlorosis is as a name States it's clear rhotic it's yellow it's not quite dead but it doesn't look good so necrosis include roses rot soft dry firm etc lesions canker mosaic of course mosaic is from a mosaic virus or anything that causes the plant to look you know where you have some clue some chlorosis some of the crosses maybe and then of course some green tissue is very sporadic throughout the leaf than a normal cell growth so gal's tumors corals gabs not accept those are all symptoms whole plant appearance damping off blight stunted war thing rusting yellows will tick cetera those are those are all symptoms so. Another issue we've got to look to is also. Is a biopic or a biopic I mentioned this earlier so. Abiotic What is that. That means. It is not associated with biology in other words it could be air pollution like ozone nations so for it could be so oil chemical imbalances if your skin missed your soil is way out of whack that could cause issues as well or. Frost or physical damage mechanical damage could also be added to this so anything you know broken by trucks maybe running over it or farm equipment etc A biopic Now what is that. Biological organism a living organism of some type is actually attacking your crop so mainly for diseases to be a disease it needs to be a biological or biologic pathogen of some sort in order to it to be technically classified as a disease of course a lot of times when it comes to insects they don't look at that as diseases the Tekken technically defined as pest pressure pest damage which I'm not going to get into much damage today mostly just biopics So here's some examples of the symptoms of abiotic injuries so what you guys think this one is here on the top left that's that's frost damage so you get a heavy snow usually after a big heavy snow storm where you get huge drop in temperature so you've got heavy snow then you've got a serious frost and on the top what about this leaf here and the and the grass right there that grass is kind of a dead giveaway salt burn both of these are Saltburn So that's a saw that they plow the salt on the road they plow the road they dump all that salt when they plow that road they dump all that snow over the grass and then of course the salt that Senate will throw off will cause imbalances in the chemistry in the soil and and burn the grass what about these tomatoes down here. What disease is that a disease. That's calcium deficiency what about this or orange right here and that pair that doesn't quite look like a parity more that's frost damage so this this of course right here is the late frost came in and damage the cells here in this orange and this is a early frost that damaged the partial damage to the bud early in the growing season so here again winter damage saw damage like a calcium Frost etc All right what about this one here to see this think that's a soybean field there see this this death right here in the middle where you think that is now that's actually a lightning strike. So it's not always a terrible disease as lightning strike. What about these 3 right here you got apples and then you got. Eggplant there. Sunburned right. What about this right here is a demon you have to you have too much water retention another this is a this is Q curb it's your electron conative it is too high. But more water in a tank of you don't normally deal with that unless you're dealing with hydroponics what about this guy right here at the bottom bottom left there is Boron toxicity what about these see right here in the middle that was so for burn what about the see here this one of the bottom right herbicide damage. Sometimes it's really simple stuff sometimes it's not a disease so one of the most important things you've got to figure out is that when you're dealing with disease in your crops a lot of times it's not a disease. It's some other thing very I think I didn't put a picture in here actually I did not I wanted to put a picture of another one this looks very similar to a mutation but it's not a mutation you can get mutations on the external portion of the cells depends on what cells mutated but if you get mutations a lot of times people think oh I've got some terrible disease and no it's actually just a mutation it's not anything that serious OK so a biopic causes. Different ways that you can understand when something is a biopic versus a biopic is to observe. The spread of the disease so is that episode in other words. Or is it acute is it you just had one incident and then it was gone or you had one incident and it's getting worse and it's spreading you see so a lot of times when we're looking for a disease as a farmers and growers You can't just you know I get it I get this all the time somebody sent me a picture of something is a hey what do you think this is like I don't know. You have to watch something for a long period of time so if you just text me a picture like this right here I don't know it could be me just like you guys everybody gets something different you know somebody said spider mind somebody else said potassium or something all that was over your potassium burn it could be anything you know so you have to observe that pattern over a period of time so if you're in the farm and you're looking at your crops like looking over I'm like you ought to be you know one day you're just going to walk up you're going to see this leaf damage like that and then you're going to probably freak out but if you keep watching it and it doesn't get any worse then you realize oh well that's right I sprayed or maybe the neighbor sprayed and you know this is all next to your property line and you know your neighbor sprays Well then you know that maybe had something to do with your neighbor's sprayed so there's a lot of things you have to take into consideration when you're trying to diagnose and figure out what is wrong with your crop you can't just jump to conclusions based off the picture in a textbook. So a lot of what you need to learn and understand is that you have to understand all the various things that are going on and of course the amount of time is it spreading or is it staying the same of course as regular distribution or uniform damage so as to just ride along the fence along next to the neighbor that maybe sprayed or you have it on the by your fence line and maybe a little bit in the field or maybe a little bit more somewhere else and you know that this is not your neighbor your neighbors not the bling. Then there's of course that's what I mean clear lines demarcating healthy and damaged tissue so if you see that you know all the maybe all the tree branches on the right are sick or blighted or something and but everything on the left does not then you have a clear definition there it's probably a bionic it's probably not biologic then there's more than one plant species may be affected so you you notice that like in the picture going back here to the herbicide damage maybe with pretend that's a weed on the ground but you also have your trees or your berries or whatever are seeing the same damage so you have multiple species that are affected by the same exact damage then you know that you're not dealing with something where you're most likely not dealing with something that is biog. Then there's linear strides there's more common near the edges of the host population which means it's probably something to do with osmotic pressure or nutrition. Here's some biopic in this particular case we have a. Fungus in here so turf turfgrass fungus So you see you've got these really weird patterns are kind of everywhere it's worse it's very necrotic in the center than getting chloride if you can tell it's spreading this is most likely biopic. It has a very strange pattern unless you think that maybe you oppose landed in your field or something but no I mean this is clearly Byock. You look at this pattern again up here on this leaf you see that you have some Some least spot on on I believe that's I think that was citrus but I don't remember any how again very spread out that's not up to so tick down here as well they're arranged irregularly symptoms are symptoms for buyout it causes symptoms are typically arranged arranged irregularly the transition from health injured to healthy is more diffused varying sizes and stages of severity like here you can see that these are this this ring is much much larger than that ring there and then of course here this is a little smaller in between so you can see that looks like a lot of not going landed on this field this is probably a. Poly seqlock disease which means you have multiple an ocular them not go into the season so maybe it started here here here here and here and it's spread since then so this is how you know OK this is probably a biopic The same with this leaf you can see multiple and not with multiple knuckle ation points there's a reason why on leaves I'll talk about it later there's a reason why you you have these spreads like that and it only goes so far and then it stops because then you have a whole system of defenses take off and different enzymes are produced by the plant to actually prevent it from spreading any further but it can only go so far so that's how you end up with that same monocular maybe just a few centimeters over and starting again so here's another observation pattern so random distribution so like in this particular example the square right here that could be 100 acres that could be 20 acres that could be just one greenhouse It could be a great garden bed but you have multiple points where that particular problem has sprung up whatever that might be. So that's a random distribution there aggregated or contagious distribution so you have similar things so maybe it started here but now it's contagious so it's moving like in those circles we saw fungal circles of turfgrass you have multiple different spots where it starts but then it starts to spread which means it's contagious it's beginning to move and take over your crop and then patch distribution like for example in this particular area here you could have a toads that took off in maybe that part of the field oh Or you could have a blight that took off but another thing again that you have to take for account of if this is a 10 acre field and there's a river that runs this way and you know that this part of the field is always flooded then maybe you're dealing with 50 or so you know these are the kind of things that as a farmer you have to take into consideration that this is a very 3 dimensional demand dynamic world that we live in and there's a lot of things that you need to take into consideration when trying to diagnose what's wrong with your crops. So observation patterns within a plant. There is the primary versus secondary symptoms this is another issue so I touched a little bit on it earlier in this particular case I think we're looking at. Here possibly a pithy. And then we're looking at a will to wilted or ornamental. When we see that it's wilted you know that's the best the primary the primary symptom that necrosis right there at by the Crown I'm sorry that's just this is your secondary symptom this is your primary symptom up here so to figure out exactly what that is then we know by seeing that the plant is wilted that we have the vascular system has been under attack now why is the vascular system being attacked how is it being restricted Of course you've got to start looking at the stem you've got to start looking at the vascular system perhaps you've got to rip that crop out and take a closer look which I'll take a 2nd to say. When it comes to the subject of plant pathology as well as entomology which is pest insects and disease it really folks it really really does a lot of good to get microscopes this stuff is all in the microscopic level. I mean you can hardly see anything without a microscope so if you don't have lenses to be looking in closely. Microscopes even if they're just dissecting microscopes if you were to put this particular route right here and you were to cut up you know say right there by the Crown and put it under a dissecting microscope with the amplification of say maybe a 100 Boy when you look at see what's going on in there it's a real wake up you'll know right away what's going on but a lot of times we don't we get real comfortable thinking that it's something and then we want to rip it out and throw it away and it's very important for us to understand I'll talk about it later towards the end but we really need to understand what is what exactly it's very very important to diagnose your problems down to exactly what it is and the reason why I say this is because there's a lot of time to farmers make mistakes where they think you know I don't know what I'll just pretend like an example is tomato or potato late blight let's just say this is the potato plant which it's not and these are potato roots so you go and you pull this out and I got like like. What if you don't have leave like well 1st off 1st off what if you do have late blight What are you going to do. You find this out in the middle your potato field we're going to do if you got laid like. Most farmers would just rip the whole crop down so forget it. But it's not like. Oh what it was just a couple of Nima toads and you could have just inoculated it was you know some star or norm or something and got rid of the name of toads but you ripped a whole crop out but it cost a lot of money so when you jump to these conclusions and you think worst case scenario it cost you a ton of money and folks do it all the time they think you know we were going to made it was we we I asked one of the guys to spray some sort of acid and he got some on some of the tomatoes so some of the tomatoes got burned and it looked like like like like like fight off there and 1st and so when the tomatoes went out everybody got like multiple reports all you got to fight off to fight off the guys freaked out and they wanted to get the whole thing out and I went I looked at this is a tougher this is such a capacitor when I took the pieces and I put it in the microscope I didn't see anything but the plantations there were no fungal hifi at all had nothing to do with the fungus yet some folks are ready to rip the crop out. It's very important to diagnose down to exactly what it is that you don't have that skill set every single university has a disease clinic a lot of them are free you could take samples and they'll do it for you another one in Oregon is free down in Corvallis and quarterly hall in the 1st floor. How many of you guys are from Oregon Wow Really Washington OK We got a good number I don't whoa California. Well every single one of you guys is blessed with a really good disease. Extension So U.C. Davis. Oregon State Washington state I'm sorry Washington no Washington State University I think is University of Idaho got them all right anyway all of them have disease clinics they're very good disease clinics I think all of them are free I'm not sure about California the New England has been the only one to charge as Massachusetts all the other states are free Florida has a really good one in Gainesville as well you can melt your stuff in if you don't know what it is but definitely definitely definitely before you make drastic decisions figure out what it is if you got nothing out of this course please get that out of this course as it will save you sometimes thousands of dollars just to diagnose properly what is really affecting your crop. OK very very important so well then plan patterns you've got route routes you've got wills wilt so this all of this right here affects wilting So you see that your crop is wilted you could have you could have willed she could have least with both of these appear both of those will cause wilting ultimately So if your roots are rotting and you don't see that because it's in the ground of course but you see that the crop is wilting. Could be any number of different pathogens that affect the roots it could be pathogens that affect the vascular system it could be. Toads or it could even be just as simple as too much water then you have leased spots and stem cankers and they all have primary and secondary symptoms so for through you have lesions on the roots you have secondary symptoms or fully or chlorosis of stunting a root in top die back you know with Will to see very similar vascular discoloration secondary symptom is a unilateral will that leaves an defoliation roots remain healthy but the actual vascular system is damaged which has the same secondary something as a very different primary sometimes so you can eliminate them right away so laboratory test of course very important like I mentioned for identifying things microscopic observation of signs and incubate disease tissue Well if you if you take your plants into a laboratory they're going to take them. And they're going to look at everything under a microscope they're going to take the an ocular and they going to try to reenact laid it someplace else and see what exactly it is and follow those patterns are going to look at the root at the actual fruiting structures and figure out exactly what type of fungus it is so are you dealing with you very unwell or are you dealing with some other act of my seat or the city Almighty or or my seat or with Dr what type of fungus you're dealing with if you really want to pay the money you can even have the D.N.A. tested and you can figure out exactly what race it is so my example I have rootstocks is supposed to be genetically resistance against if you. Will race one and 2 but not 3 and guess what I got hit with 3 so it happens it happens of course that didn't happen until the calcium went. Down to about 40 percent base actuation I'll talk about that later final diagnosis diagnosis is a form of hypothesis testing diagnosis is detective work so they're really digging for this information multiple pieces of evidence must be required so they don't just jump to conclusions evidence must be weighed accordingly and to come to draw conclusions and give you a final diagnosis diagnosis and be able to tell you exactly what pathogen is actually attacking it. Of course once you know that you know what what's If you're going to turn to the sprays which I. I don't want to get into too much right now but I have some manuals here that I want to give out a little later I have 3 of them that I'll give out and then I've got these as well very very good sources but anyhow you go to you go to so for I'll give you an example of what's come over to try to sell me stuff all the time I mean everybody that sells chemicals is going to show up to your farm they're going to want to sell you chemicals they've got a sales line he's going to want to sell you a line the guy that sells seeds he's always got the best seeds somebody is always going to show up to your farm trying to sell you the best whatever they got so what you have to understand is whether or not those are any good so when I have issues with certain past you know what happens they've got to sell sprays just Brian they gotta sells biologicals I got the best biological for you and you know another guy would tell me well not do this other fertilizer thing everybody wants to sell me a product but which one really is going to work you have to get intelligence on exactly what organism is attacking you because when you understand what organism is attacking you can go to tables like this and look at a large list of chemicals look at the active ingredient and figure out exactly which pathogens they work on and which ones they don't and I've seen farmers that will take certain sprays that are intended for prohibit for prohibiting ask of my seat fungal spores from germinating and then they'll put them into a tank and the put it into the ground and what does it do for you nothing absolutely nothing there goes 400 bucks plus the labor it did nothing for you. So you have to understand what those chemicals are used for and what pathogens they can attack because if you think you have a fungal disease but you really don't have a bacterial disease and you spring fungus eyes were goods are going to do nothing you're just wasting your money. Another fine example of why you got to know what is hidden your plants very important to diagnose the diseases properly and come to serious conclusions this media was brought to you by audio verse a website dedicated to spreading God's word through free sermon audio and much more if you would like to know more about audio verse if you would like to listen to more sermons lead to visit W W W audio verse or.


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