Breeding for Rust Resistance in Daylilies: 

Part 3

In this installment we look at realistic goals for our projects. Not everyone can or will have the same goals. What I outline here is my ideas concerning the goals that the entire daylily community might have overall or in the broader sense. However, each person's goals may vary, as their conditions and interest will vary. Some will have more ambitious goals, while others will have less ambitious goals, and that is ok. We can't all have the same goals, as we don't all have an equal situation or interest. There is no one goal that is 'right' while others are 'wrong'. I simply don't work from an 'either/or' proposition, but rather, from a 'both/and' position. It is up to each person to find the point that works for them. For my part, I believe we need a diversity of goals and interests, some working on the plant, others on the flower, some on both. In that way, we can push all the boundaries, and not just one or two. Please know that no matter what you decide you can or cannot do, I support you and appreciate your contribution to the vast and varied world of daylilies! Read on...

Being Realistic About Our Goals

Now that we have our terms defined, let us move on to consider what it means to be realistic about breeding for rust resistance. To begin with, from reading over many years of threads on various message boards and robins and speaking privately with many daylily breeders and growers, as well as general gardeners, master gardeners and landscapers, I see that there have been two equally unrealistic approaches to rust in the daylily world. The first I call the ‘ostrich syndrome’, which has been to ignore it, pretend it isn’t there, isn’t a big deal and won’t impact daylilies, and to either suffer through it and hope others don’t notice, not talk about it and attack anyone who does or just spray and pretend the problem is solved. The second is the opposite extreme, and is the ‘we must breed total resistance right now, at all costs’ approach. Both are too extreme and unrealistic to succeed and neither has succeeded.

On the one hand, rust has continued to spread, invading more and more gardens and moving further north each year and each year since rust appeared the word behind the scene is that daylily sales are diminishing and continue to diminish unabated, at least in the southern states (though clearly, recent economic uncertainty has contributed to this downturn in daylily sales, as has the aging and passing of many of the most committed collectors). On the other hand, many who began attempting to breed for total resistance (immunity) and nothing less have become disillusioned and stopped their pursuit of resistance breeding, either giving up entirely or throwing in the towel and getting in the ‘spray and ignore’ mode, because total resistance didn’t come about instantly. 

I believe that both approaches have been too extreme, ignoring the common middle ground where average breeders, hobbyists, gardeners and landscapers reside. Fear and uncertainty have certainly been a big part of this, but in addition to fear, I see a certain kind of laziness that manifests as a fear of the effort, as well as a lack of good information on realistically breeding for disease resistance that has caused a lot of uncertainty and only contributed to this situation.

There is much good information on breeding for disease resistance if one looks outside the daylily world. Many plant species have devoted breeders, professional/commercial breeders and/or hobby breeders, who have pursued various types of resistance in the breeding programs they have undertaken. Some have not succeeded, but many have succeeded well and should be studied and emulated. One of the most important things we can do is to get realistic about what our aims should be.

It should be obvious that I do not advocate a ‘total resistance’ or ‘absolute immunity’ approach, because I think this is highly unrealistic. The notion that we are only going to introduce plants that show immunity forgets that there is more than one strain of rust and rust will continue to mutate. In short, my aim would be to begin to focus on the production of plants showing good to high resistance through combining multiple genes for resistance, or conversely to make the removal of highly susceptible individuals a major goal of breeding, thus beginning to eliminate the introduction of more and more new rust magnets. Perhaps the most astonishing thing to me is that so many highly susceptible plants have been continually introduced since rust first reared its orange-speckled head in 2000. In my opinion, this reflects poorly on the daylily community (and is something I have heard echoed from daylily growers, master gardeners, home gardeners and landscapers alike, repeatedly).

So in practical terms, what am I actually suggesting the hobbyist do? Well, first of all, except for those few plants that show low tolerance or in those few areas of the country where rust is a continuous presence (and sometimes lethal problem), having some rust is not a great tragedy, especially where many of the plants you grow show good to high resistance and there is some effort made to reduce the presence of the least tolerant and/or most susceptible, so that the garden is still attractive and does not look like a disaster area.

It goes without saying that the first time rust shows up in your garden, you are in for a shock, because many things you grow may be highly susceptible. Sentimental favorites and expensive new introductions can quickly become hideous rust-fountains and may even show poor tolerance and be adversely effected for a whole growing season or more, but once the initial shock wears off, you can take a deep breath and start to note those that show minimal rust or even no rust. Then you can begin to research and communicate with others concerning cultivars that show good to high resistance or immunity. As you eliminate the most susceptible (or those with low tolerance are eliminated for you), you can then begin to divide and increase plantings of you own resistant plants and add new cultivars that show some resistance or immunity for other gardeners, knowing that results may be slightly variable in your garden, depending on the environment and the particular strain of rust you have as opposed to those that others have experienced.

It is a wise thing during this phase to focus on less expensive cultivars with a long track record of exposure to rust. Not buying large numbers of new introductions, unless some data about their rust resistance is available, would also be a wise approach. Or if you simply can’t part with some sentimental favorite or new expensive introduction or must have something that is unknown, spraying may be a viable option for you and information about sprays is readily available online.

Do note though that spraying is expensive and only masks the problem, so I do not feel it is actually a viable approach for breeders, but at least you won’t see rust. If you are selling plants, it will probably be necessary for you to spray, but that does not mean you have to spray year round. If you spray in spring, but then stop spraying in late summer, you can still rate cultivars and especially any seedlings you may raise for their rust response. I personally consider this the most responsible spraying regimen for sellers, as it allows some awareness and culling for rust susceptibility. It must be noted though, that no one who is spraying in order to sell is actually verifiably ‘rust free’, because spraying does not kill rust in the plant, but only suppresses the sporation, thus any plant purchased from a ‘rust free garden with a spraying program’ can sporate once they are in their new home and no spray is being applied, if there was any exposure in that sell-garden in the past. This happens frequently and is one of the major ways that rust is spread. Spraying is only a prophylactic, not a cure!

So once you are past the initial shock of your first rust outbreak, and all the heartbreak has ensued, tears have been shed, curses have been uttered and hair has been pulled, you may begin to find that once the most susceptible are gone, rust is not too unbearable in a garden setting. This has been my experience and has helped me to see the middle ground approach I am advocating here. A garden full of rust-fountains is traumatic, but a garden full of plants with some slight amount of rust and some plants with no rust at all is quite manageable and not too terribly noticeable. 

I manage a garden where this is the approach we have taken and now our annual fall outbreak is barely even noticeable unless you go out and start actively looking on the undersides of the leaves. So how was this accomplished? By removing the highly susceptible altogether and only keeping or adding those with high resistance and/or immunity, most notably by dividing those of that nature in the garden and increasing the plantings of those cultivars and by then judiciously and slowly adding new cultivars that have been shown to have some resistance and then removing any of those that failed and increasing those that have shown suitable resistance in that garden. 

I consider this approach to simply be an aspect of garden maintenance and building. With experience, you too will come to realize that not everything you plant succeeds and some things fail and must be redone, replanted, rethought. This is life in the real world. However, this garden is not a breeding garden and in such I would take a different approach, but I think the approach I have taken in this garden is a realistic approach for the average gardener.

The major difference in a breeding garden would be that I would leave a good number of the most rust susceptible in order to be sure the seedlings and potential breeders were sufficiently exposed to rust to confirm their resistance levels. The cultivars that I would personally tend to keep to ensure proper rust exposure also would tend to be those I would be most interested in using for ‘salvage projects’, so such cultivars in my hybridizing garden serve two purposes – to infect the future generations and to preserve a special trait for later blending into resistant lines.

Since a small amount of rust in a garden is neither unsightly nor deeply traumatizing (to the gardener or the plants) and since the goal of breeding for total immunity is highly unrealistic for the average breeder, I tend to find that breeding for good to high resistance is the most realistic approach, with immunity both welcome and sought after, but not the only goal of the breeder. To make full immunity the sole goal of a breeding project is to invite failure and disillusionment, both of which usually lead to giving up, but when the focus is both plants with usable resistance and the removal (or non-introduction) of those with high susceptibility, we can see progress and be encouraged enough to continue our work. This is a realistic goal that is achievable and will lead to plants that can be useful and valuable to gardeners, landscapers, breeders and collectors. Further, it serves the purpose of eliminating new rust magnets, which are so disheartening and angering to so many, now that rust is simply a reality of growing daylilies.

The old rust magnets from the pre-rust days may be excusable because they were introduced before rust appeared, but the same cannot be said for those introductions made since rust appeared, especially those from recent years. I would strongly encourage the identification of resistant cultivars and the introduction of new cultivars showing resistance to help the daylily maintain its place amongst the gardens of the world and not continue to slide further and further out of favor. For the average gardener, plants showing acceptable resistance are going to become more and more important if they are to continue to grow daylilies.

I would stress that I do not advocate a rush to compost every rust magnet, or highly susceptible cultivar. There are reasons for this. The first and foremost is that one of those that is highly susceptible to a current form of rust may have resistance to a new form of rust that may emerge, or there may be other important genes there. I do think that identifying those with high susceptibility is important both to allow gardeners to avoid them and to allow those who wish to maintain them to know what they are getting into. In that vein, I do encourage that those who are going to spray anyhow to maintain as many of these as they can, just to keep the gene pool present, but I would encourage them to note their susceptibility to prospective buyers and perhaps use them with great care in breeding projects, possibly only in a salvage project wherein the offspring will be exposed to rust and culled for susceptibility.

I do not advocate the destruction of huge swaths of the domestic daylily gene pool, and I do not think a breeder should rush in and destroy all their seedlings from a given cultivar, just because it is highly susceptible. Rather, watch those seedlings carefully and look for any improvement in resistance over the susceptible parent and use them to continue the salvage project. A salvage project of this nature can take generations to achieve, after all. 

There will be a difference in what is maintained by a collector who is spraying their garden, by a breeder who is responsibly trying to continue improving the entire daylily and the average gardener or landscaper who wishes to grow daylilies. The first of these may wish to spray, the second may even spray for part of the year, but the last two aren’t likely going to spray and until we acknowledge this fact and begin to think of their interests, we condemn our beloved plant to a future of obscurity and infamy amongst such people, especially in warmer areas. Ask yourself this – How many average gardeners or landscapers use tea roses?

Now some may come along and say, “But what will you do when a new strain of rust comes your way? Then all your work will be for nothing!” Well, not necessarily. To begin with, we do not know how much variation of effect there may be in the various strains of rust. Secondly, we do not know how much variability of response there may already be in resistance genes in the current daylily gene pool, and just as new strains of daylily rust will appear, so too will new mutations for resistance appear (or be recognized as already present) in the daylily. This is a genetic dance after all between pathogen and host. 

Further, my personal approach to various strains of rust will be to simply note how a given cultivar showing high resistance over many years responds to a new strain that it has susceptibility to and then to cross it to a cultivar that shows good resistance to that strain. Thereby I can combine genes for resistance to various strains of rust. In other words, as rust continues to mutate, my work continues, so there is never a point at which one is ‘done’ and has developed ‘proven lines of daylilies that can never get rust’. In reality, there is no such thing, so rust resistance becomes just another trait that the breeder is observing, recording information about and selecting for, just as any other trait such as branching, foliage type, sun-fastness, water resistance of flowers (non-water-spotting), etc. In the end, time and time again, we see that most breeders can walk and chew gum at the same time…I believe selection for rust resistance is just another aspect of selection and nothing more.

To end this section, let us reiterate the practical methods of dealing with rust for various settings.

1. For average gardeners and landscapers, identification and use of good to highly resistant or immune cultivars is paramount, as is removal of highly susceptible cultivars and replacement with another species or another cultivar of daylily known to show resistance or immunity. In this way, the garden is kept attractive and expensive spraying programs are avoided. Production of resistant, garden-worthy daylily cultivars then becomes paramount for breeders, as well as education and identification of resistant cultivars amongst collectors and sellers, in order to maintain the interest in daylilies of this segment of the gardening population.

2. Collectors and sellers use a spraying program if desired or legally required, at least through their sell/display season. They maintain both resistant and no-resistant stocks, but make some effort to know which is which, at least marginally. No more ‘ostrich syndrome’ as if it is irrelevant or they can’t be bothered with such trivialities. Become part of the solution, rather than part of the problem. Sellers should be able to advise prospective clients on those cultivars showing some resistance to attempt to ensure happy customers and to not further damage the reputation of the daylily in the eyes of people becoming increasingly wary.

3. Breeders begin to identify cultivars showing good to high resistance and/or immunity and use those cultivars. Breeders maintain a suitable number of susceptible individuals to assure rust infection of their seedlings and where they must use their highly susceptible cultivars and seedlings in their breeding work, make them part of a salvage program to bring desired traits onto a resistant plant by crossing them to known resistant and/or immune plants. The goal of the breeder is not to create total immunity, but acceptable resistance, with the presence of occasional immune individuals as an added bonus, while also eliminating (and not introducing) the highly susceptible. Breeders seek out, identify and use resistant cultivars and expose (at least) their seedlings to rust in order to eliminate the most susceptible. 

Elimination of the most susceptible individuals becomes the most important aspect of breeding programs. The more of these that can be eliminated as future breeders or introductions, the better it is for the potential resistance of your overall gene pool. In other words, exposing your seedlings and eliminating the highly susceptible becomes the most important aspect of breeding for resistance along with using cultivars and seedlings that have shown consistent resistance over a long period of time and in multiple locations. We will look at these points in much greater detail when we discuss breeding strategies.

For our next installment, we will consider the importance of identifying consistently resistant cultivars...

Breeding For Rust Resistance In Daylilies:

Part 2

In this installment, I want to focus on some basic definitions that we absolutely must have some understanding of before we can proceed further. I frequently see discussion on various forums that don't get anywhere and often because people are using the same words, but meaning different things. The greatest fallacy is that 'resistant/resistance' implies fully immunity to rust. This is not the case, as I discuss below, but the notion that this is the case seems to be one of the biggest stumbling blocks to understanding and communication.

Resistance, Immunity, Susceptibility and Tolerance

Before we begin to talk about various strategies for breeding for resistance, there are a few terms we need to define and discuss a bit. As this sections header suggests, resistance and immunity are not the same thing, and while resistance and susceptibility can encompass various points of a spectrum, they are neither the same as tolerance. So what do I mean when I use any of these terms.

First, let us consider immunity. This is the simplest of the terms to define, as immunity means exactly what it implies. An individual that shows immunity to a pathogen is not able to be infected by or show symptoms of infection of a given pathogen. In terms of rust, this means that a cultivar that is immune or that shows immunity does not display any symptoms of rust to the naked eye. Under a microscope or in lab conditions, rust may be found to be present, but such an individual will not show the visible effects of rust – spores or active, visible rust.

Some individual plants may show immunity due to environmental reasons, but others may be due to an actual gene or genes giving full immunity to rust. This is likely rare. More rare would be complete immunity to multiple strains of rust, so while cultivar may prove to be immune to one strain of rust, it may not be immune to another, and the level of susceptibility to any given strain could vary, even in the individual plant is highly immune to one or two strains of rust. While full immunity to multiple strains of rust is likely very rare, if it even exists, there is always the chance that it could exist. Without gathering information on individual clones over many locations and many years, the discovery of such a multi-immune plant will be very difficult.

In many plants and animals, total immunity is often a single, dominant gene expression and is frequently more easily circumvented by new mutations of the pathogen than multigenic resistance. However, if a single dominant gene that confers immunity (or high resistance) is combined with multiple other genes giving resistance in various levels, that can create a very strong level of immunity/resistance that can be both difficult for a pathogen to breach and offer some resistance to multiple strains of a given pathogen. Thus these single gene dominants should not be ignored and make an important component of a resistance-breeding program.

Now let us consider resistance and susceptibility together, as they go hand-in-hand and are actually interchangeable terms. First, resistance is not immunity. I can’t stress this enough. The only time that resistance is immunity is if we were to refer to ‘total resistance’ or ‘complete resistance’. However, more frequently, resistance is aimed more at meaning the ability to resist a pathogen to some extent, variable by cultivar or clone, though certainly in the hobby, the term resistance is often used to mean immunity by some, but then will be used to infer variable levels of resistance, but not immunity by others. This has caused a great deal of confusion and when the term resistance is used to imply immunity or the meaning is left vague, it can leave people both intimidated as to the difficulty of achieving such a goal and disheartened when a “resistant” cultivar then shows some rust in their garden. We need to be very clear about what we are actually meaning when we use a given term.

When dealing with multigenic, quantitative traits, we generally use a bell curve to express the array of phenotype expressions seen. So the two extreme points of any bell curve could be strong resistance/poor resistance with many shadings in between, or equally, the two extremes could be called low susceptibility/high susceptibility and be equally accurate. Said either way, they basically are saying the same thing. However, I have heard those who don’t want to acknowledge the importance of highly resistant plants to the actuality of there being genetic resistance that is selectable within the Hemerocallis suggest that because the two terms are interchangeable, that means that all daylilies get rust and even if you have one that is highly resistant and you see a few spores on it, then you still have rust, so it is really no better than the most susceptible rust magnet. This is complete nonsense, of course and is usually being stated by persons selling or breeding and selling daylilies. Any grower who has ever experienced rust knows that the visual effect, as well as the effect on the health of the plants, is profoundly different between a cultivar that gets a few rust spores and one that is such a magnet as to become an orange rust-fountain. We will discuss this more a little later in this section when we look at realistic goals for our breeding projects. Suffice to say for now that ‘resistance’ and ‘susceptibility’ is interchangeable terms that describe a wide range of expressions, but not necessarily immunity.

Tolerance is a somewhat different term that means the ability to be infected by a pathogen, express the pathogen, and yet show little negative impact on health, vigor or performance. In short for our example, it is the ability of a plant to have rust, show sporation and yet have little negative impact on the performance and/or health of the given plant, even in some instances when the rust expression is extreme (low resistance or high susceptibility). This is also an important point in breeding consideration and one that is often overlooked. There are plants that will contract rust and show strong negative effects either the year that rust is present and/or in the next growing season, even if the rust is eradicated by winter freezes or spraying. These plants may show symptoms such as reduced scapes count and/or height, poor bud count, poor branching, poor plant habits, reduced increase or fan-count, or even withering of the overall plant size along with several of the other expressions mentioned here. In extreme cases, some plants are so compromised by rust that they never fully recover or perform at full capacity again, and in areas where rust is seen in both spring and fall, such plants may become so compromised that they die outright, even if their other cultural needs are being met.

In our breeder selection and breeding consideration, especially where we want to pursue a ‘salvage project’ with a very susceptible plant, we may make better strides by using a highly susceptible plant that shows high tolerance to the presence of rust, rather than one that is highly compromised by rust infection. Then, at the very least, even if we do not make great strides toward high resistance in the first generation, our f1 should at least flourish and survive to make an F2 or BC1 (back cross first generation) and perhaps then draw together the flower traits we want with higher resistance. In short, tolerance to rust can’t hurt and likely will help, but low tolerance to rust can be deadly and certainly creates more obstacles to overcome.

Breeding for Rust Resistance in Daylilies - Part 1

Breeding for Rust Resistance in Daylilies:

Part 1

This is the first part in a series of blog posts that are actually one document I have been working on for the last couple of years. It is simply far too long, with far too many topics and too much information to be made into one post. For our first installment, I wanted to give a short overview of my background and experience and then introduce one simple concept - the difference between hobby breeding and professional research breeding. The first few posts will deal with concepts. Then we will move on to actual breeding methods in the later posts. It is important to get our concepts and definitions under out belt before we get into any complicated breeding strategies.

With that said, one of my goals with this series of posts is to make this information accessible to hobbyists. I will at times use the language of science, but I will also go out of my way to either offer examples or use more common language that the average hobbyist can relate to. The goal of this series is to demystify 'resistance breeding' and to help you, the hobbyist breeder, to see that breeding for some level of rust resistance is not some magical endeavor beyond the scope of the average backyard breeder, and that it is actually possible to approach selection for rust (or any other pathogen) just in the manner you currently approach any other trait you select for.

You don't have to have a PhD, a laboratory or many acres of grow-out fields to make some progress in selecting for resistance, any more than you have to have those things to make progress selecting for better branching, cool morning opening, dormant foliage or any of the many other traits you already select for. 

Introduction and Bio

First, I would like to present some of my background for those who do not know me and are not familiar with my work in selection and breeding for disease resistance over the last two decades.

It is important to state first and foremost that I am not a professional genetic researcher affiliated with any university or industry. I am an independent researcher and breeder, but I have worked with several professional researchers over the last two decades in my research and the practical application of my findings through breeding and selection.

My road to working with immuno-genetics (the study of genetic, heritable disease resistance) started early due to the fact that every group of animals or plants I worked with from childhood on was beset by some plague or another. For many years, through my childhood and into my early twenties, I followed the standard prescription of ‘medicate, and then medicate some more’. Over time though, I came to realize that this was no answer, only a prophylactic to keep the problem invisible.

In the early nineteen-nineties I began breeding rare chickens to study their feather color and patterning genes as well as their feathering and form genes. However, the most immediate issue became clear very quickly: chronic disease. At first I considered inbreeding to be the source of the suppressed immune systems, but even in very wide outcrosses, the problems persisted. Then I had blood work done and found the causative pathogens. Medications were prescribed, but they did nothing more than mask the problems and as soon as the treatment was withdrawn, the problems returned within 7-10 days.

So that set me on a path of research to understand how people in the pre-medication past dealt with such problems, what the poultry research community had learned about genes that impart resistance to given pathogens and how to practically apply that information to a breeding program to produce lines of genetically resistant birds. To spare the reader and daylily enthusiast the pain of reading many pages of details about breeding for chicken disease resistance, I will simply state that through combining multiple genes for resistance, I have been able to create lines that are fully immune for two major pathogens: Mycoplasma gallisepticum and the Marek’s Virus complex.

Practical Breeding versus Scientific Research

I want to state for the record that there is a difference between what we do as breeders and the research and experimentation we may pursue, and the research that is done by scientists in university or industry settings. It is so important to emphasize that they are not the same thing. I have done both types of ‘research’ and I know that they are both useful and have their place. I want to stress the difference in these two approaches, because I do not want any of the real professional researchers who may read this to assume that I don’t know the difference, or that I am leading any lay-persons reading this to believe that one is the equivalent of the other.

Professional research is designed to obtain factual, quantifiable, replicable proof of a given issue. Breeding research and experimentation is to allow the breeder to make advances in their chosen goals and intelligent choices in their own breeding programs, to gain the desired results. Professional research is important, but it often does not translate well to the hobbyist breeder and may even be relatively useless for practical application by hobbyist breeders. Conversely, hobbyist research and experimentation is aimed toward achieving desired results, and often has little value to the professional researcher because it does not follow the strict controls of real scientific research programs and generally the hobbyist is not working with the numbers required to acquire sufficient data to make claims of proof. Our results in the hobby tend toward being evidence of a particular pattern of heritability, but are generally not proof as the professionals mean the term, and it is important to recognize this up front. This, of course, is generally of little concern to the hobbyist breeder who only wants to be able to replicate desired results with some accuracy.

With that said though, I will state that while the professionals are seeking quantifiable, replicable proof, the breeder is generally only seeking indications of trends that can help them achieve their desired results. For instance, professionals will often criticize hobbyist breeders for making claims such as ‘so-and-so shows resistance or immunity, recessiveness or dominance, single gene or quantitative effects, etc’, because to the professional researcher, such a claim could only be made after sufficient numbers had been observed under strict protocols to prove such a statement in a quantifiable, replicable manner. However, the breeder really doesn’t need that kind of proof to pursue a breeding program. The breeder only wants to see trends that appear to fit such patterns of inheritance so that he or she can have some idea of how to pursue a breeding program to obtain the desired results.

For instance, Dr. Stout had no proof, in the current scientific sense, that a red daylily could be created. Yet, he spent twenty years pursuing the goal and created ‘THERON’, the first red daylily hybrid, as a result. Further, no scientific research project was initiated to prove that toothed, wildly ruffled or pie-crusted edges could be bred onto daylilies. Instead, breeders simply pursued the goal of such edges based on the presence of very minute examples of such edges. Through breeding such individual cultivars together, selecting for the highest expression of the trait and continually concentrating the target trait, such edges became a reality. We can see the results of that effort and selection process today. The presence of such edges in many modern daylily cultivars is proof, after the fact, that such edges are possible, but there was no proof at the beginning, only the suggestion that such was possible. These are only two of many examples of such breeding and selection in the many cultivars of hybrid daylilies that we know today, and many more examples exist in all domestically bred plants and animals.

This is the big difference between professional researchers and hobbyist breeders and researchers. The professionals are seeking proof, while the breeder is seeking results. The professional is seeking quantifiable, replicable proof through their research that can then be peer-reviewed (which is often a rather savage process), while the hobbyist breeder is seeking trends and results through their research and experimentation. That does not mean that the research and experimentation of hobbyists cannot be pursued in a scientific manner, using sound scientific principals. It simply means that hobbyist research is not of the standard to constitute proof in the modern, scientifically accepted sense. It does though, often, produce results. Both types of research, experimentation and breeding have their place, but they are not the same thing and it is important to be aware of that and to acknowledge the difference.