Healthy Crops: A New Agricultural Revolution
Francis Chaboussou was an agronomist at the French National Institute of Agricultural Research. He introduced the term trophobiosis to describe the symbiotic association between organisms where food is to be obtained or provided. The provider of the food is referred to as a trophobiont. The term is also used for a theory of pest resurgence on crops to which pesticides have been applied causing an increasing dependence upon pesticides. This book is a translation from the French edition of 1985.
Although it is difficult to find any information about Francis Chaboussou, he left a legacy that can transform the way we think about insects and agriculture. In the commentary with which the book begins, Dr. Ulrich E. Loening says that Charboussou’s thesis is quite simple: “most pest and disease organisms depend for their growth on free amino acids and reducing sugars in solution in the plant’s cell sap.” Charoussou’s studies range over fifty years, and his conclusions as to the how and why the free amino acids and reducing sugars are produced in the sap are the subject of this book.
The author of the preface, Dr. J. A. Lutzenberger, who was very influential in getting this English language edition published, says that when plants are in repose the sap is poor in amino acids as they were used in preparing for the quiescent state. When the plant is growing vigorously the amino acids are used immediately as they are formed for the growth of the plant. At these times insects may be able to survive on the plant but they cannot thrive as they need very high levels of nutrition in the plant sap to build their own complete proteins, DNA and so forth. They need a very high level of soluble food for these proteins, not only amino acids but also sugars and mineral nutrients. Plants that are not nutritious for the insects are also not palatable to them. So when is the plant nutritious for the insects? When it has an excess amount of soluble nutrients, or when it becomes metabolically unbalanced. Plant metabolism is easy to disarrange, deep tillage, disking, frequent harrowing, and keeping the soil naked are difficult for plant metabolism. But, and contrary to all expectation, the best way to upset plant metabolism and invite insect infestation is to put pesticides and artificial fertilizers on the plant and soil. Excess nutrients are produced in a plant when it is forced to produce more than it needs as with the use of high ammonia fertilizers. The double edged sword of pesticides and fertilizers merely invites insects to the buffet.
The book is divided into three main parts, pesticides and imbalances, and unfortunately this includes pests that used not to be problems for growers like psyllids, mites, numerous cereal diseases, including viral ones, withering diseases, and the viral diseases of fruit trees and the grapevine. The basic conclusion is that the relations between plant and insect are nutritional.
The theory of trophobiosis is this: that plants are made immune to attack to the extent that they lack the nutritional factors that parasites require for their development. The alternate theory of insect infestation is based on the possible presence of substances (phytoalexines) that are toxic or repellent to the insect. Chaboussou determined that it is the former theory that is true. Restating this theory has the virtue of impressing it as it goes against all the teaching of the agro/chemical-industry. This says Lutzenberger, may be the most important discovery in agricultural chemistry since Liebig.
So, since the intensive agricultural practices including pesticides and chemical fertilizers lead to inhibition of protein synthesis, the second part of the book is called “deficiencies and parasitic diseases”. It is no accident, we are told, that the symptoms of viral diseases are confused with nutritional deficiencies but the symptoms are from the deficiencies. The chemical shift from mineral and elemental products like copper and sulfur to chemical pesticides is implicated. This section of the book is dedicated to the research of Constantin Vago. Vago’s research suggests that there might be a general law applying to both plants and animals that would explain ‘disease’ in the same way for both.
The last section is called ‘agricultural techniques and the health of crops, and deals with the results obtained through the process of stimulating protein synthesis. In the last two chapters of the book, various examples of agricultural techniques are reviewed.
The goal of this book, our author states, “is to explain the reasons for the failure of chemical pesticides, whether fungicides, insecticides, or (above all) herbicides.”
The classic explanation for outbreaks of pests is that the predators of the pests have been eradicated. But this seems not to be true. Some pesticides do kill predator insects but studies on mites show that the pests proliferate as a result of pesticides and increase in the fecundity, longevity, fertility and ratio of females to males in the insect population. Fungicides, herbicides and pesticides all have an effect on the nutritional make up of the plant. Studies with grapes show that treating with pure water causes fewer attacks of Oidium (Uncinula necator) and grey mould (Botrytis cinerea). Captan, which is harmless to natural predators, causes attacks of mites, increases susceptibility to Oidium on apple trees, and causes crown gall on cherry trees.
At the moment of flowering, plants lose their capacity to perform photosynthesis, they even decompose and use some of their protein to add soluble nutrients to the reproductive organs. The flowering period of the plant is a primary period of vulnerability to attack. The age of the plant, temperature and humidity are also factors. Very young leaves are not attacked because they contain a large amount of albumin and an “almost total lack of soluble compounds in the water,” while older leaves have a high proportion of sugar compared to starch and have low levels of nitrogen compounds since they are tied up in proteins.
The Colorado potato beetle has rendered a great service to humankind. The studies done on the beetle have taught us much about how the soil conditions relate to the feeding activities of the beetle. It was found that traditional methods of potato cultivation such as using manure and compost encourage resistance to the beetle and even to disease due to the biochemical state they produce in the plants. Any deficiency, especially in micro-nutrients, leads to an inhibition of the protein synthesis, with a corresponding rise in free amino acids (which insects eat). Even with everything in place, if the pH is off and the plants cannot absorb the nutrients, attacks will still occur.
The trophobiosis theory (from “trophic”, of or pertaining to food—Greek) was Chaboussou’s statement that “all vital processes depend on the satisfaction of the needs of the living organism, whether animal or vegetable.” Insects do not all have the same nutritional needs but they all do draw from the pool of soluble nitrogen (free amino acids) and reducing sugars. (Reducing sugar: any sugar that, when in solution, has an aldehyde or ketone group). When the process of protein synthesis is greater than protein breakdown the plants have the greatest resistance. And, determining the ratio of N2 compounds to reducing sugars could serve as a method for determining susceptibility to attack.
Originally, it was thought that pesticides acted only on the surface of plants — among these were copper based products and the arsenic compounds that were to be eaten by the insects. More recent chemicals, systemic insecticides and herbicides are meant to be absorbed. The use of foliar fertilizers and herbicides show that plant tissues are penetrated by the liposoluble compounds that are helped by the lipids in the cell walls of the plants. This explains how metallic salts can penetrate the plant and why plants have differing susceptibility to these chemicals. Pesticides are taken up by the plant in varying degrees depending upon the time of day, temperature, and the nutrition level and age of the plant. The chemicals are taken up through the leaf, through the root and through apoplastic pathways (through the gap between the cell wall and the cuticle that gives solutes access to the cell). Pesticides can also travel from cell to cell by the same pathways that allow cells to communicate: symplastic pathways. Researchers, we are told, are struck by the drastic consequences, such as sterilization of the soil after cupric treatments or the elimination of earthworms after dithiocarbamates. But worse than these is the rendering of crops susceptible to parasites. This happens through the seeds by coating them and through the trunk and main branches of fruit trees and grapevines during the application of both fungicides and insecticides. Even in winter a tree can absorb sprayed chemicals.
DDT and 2,4-D, both common pesticides that have trophic effects on plants. (DDT was banned in the US in 1972 but the ingredients were exported to, among other places, Mexico where they combined them and used them on crops exported to the US until the UN banned its agricultural use worldwide, effective 2004). As early as 1960 it was known that applications of these pesticides increased insect and mold attacks within days. Eight to fifteen days after DDT on flower stalks there is an increase of aphid attack due to the rise in non-protein nitrogen and an increase in sugars in the stalks. Across the board, all types of chemical amendments usually applied to crops cause similar reactions, in the plants, to one degree or another, of increasing amino acids, decreasing protein synthesis and increasing soluble sugars rendering the plant susceptible to attacks from insects and infections. While it has been noted that some plants increase growth due to a hormone type reaction of the pesticide, the author did not note any nutritional gain, nor consider the effects of pesticide residues on human health.
The author begins the second part of the book with the statement, “From this point on we shall look, (from a rather different perspective) at the repeated failure of chemical pesticides to protect fruit trees and grape vines.” Normally, we would consider that a rather biased opinion, but it is backed up by much research. It is not that the pesticide is ineffective, but that it offers nutritional stimulation of the virulence of the pest by altering the biochemistry of the host plant. We are told that we must not aggravate the “parasitic complex” of plant, virus and vector. We can have a disease, caused by an insect on a particular plant. Through intensive cultivation bacterial diseases are becoming more difficult to control. This is due to two things: the use of new chemical pesticides, often in multiple applications without a serious examination of their effects on the biochemistry of the plant and the excessive use of chemical fertilizers, most especially nitrate fertilizers which generally increase the soluble nitrogen in the plant tissues making them vulnerable to insect and disease attack. Remember that protein synthesis is the end product of amino acid synthesis, there can be considerable amino acid content in the plant without a corresponding synthesis of complete proteins.
Of special interest to the members of the BFA is that chemical fertilizers and fungicides interfere with micro nutrients. Copper is discussed extensively because, while copper has little effect against bacteria, it still offers a “prolonged positive effect” against bacterial diseases. This could be because the copper has a beneficial influence on the metabolism of the plant. Primavesi et al. found that in rice, a copper deficiency creates an excess of nitrogen which opens the plant to attack. The N/Cu changes from 35.0 in healthy rice to 54.7 in diseased rice, through a deficiency in copper. They concluded that level of 18ppm of Mn and 2ppm of Cu are sufficient in the soil they studied. Other levels could be similarly effective in our soils. Since boron is lacking in New England soils, we should note that with applications of nitrate fertilizers the levels of boron in the leaves of cherry trees go down, more so with multiple applications.
Some treatments against bacterial disease are taking a different path. Instead of killing the bacteria the aim is to prevent it from attacking and multiplying. It is useless to try to destroy bacteria with toxic agents, and they affect the plants adversely by inhibiting protein synthesis. If there is a fairly direct relationship between the disease and one or two deficiencies, we should be able to detect these and remedy them. Apart from micro nutrients, the balance of cationic elements must be considered such as the K/Ca ratio. Boron will keep Ca in soluble form and it is only active in combination with magnesium, manganese and molybdenum. The author cites a case where foliar sprays with a micronutrient base led to an increase on the ration of B/Zn, from 11 to 47, and eliminated the failure of the fruit to set in grape vines. Incidentally, a great deal of this research was done on grapes grown in France to increase the success of their wines.
But, the lowly potato has also been the subject of much research. From 1966 to 1969 potatoes were grown under glass and given various nutritional treatments. Surprisingly, the greatest number of healthy plants, 40.9%, were found in the group that received the “nutrient free” treatment or the treatment with P2O5, (phosphorous pent-oxide), 32.2%. Nitrogen, given in excess, resulted in only 16% healthy plants and phosphorous in excess, only 16.4% healthy plants. Prolonged vegetative state, that of immaturity, caused by nitrogen applications retarded maturity and thus retarded the resistance that the mature plants full of complete protein have.
While nitrogen applied excessively tends to make plants susceptible to viral (and bacterial and fungal) diseases it is just the opposite for potassium fertilization. Its effects vary according to the type of K fertilizer. On beets, the yellow virus symptoms are least where K is highest. Yellow virus increases the content of reducing sugars and K counteracts this, reducing the plants sugar loss and increasing yields where K is in the nutritive solution. A potassium deficiency can lead to the decomposition of proteins. A good NPK balance leads to a decrease on the amino acid content of tissues, an acceleration of their incorporation into proteins and an increase in yields. The choice is that a disease causes a deficiency or a deficiency causes a disease. In the theory of trophobiosis, the latter is determined to be true.
It is the herbicides that through their specific and drastic effects, provide the greatest insight in the relationships among these three factors of disease, the pesticide, the plant and the virus. McKenzie et al. (1968) in controlled lab experiments on resistant or semi-resistant corn to the maize dwarf mosaic virus showed that the MDMV increased as a direct result of the application of atrazine from 19% at 1ppm to 100% infection at 20ppm. Since all herbicides are toxic far all plants, i.e. protein synthesis inhibitors, all such herbicides may be causal factors in the spread of viral disease, as in the example of the atrazine.
The concept of disease is changing. Vago writes, “After more than two centuries of research in every domain of pathology, aiming to define pathologic processes as morbid entities, there is a new trend that acknowledges the difficulty of trying to explain numerous pathologic states on the basis of the isolated unit called ‘disease’. “Vago’s work began with the study of the problem of silk worms being grown in an area bounded by chemical factories. These worms get a virus called NPV. When fed washed leaves 13% of the worms got NPV, when fed unwashed leaves 23% of the worms got NPV. When healthy leaves were fed, that is, those that had not been exposed to the air coming from the chemical factories, only 2% of the worms got NPV. Vago understood that this disease was unleashed by the contamination of the leaves with sodium fluoride which was the main effluent from the factories. But Vago felt that the disease went farther than mere poisoning. He fed the worms on various diets short of nutrients and found that these deficient diets also promoted NPV. Using a control group in which no NPV was present he fed the worms on leaves that had been soaked in a 0.01% solution of NaF, the same amount found in the effluent from the factories. The healthy worms developed 85% NVP infection, while the group fed uncontaminated leaves had only 8% NVP.
Vago concluded that as he said, “It appears possible to trigger an acute virosis without previous infection and in the controlled absence of any sign of virus…the underlying factors may be linked to diet, to poisoning by certain chemical substances or to climatic and conditions.” “These two considerations suggest that the factors behind the triggering of the virosis are physiological disturbances. In spite of the varied nature of their external effects, these may have in common a specific mechanism at the cellular level.” The unleashing of viroses by noninfectious factors seems to us to have the form of a complex. The first stage of this complex consists of various pathological processes, while the second stage is represented by the virosis.
Chaboussou found Vago’s conclusions so important that he reproduced them in full.
This explains the difficulty of eliminating viral diseases if one does not take into consideration the physiological state of the plant, and especially true if pesticides and artificial fertilizers are applied to the plant.
Chlorine has a tendency to reduce the synthesis of proteins allowing free amino acids and at the same time, promoting the decomposition of proteins in the plant which invites aphids and viruses but the question is, which comes first, the aphid or the virus? In extensive studies on aphids and potatoes the researchers could not actually find a virus vector between the aphid and the potato. They concluded that conditioning the plant to promote a good rate of protein synthesis by balancing nutrition and minerals was more effective than the use of nitrogenous and chlorinated pesticides.
At the beginning of part three, there is a quote from a publicity booklet put out by the Procida pesticide company in 1980. “How the devil can all these diseases, already catastrophic enough, blackmail cereal crops in such a fantastic, ceaseless way? What sort of curse has been placed on these fields? Is there no way out of this infernal spiral?” I couldn’t help thinking of all the Biblical patriarchs who lamented in similar ways…
Beginning in the early 1980s there was an increase in the numbers and kinds of viral infections of cereal crops and a previously rare condition involving ‘parasitic complexes’, that is, a group of viruses of differing kinds attacking the crops simultaneously. Even the Procida pesticide company was bewildered, and decided that there must be “other aggravating factors not accounted for simply by natural and climatic conditions.”
Chaboussou says that these factors are increased fertilization, in particular the massive use of nitrogen fertilizers and the equally massive use of chemical pesticides, especially herbicides and fungicides. Other researchers found that the causative factors in Helminthosporiosis (brown stain) were early and dense sowing, nitrogenous fertilizers and fungicide treatments applied during the course of vegetative growth. A non-persistent chemical (supposedly) acting on the surface of the plant as a fungicide can alter the cereal’s physiology and it’s susceptibility to its various parasites.
There is a belief that the various fungi have developed resistance to the fungicides. But how much credit should we give these “alleged resistances” in the face of our knowledge of how the plant is adversely altered by chemical applications that leave them vulnerable?
That Chaboussou and others are on the right track can be seen in the re-conversion of crop fields to ‘organic’ or traditional farming methods. Weeds such as couch grass, thistles, wild oats and foxtail grew on the sprayed farms. When they switched, these weeds disappeared over time. Deep ploughing took care of the couch grass, greater emphasis on leguminous plants and companion planting cleaned and enriched the soil. Halting pesticide use lead to an excellent state of the crop and took care of the aphid problem, and this led to better livestock and the elimination of septicaemia and mastitis, and ticks—which our author says, would be unreasonable to neglect if this shows a certain level of physiological resistance in the animals. (Interesting, but unproven, alas.) Finally, the savings were excellent, the organic methods using two to three times less energy than the “conventional” methods. All this, of course, results in the improvement of the nutritional value of the food.
Rice is one of the most important food crops in the world feeding billions of people every day. It would be unthinkable that this crop should ever fail or even be diminished. Primavesi et al., found that there is a high, statistically significant correlation between yield and levels of Ca and Mg. The pH has an impact on the severity of disease: healthy rice grows in water at pH 5.4-5.8; rice suffering from Pyricularia grows in water at pH 6.8-7.9. Nitrogen-rich fertilizers increase the susceptibility of rice while potassium lowers it, maximum yield is obtained with an average level of K and higher levels of K are found in healthy rice that in that with Pyricularia. All of this is no surprise. Addressing environmental factors (the pH), mineral deficiencies and nutritional deficiencies, and eliminating the use of pesticides and chemical fertilizers could enrich rice crops worldwide, and feed more people adequately. If anything points up the purpose of our campaign to raise bionutrient dense food, this issue is at the forefront.
In practice, optimum nutrition can be seen from two angles, the major elements, like N, P, and K, Ca Mg and others and the micronutrients, Cu, Fe, Zn, Mo, Mn, Li B, and so forth. The first thing we must do is avoid deficiencies, and then learn how to correct them. Traditional anti-fungal methods do just this. Potassium seems to be the element that offers the most resistance to plant parasites. There are over 40 enzymes connected to K, and accordingly a lack leads to an increase of reducing sugars and amino acids. There are at least 30 diseases or disorders associated with calcium which has effect on the circulation of carbohydrates.
It is, we are told, important to remember that all synthetic fungicide applications increase total nitrogen levels in the plant being treated. And, what happens in the soil, after repeated applications, may be a factor in the frequent boron deficiencies found in orchards and vineyards. It is no surprise that some of the preparations used against fruit scab contain what are essential nutrients for plants such as copper, sulfur and potassium permanganate which also provides manganese. Potassium plays a major role in protein synthesis, but it must be balanced with calcium and these balances can be tricky. In one species, Mentha piperita (peppermint), it was found that if calcium were dominant, it stimulated proteolysis (protein breakdown) and the production of asparagine, which encourages fruit scab, and when potassium is dominant, it stimulates protein synthesis with a high glutamine content. Which shows us that even when we think we have everything in order and all the necessary elements present, we must also have the necessary ratios.
As another method of disease control, Polyakov, in 1971, tried soaking seeds before planting in micronutrient solutions. One experiment used sunflower seeds and copper, manganese, cobalt and boron, in 0.1% solutions for ten hours (2 liters being sufficient for seeds to plant 2.4 acres). All of these elements used separately caused a reduction in the Sclerotinia or grey mould.
After all this, restating the premise: a predominance of protein breakdown increases the plants susceptibility, and a predominance of protein synthesis increases the plants resistance or immunity. Increased vulnerability is caused by abandoning mineral products like copper and zinc in favor of chemical pesticides especially dithiocarbamates. Deficiency leads to inhibition of protein synthesis leading to accumulation of soluble substances which improved the nutrition of parasites leading to rapid multiplication and virulence of bacteria and viruses. This is the trophobiotic theory. It explains why symptoms of deficiency coincide with those caused by diseases. At the same time it explains why chemical fertilizers can cause the deficiencies which have such drastic underlying consequences for the plant. According to Vago, both plants and animals are susceptible to disease because of metabolic problems.
To conclude, our author says, a theory only acquires value through the results it provides. In this respect, we can already say that the results so far obtained concerning the protection of various plants from different diseases serve to confirm our ideas and encourage us to continue along this path. These results are based on achieving well-balanced fertilization and stimulation of protein synthesis through the use of complexes of micronutrients.
We are also told that we need to overcome the idea of “the battle”. We must not try annihilate the parasite with toxins that have been shown to have harmful effects on the plant, yielding the opposite effect to the one desired. We need to stimulate resistance by dissuading the parasite from attacking. All of which implies a revolution in attitude, followed by a complete change in the nature of research.