PLANT PROTECTION CORNER Innovation in integrated control of greenhouse pests: An urgent need! In greenhouse crops, PROGRESS IN IPM BASED ON THE modes of action. Traditional biological control as a DEVELOPMENT OF NEW (SYNTHETIC broad-spectrum insecticides like component of Integrated AND MICROBIAL) CHEMICAL organophosphates, carbamates PESTICIDES and pyrethroids have been Pest Management (IPM) ccording to Ramakers, most replaced by selective products went through a considerable of the antagonists used in like nicotinoids, spinosyns and Abiocontrol have been hydrazines. So it is actually the growth in the first years of available for decades, with the progress in the chemical field this millennium, after a phytoseiid mite Typhlodromips that has allowed a wider virtual standstill in the swirskii (predator of thrips and application of biologicals, most whiteflies simultaneously) as a of which were known before! nineties. Already common rare exception. New pesticides, practice in the production however, appear regularly, often LACK OF INNOVATION IN P.M.J. Ramakers representing completely new BIOCONTROL of fruiting vegetables, Courtesy of NAI chemical groups with novel Why is there a lack of innovation biocontrol is now on the increase in floriculture, mainly in cut flowers, and to a lesser extent in potted plants. Moreover, we witness regional expansion from the moderate climate zone towards subtropical areas. The driving force behind the trend is the increasing social and political call for sustainable production. With respect to acceptable pesticide residues on vegetables, supermarkets impose stricter standards than health authorities. In ornamental production, presence of pesticide residues is not so much of an issue. These growers appear to have other motivations: pesticide resistance prevention, labour, environmental concerns, product reputation and sometimes even yield increase. Curiously, while IPM is increasing, little innovation can be observed in the field of biocontrol itself. Why is that so and what needs to be done to change the situation were the two main questions addressed by P.M.J. Ramakers, Wageningen UR Greenhouse Horticulture in the Netherlands, during his excellent keynote lecture at the opening session of the Miami conference. 24 NEW AG INTERNATIONAL PLANT PROTECTION CORNER in biocontrol? Ramakers sees a of sometimes doubtful quality. with other (chemical or biological) Ramakers concluded his lecture series of reasons to this situation. These doubts relate to the pesticides. by raising the question of First reason is that biocontrol biological effectiveness in the whether investing in biocontrol products are products of nature, first place, to the targets WHAT DO WE NEED? agents pays? He balanced ther not patentable. This is actually recommended and to the sheer For Ramakers, there are four positive and negative arguments. the main reason why there is quality (viability) of the finished pillars to build on in order to The positive ones: an urgent and such a discrepancy between product. The most common error change the situation. increasing demand, a simple chemical versus biological is the translation of petri dish First and most urgent, search for registration procedure (except for innovation. observations into conclusions new pest antagonists everywhere microbials), a market targeting The second reason is that about field efficacy without too in nature, in agricultural well-educated growers who can biocontrol products have a much of evidence. ecosystems and in the area of handle complicated strategies specific mode of action and It may be tenable to leave field pest origin. Next is to develop and used to relatively high therefore there is only a small evaluation to the growers and microbial pesticides such as product prices. market niche for each of them, their advisors in cases where the bacterial insecticides, soilborne On the “negative side”, products with a few exceptions of course. effect of the antagonist is fungi, NP viruses and EP are not patentable, they are niche Biocontrol manufacturers are not obvious. However, with some of nematodes. Then there is a products, the growers are in able to make in-depth the antagonists recently compulsory need to confirm demand for extremely high investments, knowing that fast- commercialized, field evaluation efficacy in field experiments with quality and …..the growers are following competitors will soon is difficult if not impossible since an adequate monitoring of both well educated, which prevents come alongside, often within a the biological interaction with the the pest and the antagonist. Last snake oil products to stay long in year. Hence, innovative efforts are target is concealed. Alertness is but not least, there is a need for the market. Is this really directed at mass-production, particularly recommendable if continuous quality control: those negative? In any case, reliable storing, formulation (of products are claimed to be products are living organisms suppliers to this market will not microbials) and application effective only when used and there is a risk of complain. The biocontrol techniques, rather than at preventively or in combination contamination and genetic drift. industry needs to mature. ■ developing different antagonists. The last but not least reasons listed by Ramakers to explain the lack of innovation in the biocontrol industry are the privatization of independent research & extension services with public and cooperative funds shrinking as well. Biocontrol is thus widely adopted, but based on relatively few products. Considering the huge assortment of botanical species and cultivars in floriculture, grown under a wide variety of climatic conditions, it is highly unlikely that biocontrol can conquer this field with the few antagonists currently available. This gap between growers’ demands and availability in the marketplace has created a vacuum, which seems to suck in new suppliers offering products NEW AG INTERNATIONAL 27 PLANT PROTECTION CORNER Role of Mineral Nutrition in IPM Mineral nutrients are utrients that are known to that the form of K may be more influence diseases in some important than the amount involved in many Nplants are N-form, K, Ca, Cl, applied. physiological and S, Mn, Ni, and Si. SULPHUR biochemical processes as NITROGEN Sulphur (S) deficiency impairs enzyme activators, Nitrogen can be absorbed as a crop productivity and quality. reduced (NH4) or oxidized form Suphur Induced Resistance (SIR) structural components, (NO3). The form of nitrogen denotes the reinforcement of the metabolic regulators, affects disease as diseases can natural resistance of plants react differently to each N-form. against fungal pathogens by substrates, and osmotica. NH4-N is associated with sulphate-based, soil-applied reductions in pH while NO3-N fertilization and is one The nutritional status of a increases pH. N03-N suppresses constituent of the complex plant affects inherent Prof Lawrence E. Datnoff Fusarium diseases. NH4-N phenomenon of induced Courtesy of NAI suppresses most other soilborne resistance. The potential efficacy disease resistance which affects disease escapes, alters diseases. Datnoff developed on of SIR expressed as a reduction pathogenesis, and modifies the virulence of the pathogen several examples such as of the disease index ranged from Fusarium wilt being suppressed 5-50% to 17-35% in greenhouse and its ability to survive. Proper nutrition is first line of by NO3 on tomatoes as well as and field experiments, Rhizoctonia root rot on beets, respectively. defense. Any nutrient that is deficient or in excess will Verticillium wilt being increase a plant’s susceptibility to disease. Because suppressed by NH4 on potato as well as Black root rot on nutrients influence the relationship between the plant and strawberries. the pathogen, growers have a valuable IPM method CALCIUM already in place to effectively reduce damage from plant Ca reinforces cell wall diseases. In his keynote address at the opening session of components to resist infection. It suppresses a number of the New Ag International conference in Miami, Prof diseases such as Club root of cabbage, Southern blight and Lawrence E. Datnoff, Department of Plant Pathology & cavity spot of carrot, Fusarium Crop Physiology, Louisiana State University, and a world wilt of tomato, Erwinia soft rot of potato or Botrytis blight of many expert on the topic, presented the interactions and effects, vegetables. The book of Prof Datnoff is the and prescribed nutritional regimes that will minimize world reference book on the POTASSIUM subject. It can be ordered from crop loss to disease and improve overall plant health and Potassium is absorbed solely as www.shopapspress.org K. Effects on disease are development. numerous and variable. Results CHLORINE often depends on the form of K - Long before the role of Cl in KCl, K2SO4, KNO3. K provides crop production was recognized, proper ion balance and turgor Cl was routinely applied as maintenance. Datnoff underlines chloride in NH4-N, K, and Ca 26 NEW AG INTERNATIONAL PLANT PROTECTION CORNER for Suppressing Plant Diseases fertilizers. However, even in the Manganese (Mn) content in the metals e.g. Ca, Mg, Mn, Fe, Cu, susceptible cultivars is last decade, the disease- plant. Many disease-suppressing Zn), or certain agrichemicals dramatically improved. Silicon suppressing benefits of chloride activities, such as mulching, no- such as glyphosate, might be also has been shown to suppress salts are still mistakenly being till,