Non-chemical Control Research Articles

Nutritional and Biological Control Synergism against Gastrointestinal Nematodes in Small Ruminants

Parasitic gastroenteritis caused by gastrointestinal nematodes (GIN) continues to be a major constraint against profitable small rumi nant production. The increasing prevalence and severity of anthelmintic-resistant nematodes in many parts of the world has led to a search for non-chemical control options. Approaches alternative or adjunct to chemotherapy for the control of GIN in ruminants are being increasingly important in India because of rapidly developing anthelmintic resistance in nematodes and the increasing concern of chemical residues in animal products and environment. Significant advances have been made in biological control by exploiting nematophagous fungi in different parts of the world including India. Initial studies in India demonstrate that GIN control by larvaetrapping fungi looks promising but suitable system for delivering the fungi to ruminants and practical dosing regimes integrated with nutritional and managemental control measures hold promise for sustainable control measure. Synergism of fungal control measures with feeding and nutritional manipulation accentuate correction of nutrient deficiency in grazing animals as well as recuperation of supra-nutritional demand in the event of GIN infection. This papers reviews the work done on both these aspects including delineation of possibilities for a synergistic approach for control of GIN infection in small ruminants. Adoption of this synergistic model for GIN control measures will definitely reduce parasite pathogenesis and the use of chemical anthelmintics, as well.

Non-chemical weed control systems in organically grown spring oilseed rape

This study aims to determine the impact of different non-chemical weed control systems on organically grown spring oilseed rape ( Brassica napus L.) crop weediness and yield of seeds. Non-chemical weed control systems: 1) thermal (water steam), 2) mechanical (inter-row loosening), and 3) smothering (self-regulation). Thermal (1.5–1.8 times) and mechanical (2.5–6.8 times) weed control systems significantly reduced the number of weed seedlings in spring oilseed rape crop, compared with the weed smothering system. The most effective system of weed control in rape crop was mechanical (efficiency 30.9–75.5 %). Efficiency of thermal weed control system, compared with mechanical, was lower, 28.4–40.0 %. Before rape harvesting in plots where mechanical weed control was applied, compared with plots where weed smothering was used, the number of weeds was significantly 3.2–4.4 times lower, and dry matter mass of weeds was 2.2–3.1 times lower. The yield of rape seeds increased with increasing efficiency of thermal and mechanical weed control. In 2014, the yield of rape seeds depended on number of weed seedlings and dry matter mass of weeds before rape harvesting. Keywords: spring oilseed rape, weed control systems, weed, yield, organic farming

Fungicide resistance: facing the challenge - a review

Fungicide resistance continues to generate disease control problems in many crops. Experience amassed over the past fifty years has emphasised the importance of diversity in modes of action in anti-resistance strategies. Because of losses, not only from resistance, but increasingly from environmental and health concerns, the number of modes of action has become dangerously small. This paper considers three challenges facing crop protection in the search for durable disease control systems. Greater understanding of the biochemistry surrounding fungal development and pathogenicity provides opportunities for the discovery and development of novel modes of action, and some recent advances in this area are discussed. To ensure sufficient resources available to take a novel discovery forward to a commercial product, a second challenge facing manufacturers involves early assessment of resistance risk. A third challenge facing researchers, manufacturers and growers requires translation of resistance risk into effective and durable disease control strategies in actual crops. At the core of this challenge is using resistance risk evidence obtained in laboratory and glasshouse studies using individual isolates of target pathogens, to evaluate the fitness cost of resistance in pathogen populations in field crops. Increasingly, management of resistance is seen as the integration of fungicides with non-chemical disease control methods. But success of any Integrated Disease Management (IDM) strategy ultimately depends on the ability of growers to maintain production and profitability.

Capacidad predadora in vitro de hongos nematófagos nativos de Cundinamarca sobre nematodos gastrointestinales de bovinos

La dependencia y el uso indiscriminado de antihelmínticos químicos como único método de control de los nematodos gastrointestinales (NGI) de bovinos ocasiona problemas en el medio ambiente, la salud pública y la productividad de la ganadería bovina. Es necesario desarrollar estrategias no químicas de control. Los hongos nematófagos pueden ser una alternativa viable y promisoria para el control de estos endoparásitos. El objetivo de este estudio fue aislar, identificar y evaluar in vitro el potencial nematófago de hongos de Cundinamarca sobre larvas L3 de NGI de bovinos. Se sembraron 60 muestras de suelo de fincas ganaderas en cajas de Petri con medio agar-agua para el atrapamiento de los hongos, y se identificaron mediante claves morfométricas tres cepas del hongo Arthrobotrys oligospora (L1, XVIII y XXI) y una de Arthrobotrys musiformis (XXIV). Se utilizaron 1 × 106 conidios o clamidosporas de cada hongo, los cuales se enfrentaron a 100 larvas de nematodos. El aislamiento XXIV (A. musiformis) demostró mayor capacidad predadora (96,8 %) que los aislamientos (A. oligospora) XVIII, L1 y XXI (69, 68, 71,1 y 87,62 %, respectivamente). No hubo diferencias estadísticamente significativas (p > 0,05) entre las cepas de mayor capacidad predadora. Este es el primer registro de identificación y evaluación in vitro de la capacidad predadora de los hongos A. oligospora y A. musiformis nativos de Cundinamarca. Los resultados sugieren que estos hongos podrían emplearse como agentes biocontroladores de nematodos de bovinos.

PP 1/271 (2) Guidance on comparative assessment

PP 1/271 (2) Guidance on comparative assessment

Impact of Kaolin Particle Film and Synthetic Insecticide Applications on Whitefly Populations Trialeurodes vaporariorum (Hemiptera: Aleyrodidae) and Physiological Attributes in Bean (Phaseolus vulgaris) Crop

The bean crop is of great importance for human consumption as a source of protein. One of the most limiting insect pests of this crop in Colombia is the whitefly, Trialeurodes vaporariorum (Westwood). Currently, various nonchemical pest control alternatives for cleaner production are being sought. This study aimed to determine the influence of kaolin on the development of populations of whitefly in greenhouses, and its effect on the physiological characteristics of the bean crop [Phaseolus vulgaris (L.)]. This work was conducted in the greenhouses of the Universidad Nacional de Colombia, in Bogotá. Three experiments were carried out and four treatments were evaluated: 1) control (without any insecticide), 2) synthetic chemical insecticides, and foliar applications of kaolin at 3) 2.5%, and 4) 5% (W/V). Generally, the results showed a high percentage of efficacy (≈91%) on whitefly control in plants treated with 5% kaolin, compared with the plants not treated with insecticides in the three different experiments. In addition, foliar applications of kaolin decreased transpiration by 40% and enhanced by 43% the contents of leaf chlorophyll without affecting bean yield. In conclusion, the use of kaolin particle can be considered as an alternative tool in a program of agricultural management on the bean crop since it can control a high percentage of whitefly and it may help the plant physiology, especially under conditions of abiotic stress such as drought stress.

Developing Cotton IPM by Conserving Parasitoids and Predators of The Main Pest

On early development of intensive cotton program, insect pests were considered as an important aspect in cotton cultivation, so that it needed to be scheduled sprays. The frequency of sprays was 7 times used 12L of chemical insecticides per hectare per season. Development of cotton IPM was emphasized on non-chemical control methods through optimally utilize natural enemies of the cotton main pests (Amrasca biguttulla (Ishida)Helicoverpa armigera (Hübner)). Conservation of parasitoids and predators by providing the environment that support their population development is an act of supporting the natural enemies as an effective biotic mortality factor of the insect pests. The conservation could be done by improving the plant matter and cultivation techniques that include the use of resistant variety to leafhopper, intercropping cotton with secondary food plants, mulch utilization, using action threshold that considered the presence of natural enemies, and application of botanical insecticides, if needed. Conservation of parasitoids and predators in cotton IPM could control the insect pests without any insecticide spray in obtaining the production of cotton seed. As such, the use of IPM method would increase farmers’ income.

Importância das vacinas sintéticas contra o carrapato Rhipicephalus microplus

Rhipicephalus microplus, from an economic standpoint, is the most important parasite of cattle herds in Central and South America and Australia, it causes severe direct and indirect losses in animal production. Control of this parasite rests primarily on the use of acaricides drugs that are responsible for the selection of resistant of populations and cause contamination with residues in meat, dairy products and in the environment. This creates a need to the development of alternative, safe and efficient control, which may act in an integrated manner. Advances in molecular biology techniques have driven several lines of research in veterinary parasitology, particularly in vaccine development. Vaccines derived from the intestinal glycoprotein of R. microplus, the Bm86, have broad potential as a non-chemical control of ticks. The synthetic peptide SBm7462®, a synthetic vaccine derivative of the Bm86, has demonstrated its effectiveness in inducing the immune response of animals immunized with it.

The use of bio-based liquid formulations in pest control of citrus groves

Over the last decade, many pest control techniques have seen substantial changes mainly due to the EU directive 2009/128/EC which relates to the registration process for new products and their toxicity. Thus, the list of pesticides is continuously revised and modified to include new plant protection products which have to be safer for human health, food quality and less polluting for the environment. These decisions increase the importance of and consequently the interest in non-chemical alternatives, including physical systems and bio-based products and the Directive clearly reports the need to define new non-chemical control systems in crop management and defense, as a partial or total alternative to conventional pesticides.At the same time, several crops particularly adapted to the pedoclimatic conditions of southern Italy, such as trees belonging to the genus Citrus, are suffering due to presence of several pests and pathogens that can lead to considerable reductions of yield quality and quantity, and that are often resistant to the most common pesticides. This paper reports and discusses the results of trials carried out in 2011 on the efficacy of natural formulations based on products deriving from Brassica carinata (Ethiopian mustard) on Citrus groves in southern Italy against aphids (Aphis gossypi), mites (Tetranychus urticae, Panonychus citri), scales (Protopulvinaria pyriformis, Icerya purchasi, Unaspis yanonensis) and whiteflies (Aleurothrixus floccosus,). In general, the results were positive, suggesting that the experimental liquid formulations can represent a total or partial alternative to agrochemical pesticides and also an interesting option for organic farming.

A Review of Weed Control Practices in Landscape Planting Beds: Part I–Nonchemical Weed Control Methods

Weed control continues to be one of the most expensive and time consuming aspects of landscape maintenance. Many homeowners are becoming more interested in nonchemical pest-management strategies due to increasing concern over the environmental impact of pesticide use. Nonchemical landscape weed control can be achieved using mechanical disruption (e.g., mowing, hand-pulling, hoeing, and tilling), physical barriers, or cultural control methods (e.g., mulching and plant selection). However, the best results are almost always achieved when employing a variety of methods (often involving chemical control methods). In adopting a weed control strategy, client expectations and weed tolerances must be addressed. While a virtually weed-free landscape is possible without the use of herbicides, this goal often requires a significant amount of time and money, and requires more planning to be successful. The goal of this manuscript is survey the literature pertaining to nonchemical weed control in landscape planting beds and determine: 1) the most effective strategies; 2) the advantages and disadvantages of common practices; and 3) highlight areas where research is needed or improvements could be made.

Operational Evaluation Of Vectomax® WSP (Bacillus thuringiensis Subsp. israelensis+Bacillus sphaericus) Against Larval Culex pipiens in Septic Tanks (1).

The residual effectiveness of VectoMax® WSP (a water-soluble pouch formulation containing a combination of Bacillus thuringiensis subsp. israelensis strain AM65-52 and B. sphaericus strain ABTS 1743) when applied to septic tanks against 3rd- and 4th-stage larvae of Culex pipiens L. was evaluated in this study. This formulation was evaluated at operational application rates of 1 pouch (10 g) and 2 pouches (20 g) per septic tank. Both application rates resulted in >96% control of larvae for 24 days. Operationally, VectoMax WSP has proven to be a useful tool for the nonchemical control of Culex species in septic tank environments.

Weed Management in Autumn Fresh Market Spinach: A Nonchemical Alternative

Physical rather than chemical treatments are preferred for integrated production and are required for organic production to ensure a sustainable production. Weed management in many horticultural crops is heavily constrained by the limited number of herbicides available. Physical weed control strategies, on the other hand, are essential to organic vegetable production and greatly assist conventional vegetable farmers. A physical weed control strategy was developed and compared with a standard chemical strategy within an integrated farming system in fresh market spinach (Spinacia oleracea). The experiment was conducted on a farm in the Serchio Valley (Tuscany, central Italy) in 2004 and 2005, where spinach is one of the most important crops. The physical weed control strategy consisted of a stale seedbed technique and postemergence treatments using various mechanical and thermal machines. The chemical weed control strategy consisted of a single postemergence herbicide treatment using phenmedipham at 15.8% in compliance with integrated production norms in Italy. Strategy performance was assessed in terms of weed density and biomass, total labor requirement, and crop yield. Compared with the chemical system, the physical system required a substantially larger labor input (19 vs. 6 h·ha−1), but like the chemical system, did not require hand weeding. In addition, the physical system reduced weed dry biomass at harvest by 50% and increased spinach fresh yield by 35%. Physical strategies therefore are a valid alternative to the use of herbicides in fresh market spinach and may be especially desirable given the increasing importance of nonchemical weed control in integrated, organic, and conventional farming systems in Europe and the United States.

A non-chemical system for online weed control.

Non-chemical weed control methods need to be directed towards a site-specific weeding approach, in order to be able to compete the conventional herbicide equivalents. A system for online weed control was developed. It automatically adjusts the tine angle of a harrow and creates different levels of intensity: from gentle to aggressive. Two experimental plots in a maize field were harrowed with two consecutive passes. The plots presented from low to high weed infestation levels. Discriminant capabilities of an ultrasonic sensor were used to determine the crop and weed variability of the field. A controlling unit used ultrasonic readings to adjust the tine angle, producing an appropriate harrowing intensity. Thus, areas with high crop and weed densities were more aggressively harrowed, while areas with lower densities were cultivated with a gentler treatment; areas with very low densities or without weeds were not treated. Although the weed development was relatively advanced and the soil surface was hard, the weed control achieved by the system reached an average of 51% (20%–91%), without causing significant crop damage as a result of harrowing. This system is proposed as a relatively low cost, online, and real-time automatic harrow that improves the weed control efficacy, reduces energy consumption, and avoids the usage of herbicide.

Field Study of the Comparative Efficacy of Three Pyrethroid/Neonicotinoid Mixture Products for the Control of the Common Bed Bug, Cimex lectularius.

Three insecticide mixtures that contain two classes of insecticides (pyrethroid and neonicotinoid) were recently developed to control bed bugs. We evaluated three integrated bed bug management strategies in apartments, each using the same non-chemical control methods and one of the three insecticide mixture products: Tandem (lambda-cyhalothrin + thiamethoxam), Temprid SC (beta-cyfluthrin + imidacloprid), and Transport Mikron (bifenthrin + acetamiprid). No insecticides were applied in the Control apartments. In all apartments, we installed vinyl mattress encasements (if not already present) and applied steam to beds and other infested upholstered furniture. Insecticide sprays were applied in the three treatments. Each treatment and the Control included 8–10 occupied apartments. Re-treatment was conducted during biweekly inspections if necessary. After eight weeks, the mean (± SEM) bed bug count reduction in the Tandem, Temprid SC, Transport Mikron, and Control was 89 ± 9, 87 ± 6, 98 ± 1, and 23 ± 54%, respectively. Only Tandem and Transport Mikron treatments resulted in significantly higher population reduction than the Control at eight weeks. There were no significant differences in mean percent reduction among the three treatments (Tandem, Temprid SC, Transport Mikron) at eight weeks. Tandem spray caused significantly faster bed bug reduction than Temprid SC spray and Transport Mikron spray.

Intelligent versus non-intelligent mechanical intra-row weed control in transplanted onion and cabbage

Non-chemical weed control methods are increasingly in demand for conventional field vegetables, mainly accentuated by regulatory restrictions on the use of herbicides. Intelligent camera-based systems capable of guiding mechanical weeding devices so as to avoid injuring crop plants are now available for practise. The aim of the present study was to compare the weeding performance of an intelligent mechanical weeding machine with non-intelligent tools such as a weed harrow, finger and torsion weeders. Two experiments were conducted in transplanted onion and two in transplanted white cabbage, focussing on weed and crop effects. In broad terms, intelligent weeding was not superior to the simpler tools in onion, and only minor differences were found that could be attributed to the settings of the non-intelligent implements. It was only possible to estimate the effects on weeds in the one cabbage experiment with intelligent weeding, which showed no noteworthy differences between the intelligent tool and the simpler ones. Finally, a competition study was conducted on the importance of untreated weeds in close proximity to the transplant as a result of intelligent weeding. It showed that intelligent weeding capable of cultivating the soil close to cabbage plants can provide satisfactory weed control without any need for subsequent manual weeding.

Heat treatment of apple fruit after harvest before storage

The cyclic effect of heat and light on the fruit scald development (skin browning) in Anotonvka obyknovennaya has been studied in order to work out new nonchemical control of scald during storage. The content of chlorophyll in the apple skin has been measured during ripening. It has been established that such treatment of fruit with the minimum content of chlorophyll in their skin completely eliminates the risk of fruit browning.

Predictive Model of Soil Temperature and Moisture During Solarization in Closed Greenhouse

<abstract> <bold><sc>Abstract.</sc></bold> Soil solarization is a method of non-chemical disease control that employs solar radiation to heat the soil to temperatures that are lethal for soilborne pathogens. Application of this technique in closed greenhouses has allowed it to spread in areas characterized by temperate climate, such as the Mediterranean basin. Optimization of the technique requires knowledge of the physical processes inside the soil-mulch-greenhouse system that determine the thermal regimes in the soil. In this work, a one-dimensional physical model is developed for simulation of the temperature and moisture content in mulched soil during solarization treatment in a closed greenhouse. The model also calculates the air temperature and relative humidity inside the greenhouse. The model includes heat transfer in the soil by both apparent conduction (which incorporates transfer of latent heat by vapor movement under the influence of a temperature gradient) and enthalpy transport by liquid and vapor flow. The temperature and water content in the soil are calculated using coupled partial differential equations of heat and moisture diffusion. Furthermore, in the calculations of radiative fluxes, infinite reflections are considered. The input variables required are outside air temperature and relative humidity, outside solar radiation flux, wind velocity, soil texture and bulk density, and radiometric properties of the soil as well as of the covering and mulching films. The model is validated using data collected during a soil solarization treatment carried out in a full-scale commercial greenhouse. The results show good agreement between measured and modeled data, especially concerning soil temperature. A sensitivity analysis is also carried out in order to investigate soil temperature changes induced by variations in the radiometric properties of the films. The results show that the highest temperature changes in the soil are determined by the shortwave transmittance of the cover.

Integrating Economics in the Critical Period for Weed Control Concept in Corn

The effect of weed interference on corn yield and the critical period for weed control (CPWC) were determined in Germany and Benin. Treatments with weed control starting at different crop growth stages and continuously kept weed-free until harvest represented the “weed-infested interval.” Treatments that were kept weed-free from sowing until different crop growth stages represented the “weed-free interval.” Michaelis–Menten, Gompertz, logistic and log–logistic models were employed to model the weed interference on yield. Cross-validation revealed that the log–logistic model fitted the weed-infested interval data equally well as the logistic and slightly better than the Gompertz model fitted the weed-free interval. For Benin, economic calculations considered yield revenue and cost increase due to mechanical weeding operations. Weeding once at the ten-leaf stage of corn resulted already profitable in three out of four cases. One additional weeding operation may optimize and assure profit. Economic calculations for Germany determined a CPWC starting earlier than the four-leaf stage, challenging the decade-long propagated CPWC for corn. Differences between Germany and Benin are probably due to the higher yields and high costs in Germany. This study provides a straightforward method to implement economic data in the determination of the CPWC for chemical and nonchemical weed control strategies.

Optimal Integrated Strategies to Control an Invasive Weed

Although there have been numerous studies on the economics of weed control in agriculture, relatively few studies have focused on weeds in natural ecosystems. A stochastic dynamic simulation model and a stochastic dynamic programming model are developed to: (A) identify the combination of control options that is optimal for blackberry (Rubus anglocandicans) in Australian natural ecosystems, (B) assess whether an integrated control strategy is superior to chemical‐only strategies, (C) evaluate the net benefits of biological control (a rust and grazing by goats), and (D) determine how changes in model parameters affect the optimal control strategy. The results indicate that, while an integrated strategy combining chemical and nonchemical control methods may be optimal in certain circumstances, it is not necessarily superior to a chemical‐dominant strategy in all cases. The results show that grazing goats for control of blackberry can be optimal despite uncertainty about its effectiveness. Policy makers need to be aware of the trade‐offs between choosing more effective control options that may impose environmental and health risks versus less effective control strategies that are safer to the environment and human health.

Pore size criteria of mesh crop covers for the exclusion of tomato-potato psyllid (Bactericera cockerelli)

Control methods for tomato-potato psyllid (TPP; Bactericera cockerelli) are currently dominated by the use of synthetic biocides. A non-chemical alternative for TPP management is crop mesh, which forms a physical barrier between crop and pest. This study examined the ability of TPP adults to penetrate, or lay eggs through, 22 commercially available crop meshes using a laboratory bioassay. Adult TPP were prevented from moving through the mesh if the mesh complied with any one of the following criteria: shortest pore length <0.55 mm; longest pore length <0.60 mm; diagonal length <0.85 mm; area <0.3 mm2. Eggs were found on foliage only when TPP adults had penetrated the mesh, suggesting that eggs could not be laid through the mesh. The results indicate that crop meshes may provide non-chemical control for TPP that can be used by organic growers, and producers attempting to reduce chemical inputs as part of integrated pest management.