Integrated pest management in field vegetable crops in northern Europe — with focus on two key pests

Improvements in (1) insecticide application, (2) supervised control, and (3) pest forecasting systems have each helped to reduce considerably the amounts of insecticides required to control fly, caterpillar and aphid infestations in vegetable crops in northern Europe. By growing plants that are partially resistant to certain major pests, it is now possible to apply even less insecticide than the dose recommended for the crop. In crops where only small amounts of insecticides are applied, natural predators should prevent large increases in pest insect populations and natural parasitoids should reduce the numbers of pest insects entering subsequent generations. The possible impact of introducing transgenic plants and the use of physical (crop covers), cultural (crop rotation, undersowing) and microbial (e.g. fungi, bacteria and nematodes) methods of control are also discussed. The withdrawal of certain insecticides, as a result of environmental and commercial pressures, means that some crops may soon be without appropriate insecticides for controlling one or more of the major pest species. Whether such systems will be sustainable, remains to be seen.     

The effects of irrigation method, age of seedling and spacing on crop performance, productivity and water-wise rice production in Japan

A field experiment using system of rice intensification (SRI) techniques was conducted in Chiba, Japan during the 2008 rice-growing season (May–September) with eight treatment combinations in a split–split plot design (S–SPD) to observe the potential of SRI methods under the temperate climatic conditions in Japan. Intermittent irrigation with alternate wetting and drying intervals (AWDI) and continuous flooding throughout the cropping season were the two main-plot factors, while the effects of age of seedlings and plant spacing were evaluated as sub and sub–sub plot factors, respectively. The experiment results revealed that the proposed AWDI can save a significant amount of irrigation water (28%) without reduced grain yield (7.4 t/h compared with 7.37 t/h from normal planting with ordinary water management). Water productivity was observed to be significantly higher in all combinations of practices in the intermittent irrigation plots: 1.74 g/l with SRI management and AWDI as compared to 1.23 g/l from normal planting methods with ordinary water management. In addition, the research outcomes showed a role of AWDI in minimizing pest and disease incidence, shortening the rice crop cycle, and also improving plant stand until harvest. Synergistic effects of younger seedlings and wider spacing were seen in tillering ability, panicle length, and number of filled grains that ultimately led to higher productivity with better grain quality. However, comparatively better crop growth and yields when using the same SRI practices with ordinary water management underscore a need for further investigations in defining what constitute optimum wetting and drying intervals considering local soil properties, prevailing climate, and critical watering stages in rice crop management.     

Potato blackleg disease

Blackleg, a bacterial soft-rot of potatoes caused byErwinia atroseptica, has been recognized since the turn of the century as a disease capable of causing tremendous losses to the crop in the field or in storage. The pathogen is both seed- and soil-borne, and generally attacks the seed piece through wounds caused by insect larvae, fertilizer burns, frost injury, bruises, or lesions caused by other pathogenic bacteria and fungi. Infection is increased by low temperature and high moisture, especially in the soil. These conditons are less than optimum for the pathogen, but are less favorable for the infected plant, as they slow normal growth and prevent formation of protective cork tissue which would restrict the spread of the infection. Partial control of this disease can be effected by using seed free from disease, sanitation, crop rotation, planting in well-drained soils, prevention of any wounds or diseases which would permit entry of the pathogen, planting resistant varieties, seed treatment, and proper storage conditions for freshly dug tubers and cut tubers if they cannot be planted immediately.     

A methodology to assess the profitability of Bt-cotton: case study results from the state of Karnataka, India

Bt-cotton varieties can control lepidopterous pests, hence offering the possibility to reduce chemical pesticide use. India, with the largest cotton-growing area globally, gave commercial approval for Bt cotton in 2002 and a rapid adoption of the technology is expected. This paper uses a stochastic partial budgeting approach that captures the key pest control properties of Bt cotton taking into account uncertainty of pest pressure, control effectiveness and prices to assess the profitability effects of Bt varieties and hence complements previous studies that generally excluded such issues. Results of the simulation model reveal that under the current price situation a prophylactic chemical control strategy dominates the use of Bt varieties in both, irrigated and non-irrigated cotton. The effect of a higher cotton price is assessed in a second scenario that depicts a Bt cotton variety with improved fiber quality than varieties currently approved for commercial planting. Under this assumption, the Bt strategy would be slightly better than the prophylactic use of chemical pesticides. The model can be extended to include pests other than the bollworm and correlations among variables, e.g. prices and yield, provided sufficient evidence for such correlation exists. Results of this analysis show the impact of uncertainty in the main variables that influence the profitability of Bt cotton and alternative crop protection methods.     

Potato Common Scab: a Review of the Causal Pathogens,Management Practices,Varietal Resistance Screening Methods,and Host Resistance

Potato common scab is a widespread disease in which scab-like lesions develop on tubers. The disease is caused by pathogenic Streptomyces species, which synthesize the phytotoxin thaxtomin. The txtAB operon, responsible for thaxtomin production, can be used as a marker to identify pathogenic strains of the bacterium. Screening methods to assess scab susceptibility in breeding programs are time-consuming and can produce variable results. Management practices to control the disease vary and include crop rotation, tolerant varieties, monitoring soil pH, avoiding low soil moisture at tuber initiation, and application of soil- and/or seed-applied pesticides. There is a wide range in levels of tolerance among potato varieties. Many public research programs are committed to breeding for scab-tolerant varieties and evaluating management methods. Topics reviewed target readers focused on breeding and disease management objectives to reduce the incidence and severity of potato common scab.     

Agrarbiologische Voraussetzungen des Integrierten Pflanzenschutzes

The paper discusses the problem of how to apply the principles of integrated plant protection as practised in orchard work to agriculture and vegetable growing. Agricultural and vegetable crops are subject to rotation and cannot be made subject to a continuous and thorough control of pest populations and hence the magnitude of future attacks cannot be adequately estimated. Nevertheless, a series of measures can be taken to lower the incidence of attack and disease, thus reducing the necessity for pesticides. This justifies the use of the concept of “integrated plant protection” in agriculture and vegetable growing. Thus the selection of correct sites for cultivation (soil, climate, weather, topography), use of suitable cultivars, choice of appropriate cultural methods (crop rotation, organic and mineral fertilizers) are some of the elements of “integrated plant protection”. The interdependance of the various factors and the close connection with attack and disease problems is extensively discussed.     

稻田应用“水肥一体化”的现状、问题与思考

水肥一体化技术是在灌溉的同时将肥料混合施入土壤的集灌溉和施肥于一体的技术。发展和应用水肥一体化技术不仅可以达到节水省肥的目的,还是实现农业精确定量、智慧管理的重要途径。本文概述了水肥一体化在国内外的研究进展和水肥一体化中滴灌等技术在设施栽培以及玉米、棉花等作物生产中的应用现状。对滴灌技术在水稻中应用存在的成本高、环境不友好、品种适应性差等问题进行了分析,并提出对应的沟渠改造、加强滴灌管道建设、垄畦栽培结合、水肥药一体化和筛选新品种等解决方法。本文为水肥一体化在水稻栽培中的应用提供了参考,探索了水肥一体化水稻栽培未来的方向。     

Assessing crop management options with crop simulation models based on generated weather data

The efficient use of crop simulation models is an effective complement to experimental research. Long-term weather data obtained at a specific site are normally required for the application of these crop simulation models to help determine alternate management practices and associated decisions. Stochastic weather generators sometimes are used to complement or substitute historical weather data. The objective of this study was to evaluate the suitability of weather data generated by the weather generators WGEN and SIMMETEO as input for crop simulation models in order to determine the best option(s) among a number of different crop management practices. Five locations across Iran representing different climates were selected. The wheat, maize, and soybean models of the Decision Support System for Agrotechnology Transfer (DSSAT) were applied in this study, using 30 years of observed weather data and 90 years of weather data generated by WGEN and SIMMETEO. Simulated grain yield using either observed weather data or weather data generated by WGEN and SIMMETEO in response to various ‘experimental’ factors, e.g., cultivar selection, planting date, planting density, irrigation threshold, and change in precipitation under irrigated and rainfed conditions were compared. The statistical evaluation was based on t, F, and Kolomogrov-Smirnov (K-S) tests. The average of the percentage rejected tests was 20% and the parameter estimation method had no impact on the number of rejected tests. Irrespective of some significant differences between simulated yield based on observed weather data and those based on weather data generated by WGEN and SIMMETEO, a similar conclusion could be drawn about the best cultivar, planting date, plant density and irrigation threshold and response to changes in the amount of precipitation. Based on the results of this study it can be concluded that for many crop model applications where only relative estimates or determination of the best management option(s) rather than absolute values are required, weather data generated by either WGEN and SIMMETEO are accurate and sufficient.     

Establishment of legumes in grass swards: effects of pesticides on slugs,insects, legume seedling numbers and forage yield and quality*

Three legumes, red clover (Trifolium pratense L.), alfalfa (Medicago sativa L.) and birdsfoot trefoil (Lotus corniculatus L.), were planted with a minimum-tillage drill into eight grass fields, three in early spring, two in late spring and three in late summer, in Pennsylvania. The objective was to use pesticides at planting time to control slugs and insects which attack legume seedlings and ascertain whether pest control prevented seedling loss and increased yields of grass and legume dry matter (DM), in vitro DM digestibility and crude protein (CP). Methiocarb bait alone or in combination with carbofuran granules or spray applied at planting sometimes controlled the slugs Derocerus reticulatum (Müller), D. laeve (Müller) and Arion fasciatus Nilsson and improved establishment of seedling red clover and alfalfa but not birdsfoot trefoil. Increased yields of DM, digestible DM, CP and legume DM after treatment was greatest in late-spring sowings. Larvae of the clover root curculio, Sitona hispidulus (F.), attacked roots of legumes in the spring following the year of sowing. Late spring and summer sowings without pesticides sustained considerable seedling losses from pests, whereas seedlings from early spring sowings in untreated areas were injured less.     

Pest management challenges for smallholder vegetable farmers in Zimbabwe

Smallholder vegetable production is expanding rapidly in Zimbabwe both for local sale in urban markets and for export. Pest management practices of 12 small-scale vegetable farmers in two areas of Zimbabwe were surveyed over a five-month period to gather information on crops, pests, diseases and crop protection methods. A range of serious pests and diseases affects non-indigenous vegetables such as Brassicas, tomatoes, onions and cucurbits. Although farmers use some cultural control methods and occasionally botanical pesticides, pest control is predominantly by the use of conventional synthetic pesticides. These are usually applied through lever operated knapsack sprayers although some less orthodox application methods are occasionally used. Results are variable and there are concerns about risks to sprayer operators, consumers and the environment (including natural enemies) due to shortcomings in protective clothing, large deviations from recommended doses and excessive run-off to the soil. Field trials were carried out to evaluate a modified sprayer lance which directs the spray upwards rather than downwards in an attempt to place more of the spray under the leaves where most of the arthropod pests are found. The ‘V lance’ as it is called improved the uniformity of spray coverage on the upper and lower leaf surfaces and is expected to improve efficacy of spraying and/or offer the opportunity to reduce doses or spray frequencies. Farmers who tested the device reported good results and gave constructive feedback for future improvements. The smallholder vegetable sector requires support in the form of improved access to existing pest management information (in an appropriate form) and focused research targeted at the knowledge gaps which currently impede implementation of sustainable IPM.     

Effects of integrated pest management, biological control and prophylactic use of insecticides on the management and sustainability of soybean

This study aimed to evaluate the prophylactic use of insecticides (PUI) in comparison with integrated pest management (IPM) and biological control (BC) strategies. Five replicated experiments were carried out independently in two Brazilian soybean-producing states, Goiás and Paraná, where those pest-control strategies were evaluated during two consecutive growing seasons. The evaluated treatments were integrated pest management (IPM); prophylactic use of insecticides (PUI), a practice that has been increasingly adopted by soybean growers in Brazil as well as in other Latin American countries; biological control (BC) and the control (C), which involved no pest treatment. Although the pest infestation rates in the BC and IPM treatments were higher than that in the PUI treatment, crop productivity, in general, was similar among these treatments and differed only from the control with no pest treatment. These results indicate that the prophylactic use of insecticides on soybeans does not result in higher productivity in the field and that this practice merely requires larger amounts of pesticides, which can impair the sustainability of the soybean crop. Therefore, the use of IPM still remains the best alternative for pest management in soybean fields.     

The effect of ridge planting and earliness of durum wheat varieties on sunn pest (Eurygaster spp.) damage and grain yield

Sunn pests (Eurygaster spp.) are among the most important insect pests of wheat (Triticum sativum L.) and barley (Hordeum vulgare L.). Cultural practices can prevent or minimize common sunn pest (Eurygaster integriceps Puton) population densities and crop damage. A three-year field experiment (Jun 05 to Aug 07) was conducted in Diyarbakır in the southeast Antolia region of Turkey, to evaluate the effects of planting method (no-till ridge planting and conventional planting) and earliness of durum wheat (Triticum durum L.) varieties (early, mid-season and late varieties) on E. integriceps density, grain damage and overall grain yield. The effect of the planting method on the sunn pest density and percent of grains damaged by sunn pest was not significant; however, there was a significant difference among the different varieties used in this study. While Çeşit-1252 (late wheat variety) had the highest nymph density (11.2 nymphs m⁻²) and percent of sunn pest damaged grains (2.8%), Sarıçanak-98 (early wheat variety) had the lowest nymph density (4.3 nymphs m⁻²) and percent of sunn pest damaged grains (0.8%). Grain yield was the highest (5.99 t ha⁻¹) for Sarıçanak-98 while there was no significant difference between Aydın-93 (5.06 t ha⁻¹) and Çeşit-1252 (4.99 t ha⁻¹). In conclusion, this study suggests that planting methods may not have a significant effect on sunn pest density, percent of sunn pest damaged grains or grain yield; however, the use of early durum wheat varieties, such asSarıçanak-98, may reduce sunn pest population densities, percent of damaged grains, allowing increases in grain yield in southeast Anatolia region, Turkey.     

Forage production and quality of several crop rotations and pastures in northwestern Spain

Multiple cropping has been used for many years to increase production in temperate areas of Europe where the growing season is favourable and is important when land area is limiting.
The purpose of this 3-year study was to determine how several different cropping systems affected forage production potential at three rainfed locations in northwestern Spain (Galicia). The cropping systems compared were: single crop maize; double crop systems of maize-rye, maize oats+ vetch, and maize-Italian ryegrass; three crops in a two-year rotation of maize-Italian ryegrass (12-months) forage rape; 2-year pasture maize and two contrasting 3-year grass-legume mixtures.
There was an increase in dry matter (DM) production as cropping intensity increased. The one-year double cropping systems always yielded more than three crops in two years, which in turn outyielded single crop maize or 3-year pastures. The highest DM yields were 20–9 t ha-¹ from the maize-oats-I-vetch rotation. Maize was the principal crop determining total production, yielding about 70% of the total DM for the double cropping systems. The maize component gave similar annual yields in the multiple crop and maize-pasture rotations, but the use of maize allowed double cropping, which increased production compared with 3-year pasture.
Forage rape gave the highest in vitro dry matter digestibility (IVDMD) of 773–815 g kg-¹ while the oats-I-vetch mixture gave the highest crude protein (CP) concentration (105-217 g kg-¹). The maize crops had the lowest CP content (62-76 g kg-¹) though digestibility was high (653-713 g kg-¹).     

Multiple effects of two drivers of agricultural change,labour shortage and water scarcity,on rice pest profiles in tropical Asia

The effects of shortage of agricultural labour, represented by direct-seeding technologies replacing transplanting, and of water scarcity, represented by limited water supply, on rice pests (pathogens, weeds, insects) were studied. The analysis was based on a field characterisation data set covering six sites in tropical Asia and several cropping seasons. Two-way ANOVAs and MANOVA were, respectively, used to test the effects of the two factors on individual rice pest injuries, and on the profile of injuries that an individual rice crop experiences over a cropping season. Fourteen injuries were considered, which individually were significantly (P < 0.05) influenced by crop establishment (nine injuries), by water management (11 injuries), or their interaction (nine injuries). Multiple analysis of variance indicated that rice injury profiles, regionally, are altered by both factors. The results suggested that injuries caused by some pests would be enhanced (e.g., brown spot, planthoppers) or reduced (e.g., stem rot, sheath blight, rice whorl maggot) by crop establishment shifting from transplanting to direct-seeding. Water shortages, proxied in our data by poor water management, would favour some injuries (e.g., sheath rot, brown spot, neck blast, whiteheads) or suppress others (e.g., stem rot, sheath blight). Very strong increases in weed infestation were observed with both direct-seeding and poor water management. The results are discussed with respect to pest management in rice.     

东北中西部地区玉米田农药使用现状与分析

2015～2018年对东北中西部春玉米区玉米病虫草害防治用药情况进行调查.结果表明,该区域玉米田化学农药的使用量占农药总使用量的99％以上.吉林省玉米田农药年均用量为3 216.45 g a.i./hm2,内蒙玉米田化学农药年均用量为1 133.44 g a.i./hm2.各类化学农药按照使用量排序依次为除草剂＞杀虫剂...     

Crop Allelopathy and Its Role in Ecological Agriculture

Summary

A number of crops exhibit allelopathic interactions that play a significant role in the complex environment of agroecosystems. Several studies have shown that allelopathic crops reduce growth, development and yield of other crops growing simultaneously or subsequently in the fields. Another aspect of interest regarding crop allelopathy is that allelochemicals may exhibit inhibitory effect on the same crop which is commonly called as crop autotoxicity. It is predominantly common in fields where sole cropping under reduced or no-tillage system is practiced. Though any crop part can be allelopathic, including even the pollens, but decomposing crop residues exhibit more influence on other plants. Furthermore, the extent of allelopathy by a crop plant varies with age, part and type of cultivar being used. Nowadays allelo-pathic crops are being used as an important tool in managing weeds and harmful pests under sustainable pest management programs. In this context several cover/smother and green manure crops with allelopathic nature hold a good promise as well as challenge for the future as they have a potential to suppress noxious weeds. Likewise, the decomposing residues of such crops can also be used for managing harmful weeds and pests vis-à-vis maintaining the sustainability of the system. The traditional practice of crop rotation which declined with the discovery of synthetic herbicides can also be revived, if allelopathic potential of rotational crops is well understood. Selection of cultivars with high allelopathic potential/high competitiveness is another possible way by which crop allelopathy can be better utilized for weed control and yield enhancement. Crops with less allelopathic potential can be genetically improved by incorporating desired genes encoding the synthesis of allelochemicals. Pure allelochemicals extracted and identified from some crop plants can also be used as bioherbicides.     

Comparison of aircraft,ground-rig and center pivot irrigation systems for application of pesticides to potatoes

Studies were conducted from 1979 to 1983 in central Wisconsin to investigate the utilization of center pivot irrigation systems for the application of pesticides to potatoes. Fungicides, herbicides and insecticides were applied with a conventional tractor-mounted boom sprayer, a boom mounted beneath the center pivot (underslung boom), direct injection into the center pivot irrigation water and by aircraft. In comparisons between irrigation system application and tractor-mounted boom application, materials through both the underslung boom and center pivot system provided comparable pest control to the tractor-mounted boom, with the exception of water soluble insecticides which were ineffective when applied through the irrigation system. In addition, under intense disease pressure a somewhat reduced efficacy was associated with fungicides applied through the center pivot system compared to tractor-mounted boom applications. Comparison of center pivot pesticide applications with aerial and tractor-mounted boom applications in 65 ha commercial fields in 1982 and 1983, showed that all application methods provided acceptable levels of pest control, and comparable tuber yields.     

The role of synthetic pesticides in the intensification of highland agriculture in Thailand

The objective of this study is to quantify the relationship between synthetic pesticide use and agricultural intensification in the northern highlands of Thailand. We surveyed the crop management decisions of 295 farmers across 12 villages, and assessed the level of pesticide use in terms of monetary value, the active ingredients used, and using the Environmental Impact Quotient method. The results show that 77% of the farmers relied solely on synthetic pesticides for their pest management activities. The average farmer used 13.3 kg of active ingredients per hectare of agricultural land, but the variation was large. The highest levels of pesticide use were observed with the cultivation of cut flowers and greenhouse vegetables, while greater land use intensity was associated with increased usage of synthetic pesticides and a greater potential environmental impact. We found that those farmers following public certification of Good Agricultural Practices (Q-GAP), were neither able to reduce pesticide use nor its environmental impact. The findings suggest that to limit the environmental impact caused by the use of synthetic pesticides, greater priority must be given to developing and promoting non-synthetic methods of pest control together with gradually restricting the supply of highly hazardous pesticides.     

Perspectives of integrated pest management

Integrated pest management (IPM) programmes require joint interdisciplinary scientific efforts to assemble sound information about: (1) the ecological basis of the pest problem; (2) factors in the agroecosystem that can be manipulated to make the crop environment unfavourable for pests; (3) pest and natural enemy population trends to determine if and when pesticide treatments are necessary; and (4) the benefits and risks of the IPM strategy for agriculture and society. The IPM technology is complex and this is partly why implementation of IPM has been slow. Projections are that if IPM is adopted by agriculture, pesticide use could be reduced by 35–50% from present use levels. Concurrently there would be a reduction in environmental and social problems caused by pesticides.     

Effective invertebrate pest management in dryland cropping in southern Australia: The challenge of marginality

Despite research efforts spanning many decades, invertebrate pest control in arable farming systems is still heavily reliant on broad-spectrum pesticides. Yet industry wants to implement Integrated Pest Management (IPM) principles. We suspect that the lack of implementation to date reflects the unpredictable nature of outbreaks of pests and unpredictable profit margins, creating an environment where growers prefer to follow a cautious chemical-based approach. Using southern Australia as a case study, we argue for a new approach where the concept of rigid management strategies is abandoned in favor of landscape changes, host plant resistance, ecological indicators, reliable predictors and emergency intervention strategies. This approach needs to be based on developing more stable crop environments that can limit fundamental niches available for exploitation by sporadic pest populations, and increasing crop resilience to resident herbivores. Fall-back strategies, including broad-spectrum chemical control, may still be required to protect productivity at times when outbreaks of pest populations take place. These are likely to be unavoidable, particularly given emerging climate challenges.