Assessment of Trap Crops for The Wheat Bug, Nysius huttoni Management: A Cage Study

The wheat bug, Nysius huttoni, is an endemic New Zealand insect pest. Its feeding can seriously reduce crop establishment in forage A cage study was conducted in Lincoln University, New Zealand to evaluate the pest’s host preferences on four plant species. Kale plants (Brassica oleracea) were used as a potentially susceptible control and other four trap plants were tested to evaluate as potential trap-plants. These were: Lobularia maritima (alyssum), Triticum aestivum (wheat), Coriandrum sativum (coriander) and Trifolium repens (white clover). The alyssum plant was more attractive to the wheat bug. The survival rate and preferences of the wheat bug was significantly better than other four plants. The deployment of such flowering trap crops can potentially trap the wheat bug and also provide multiple ecosystem services (ES) in an agro-ecosystem. The findings can be used to develop the wheat bug management protocol and also potentially provide ecosystem services in brassica fields.

Assessment of Traditional Methods of Controlling Striga on Cultivated Crops in Sudanian Agricultural Zone of Chad

The phytoparasite, Striga spp., is a major biotic constraint to cereals production in sub-Saharan Africa. This study was carried out at station of Bébédjia of Chadian Institute of Agronomic Research for the Development in Sudanian agricultural zone of Chad, on traditional methods of controlling Striga spp. This study helped to find out several methods of controlling Striga among which the most important is the agronomic method including organic and or mineral fertilization, associated crops, crop rotation and the use of false hosts and trap crops. Some farmers cultivated resistant varieties and early maturing varieties to control pest attack and some others used shea flour and herbicide treatment to reduce the effect of Striga on the farm. Most of these methods were applied by farmers from generation to generation, without a thorough study to understand their mechanism. Thus, the listed methods will be analysed by research in station to find out scientific explanations for each applied method. Then experiments will be carried out to evaluate the effectiveness of some methods previously identified by extension rural services in farmers’ area after improvement.

Irrigated trap crops impact key hemipteran pests in organic pistachio orchard

Using sown groundcovers as trap crops to protect a cash crop is a traditional pest management tool. Pistachio is a major crop in California’s Central Valley, where high summer temperatures and little to no precipitation between May and November lead to summer dry-down of annual groundcover. Hemipteran pests that consist of ‘small bugs’ and ‘large bugs’ are a major contributor to nut damage, especially in organic production. In this 2-year field study, we tested the use of irrigated trap crop mixtures, sown between tree rows, to reduce those hemipteran pests’ abundance or damage. Biweekly beat samples of the tree canopy and sweep samples of the sown groundcovers in trap crop plots and resident weedy vegetation in control plots were taken over two consecutive growing seasons. Arthropod richness and abundance were highest in the groundcover and tree canopy in the trap crop plots. Small and large bug pest populations were higher and lower, respectively, in the tree canopy in trap crop plots, indicating a mixed response of these hemipterans to the presence of the trap crops. Additionally, natural enemy populations were more abundant in the tree canopy in trap crop plots than in control plots. There was no difference in nut damage between plots with and without the trap crop. These findings suggest that populations of hemipteran pests and beneficials can be manipulated successfully with irrigated trap crops, but future studies will need to focus on doing so in a way that decreases hemipteran pistachio damage.

Načini zatiranja marmorirane smrdljivke (Halyomorpha halys [Stål, 1855], Hemiptera, Pentatomidae)

The brown marmorated stink bug (Halyomorpha halys (Stål, 1855); [Hemiptera, Pentatomidae]) is an invasive, alien and polyphagous insect species native to East Asia. It was introduced to the United States in the mid-1990s and to Europe in 2004. Today it is present in most European countries. In new environments, it adapts quickly and reproduces successfully, developing at least one complete generation per year. With the growth of populations, it is becoming a disturbing factor in the urban areas and recently one of the most dangerous pests in agricultural production. It was first discovered in Slovenia in 2017 in Šempeter near Gorica. In less than two years, it spread to the entire territory od Slovenia and began to cause damage to agricultural production. In a review paper, we have collected research by foreign and domestic researchers related to the study of different ways of controlling the brown marmorated stink bug. The article presents chemical methods of control, the use of insecticide nets, the use of attractants and repellents, trap crops, as well as methods of biotic protection using predators and parasitoids.

Sunflower Metabolites Involved in Resistance Mechanisms against Broomrape

Several strategies have been proposed to control parasitic plants and these include biological control, the use of herbicides, and suicidal germination or trap crops. In the case of sunflower, the most effective solution is genetic resistance. Nevertheless, the use of resistant cultivars is followed by the appearance of new and more virulent races of the parasite that overcome the existing sources of resistance. For this reason, it is necessary to increase our knowledge of the mechanisms involved in the resistant varieties. In this study, the presence of compounds involved in pre-attachment resistance mechanisms in sunflower varieties was analyzed. The production of stimulators of the germination of parasitic plant seeds and the concentration of the haustorial elongation inhibitor, scopoletin, were measured in exudates of resistant and susceptible sunflower varieties. It was found that dehydrocostuslactone and orobanchyl acetate are not involved in the resistance of the sunflower varieties studied. The results demonstrate that costunolide, heliolactone, and scopoletin are related to sunflower resistance. The sunflower varieties studied do not use all available options to fight parasitic plants. This could be one of the reasons that sunflower resistance is rapidly overcome by broomrape.

Oviposition Preference of Bactrocera dorsalis Hendel (Diptera: Tephritidae) on Different Fruit in Snake Fruit Orchard

The oriental fruit fly Bactocera dorsalis (Hendel) is an important pest of snake fruit (Salacca zalacca) in Sleman District. Due to the high level of damage by the fruit flies, it is necessary to do. The aim of this research was to find out suitable fruit traps, by testing the oviposition preferences of the fruit flies in the orchard to lay eggs on several types of fruit. The research was done in snake fruit orchard located at Sleman Yogyakarta and owned by farmers, while the Lab works were done at the Laboratory of Entomology, Department of Plant Protection, Faculty of Agriculture, Universitas Gadjah Mada. All researches were done between April-June 2019. Guava (Psidium guajava), watery rose apples (Syzygium aqueum), starfruit (Averrhoa carambolae), and snake fruit (Salacca zalacca) were used as trap crops. Each fruit, with the same maturity level, was hung 1.5 m above the ground for 4 days with 12 days total trapping at intervals of 3 times. After the test, each fruit was taken and the insects in it were reared in the laboratory. The number of pupae and flies that emerged from each fruit was counted and compared. The results showed that in the orchard 1 as well as 2, of guava fruit produced the highest number of (151 pupae) followed by salak (94 pupae), star fruit (83 pupae), and water guava (2 pupae). The finding of seeds shows that guava fruit is the most suitable host for the fruit flies to be used in the trapping, followed by star fruit and watery guava.

Control of Meloidogyne graminicola a Root-Knot Nematode Using Rice Plants as Trap Crops: Preliminary Results

Meloidogyne graminicola is one of the most harmful organisms in rice cultivation throughout the world. This pest was detected for the first time in mainland Europe (Northern Italy) in 2016 and was subsequently added to the EPPO Alert List. To date, few methods are available for the control of M. graminicola and new solutions are required. In 2019, field trials using rice plants as trap crops were performed in a Lombardy region rice field where five plots for three different management approaches were staked out: (i) Uncultivated; (ii) Treated: three separate cycles of rice production where plants were sown and destroyed each time at the second leaf stage; (iii) Control: rice was sown and left to grow until the end of the three cycles in treated plots. The results showed that in the treated plots, the nematode density and the root gall index were lower than for the other two management approaches. Moreover, the plant population density and rice plant growth were higher than the uncultivated and control plots. In conclusion, the use of the trap crop technique for the control of M. graminicola gave good results and thus it could be a new phytosanitary measure to control this pest in rice crop areas.

Technologies for integrated nematode management in smallholder farming systems: no one-size-fits-all.

In this chapter, the need to take a more critical look at the highly precarious and vulnerable situation of smallholder farming systems, the predominant type of the agricultural output worldwide, is emphasized. These farmers represent 98% of the farmers in the world that sustain the local production of staple crops such as rice, maize, cassava, groundnut and millet. Although there is some disparity in the figures, recent data estimates that there are between 380 and 500 million smallholder farming households globally. The productivity of the smallholders' farms depends on soil health and quality, agroecological conditions (irrigated versus rainfed), access to agricultural inputs and new technologies. These last two also critically influence smallholders' ability to manage pests and diseases, including plant parasitic nematodes (PPN). This chapter discusses the epidemiological perspective, diagnostics and surveillance, alternate host and in-field spread of PPN. Breeding programmes for PPN resistance, seed delivery system, importance of clean planting material, influence of land availability to smallholders' ability to practice fallow and rotation for nematode management are described. The use of trap crops, cover crops, nematicides and biological control agents for nematode suppression are also discussed. Future developments aimed at promoting the progress of smallholder farming systems are also mentioned.

Gene flow mitigation by ecological approaches.

With an increased area of cultivating genetically modified (GM) plants worldwide, the ecological risks of transgenic plants released into the environment have caused concern. One of the risks is the occurrence of gene flow between GM plants and non-GM plants, including their wild relatives. Gene flow data from oilseed rape (Brassica napus), cotton (Gossypium hirsutum), maize (Zea mays), soybean (Glycine max), rice (Oryza sativa), and wheat (Triticum aestivum) indicate that the frequency of pollen-mediated gene flow is negatively related with distance between donor and recipient plants, and the frequency is relatively high in closely related species. We discuss five main ecological approaches to mitigate gene flow from GM plants to non-GM plants, including distance isolation, border or trap crops, barrier crops, agricultural practices, and through biological means. The required isolation distance has been adopted in managing GM crops in some countries, and cultivating tall crops, or border or trap crops, can decrease the requisite isolation distance to mitigate gene flow. Combining several approaches is more effective than a single approach in mitigating gene flow, because the frequency of pollen-mediated gene flow depends on plant genotype, flowering time, wind speed and direction, and other factors. Thus, in the framework of biosafety assessment of GM plants, mitigating the occurrence of gene flow between GM and non-GM plants is a key step to decrease the ecological risk of post- commercial cultivation of GM plants.