N. Greco

Bio: N. Greco is an academic researcher. The author has contributed to research in topics: Dazomet & Globodera rostochiensis. The author has an hindex of 1, co-authored 2 publications receiving 7 citations.

Control of the potato cyst nematode, globodera rostochiensis, with soil solarization and nematicides

Abstract: A trial was undertaken in Italy in 1997/98 to assess the effectiveness of different soil treatments for the control of the potato cyst nematode, Globodera rostochiensis, on potato. Soil solarization periods were four, six and eight weeks. The fumigant nematicides were applied seven months before planting at the rate of 150 l/ha 1,3-D and 500 kg/ha dazomet. The non-fumigant nernaticides were applied at the rate of 10 kg/ha aldicarb and fenamiphos and 12 kg/ha ethoprophos, as a single application before planting or split between planting and one month after potato germination. Maximum soil temperature 43-44 °C in solarized soil occurred at 10 cm depth. Nematode egg survival was 6.8-17, 27.8 and 6.1% in plots treated with soil solarization, dazomet and 1,3-D, respectively. These treatments and the non-volatile nematicides aldicarb, fenamiphos and ethoprophos significantly suppressed nematode reproduction with a split application of aldicarb giving the least (0.82) reproduction rate. All treatments greatly reduced the numbers of nematodes in potato roots. Marketable potato tuber yield increased significantly in all plots (20-43.4%) except in those treated with split applications of fenamiphos and ethoprophos.

Control of the potato cyst nematode - Globodera rostochiensis - with soil solarization and nematicides [Solanum tuberosum L. - Italy]

Abstract: [Nel 1997/98, in Italia, e' stata condotta una prova per accertare l'efficacia di trattamenti diversi del terreno per il controllo del nematode galligeno della patata, Globodera rostochiensis, su patata. I periodi di solarizzazione erano di 4, 6 e 8 settimane. I nematocidi fumiganti sono stati applicati 7 mesi prima della semina alla dose di 150 l/ha di 1,3-D e di 500 kg/ha di dazomet. I nematocidi non fumiganti sono stati distribuiti alla dose di 10 kg/ha di aldicarb e fenamiphos e di 12 kg/ha di ethoprophos, come trattamento unico prima della semina o suddiviso fra epoca di semina e un mese dopo la germogliazione delle patate. La temperatura massima del terreno di 43-44 gradi C nel terreno solarizzato si verificava alla profondita' di 10 cm. La sopravvivenza delle uova del nematode risultava pari al 6,8-17, 27,8 e 6,1% nelle parcelle trattate, rispettivamente, con solarizzazione, dazomet e 1,3-D. Questi trattamenti e i nematocidi non volatili aldicarb, fenamiphos ed ethoprophos inibivano significativamente la riproduzione dei nematodi,; la distribuzione frazionata di aldicarb dava il livello piu' basso di riproduzione (0,82). Tutti i trattamenti riducevano grandemente i numeri di nematodi nelle radici di patata. La resa in tuberi di patata commercializzabili aumentava significativamente in tutte le parcelle (20-43%), eccetto che in quelle trattate con applicazioni frazionate di fenamiphos e di ethoprophos]

Soil solarization and sustainable agriculture

Abstract: Pesticide treatments provide an effective control of soilborne pests in vegetable and fruit crops, but their toxicity to animals and people and residual toxicity in plants and soil, and high cost make their use hazardous and economically inconvenient. Moreover, actual environmental legislation is imposing severe restrictions on the use or the total withdrawal of most soil-applied pesticides. Therefore, an increasing emphasis has been placed on the use of nonchemical or pesticide-reduced control methods. Soil solarization is a nonpesticidal technique which kills a wide range of soil pathogens, nematodes, and weed seed and seedlings through the high soil temperatures raised by placing plastic sheets on moist soil during periods of high ambient temperature. Direct thermal inactivation of target organisms was found to be the most important mechanism of solarization biocidal effect, contributed also by a heat-induced release of toxic volatile compounds and a shift of soil microflora to microorganisms antagonist of plant pathogens. Soil temperature and moisture are critical variables in solarization thermal effect, though the role of plastic film is also fundamental for the solarizing process, as it should increase soil temperature by allowing the passage of solar radiation while reducing energetic radiative and convective losses. Best solarizing properties were shown by low-density or vynilacetate-coextruded polyethylene formulations, but a wide range of plastic materials were documented as also suitable to soil solarization. Solar heating was normally reported to improve soil structure and increase soil content of soluble nutrients, particularly dissolved organic matter, inorganic nitrogen forms, and available cations, and shift composition and richness of soil microbial communities, with a marked increase of plant growth beneficial, plant pathogen antagonistic or root quick recolonizer microorganisms. As a consequence of these effects, soil solarization was largely documented to increase plant growth and crop yield and quality along more than two crop cycles. Most important fungal plant pathogenic species were found strongly suppressed by the solarizing treatment, as several studies documented an almost complete eradication of economically relevant pathogens, such as Fusarium spp., Phytophthora spp., Pythium spp., Sclerotium spp., Verticillium spp., and their related diseases in many vegetable and fruit crops and different experimental conditions. Beneficial effects on fungal pathogens were stated to commonly last for about two growing seasons and also longer. Soil solarization demonstrated to be effective for the control of bacterial diseases caused by Agrobacterium spp., Clavibacter michiganensis, and Erwinia amylovora, but failed to reduce incidence of tomato diseases caused by Pseudomonas solanacearum. Solarization was generally found less effective on phytoparasitic nematodes than on other organisms, due to their quicker soil recolonization compared to fungal pathogens and weeds, but field and greenhouse studies documented consistent reductions of root-knot severity and population densities of root-knot nematodes, Meloidogyne spp., as well as a satisfactory control of cyst nematode species, such as Globodera rostochiensis and Heterodera carotae, and bulb nematode Ditylenchus dipsaci. Weeds were variously affected by solar heating, as annual species were generally found almost completely suppressed and perennial species more difficult to control, due to the occurrence deep propagules not exposed to lethal temperature. Residual effect of solarization on weeds was found much more pronounced than on nematodes and most fungal pathogens. Soil solarization may be a perfect fit for all situations in which use of pesticides is restricted or completely banned, such as in organic production, or in farms located next to urban areas, or specialty crops with few labeled pesticides. Advantages of solarization also include economic convenience, as demonstrated by many comparative benefit/cost analyses, ease of use by growers, adaptability to many cropping systems, and a full integration with other control tools, which makes this technique perfectly compatible with principles of integrated pest management required by sustainable agriculture.

Effect of water, soil temperatures, and exposure times on the survival of the sugar beet cyst nematode, heterodera schachtii.

Abstract: The effect of different combinations of temperatures and exposure times on the mortality of Heterodera schachtii eggs was assessed in two different experiments under laboratory conditions. In the first experiment, cysts in water were exposed to 25, 35, 37.5, 40, 42.5, 45, 47.5, 50, or 52.5°C for a maximum period of 2 h. In the second experiment, cysts in naturally infested soil were exposed to 25, 32.5, 35, 37.5, 40, 42.5, or 45°C for a minimum period of 2 h to a maximum of 2,048 h. Viability of eggs in cysts was assessed by a hatching test in 3 mM zinc chloride solution. Viability in water was suppressed after 2-h exposure at 50°C and inhibited after 1 to 2 h at 52.5°C. Emergence of juveniles from cysts in soil was greater at the lower temperature × exposure time combinations and suppressed at higher combinations. Egg mortality started after exposure for 256 h at 40°C, 32 h at 42.5°C, and 16 h at 45°C, and 81, 31, and 7 h of exposure were necessary to kill 50% of the nematode egg population at 4...

Review on Control Methods against Plant Parasitic Nematodes Applied in Southern Member States (C Zone) of the European Union

Abstract: The European legislative on the use of different control strategies against plant-parasitic nematodes, with particular reference to pesticides, is constantly evolving, sometimes causing confusion in the sector operators. This article highlights the nematode control management allowed in the C Zone of the European Union, which includes the use of chemical nematicides (both fumigant and non-fumigant), agronomic control strategies (crop rotations, biofumigation, cover crops, soil amendments), the physical method of soil solarization, the application of biopesticides (fungi, bacteria and their derivatives) and plant-derived formulations. The authors analyze the use of these strategies and substances in organic agriculture as well as in Integrated Pest Management (IPM) programs.

Resistance of new italian potato breeding clones to cyst and root-knot nematodes

Abstract: Screening tests were conducted in glass-houses in 2006 and 2007 to assess the reaction of 27 new Italian potato (Solanum tuberosum) breeding clones to the potato cyst nematode, Globodera rostochiensis pathotypes Ro1 and Ro2, and to rootknot nematodes, Meloidogyne incognita host race 1 and M. javanica. Seven potato cultivars, known to be resistant to cyst nematodes, were also screened for their response to root-knot nematodes. The tests were conducted in 1 dm3 clay pots containing steam sterilized sandy soil infested with 10-15 eggs/cm3 of either pathotype of G. rostochiensis or 10,000 eggs and second stage juveniles/ pot of either root-knot nematode species. The glass-houses were maintained at 20 ± 2 °C for G. rostochiensis and at 26 ± 2 °C for Meloidogyne spp. The clones CS 8617 and MN 3-1469 R2 were resistant to all three nematode species, and the clone AND 97-15, known to be resistant to all European pathotypes of G. rostochiensis and G. pallida, was also resistant to M. incognita and moderately resistant to M. javanica. Fourteen of eighteen clones tested in 2006 and seven of the nine clones tested in 2007 were resistant to both pathotypes of G. rostochiensis. Two clones were resistant to both root-knot nematode species in 2006 and one clone moderately resistant to M. incognita and one moderately resistant to M. javanica in 2007. Some of the clones resistant to G. rostochiensis also possess good agronomic traits and have potential for registration as new cultivars.