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Ghermandi A.,Ben - Gurion University of the Negev | Ghermandi A.,Haifa University | Messalem R.,Ben - Gurion University of the Negev | Offenbach R.,Central and Northern Arava Research and Development | Cohen S.,Central and Northern Arava Research and Development
Renewable Agriculture and Food Systems | Year: 2014

An agricultural facility aimed at sustainable production of crops in arid environments was built and tested in Hatzeva, Israel. The facility relies on solar-powered desalination with nanofiltration membranes to treat the local brackish water (EC=2.32 dS m-1) and produce high-quality irrigation water (EC=0.71 dS m-1). Red beet, a salt-tolerant crop, was grown with the concentrate stream (EC=4.73 dS m-1), eliminating the need for concentrate disposal and with potential net economic benefits. Agricultural experiments with variable irrigation water quality, application rate, and four staple crops (potato, maize, millet and sorghum) were conducted over two growing seasons between September 2010 and June 2011. The desalination plant operated at low pressure (4.3 bar) and energy consumption (1.37 kWh m-3) and with little maintenance over the entire study period. The results of the agricultural experiments consistently showed that irrigation with desalinated water promoted more efficient use of resources such as water and inorganic fertilizers. A reduction of 25% in the irrigation rate and use of fertilizers compared with best-practice guidelines was achieved with desalinated water, with no detectable detrimental effect on the marketable yield. On the contrary, a statistically significant yield increase was observed for sorghum (+10%). An increase in water productivity with desalinated water was observed for all four staple crops. Copyright © Cambridge University Press 2013.

Pivonia S.,Central and Northern Arava Research and Development | de Cock A.W.A.M.,Fungal Biodiversity Center | Levita R.,Central and Northern Arava Research and Development | Etiel E.,Extension Service | Cohen R.,Newe Ya'ar Research Center
Phytoparasitica | Year: 2012

Pepper is the main vegetable crop grown in the Arava region of southern Israel. It is grown in the winter in nethouses and greenhouses. Low temperature wilt of mature pepper plants has been known for years in this region. The incidence of plant wilting was usually low when the soil was pretreated with methyl bromide. In recent years methyl bromide usage has been banned and disease incidence has increased. The causal agent of this phenomenon was unknown until the current study. Pythium sp. was the most common microorganism genus isolated from wilted plant roots. Young pepper plants were artificially inoculated with Pythium isolated from wilted plants and maintained at temperatures of 20°, 14°, 10. 5° and 8. 6°C. Significant wilting was observed in plants grown at 8. 6°C, with symptoms starting 2 weeks after inoculation. At 10. 5°C wilting developed more slowly and inoculated plants maintained at 14° and 20°C did not exhibit any wilting symptoms. The unique variation in sporangium morphology and the sequence of the ribosomal internal transcribed spacer (ITS) suggest that a new species of Pythium is involved. The fungicide metalaxyl-M was found effective in controlling the disease in pot experiments. The relationship between low temperatures and high disease incidence can explain the high disease incidence in the Arava Valley of Israel during the cold winters of 1999-2000, 2004-2005 and 2006-2007. © 2012 Springer Science + Business Media B.V.

Levi-Zada A.,Israel Agricultural Research Organization | David M.,Israel Agricultural Research Organization | Fefer D.,Israel Agricultural Research Organization | Seplyarsky V.,Ministry of Agriculture | And 6 more authors.
Journal of Chemical Ecology | Year: 2014

The greater date moth (GDM), Aphomia sabella Hampson (Lepidoptera: Pyralidae: Galleriinae), is a serious pest of date palms, Phoenix dactylifera. The release of volatiles from both males and females was investigated using sequential SPME/GC/MS analysis. Males release a complex mixture of compounds in a circadian rhythm during the night between 03:00 and 05:00 hr. Six compounds were identified: benzaldehyde, sulcatol (6-methyl-5-hepten-2-ol), geranyl acetone [(E)-6,10-dimethyl-5,9-undecadien-2-one], phenylacetaldehyde, 2-phenylpropenal, and (R)-fuscumol [(R)-(E)-6, 10-dimethyl-5, 9-undecadien-2-ol]. Benzaldehyde, sulcatol, and geranyl acetone were found only in trace amounts. These compounds were in glands located in the forewing of males only. Small amounts of acetoin and 2,3-butanediol were found sporadically in the SPME/GC/MS analyses of volatiles from females, and these compounds probably originate from microorganisms. This is the first finding of a circadian release of male-specific compounds in moths. GC/EAD analyses with synthetic standards of compounds released by males showed that the female antenna is stimulated by all six compounds, while the male antenna responded only to phenylacetaldehyde. A possible pheromonal role for the male-specific compounds is suggested by the circadian rhythm of their release and the EAD response of females to them. However, trapping tests with the main male-specific compounds in screen cages in the laboratory or in the field did not reveal any significant behavioral responses from females or males. Copulation in the laboratory was observed only in the presence of date palm tissue, thus suggesting that sexual communication and mating of GDM moths probably occurs in the crown of date palms. © 2014 Springer Science+Business Media New York.

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