Research

Filter results

Research

• 25

  Mar
  Evaluation of a nanofiltration desalination unit: Combined production of strawberries irrigated with desalinated water and Salicornia irrigated with the desalination concentrate

  Vegetables

  by Andrea Ghermandi

  תחום או ענף אגרוטכנולוגיה; ירקות; תבלינים

  תאריך עדכון 14/3/2012

  Evaluation of a nanofiltration desalination unit: Combined production of strawberries irrigated with desalinated water and Salicornia irrigated with the desalination concentrate
  Andrea Ghermandi, Rami Messalem – Ben-Gurion University of the Negev, Zuckerberg Inst. for Water Research, Desalination & Water Treatment, Israel
  Rivka Offenbach, Shabtai Cohen – Central and Northern Arava Research and Development, M.P. Arava, Sapir, Israel
  E-mail address for correspondence: sab@inter.net.il

  Abstract
  The quality of irrigation water, specifically its high salinity, is a limiting factor for the expansion of the range of crops grown in the Arava. During the 2010/11 growing season, an experimental apparatus (model) was used at the Yair Station in the Arava to improve the local water using a principle similar to that used in reverse-osmosis systems. This involved the use of sophisticated membranes that allow for the selective penetration of ions, in contrast to the membranes used in reverse-osmosis systems, which “clean out” all of the salts from the water that passes through the system. That water then needs to be supplemented with calcium, magnesium, sulfur and bicarbonate before it can be used for agriculture. The use of a nanofiltration system will improve this situation, so that some of the elements are passed through to the final product (including limited amounts of chloride compounds and sodium). The nanofiltration system also provides a significant energy savings, specifically a 50% energy savings when compared with conventional reverse-osmosis systems, because the pressure levels necessary for its use are relatively low, making it possible to power the system with solar cells.
  This experiment was designed to investigate the use of nanofiltration for desalination and the intelligent use of water for producing strawberry crops for export in raised/artificial beds that are irrigated with high qualtiy water, with the goal of expanding the variety of crops grown in the Arava for export, in combination with the production of halophytes, such as Salicornia for the export market, that are irrigated with the brine that is a side-product of the desalination process.
  The experiment was conducted in a 350-m2 greenhouse at the Yair Experimental Station. The greenhouse was equipped with hanging beds that were hung 1.7 m above the soil surface. The growth medium was coconut in growth bags. The coconut was tightly compressed and when it was saturated with water it expanded to fill the plastic growth bags. In each plastic sack, there were 12 holes to allow for the stand density desired in this type of system. The distance between drainpipes was 0.6 m. Transplanting was carried out on 26 September 2010. The greenhouse was equipped with a fan and pad evaporative cooling system and a climate-control system, in order to keep temperatures relatively low during the first stages of the crop’s growth. High-quality water with an electrical conductivity of 0.8 dS/m was used to irrigate the strawberries and to operate the cooling system. Two-thirds of the greenhouse was used for strawberry production. We evaluated the cv. Tamir, which was developed by Nir Dai at the Vegetable Department at Beit Dagan, and the cv. Yuval, which was developed by the Fertiseeds company. A hive of honey bees was put into the greenhouse and when that did not bring the expected results, a hive of bumblebees was added as well.
  The remaining third of the greenhouse was used to grow Salicornia. The Salicornia was planted on 20 December 2011. The halophyte was irrigated with the brine produced in the desalination process, which had an electrical conductivity of 4.5 dS/m, mixed with table salt (NaCl) that was dissolved in water at a rate of 6 kg/m3, in order to bring the electrical conductivity of the irrigation water to the optimal level for Salicornia production (15 dS/m).
  Strawberry yield. Both strawberry cultivars began to bear fruit in November, but the yield from cv. Tamir was almost double that of cv. Yuval (0.81 kg/m2). This was surprising, since cv. Yuval is considered to be the earlier-bearing cultivar. This yield advantage persisted until February. During this period, the accumulated yield for cv. Tamir was 4.58 kg/m2 and the accumulated yield for Yuval was 3.47 kg/m2. During the month of December, there was almost no marketable yield due to fruiting problems related to the beehive situation. The fruiting period of strawberry has great economic importance. During November, strawberries sell for 20 to 25 shekels/kg, as compared to only 5 shekels/kg at the end of the season. We recommend the continued evaluation of production methods and additonal cultivars, in order to maximize yield per unit area.
  Salicornia yield. Salicornia harvesting began in the middle of April. Over the course of 50 days of harvesting, we collected a yield with a fresh weight of 5 kg/m2. Ninety percent of this yield was of export quality. The combination of crops modeled in this study was found to be feasible. We recommend continuing research in this area and evaluating other crop combinations, in order to increase the profitability per unit area of crops irrigated with desalinated water.

  Acknowledgements
  We would like to thank the JCA Charitable Foundation for their financial support of this project, Avi Osherovitz and Dorit Hashmonai from the staff of the Yair Station (Arava R&D) for their dedicated work on this project and Ramat HaNegev R&D for supplying the Salicornia seed that made this project possible.

  שפה English
  AUTHORS Andrea Ghermandi, Rami Messalem, Rivka Offenbach, Shabtai Cohen,
  שנה 2011
  שייכות yzvieli
  תאריך יצירה 14/3/2012
  תאריך עדכון 14/3/2012
• 25

  Mar
  Blending of desalinated and saline water for efficient, environmentally responsible agricultural use

  Vegetables

  by Naftali Lazarovitch

  תחום או ענף ירקות; תבלינים

  תאריך עדכון 14/3/2012

  Blending of desalinated and saline water for efficient, environmentally responsible agricultural use
  Naftali Lazarovitch – Institutes for Desert Research, Ben-Gurion University of the Negev
  Alon Ben-Gal, Uri Yermiyahu, Ina Finegold, Lodmilla Yosofov – Gilat Research Center, ARO
  Dafna Harari, Ami Maduel, Uri Zeiri, Aviram Asraf, Rami Golan, Svetlana Gogio, Shabtai Cohen – Central and Northern Arava R&D
  David Silverman – Extension Service (SHAHAM), Israel Ministry of Agriculture and Rural Development
  Shoshana Soriano – Institute of Plant Protection, Agricultural Research Organization, Volcani Center
  Corresponding author’s address: lazarovi@bgu.ac.il, Wyler Department of Dryland Agriculture, French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev. Sede-Boqer Campus, Midreshet Ben-Gurion, 84990, Israel

  Abstract
  The minerals needed by agricultural crops that are missing from desalinated water can be applied to those crops as fertilizer. Alternatively, they can be supplied by mixing the desalinated water with saline water in which the concentrations of these minerals are high. Our research question is whether the blending of desalinated water with saline water, as a method for adding minerals that were removed in the desalination process and are necessary for optimal crop yield, is economical and sustainable from an environmental perspective. The goal of the research was to evaluate different approaches for supplying the minerals that crops irrigated with desalinated water lack: blending or adding fertilizer.
  This study included experiments carried out under controlled conditions and in semi-commercial plots. During the 2010/11 season, two experiments were conducted in basil (Ocimum basilicum). One experiment was carried out in a system of 24 lysimeters in a greenhouse at the Gilat Research Center and the other was carried out in a system of 12 lysimeters and in field plots in a semi-commercial greenhouse at the Zohar Experimental Station in Sodom Valley. Basil was found to be very tolerant of salinity. Plants irrigated with saline water and blended water produced yields equivalent to those of plants that were irrigated with desalinated water and treated with fertilizer, but only when the irrigation volume was increased more than 20%.

  Acknowledgements
  We would like to thank the Chief Scientist of the Ministry of Agriculture for funding research project no. 304-0393-10, the JCA Charitable Foundation, the management of the Vegetable Division of the Plant Board and the Herb Growers’ Association for their financial support of this project. We extend heartfelt thanks to herb grower Eran Wein from Moshav Ein Tamar for his help with the harvests.

  שפה English
  KEYWORDS Sweet basil, saline water, desalinated water
  AUTHERS Naftali Lazarovitch, Alon Ben-Gal, Uri Yermiyahu, Ina Finegold, Lodmilla Yosofov, Dafna Harari, Ami Maduel, Uri Zeiri, Aviram Asraf, Rami Golan, Svetlana Gogio, Shabtai Cohen, David Silverman, Shoshana Soriano
  שנה 2011
  שייכות yzvieli
  תאריך יצירה 14/3/2012
  תאריך עדכון 14/3/2012
• 25

  Mar
  Optimizing winter basil production in Sodom Valley without heating

  Vegetables

  by Dafna Harari

  4 תחום או ענף אגרוטכנולוגיה; הגה"צ; ירקות; תבלינים

  תאריך עדכון 14/3/2012

  Optimizing winter basil production in Sodom Valley without heating
  Dafna Harari, Uri Zairi, Ami Maduel, Aviran Asraf, Rami Golan, Shimon Pivonia – Central and Northern Arava R&D
  Izik Esquira – Israeli Plant Board
  David Silverman, Svetlana Dobrinin – Extension Service (Shaham), Ministry of Agriculture and Rural Development
  David Kenigsbuch, Meir Teitel, Yigal Elad – Institute of Plant Protection, Volcani Center, Agricultural Research Organization
  E-mail address for correspondence: dafnahr@arava.co.il

  Abstract
  Basil is strictly a summer crop; high temperatures are required for its proper development. In the past, most of the basil crop was grown in the Beit Shean area, the Jordan Valley and the Besor area in greenhouses that were heated to 16–18°C during the winter. With increased fuel prices and a decrease in economic returns, most basil production shifted to Sodom Valley, which enjoys higher winter temperatures. The continuous supply of quality basil from this area throughout the winter is possible if we understand the conditions that are necessary for growing basil free of any cold damage and suitable for export via ship. The goal of this research is to study the optimal and efficient use of low-cost agro-techniques that can substitute for supplemental heating for the production of quality winter basil crops.
  The basil-production experiments were conducted over four seasons (2007/8 through 2010/11) in 12 polyethylene walk-in tunnels whose ventilation openings were covered with 50 mesh. The following agro-techniques were evaluated: 100- to 200-micron-thick sheeting and floating row covers (woven cloth, Agril) of two thicknesses and two different durations of coverage. The crop was evaluated in covered and uncovered soil in combination with two types of tunnel coverings: a 100-micron-thick thermal screen and a 150-micron-thick thermal screen; in a cold winter and in a warm winter. We examined the crop in ventilated and closed tunnels, as well as in closed tunnels with water sleeves (water in plastic pipes), and in combination with floating row covers. We monitored the temperature and humidity in the tunnels, checked the incidence of diseases in the area, examined the weight and quality of the harvested crop and evaluated its shelf-life in a system designed to simulate the conditions typically faced by produce shipped by sea.
  The results from the four years of this study indicate that the use of sheeting to cover the tunnels and soil did not contribute to significant differences in the temperature and relative humidity inside the tunnels. High-quality yields were collected from each of the different covering treatments each year. Beginning with the fourth harvest, we noticed advantages to growing the crop under floating row covers that were spread out 24 hours a day and to the use of ventilated tunnels. The use of a 50%-sealed thermal screen during a relatively warm winter had a negative effect on yield quality. Water sleeves moderated the temperature in the tunnel during the day and decreased the humidity in the tunnel during the night. Covering the tunnels and/or soil with sheeting can help reduce input expenses during both cold and warm winters.
  The choice of which type of polyethylene sheeting to use for basil crops in Sodom Valley should be based on the needs of the grower, based only on the strength of the polyethylene. Generally, covering the soil with polyethylene will not increase the quality of the winter basil.
  The use of a thermal screen significantly increased the temperature in the tunnels on cold nights. That is, additional energy was obtained in those tunnels. Together with this, there was an increase in humidity over the night. Humidity has a negative effect on the shelf-life of basil. We still have not identified the best way to set up the thermal screen to improve the quality of winter basil in Sodom Valley. The use of floating row covers that are kept spread out 24 hours a day is very convenient and, in certain seasons, this practice has had a positive effect on yield. Overnight humidity levels in these tunnels were lower than those in tunnels in which a thermal screen was used, but higher than those in the ventilated tunnels, and this may harm the quality of the yield. The use of floating row covers can improve yield quantity and quality, but we were not able to apply this method in each of the years of the study. The use of a ventilated tunnel during a relatively mild winter decreased the development of canopy diseases such as botrytis, thereby improving the shelf-life of the basil. The use of water sleeves was found to be problematic, as holes often developed in the sleeves, causing them to leak.
  The standard planting density currently used by growers is 30 plants per m2. In each year of the study, the use of lower planting densities (20, 15 and 10 plants per m2) led to lower yields only at the first harvest. After that point, there was no difference in overall yield. Together with this, the use of a lower planting density in closed tunnels led to improved shelf-life. This finding suggests that growers can plant winter basil at a lower density over large areas and save on input costs.

  Acknowledgements
  We thank the Scientist’s Fund for funding research project 603-0237-10, as well as the management of the Vegetable Division of the Plant Board and the Herb Growers’ Association for their help in funding this study. We thank herb growers Eran Wein and Yoram Ozri from Ein Tamar and the Adafresh Company for their cooperation and for storing and transporting the basil for shelf-life testing.

  שפה English
  KEYWORDS Botrytis, resistance, plant protection, insecticides, management, fresh herbs, polyethylene, Arava Israel, thermal screens, walk-in tunnels, Bemisia tabaci
  AUTHERS Dafna Harari, Uri Zairi, Ami Maduel, Aviran Asraf, Rami Golan, Shimon Pivonia, Izik Esquira, David Silverman, Svetlana Dobrinin, David Kenigsbuch, Meir Teitel, Yigal Elad
  שנה 2011
  שייכות yzvieli
  תאריך יצירה 14/3/2012
  תאריך עדכון 14/3/2012

  OPEN
• 25

  Mar
  Impact of the endomycorrhizal fungus (Glomus intraradices) on water balance and salt stress tolerance in pepper

  Vegetables

  by Shabtai Cohen

  ירקות
  תאריך עדכון 14/3/2012

  תיאור מלא Impact of the endomycorrhizal fungus (Glomus intraradices) on water balance and salt stress tolerance in pepper
  Shabtai Cohen, Rivka Offenbach, Yoram Zvieli, Israel Tsabari, Rami Golan – Central and Northern Arava R&D
  Uri Yermiyahu, Alon Ben-Gal, Ina Finegold, Ahmed Oshala – Environmental Physics and Irrigation, Gilat Research Center, Agricultural Research Organization (ARO)
  Yoram Kapulnik – Institute of Plant Science, The Volcani Center, Agricultural Research Organization
  Shoshana Soriano – Institute of Soil Sciences, The Volcani Center, Agricultural Research Organization
  E-mail address for correspondence: sab@inter.net.il

  Abstract
  Pepper is the main crop in the Arava. This crop is irrigated with saline water as the availability of water in the Arava is limited. The increase in the concentration of salts causes damage that is expressed as reduced canopy size, leaf burn, an increase in the appearance of black coloring on the tips of the fruit and decreased fruiting potential of the pepper plants. The goal of this research was to evaluate the effect of mycorrhizae on water use and salt tolerance in pepper plants, as a means of preventing damage to plants exposed to drought or salt stress and providing future water savings (decreased water consumption) in production areas. This research was based on two field experiments that were conducted at the Yair Research Station during the 2009/10 and 2010/11 growing seasons and three experiments involving potted plants that were conducted at the Gilat Research Center. In Field Experiment 1, we evaluated two levels of phosphorous fertilization (standard and low-level) at three different irrigation levels (50, 75 and 100% of the recommended level) and two levels of mycorrhizae (with and without).
  In Field Experiment 2, we evaluated the effects of mycorrhizal infection and the use of a barrier in a system in which compost was applied. This experiment included three levels of irrigation (50, 75 and 100% of the recommended level) and an examination of the effects of these different treatments on infection in plots with a sand barrier as compared to plots in which plants were transplanted directly into soil rich in compost.
  In the experiment involving potted plants, three factors were evaluated: salinity (five NaCl treatments, specifically 0, 7.5, 15, 25 and 35 mM NaCl), potassium level (two treatments, specifically 5 and 20 ppm) and mycorrhiza (two treatments, infected and uninfected).
  In the first year (2009/10), Field Experiment I was conducted on ground to which no compost had been applied in the past and no compost was applied during the experiment. The results indicate that the fertilizer treatments significantly affected yield. The yield in the treatment that received the standard level of phosphorous fertilizer was greater than the yield from the low-phosphorous treatment. In the low-phosphorous treatments, the mycorrhizae had a significant yield effect.
  In the experiment that was conducted in the 2010-2011season, we found that the application of compost inhibits the positive yield effect that was observed the year before. This was due to the mycorrhiza-suppressant effect of the compost.
  In the experiment with the potted plants, the presence of mycorrhizae did not improve growth under saline conditions when water and phosphorous levels were adequate. At this point, mycorrhizal fungi will not be applied to commercial plots because the majority of these plots are treated with large amounts of compost each year, in a manner that inhibits the ability of mycorrhizae to help alleviate abiotic stress, such as drought and salt stress.

  Acknowledgements
  We would like to thank Haji Yassour of the Gilat Research Center for his help carrying out the experiments. We thank Hishitl Nurseries for their fruitful cooperation involving the application of the fungus to young pepper plants

  שפה English
  KEYWORDS Capsicum, salinity
  AUTHERS: Shabtai Cohen, Rivka Offenbach, Yoram Zvieli, Israel Tsabari, Rami Golan, Uri Yermiyahu, Alon Ben-Gal, Ina Finegold, Ahmed Oshala, Yoram Kapulnik, Shoshana Soriano
  שנה 2011
  שייכות yzvieli
  תאריך יצירה 14/3/2012
  UPDETED 14/3/2012