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• 23

  Jan
  Evaluation of different irrigation regimes in preparation for the implementation of combined irrigation systems for the re-use of leached water

  Vegetables

  by Shabtai Cohen

  Evaluation of different irrigation regimes in preparation for the implementation of combined irrigation systems for the re-use of leached water

  Shabtai Cohen, Ami Maduel, Rivka Offenbach, Yoram Zvieli, Israel Tsabari, Rami Golan – Central and Northern Arava R&D
  Eviatar Ityel - Extension Service (Shaham), Ministry of Agriculture and Rural Development
  Alon Ben-Gal – Environmental Physics and Irrigation, Gilat Research Center, Agricultural Research Organization (ARO)
  Naftali Lazarovitch – Institutes for Desert Research, Ben-Gurion University of the Negev

  E-mail address for correspondence: sab@inter.net.il

  Keywords: pepper, Capsicum, evapotranspiration, Sodom Valley, recycled water

  Abstract
  In order to conserve water and optimize the use of fertilizer, two model farms have been set up at Moshav Paran (the Barry-Porat farm and the Steiglitz farm), with the goal of reducing irrigation and fertilizer levels through the collection and re-use of water that drains from raised/artificial beds. The drainage water is collected from these beds and re-used. A third of the total area is devoted to raised/artificial beds and, in the remaining two-thirds, pepper is grown directly in the ground. Growth relations have been determined to allow the use of large irrigation volumes in these raised/artificial beds. These volumes are necessary to rinse the salts from the root zone and allow for the use of an irrigation system involving the standard water pressures that need to be used with raised/artificial beds, which are based on the fact that the volume of growth medium in the root zone in this type of system is smaller than it is for crops grown in the ground. On the other hand, a collection area is needed for the drained water, so that the appropriate amount of water can be used. All of this is necessary for the optimal functioning of this cropping system.
  When the water quality is 3 dS/m, the amount of water used is up to three times the amount lost to evapotranspiration (ET3). This volume allows good rinsing of salts from the growth medium, but also requires the use of a relatively large area to collect the water that drains from the raised/artificial beds. The lower the ratio of the area of the crop grown in the growth media to the area of the crop in the soil, the greater the efficiency of the system. Today, the quality of the water that reaches the field or other cropping area before fertilizer is applied has an electrical conductivity of between 2.5 and 3.5 dS/m. When the water is of a higher quality, smaller volumes are needed to rinse away salts.
  In an experiment conducted during the 2010/11 growing season, we evaluated the irrigation program needed when irrigating with water of the quality associated with desalinated water. The quality and quantity of the collected drainage water may have different effects on crop performance. The experiment was conducted in a plastic-covered greenhouse at the Zohar Research Station in Sodom Valley. Peppers (cv. Celica) were transplanted into the greenhouse on 13 September 2010. The quality of the irrigation water was 0.3 dS/m. The examined variable was the level of irrigation, which was determined based on the ET MAX (maximum evapotranspiration) as obtained in a treatment with the highest ET (the amount used to allocate the water and as a basis for all of the irrigation treatments). Four different irrigation levels were evaluated: 0.7 ET, 0.9 ET, 1.1 ET and 1.3 ET. These figures were calculated based on the difference between the readings from the irrigation meters and the amount of drainage water. Over the course of the experiment, the irrigation water and drainage water were sampled and the fruit was harvested, weighed and sorted.
  The results of this experiment indicate that when high-quality water is used for irrigation, the drainage water can be used at a level of 16% without incurring any yield damage (Treatment ET 1.1). Increasing the amount of drainage water used to nearly 30% did not improve yield, did not affect the level of transpiration and led to an unnecessary excess of drained water. These findings indicate that in integrated systems involving raised/artificial beds, crops grown in the ground and the collection of drainage water, the use of desalinated water is more efficient than the use of saline water. For the quality of the water available in the Arava, we need two units of “collection” area to absorb the drainage water from each unit of “donor” area. When desalinated water is used, we need a collection area of no more than 10%. That is, the receiving efficiency is 90% without the problems observed when water is recycled in closed systems.

  שפה English
  מחבר Shabtai Cohen, Ami Maduel, Rivka Offenbach, Yoram Zvieli, Israel Tsabari, Rami Golan, Eviatar Ityel, Alon Ben-Gal, Naftali Lazarovitch
  שנה 2011
  שייכות yzvieli
  תאריך יצירה 14/3/2012
  תאריך עדכון 14/3/2012
• 9

  Jan
  Optimizing winter basil production without heating in the northern Arava

  Vegetables

  by Dafna Harari

  Optimizing winter basil production without heating in the northern Arava

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

  תאריך עדכון 1/10/2011

  Optimizing winter basil production without heating in the northern Arava

  Dafna Harari, Ami Maduel, Moran Kapon, Rami Golan, Shimon Pivonia, Omer Galor – Central and Northen 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, Agricultural Research Organization, Volcani Center

  Email for correspondence: dafnahr@arava.co.il

  Keywords: Botrytis, resistance, plant protection, insecticide, management, fresh herbs, polyethylene, Arava Israel, thermal screens, walk-in tunnels, Bemisia

  Over the last five years, the herb-production sector has grown at a rate of 10-15% a year. Basil accounts for 35% of herb exports. Since basil is a summer crop that needs high temperatures in order to develop properly, Israeli basil production has been concentrated in the Beit She’an, Jordan Valley and Besor regions. During the winter, the buildings in these areas in which basil is grown are heated to 16-18°C. With the increase in fuel prices and the decrease in economic returns, much of the winter basil production has shifted to the northern Arava, in order to take advantage of the mild temperatures in this region. During the 2009/10 season, an experimental system was set up at the Zohar Research Station in the northern Arava to evaluate energy-saving agro-technical methods for use as substitutes for supplemental heating of winter basil in the traditional production areas. The experiments were conducted in walk-in 1” tunnels that were covered with sheets of 100-micron polyethylene and whose ventilation openings were covered with 50-mesh netting. Each tunnel covered ¼ dunam and was 40 m long. All of the tunnel entranceways were covered with 50-mesh netting.
  We tested different coverings: A) a thermal screen spread out at night; B) Agril spread out at night; and C) an Agril covering left in place 24 hours a day, under which basil was grown in covered or uncovered ground. We also tested four stand densities: 30, 20, 15 and 10 plants/m2. The plants were transplanted in early December with the goal of harvesting quality basil during February and March. The use of a thermal screen was not associated with any advantages for the crop. In fact, the quality of the yield in the thermal-screen treatment was low. Keeping an Agril covering in place 24 hours a day led to crop yields that were significantly higher than those of the other treatments at each of the five harvests. The quality of these yields was also good. The use of an Agril covering only at night led to good-quality yields at the first four harvests. Growing the crop at a density lower than that commonly used by growers did not lead to any decrease in the total yield for the season and the material harvested from these treatments did well in a post-harvest storage test, with the exception of the material from the second harvest from the treatments with densities of 10 and 15 plants/m2. We did not observe any significant difference between covered and uncovered soil (within the tunnels). Gray mold (Botrytis cinerea) and white mold (Sclerotinia sclerotiorum) developed with the decrease in plant density and their levels increased in the thermal-screen and Agril plots. We suggest repeating the experiment with a low plant density and the addition of sleeves of polyethylene filled with water and Agril, to improve our ability to produce quality basil during the winter without energy expenditures.

  Acknowledgements
  We would like to thank the Scientist’s Fund for funding Research Program no. 603-0237-09. We thank the management of the Vegetable Division of the Plant Board and the Herb Growers Association for their help in funding this project. We also extend heartfelt thanks to herb growers Eran Wein and Yoram Ozeri from Ein Tamar and the AdaFresh Company for their cooperation and for storing and transporting the basil for shelf-life evaluations.

  שפה English
  מלות מפתח Botrytis, resistance, plant protection, insecticide, management, fresh herbs, polyethylene, Arava Israel, thermal screens, walk-in tunnels, Bemisia
  מחבר Dafna Harari, Ami Maduel, Moran Kapon, Rami Golan, Shimon Pivonia, Omer Galor, Izik Esquira, David Silverman, Svetlana Dobrinin, David Kenigsbuch, Meir Teitel, Yigal Elad
  שנה 2010
  שייכות yzvieli
  תאריך יצירה 1/10/2011
  תאריך עדכון 14/3/2012
• 12

  Dec
  Comparison of rootstocks for melon cultivation, Sodom Valley

  Vegetables

  by Yoram Zvieli

  תחום או ענף ירקות
  תאריך עדכון 29/9/2011

  תיאור מלא Comparison of rootstocks for melon cultivation, Sodom Valley

  Yoram Zvieli, Rivka Offenbach, Ami Maduel, Moran Kapun Patael, Rami Golan, Israel Tzabari – Central and Northern Arava R&D
  Eviatar Ityel, Shimshon Omer – Extension Service (Sha'am) Ministry of Agriculture and Rural Development
  Amnon Koren – Hishtil Nurseries

  Email for correspondence: yzvieli@arava.co.il

  The practice of growing grafted melons, which was developed in response to the serious, widespread problem of collapse in melon, is relatively new. In contrast, the use of grafted watermelon has been widespread for a number of years and has been quite successful. The use of grafted melon is faced with the problem of incompatibility, which is expressed through the development of defects in guided melon crops and collapse in trellised melon. Preliminary observations suggest that it might be possible to solve these problems through the development of agro-techniques that allow the cultivation of grafted melon during most seasons of the year by providing the growing conditions necessary for the optimal development of the crop’s root system.
  In an experiment carried out at the Zohar Research Station in Sodom Valley, we tested melon grafted onto nine different rootstocks, from Israeli and foreign development programs, that have improved disease resistance. From our monitoring of the development of the plants in this experiment, it appears that grafted plants develop more slowly than regular melon plants. We attribute this to the effect of high soil temperatures during the fall, which are more problematic for grafted plants. The examined rootstocks included 1042 and TZ148 (the control rootstock), which have moderate growth and among which no collapse was observed. Among the tested rootstocks, 1903 and PG14 stood out for their vigorous growth and the absence of any collapse.
  We did not observe any significant differences in yield among the different rootstock treatments, except for the inferior yield of the rootstock GAD. The overall yields of the other examined rootstocks ranged from 3.7 to 4.0 kg/m2 and the export-quality yields ranged from 2.4 to 3.0 kg/m2. Among the examined rootstocks, 1903 and PG14 stood out for their high yields. We did not find any notable differences in the distribution of fruit defects on the day of harvest among the different rootstocks, nor did we observe any differences in the quality of the fruits from the different treatments following a storage period.
  The grafted melon was transplanted at a stand density of 780 plants per dunam and produced a quantity of export-quality yield that was 50% higher than that of regular plants grown at the planting density typically used for that cultivar (3,120 plants per dunam). A calculation of the yield per plant shows that a regular 1625 melon plant yielded about 1.3 kg of export-quality fruit, as compared with 3.85 kg of export-quality fruit per grafted 1625 plant (average across all rootstocks). The additional yield of the grafted plants was expressed in the form of larger fruit, as well as greater numbers of fruit. The relatively late ripening observed among the grafted plants, as compared to the regular melon plants, appears to be due to high soil temperatures. In light of the good yield results observed for the grafted melon, these rootstocks should be included in an additional variety testing program and tested in a limited number of commercial plots.

  Acknowledgements
  We would like to thank the Hazera, Zeraim Technologies, Samco and Tarsis companies and the Cultivar Development staff of Neve Yaar for working with us on this project and for helping to fund this study. We would also like to thank the Vegetable Division of the Plant Board for their support of this study and Hishtil Nurseries for their much-appreciated help with grafting and for contributing the plants.

  שפה English
  מלות מפתח Cucumis melo, melon, yield, fruit quality, grafted plants, grafting
  מחבר Yoram Zvieli, Rivka Offenbach, Ami Maduel, Moran Kapun Patael, Rami Golan, Israel Tzabari, Eviatar Ityel, Shimshon Omer, Amnon Koren
  שנה 2010
  שייכות yzvieli
  תאריך יצירה 29/9/2011
  תאריך עדכון 29/9/2011
• 12

  Dec
  Effect of a pause in nitrogen fertilization early in the growing season on the rate of fruit yield in pepper cultivar 7158

  Vegetables

  by Shabtai Cohen

  תחום או ענף ירקות
  תאריך עדכון 29/9/2011

  תיאור מלא Effect of a pause in nitrogen fertilization early in the growing season on the rate of fruit yield in pepper cultivar 7158

  Shabatai Chohen, Rivka Ofenbach, Dorith Hashmonai, Avi Osheroviz, Yoram Zvieli - Central and Northern Arava R&D
  Eviatar Ityel – Extension Service, Ministry of Agriculture and Rural Development

  Email for correspondence: sab@inter.net.il

  Pepper cultivar 7158 (Zeraim Gedera) is widely planted in the central Arava. This cultivar is characterized by its strong resistance to different types of abiotic stress. One of the characteristics of this cultivar is its vigorous growth, which allows it to successfully withstand arid and saline conditions. However, this vigorous growth is also responsible for the fact that, sometimes, there is no fruit-setting on the first internodes; the flowers remain and never develop into fruit. The main reason for this is that the high temperatures during the growing season in the Arava sometimes cause vigorous growth together with vigorous respiration, which, in turn, cause the plant’s resources to be directed more toward the production of leaves and less toward the production of flowers and fruit. In cultivars that are particularly vigorous for genetic reasons, such as 7158, the phenomenon of a lack of fruit-setting at the beginning of the cropping season is particularly notable. The combination of excessive fertilization, vigorous growth and extreme climatic conditions intensifies the problem of fruit-setting at the beginning of the cropping season, which can significantly delay fruit production.
  Goals: 1) To test the effect of ceasing nitrogen fertilization for a limited period on the number of immature fruits, yield and yield quality in pepper grown in artificial potting material. 2) Development of field indices, based on the examination of nitrate levels in petioles, to be used in decision-support systems for stopping and starting fertilization as a way to improve fruit-setting in pepper.
  In an experiment conducted at the Yair Research Station during the 2009-2010 season, cv. 7158 was transplanted (August 15, 2009) into a greenhouse structure that was covered with 50-mesh netting at the beginning of the cropping season. In November, the structure was covered with sheets of polyethylene. The crop was grown in artificial potting material containing Perlite 2. We evaluated a control treatment (continuous fertilization as is the common practice) and treatments in which nitrogen fertilization was stopped for 15, 20 or 25 days. Fertilization with potassium, phosphorous and microelements continued in the different experimental treatments exactly as it continued in the control treatment. The treatments were initiated approximately 25 days after transplanting. Afterwards, fertilization was returned to the level of the control. The experiment was carried out in random blocks with five replicates of each treatment. The results of this experiment show that temporarily stopping fertilization led to changes in the rate of fruit production. Stopping fertilization for 15 days led to significantly advanced fruit production in the first month. In contrast, stopping fertilization for 25 days did not lead to any changes in the timing of fruit production, relative to the control.
  The fertilization-stopping treatments did not lead to significant changes in the overall yield or export-quality yield, as compared to the control, through the end of the experiment. In addition, the treatments were not associated with any significant differences in average fruit weight. The results of this experiment indicate that it is possible to eliminate 20-25 days of nitrogen fertilization, for a savings of 250 shekels per dunam or 1250 shekels per 50 dunams, without negatively affecting the yield of cv. 7158, which is currently the leading pepper cultivar in the central Arava.
  When nitrogen values in the petioles fall to 500 ppm NO3- for a period of 10 days, that stress allows for the early ripening of cv. 7158. This parameter is important as we begin to learn how to induce directed and quantified abiotic stress that will, in the future, allow us to direct fruit-production potential.

  שפה English
  מלות מפתח Capsicum
  מחבר Shabatai Chohen, Riveka Ofenbach, Dorith Hashmonai, Avi Osheroviz, Yoram Zvieli, Eviatar Ityel
  שנה 2010
  שייכות yzvieli
  תאריך יצירה 29/9/2011
  תאריך עדכון 29/9/2011