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• 25

  Mar
  Effects of root zone infrastructure, irrigation quantity and mode of compost application on organically grown pepper

  Vegetables

  by Eviatar Ityel

  10
  חום או ענף אורגני; ירקות

  תאריך עדכון 14/3/2012

  Effects of root zone infrastructure, irrigation quantity and mode of compost application on organically grown pepper
  Ityel Eviatar – Extension Service (Shaham) Ministry of Agriculture and Rural Development
  D. Chashmonai, A. Oshoroviz, R. Offenbach, Y. Zvieli, I. Tsabari – Central and Northern Arava R&D
  E-mail address for correspondence: Eviatar@arava.co.il

  Abstract
  In the Nasham restricted root zone system, a capillary barrier is used to derive high moisture levels from small volumes of water. Decreasing the volume of irrigation water applied to organic pepper crops is expected to provide great advantages in terms of fertilizer costs, as well as more efficient water use. The quantities of fertilizer dissolved in the irrigation water are expected to decrease greatly in light of the smaller irrigation volumes, thereby decreasing the contamination of the groundwater with nitrates. The trouble with the application of this method is the fact that the use of buried sheeting that surrounds roots (Palrig side-sheeting) is prohibited in organic agricultural systems. Due to the hydraulic characteristics of this sheeting, it provides for a significant decrease in the horizontal movement of water in the soil, which leads to improved removal of salts. The model that is permitted for use in organic agricultural systems includes only a barrier, without any side-sheeting.
  Pepper plants (cv. Sobek; Zeraim Gedera) were transplanted into a screen-house at the Yair Experimental Station on 1 August 2010. We examined two irrigation levels, a low level and a high level. The lower irrigation level was approx. 40% lower than the higher level. At the end of the growing season, the total volumes of irrigation applied were 760 and 1,240 m3/dunam, respectively. The irrigation levels were evaluated in two different root-zone infrastructure systems. A system with a layer of gravel buried 40 cm below the soil surface that served as a barrier was compared with a control infrastructure treatment in which the soil had not been dug up. In both infrastructure treatments and both irrigation treatments, we evaluated two ways of applying compost: (1) burying the compost under tilled soil and (2) spreading the compost on the soil surface.
  The dry weight of all of the fruit (that which had been harvested and that which was still green on the vine at the end of the study) and the dry weight of the canopy were lower in the low-level irrigation treatment than in the high-level irrigation treatment (differences of 13% for fruit and 15% for canopy). The barrier infrastructure treatment was inferior to the control in terms of dry-weight yield and harvested fruit. There was a 7% difference between the infrastructure treatments. The two methods of applying compost (distribution on the soil surface or burial under loosened soil) did not differentially affect any of the measured variables.

  Acknowledgements
  We would like to thank the staff of Arava R&D for their help with this work and the Plant Board for their financial support of this project.

  שפה English
  מלות מפתח Capsicum
  מחבר Ityel Eviatar, Dorit Chashmonai, Avi Oshoroviz, Rivka Offenbach, Yoram Zvieli, Israel Tsabari
  שנה 2011
  שייכות yzvieli
  תאריך יצירה 14/3/2012
  תאריך עדכון 14/3/2012
• 25

  Mar
  Identifying methods to improve the application of nitrogen containing solid organic fertilizer in organic pepper

  Vegetables

  by Shabtai Cohen

  9 תחום או ענף אורגני; ירקות

  תאריך עדכון 14/3/2012

  Identifying methods to improve the application of nitrogen containing solid organic fertilizer in organic pepper
  Shabatai Cohen, Rivka Ofenbach, Dorith Hashmonai, Avi Osheroviz, Yoram Zvieli – Central and Northern Arava R&D
  Itzik Coen – The Israel Bio Organic Agriculture Association
  E-mail address for correspondence: sab@inter.net.il

  Abstract
  In an experiment conducted at the Yair Research Station in the Arava during the 2010/11 growing season, we examined the effects of the rate, frequency and method of application of solid organic fertilizer (Organicum) on pepper yield and yield quality, with the goal of evaluating possibilities for decreasing production costs and improving profitability for growers. This was done with the understanding that the manual application of fertilizer is labor intensive and requires labor resources that are in short supply. For this reason, any method that will permit less frequent applications will significantly decrease growers’ costs. In an experiment conducted in a screen-house in an organic growing area, we evaluated the effects of Organicum fertilizer, which is processed poultry litter that has undergone a brief composting process under controlled conditions.
  Organicum is representative of a series of materials that have come into use in recent years as part of efforts to lower fertilizer costs in organic agriculture, take advantage of local waste materials and identify substitutes for imported organic nutritional materials, such as guano from the shores of Namibia and feather meal, which is also fed to animals and is currently imported from Europe since the local production of this material is not sufficient. Other alternatives for Organicum include liquid nutritional materials, such as Nugrow, Protomix, Nifert and others, that can be applied through an irrigation system. The disadvantages of these materials are their high cost and the fact that they are imported, with all the environmental significance of their transportation across large distances.
  This experiment included six treatments. Two of these were control treatments. One of the control treatments was treated with Tivon fertilizer for the first 20 days after transplanting. After that period, no supplemental fertilizer was applied. The other control treatment was treated with Tivon fertilizer with a nitrogen concentration of 50–70 ppm throughout the season. In three of the four Organicum treatments, the fertilizer was applied close to the plant roots every 20, 45 or 60 days. In the fourth Organicum treatment, the same amount of fertilizer was distributed on the soil surface instead of being applied to the root zone.
  The results of this study indicate that the Organicum treatments have an advantage over the control (Tivon) treatment even though the nitrogen in Tivon fertilizer is almost immediately available to the plants as ammonia or amino acids. This finding may reflect the fact that Organicum contains not only nitrogen, but also additional elements, such as potassium, phosphorous and trace elements; whereas Tivon contains only nitrogen.
  The yield of the treatment in which Organicum was applied every 20 days was higher than the yields of the other treatments. The largest amount of nitrogen was applied in this treatment, 60 units of nitrogen as opposed to half of that amount or even less in the other treatments. However, the observed results could be more indicative of the availability of the nutrients than the amount of nutritional material applied. This finding suggests that the nutritional treatment applied in this treatment about a month after transplanting greatly improved the nutritional balance of the plants during the critical period in which they began to set fruit. We know that a lack of essential nutrition during fruit development can cause increased fruit setting and the plants “getting stuck.” Therefore, in order to insure proper crop production, it is necessary to check the nutritional status of the crop relatively frequently (every 10 days) between Day 35 and Day 45 after transplanting. It is quite possible that after this critical period there is barely any need to fertilize the plants. That is, fertilizer applications could be concentrated during the necessary developmental period and not be continued through the further development of the crop, during which time the fertilizer does not appear to have much of an effect because the yield-determining events have already occurred.

  Acknowledgement
  We would like to thank the Fertilizers & Chemicals Ltd. Company for supplying the liquid fertilizers used in this experiment.

  שפה English
  מלות מפתח Capsicum
  מחבר Shabatai Cohen, Rivka Ofenbach, Dorith Hashmonai, Avi Osheroviz, Yoram Zvieli, Itzik Coen
  שנה 2011
  שייכות yzvieli
  תאריך יצירה 14/3/2012
  תאריך עדכון 14/3/2012
• 25

  Mar
  Control of broad mites and powdery mildew in organically grown pepper in the Arava

  Vegetables, Plant Protection

  by Danit Parker

  8
  תחום או ענף אורגני; ירקות

  תאריך עדכון 14/3/2012

  Control of broad mites and powdery mildew in organically grown pepper in the Arava
  Danit Parker, Ela Yosel, Rachel Levite and Shimon Pivonia – Central and Northern Arava Research and Development
  E-mail address for correspondence: shimonp@arava.co.il

  Abstract
  Broad mite (Polyphagotasnemus latus) is a serious pest of many agricultural crops, including pepper. Powdery mildew (Leveillula taurica) is a multi-host pathogen of agricultural crops, particularly pepper. To date, aside from treatment with sulfur, which is permitted in organic crops and requires large-scale treatment, there are hardly any effective options for controlling broad mite and powdery mildew in pepper. Due to concern over the accelerated deterioration of screens following the use of sulfur as well as residue on the fruit, organic growers are searching for additional chemical preparations to effectively control broad mite and powdery mildew.
  In an experiment conducted during the 2010/11 season at the Yair Experimental Station, we examined the efficacy of E.O.S., a preparation that contains 99% mineral oil, for the control of broad mites and powdery mildew in organic pepper. We found that spraying E.O.S. once every two weeks did not effectively prevent damage caused by broad mites and powdery mildew. In contrast, the spraying of a liquid colloid of sulfur did effectively control this damage. It is possible that more frequent application of E.O.S. might lead to better results.

  Acknowledgements
  We would like to thank Yuval Barzilai, Dorit Hashmonai and Avi Osherovitz from the Yair Experimental Station for their help setting up and carrying out the experiment.

  שפה English
  KEYWORDS Polyphagotasnemus latus, Leveillula taurica, Capsicum
  AUTHORS Danit Parker, Ela Yosel, Rachel Levite and Shimon Pivonia
  שנה 2011
  שייכות yzvieli
  תאריך יצירה 14/3/2012
  תאריך עדכון 14/3/2012
• 25

  Mar
  Irrigation of a mango plantation with desalinated water, Sodom Valley

  Orchard

  by Dafna Harari

  7
  תחום או ענף מטעים
  תאריך עדכון 14/3/2012

  Irrigation of a mango plantation with desalinated water, Sodom Valley
  Dafna Harari, Ami Maduel, Uri Zeiri, Aviran Asraf, Rami Golan, Svetlana Gogio – Central and Northern R&D Arava
  Baruch Luzon, Izik Kosto, Shlomo Kramer – Extension Service, Ministry of Agriculture and Rural Development
  E-mail address for correspondence: dafnahr@arava.co.il

  Abstract
  Aside from dates, no orchard or vineyard crops have been grown in the Sodom Valley area, unlike the southern areas of the Arava Valley, in which mango and grapes are grown. Despite the unique climate of the Sodom Valley area and the early-ripening advantages associated with such a climate, the area in this region planted to orchards/vineyards (excluding dates) is limited and includes small areas of Brazilian figs and papaya. The main reason for this is the quality of the water. The saline water available in the area has an EC of 3.5-4. In the case of perennial crops, such as orchard crops and grapevine, the salt accumulates in the plant, there is a subsequent decrease in growth and yield and the trees or vines eventually die. In the past, experiments were conducted involving orchard crops and vineyards in the region, but these efforts did not succeed over the long term due to the accumulation of salts. The decrease in the cost of desalinated water and the development of more effective, cheaper technologies have made possible the desalination of water for agriculture. This desalinated water can be blended with local water. The quality of this blended water is just as good as that of the piped water in the northern and central parts of the country. That is, this water has a salinity level of 1-1.5 (dS/m).
  In 2006, a mango orchard was planted on the grounds of the Zohar Experimental Station. Mango cultivars Shelly and Tommy were planted in a screen-house. Some plots were irrigated with the local piped water and the others were irrigated with desalinated water. The plots were separated by sheets of polyethylene that extended to a depth of 1.5 m, in order to prevent the roots from growing in the direction of the blended water. After six growing seasons, large differences were noted in the growth of the plants and the quantity and quality of their yields. Soil and root examinations in the treatment that was irrigated with local pipeline water revealed increased salinity in the deeper layers and, for that reason, fewer roots. The damage that the salinity caused the trees was visible in both cultivars, but was especially notable in cv. Shelly; some of those trees dried up completely. Regarding the yield, we saw heavy fruit production throughout the orchard, in both cultivars and both irrigation treatments. The cv. Tommy did comparatively better when it was irrigated with the blended water. In cv. Shelly, there was no significant difference in export-quality yield, but about 30% of the yield of this cultivar was made up of small fruit (less than 200 g) that were not fit for export. In light of the results of this study, it is clear that the expansion of the variety of orchard crops grown in Sodom Valley requires a supply of water that is significantly less saline than that currently available for agriculture. The success of the experiment will open up new ways to take advantage of the idea of building a central desalination facility for each region.

  שפה English
  KETWORDS irrigation, salinity
  AUTHORS Dafna Harari, Ami Maduel, Uri Zeiri, Aviran Asraf, Rami Golan, Svetlana Gogio, Baruch Luzon, Izik Kosto, Shlomo Kramer
  שנה 2011
  שייכות yzvieli
  תאריך יצירה 14/3/2012
  תאריך עדכון 14/3/2012