28 Feb 2019
Citrus Rootstock

The effect of chloride on four different citrus rootstocks

N. J.J. Combrink, N. Labuschagne, R. O. Barnard & J. M. Kotzé
South African Journal of Plant and Soil

Most of the world’s citrus is irrigated (Furr & Ream, 1969) and salt accumulation often results from use of poor quality irrigation water and inadequate soil drainage (Bernstein, 1975; Backlund & Hoppes, 1984). Citrus is generally considered to be a salt sensitive plant (Bernstein, 1969; Furr & Ream, 1969; Kirkpatrick & Bitters, 1969) although a wide range of salt . tolerance exists among citrus rootstocks (Cooper, 1961; Embleton, Labanauskas & Bitters, 1962; Peynado & Roger, 1962). Most rootstocks are adversely affected by salinity levels at which conductivity of the satl.l,rated soil extract (ECe) is about 250 – 300 mS m-I (Bernstein, 1975),. ‘It has been reported that heavy losses in production can occur even in the absence of visible toxicity symptoms such as leaf burn (Harding, Pratt & Jones, 1958; Pearson & Huberty, 1959; Peynado & Roger, 1962; Shalhevet, Yaron & Horowicz, 1974).

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28 Feb 2019
Chloride-stressed Citrus

Polyamines in Chloride-stressed Citrus Plants: Alleviation of Stress by Nitrate Supplementation via Irrigation Water

Yoel Bar, Akiva Apelbaum, Uzi Kafkafi, and Raphael Goren
The Kennedy–Leigh Centre for Horticultural Research
The Hebrew University of Jerusalem, Rehovot 76100, Israel

A study was conducted to elucidate the effects of chloride in the irrigation water on growth and development of two citrus rootstocks. ‘Cleopatra’ mandarin (Citrus reshni Hort. ex Tan) is salt tolerant and ‘Troyer’ citrange (Poncirus´Citrus sinensis) is salt sensitive. Increasing chloride from 2 to 48 mM in the irrigation water resulted in increased leaf chloride levels, more severe damage of the leaves, and reduced branch growth. High chloride in the irrigation water also caused increased putrescine (PUT) and decreased spermine (SPM) contents of the leaves.

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28 Feb 2019
Boron and Chlorine for Citrus Trees

Boron (B) and Chlorine (Cl) for Citrus Trees

Mongi Zekri and Tom Obreza
IFAS Extension, University of Florida

To maintain a viable citrus industry, Florida growers must consistently and economically produce large, high-quality fruit crops year after year. Efficiently producing maximum yields of high-quality fruit is difficult without understanding soil and nutrient requirements of bearing citrus trees.

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25 Jan 2019
Citrus Black Spot

EU digs in heels and remains aggressively protectionist on CBS

http://www.zestfruit.co.za

Despite one of the best seasons on record in terms of mitigating the risk of Citrus Black Spot (CBS) symptoms on fruit arriving at EU borders, the EU seems determined to meet South Africa’s best efforts with unflinching bureaucratic coldness.

At a meeting in Brussels on 27 November between the EU’s Directorate-General for Health and Food Safety (DG Sante), the Department of Agriculture, Forestry and Fisheries (DAFF) and a delegation of SA citrus producers, the EU begrudgingly acknowledged this year as a good season.

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25 Jan 2019
Orri Jaffa

Easy-Peeler Orri Jaffa expected to see 70% sales growth in North American markets

https://www.freshplaza.com

The Plant Production and Marketing Board of Israel predicts that 2019 will see significant increase in exports of the Orri Jaffa mandarin to the US and Canada. The organization set goals for expanding export of its leading, easy-to-peel mandarin in response to the increased demand for high-quality, easy-peelers.

The Jaffa Orri is a mandarin developed by scientists at the Israeli Volcani Research Center. This easy-to-peel mandarin retains an excellent, fresh, sweet flavor with a fleshy texture, and mouthful juiciness, while bearing virtually no seeds. It also carries a particularly long shelf life and appears later in the season compared to other easy peelers – from January into May.

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25 Jan 2019
Mandarin

Plant nutrition status, yield and quality of satsuma mandarin (Citrus unshiu Marc.) under soil application of Fe-EDDHA and combination with zinc and manganese in calcareous soil

Ying Zhang, Cheng-Xiao Hu∗, Qi-Ling Tan, Cang-Song Zheng, Hui-Ping Gui, Wei-Nan Zeng, Xue-Cheng Sun, Xiao-Hu Zhao
College of Resources and Environment/Micro-element Research Center, Huazhong Agricultural University, Wuhan, Hubei Province 430070, PR China

The purpose of this study was to investigate citrus tissue’s response to varying applications of Fe-EDDHA, zinc (Zn) and manganese (Mn) combinations and the resulting effects on citrus fruit yield and quality in calcareous soil. A field experiment was conducted for three years with satsuma mandarin trees planted in calcareous soil. Four treatments were conducted: (i) control; (ii) soil Fe application; (iii) soil Fe + Zn application; and (iv) soil Fe + Zn + Mn application. Soil available Fe and Zn concentrations were raised through the application of Fe-EDDHA and Zn, whereas the soil available Mn concentration was not increased through the application of Mn. Applying Fe-EDDHA raised the leaf active Fe content significantly without influencing the leaf and fruit Fe concentrations. The Zn concentrations in leaf and fruit decreased when Fe-EDDHA was applied exclusively, but increased when Fe + Zn and Fe + Zn + Mn were applied in the third year. There was no significant difference in leaf and fruit Mn concentrations among all treatments between 2010 and 2012.

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21 Dec 2018
Gerrit van der Merwe

Our deepest condolences to the Van der Merwe family in this difficult time.

Lucille Botha

Network 24.com

One of South Africa’s best-known citrus farmers and a former farmer of the year died on Wednesday after a fatal accident in Malawi.

Mr. Gerrit van der Merwe (68) of ALG farming on Citrusdal, along with his wife, Lizette, went on a tour to Uganda when he fell into a ditch in Lilongwe on Sunday night and hurt his foot.

Click here to read the full article.