21 Jul 2022
Valencia oranges

South Africa to appeal against new EU citrus rules

CGA’s Justin Chadwick said cold treatment requirement is unnecessary, unjustified and disproportionate.

The South African citrus industry is scrambling to avert disruptions in its citrus exports to the European Union due to changes in regulations governing the importation of oranges into the EU.

The new regulations, which deal specifically with orange imports from South Africa and other sub-Saharan countries, were published in the Official Journal of the European Union on Tuesday and will come into force today.

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21 Jul 2022
Leaf Abscission

Abscisic Acid Reduces Leaf Abscission and Increases Salt Tolerance in Citrus Plants

This paper describes the physiological effects of abscisic acid (ABA) and 100 mM NaCl on citrus plants. Water potential, leaf abscission, ethylene production, photosynthetic rate, stomatal conductance, and chloride accumulation in roots and leaves were measured in plants of Salustiana scion [Citrus sinensis (L) Osbeck] grafted onto Carrizo citrange (Citrus sinensis [L.] Osbeck · Poncirus trifoliata [L.] Raf) rootstock. Plants under salt stress accumulated high amounts of chloride, increased ethylene production, and induced leaf abscission. Stomatal conductance and photosynthetic rates rapidly dropped after salinization.

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22 Apr 2022
Citrus Harvest EC

The synthetic auxin 3,5,6-TPA stimulates carbohydrate accumulation and growth in citrus fruit

The application of the synthetic auxin 3,5,6-TPA at the cell enlargement stage increased hexoses in developing fruit from foliated and fully defoliated plants of Satsuma mandarin, cv. ‘Okitsu’ (Citrus unshiu Marc.). Although the sucrose concentrations also increased, in general the differences were not statistically significant. The plant growth regulator reduced fruit abscission in defoliated trees while it stimulated fruit growth in the foliated ones.

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25 Mar 2022
Citrus Export

The response of salt stressed Valencia Sweet Orange to salicylic acid and methyl jasmonate treatments

Salinity is an obstacle to citriculture worldwide, and is a concern in arid, semiarid, and coastal regions. In the current study, we irrigated one-year-old ‘Valencia’ trees budded onto Kuharske rootstock with 60 mM sodium chloride (NaCl) solution for ten weeks. Subsequently, these trees were sprayed with 50, 75, and 100 mM SA or MeJA to determine whether these phytohormones could alleviate the detrimental effects of salinity. READ MORE

28 Apr 2021
Orange Blossom

Effects of gibberellin treatment during flowering induction period on global gene expression and the transcription of flowering-control genes in Citrus buds

As we enter the flower induction stage different factor control the amount of flowering for the next season. Gibberellic acid (GA) is a strong inhibitor for the flowering genes in Citrus. The aim of the study was to determine to what length GA has got an influence. GA was applied on citrus bud and the genetics analyzed and more Leafy mRNA were transcribed in these buds.

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25 Jan 2021

Fruit load restricts the flowering promotion effect of paclobutrazol in alternate bearing Citrus spp.

The floral bud inductive period, PBZ promotes flowering in Citrus; however, our results indicate that this effect is fruit-load dependent. In ‘Salustiana’ and ‘Navelina’ sweet oranges, ‘Hernandina’ Clementine mandarin, and ‘Afourer’ and ‘Moncada’ hybrids, flowering intensity significantly increased the following spring for medium-to-low fruit-load trees treated with either 1–10 g PBZ tree−1 applied to the soil or 15 g tree−1 sprayed on the canopy. PBZ significantly increased the percentage of sprouted buds and leafless floral shoots (both single-flowered shoots and inflorescences) and reduced the number of vegetative shoots.

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05 Dec 2020
Citrus Industry

SA’s citrus beats the world’s Covid blues

Despite the Covid-19 pandemic and all the uncertainties it caused, the 2020 citrus season turned out to be one of the best that South Africa has ever had. On estimate, South Africa exported 21.3 million cartons more than the previous season. Better access to US markets due to additional ports of entry, and access to Philippine markets, have contributed to an increase in demand for South African citrus.

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05 Dec 2020
Cover Crops

Cover crops for citrus

Cover crops are specific crops not intended for sale but for soil improvement and sustainability. They are increasingly common in the agricultural fields of the Midwest and other grain-producing regions because of the wide range of benefits not just for the soil, but also the cash crop. In those systems, cover crops improve water and nutrient retention, promote microbial activity, reduce weed growth and insect pests, and improve plant growth. Similar impacts have been found in tree crops like apples and peaches, where cover crops are planted in row middles.

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23 Nov 2020
Climate Change

Potential climate change impacts on citrus water requirement across major producing areas in the world.

Understanding how potential climate change will affect availability of water resources for citrus production globally is needed. The main goal of this study is to investigate impacts of potential future climate change on citrus irrigation requirements (IRR) in major global citrus producing regions, e.g., Africa, Asia, Australia, Mediterranean, Americas. The Irrigation Management System (IManSys) model was used to calculate optimum IRR for the baseline period (1986–2005) and two future periods (2055s and 2090s) subject to combination of five and seven temperature and precipitation levels, respectively. Predicted IRR show significant spatio-temporal variations across study regions. Future annual IRR are predicted to globally decrease; however, future monthly IRR showed mixed results.

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