Girdling branches increased flowering in citrus. The number of buds sprouted increased following treatment but the response markedly depends on the time of girdling, summer being most effective. All types of shoots, except vegetative ones, are increased in number but with no differences in its characteristics.
Around 1,000 tonnes of citrus is to be distributed to disadvantaged communities this year Leading South African citrus company ClemenGold International has said that it is teaming up with a relief organisation to deliver some 1,000 tonnes of citrus to help alleviate the plight of people in some of the country’s poorer communities. “Caring for the communities surrounding our partner farms and packhouses has been a value upon which we’ve acted since the establishment of our business,” explained Adéle Ackermann, marketing manager for ClemenGold International.
“Fruit is our business and donating Vitamin C-rich citrus is a logical way of contributing towards helping communities to thrive.” The company has announced a partnership with SA Harvest, a registered non-profit and leading food rescue and hunger relief organisation, whereby 1,000 tonnes of citrus will be donated during the 2023 season.
With the latest of a series of winter storms sweeping over the South African Western Cape region, citrus and other fruit growers are facing a difficult period of recovery. For the last ten days all citrus harvesting in the Oliphant’s River Valley, the most important region supplying summer citrus to the US, has been suspended. Infrastructure in the Valley and in other parts of the Western Cape has been damaged, with key roads washed away and communities in rural regions flooded.
The winter storms in these regions have been described as the worst since 2008 when floods rose to record levels in places. It comes when significant volumes of South African citrus are due to be discharged in the US later this week, marking the real start of the marketing season. Significant volumes have also been shipped by containers since April. Industry leaders said that before the storms started enough fruit had been packed for the first three vessels, but that their departure could be delayed.
Phytophthora brown rot, caused by several species of Phytophthora, is an economically important disease of citrus in areas with rainfall during the late stages of fruit development. Recent export restrictions of California orange fruit to China due to the presence of brown rot caused by the quarantine pathogen Phytophthora syringae have mandated more rigorous disease management. We evaluated postharvest applications with the phosphonate fungicide potassium phosphite in combination with heat treatments. In timing studies, potassium phosphite at 1,500 mg/ml was most effective when applied within 18 h after inoculation of orange fruit with P. citrophthora, reducing the incidence of decay by >96% as compared with the control. Potassium phosphite was also highly effective in inoculations with P. syringae. Heated water treatments at 60°C were consistently and highly effective in reducing the incidence of brown rot after inoculation with P. citrophthora, whereas treatments at 55 or 50°C were more variable and generally less effective.
Rain is still falling over Citrusdal where food has had to be flown in by helicopter to stranded inhabitants after the town’s entrance road was washed away, and now the remaining electricity line has also fallen victim to the flood. It is expected that the rain will ease off from Wednesday. In the port of Cape Town very high swells have meant that vessels couldn’t enter the harbour; there are currently three vessels waiting to come into port.
Repairs to the town bridge over the Olifants River which was washed away are underway, including correcting the course of the swollen river.
Since the essentiality of boron (B) to plant growth was reported nearly one century ago, the implication of B in physiological performance, productivity and quality of agricultural products, and the morphogenesis of apical meristem in plants has widely been studied. B stresses (B deficiency and toxicity), which lead to atrophy of canopy and deterioration of Citrus fruits, have long been discovered in citrus orchards. This paper reviews the research progress of B stresses on Citrus growth, photosynthesis, light use efficiency, nutrient absorption, organic acid metabolism, sugar metabolism and relocation, and antioxidant system. Moreover, the beneficial effects of B on plant stress tolerance and further research in this area were also discussed.
South-easterly winds coincide with the first 12 weeks after mandarin petal drop. When these winds become more intense between October and December, they can cause up to 87% of the severe wind-scar damage seen in a season. However, says Heinrich Geldenhuys, such losses can be minimised with suitable windbreaks or other forms of wind protection, resulting in higher export volumes of quality fruit. Geldenhuys is a junior researcher who graduated in April 2022 with an MSc in Horticultural Science degree from Stellenbosch University (SU).
Fruit size is a key parameter for quality and increases the profitability for export markets in citrus production in Turkey. Fruit size can be enhanced by several techniques such as girdling and thinning. Various plant growth regulators are known to affect the growth and size of citrus fruit. Thus the effects of synthetic auxin applications (2,4-DP and 3,5,6-TPA) at different physiological periods, girdling practices, pruning practices, foliar application of potassium and various combinations of these practices on the fruit size and yield, fruit retention rate, and leaf chlorophyll concentration and fluorescence of Star Ruby grapefruit cultivar were investigated.