21 Aug 2026
Soil water management through subsurface drainage

Soil water management through subsurface drainage and ground cover influences yield and fruit quality of ‘Navelina’ sweet orange under semi-arid conditions

Sweet orange (Citrus sinensis L. Osbeck) production in Mediterranean semi-arid regions is increasingly constrained by water scarcity and soil degradation, requiring improved soil management strategies to optimize resource-use efficiency without compromising fruit quality. These practices can modify soil physical conditions and root-zone processes, with direct implications for plant growth and crop performance. This study evaluated the combined effects of anti-weed mesh and subsurface drainage on yield and fruit composition in young ‘Navelina’ trees. An 18-month field experiment was conducted using six treatments differing in ground cover and drainage configuration. Treatments incorporating drainage and ground cover improved productive performance, suggesting enhanced soil conditions and more efficient use of available resources.

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21 Aug 2026
Excessive nitrogen application

Excessive nitrogen application deteriorates integrated citrus fruit quality: A multi-dimensional field study.

Consumer evaluation of citrus fruit quality is moving beyond the traditional sugar–acid ratio toward a broader set of attributes, including texture, flavor and nutritional value. Yet the effects of excessive nitrogen (N) fertilization, a common practice in citrus orchards, on these integrated quality traits remain poorly understood. Here, we combined a long-term field experiment with integrated metabolomic, appearance, texture, flavor and aroma analyses and membership-function-based quality evaluation to reveal how excessive N drives citrus fruit quality deterioration.

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27 Jul 2026
Valencia Orange Trees

Effects of Foliar Applications of Urea or Nutriphite on Flowering and Yields of Valencia Orange Trees

Valencia orange yields have been related to the number of flowers in the spring bloom, and the number of induced flower buds is determined by climatic stress factors such as cold and drought. Winter foliar sprays of urea have been reported to enhance the number of flower buds, flowers per inflorescence and yields under California conditions. Sprays of urea (28-31 kg N/ha) or Nutriphite (6.1 l/ha of 0-28-26 product) were applied to mature Valencia trees in two locations in South Florida in 1994-95. Urea or Nutriphite applied between the dates of 25 Dec. and 11 Jan. increased flowers.

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27 Jul 2026
Citrus with Ice

Screening Citrus Cultivars for Freezing Tolerance by Reliable Methods

Citrus species are comprised of susceptible plants that can barely tolerate freezing temperatures. To determine the relationship between cold stress tolerance (LT50) and some important physiological traits, four commercial citrus cultivars of citrus species were studied. These were Citrus unshiu, Citrus sinensis var. ‘Thomson navel’, Citrus paradisi var. ‘Star Ru by’ and Citrus limon var. ‘Lisbon’. Assessments of cold-stress tolerance were carried out at 4, -4 and -8 °C. Ultimately, the results showed that the Japanese mandarin and ‘Thomson navel’ had the highest stress tolerance (LT50). Citrus unshiu tolerated cold stress up to -8.4 LT50.

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26 Jun 2026
Cold Accumulation

Cold Stress in Citrus: A Molecular, Physiological and Biochemical Perspective

Due to climate change, we are forced to face new abiotic stress challenges like cold and heat waves that currently result from global warming. Losses due to frost and low temperatures force us to better understand the physiological, hormonal, and molecular mechanisms of response to such stress to face losses, especially in tropical and subtropical crops like citrus fruit, which are well adapted to certain weather conditions.

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26 May 2026
Symptoms caused by Phytophthora- spp. on-citrus

Phytophthora-citrus interactions and management strategies: A review

Citrus production is declining worldwide due to several biotic and abiotic factors. The diseases caused by Phytophthora spp. present major economic risks since they are soil-borne and spread quickly if environmental conditions are favorable, or irrigation is poorly managed. Phytophthora species are present in all citrus-producing areas around the world causing significant losses in crop yield and affecting tree health. Bark infection, damping-off, root rot, gummosis, brown rot, and cortical root rot are among the typical symptoms caused by Phytophthora spp.

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28 Apr 2026
Frost on Citrus

Physiological and biochemical adaptive strategies in citrus plants facing cold stress

Climate change has increased extreme weather events frequency and intensity. Although the incidence of high temperatures has been studied on several plant species, the study of low temperatures has been relegated to the background, whereas crops as citrus could be particularly sensitive to chilling due to their origins in tropical and subtropical areas. In this work, plants of two citrus genotypes, Carrizo citrange (CC) and Cleopatra mandarin (CM), were subjected to cold stress at 10/4ºC (day/night) temperature, maintaining control plants at 25/18 ºC, with a 16 h photoperiod. Leaf tissue was sampled after 3 and 7 days for further analyses. The results exhibited a similar photosynthetic response in both genotypes, decreasing of gas exchange parameters. The study of different osmoprotectants revealed a major role of proline and soluble sugars in the osmotic response of citrus to chilling.

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