28 Nov 2025
Fruit Thinning

Economics of Fruit Thinning A Review Focusing on Apple and Citrus

Hundreds of fruit thinning experiments have been reported for various fruits including apple (Malus x domestica) and citrus (Citrus spp.). Unfortunately, very few of these reports attempt to evaluate the economic implications of thinning. Researchers routinely report significant cropload reduction accompanied by an increase in fruit size. Although these are crucial responses to thinning, they are not always associated with an increase in crop value, which is the commercial justification for thinning.

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27 Nov 2025

Fruit Thinning Improves Fruit Size, Yield and Return Flowering in ‘Washington Navel’ Orange (Citrus sinensis L. Osbeck)

“Washington Navel” orange is the principal mid-season maturing cultivar grown in south-eastern Australia. The cultivar has strong export potential and earns high returns for citrus growers. However, trees bear a large number of small-sized fruit in an on-year followed by a small number of largesized fruit the next year if crop load is not properly managed. Thinning can be used as a crop management strategy to adjust crop load. A thinning experiment was conducted, and crop loads were adjusted on a whole tree basis to 2, 4, 6 or 8 fruit/0.125 m3 canopy volume (CV), removing 46%, 30%, 20% and 8% of the crop respectively, and compared to non-thinned control trees. Fruit diameter was measured at regular intervals from February to July.

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30 Oct 2025

Effect of Potassium, Magnesium, and Calcium Deficiencies on Carbohydrate Pools and Metabolism in Citrus Leaves

Carbohydrate content and related enzyme activities were determined in leaves of rough-lemon (Citrus volkameriana Ten. & Pasq) plants grown under K, Mg, and Ca deficiencies. Starch content was lower and soluble sugar significantly higher in K-deficient than in control leaves. Magnesium- and Ca-deficient leaves, on the other hand, accumulated large amounts of starch. Electron micrographs also showed a reduction in the number and size of starch grains in chloroplasts of K-deficient leaves, while those of Mg- and Ca-deficient leaves were filled with large starch grains.

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30 Oct 2025
Citrus Girdling

Influences of girdling and potassium treatments on fruit quality and some physiological characters of ‘Fremont’ mandarin variety

Growing citrus involves cultural treatments such as girdling and foliar potassium treatment to increase fruit size, yield and quality. The aim of the study was to evaluate the effects of single and double stem girdling, potassium nitrate (KNO3) treatment on leaves and combinations of these treatments on the fruit yield, size and quality characteristics, leaf chlorophyll concentration and leaf nitrogen content, leaf fluorescence (PSII) and leaf sugar content of the ‘Fremont’ mandarin variety. Girdling treatments were applied on the stem by removing 4 mm wide ring of bark at the end of anthesis and after the June fruit drop.

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26 Sep 2025
Citrus Fruit Variety

Citrus fruit quality. Physiological basis and techniques of improvement.

Fruit size can be improved either by increasing carbohydrates availability to fruit or by increasing fruit sink strength. Application of synthetic auxins may act in these two ways, depending on the date of treatment. When they are applied during the physiological drop they have a thinning effect, reducing competition for carbohydrates among developing fruitlets; when applied at the onset of cell enlargement stage fruit sink strength is increased and carbohydrate accumulation in the fruit is enhanced.

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26 Sep 2025
Cross section of fruit

Primary Metabolism in Citrus Fruit as Affected by Its Unique Structure

Citrus is one of the world’s most important fruit crops, contributing essential nutrients, such as vitamin C and minerals, to the human diet. It is characterized by two important traits: first, its major edible part is composed of juice sacs, a unique structure among fruit, and second, relatively high levels of citric acid are accumulated in the vacuole of the juice sac cell. Although the major routes of primary metabolism are generally the same in citrus fruit and other plant systems, the fruit’s unique structural features challenge our understanding of carbon flow into the fruit and its movement through all of its parts.

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29 Aug 2025
Mulch

Effect of Various Mulching Materials on Crop Production and Soil Health in Acid Lime

An experiment was conducted to study the effects of mulching on acid lime during 2014-2015 in Randomized Block Design with 9 treatments and 3 replications. The highest increase on plant height (6.63 %), canopy spread in E-W (9.90 %) and N-S (7.60 %) direction was recorded by polythene mulch with black side facing upward (T8 ). The treatment also had a significant influence on yield and yield attributing parameters where T8 recorded the highest number of fruits per plant (163.0), fruit weight (50.22 g) and fruit yield per plant (7.81 kg) while dry grasses mulch (T2) recorded highest number of fruits per branch (7.50) and fruit retention (44.71 %). With respect to quality parameters of fruit, T8 recorded highest total sugar (0.40 %) and reducing sugar (0.61 %) while significant increase on titratable acidity (6.93 %) and ascorbic acid content (33.46 mg/100g) was observed in T2.

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29 Aug 2025
Fertilization

Effects of Fertilization Approaches on Plant Development and Fertilizer Use of Citrus

Fertilization is an important part of citrus crop management. However, limited details are available about the fertilization approach on citrus plant development. A pot experiment for the fertilization approaches and fertigation levels were conducted in this study. Four fertilization approaches, namely, drip fertigation (DF), broadcast fertilization (CK+), hole fertilization (HF) and pour fertilization (PF) were tested. The fertigation level treatment included 100% (DF-337.5), 80% (DF-270), 60% (DF-202.5) and 40% (DF-135) fertilizer supply with DF, and the 100% fertilizer supply with broadcast fertilization were served as control (CK). The results showed that DF not only increased the absorptions of nitrogen (N), phosphorus (P) and potassium (K) but also promoted citrus plant height, stem diameter and dry weight.

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