25 Jan 2024
Washington Navel Orange

Effect of GA3 and Potassium Nitrate in Different Dates on Fruit Set, Yield and Splitting of Washington Navel Orange

Two concentrations of GA3 were used alone or with 0.5% urea i.e. (50 and 100 ppm) and three levels of potassium nitrate (KNO3) 2 ،4 and 6% were tested as foliar sprays at different times i.e. first time application at full bloom stage , the second time application was at fruit diameter from 1.5-2.0 cm and (first and second time of application) for investigation their effects on fruit set, yield, fruit quality and splitting of 40-years-old Washington navel orange (Citrus Sinensis), trees budded on Sour Orange (Citrus aurantium, L.Osbeck) rootstock during 2008 and 2009 seasons. Data indicated that, all treatments increased fruit set, yield and fruit quality and decreased fruit splitting as compared with control treatment. Data also revealed that, foliar sprays of trees by (GA3 at 50 ppm) with or without 0.5% urea were superior for inducing the highest increase of fruit set and yield, in addition KNO3 at 4% comparing with 2% and 6%. Also, KNO3 treatments increased fruit size, peel thickness and juice acidity especially with high concentrations; on the other hand, the use of GA3 at 50 or 100 ppm alone or with 0.5% urea increased fruit T.S.S and reduced nitrite and nitrate contents in fruit juice as compared with KNO3 treatments. Moreover, it is noticed that trees sprayed at first application or first and second time of application gave the best results, while second application was the best for reducing fruit splitting.

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25 May 2023
Shade cloth over citrus

Mitigation of Heat Stress effects by using Shade Net on Washington Navel Orange Trees grown in Al-Nubaria Region, Egypt

High temperature stress can be detrimental to plants, resulting in reduced fruit yield and increased incidences of fruit disorders. One strategy that farmers can use to maintain or increase their yields in the face of a changing climate is to adjust of farm climate by using shade net on the trees. Such, the use of shade netting on Washington navel orange planted on the sandy soil in Al-Nubaria region, Egypt were studied during two successive seasons, either using a permanent shade throughout all the season or using a moveable shade for certain period from the first of March until the end of June for every season.

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23 Jan 2023
Effect of Manual Fruit Thinning on Yield and Fruit Quality of Clementine Mandarin

Effect of Manual Fruit Thinning on Yield and Fruit Quality of Clementine Mandarin

The effect of fruit thinning time and thinning rate on flowering, fruit yield and fruit quality of clementine trees (Citrus clementine Hort. ex Tanaka) was investigated during three successive seasons 2017/2018, 2018/2019 and 2019/2020. Data recorded only during 2018/2019 and 2019/2020 seasons. Thinning applied at three different times on 1st June, 15th June and 30th June. Fruit thinning rate were performed when the fruit diameter reached about 25-30 mm, as hand thinning by removing 0, 25 or 50% of fruit number/shoot per tree.

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25 Nov 2022
Fruit size in Star Ruby Grapefruit.

The usage of auxins with various cultural techniques to increase fruit size in Star Ruby Grapefruit

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.

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25 Nov 2022
Regulated deficit irrigation Clementina de Nules

Long-term response of ‘Clementina de Nules’ citrus trees to summer regulated deficit irrigation

Regulated deficit irrigation (RDI) has been assessed in a wide number of fruit crops. However, few are the studies dealing with long-term RDI strategies. In this work, we assessed the response of ‘Clementinade Nules’ citrus trees to summer RDI treatments [RDI-1, irrigated at 50% of crop evapotranspiration (ETc)and RDI-2, irrigated at 35% ETc] during six consecutive seasons (2007–2012). Although water restrictions were applied according to reductions over ETc, threshold values of stem water potential (−1.3 to −1.5 MPain the RDI-1 treatment and −1.5 to −1.7 MPa in the RDI-2) were also considered for scheduling deficitirrigation. Results showed that the water stress imposed in the RDI-2 treatment had a noticeable impacton fresh fruit weight, reducing yield and economic return over the six years and more so during the first two years in comparison to a control treatment irrigated at 100% ETc during the whole season. The RDI-1strategy had a lower impact than the RDI-2 treatment on the fresh fruit weight and did not significantly reduce yield or the economic return over the six seasons.

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