Teso subregion in Eastern Uganda is a leading production hub for citrus in Uganda. However, information on fruit quality profile of the three major varieties (Hamlin, Valencia and Washington navel) grown in this regio...Teso subregion in Eastern Uganda is a leading production hub for citrus in Uganda. However, information on fruit quality profile of the three major varieties (Hamlin, Valencia and Washington navel) grown in this region was limited and/or unreported, partly resulting in their limited use for industrial processing. The current study sought to understand the seasonal quality profile of these varieties during the wet and dry seasons for the years 2019, 2022 and 2023. The study was conducted with farmers in the districts of Kumi, Ngora, Soroti and Kalaki. Mature green oranges were periodically harvested and analysed for physical and chemical properties. The results showed that the quality of oranges varied depending on the season at harvest and the variety with significant differences (p ≤ 0.05). Mean weight per fruit was highest in wet season Washington navel (277.5 g) and lowest in dry season Hamlin (149.3 g). Similarly, fruit size varied in the wet season where Washington navel (81.2 mm) had the biggest fruits while dry season Hamlin were smallest (66.6 mm). Dry season Washington navel had had the thickest peel (7.9 mm). Valencia from the wet season had the highest juice content (36.9%) compared to Washington navel (26.5%) from the dry season with the lowest. Titratable acidity was higher in the dry season Valencia (0.9%) compared to the wet season Washington navel and Hamlin (0.3%). Similarly, Total soluble solids (TSS) was higher in the dry season (Washington navel, 10.1 ˚Brix) in contrast to the wet season (Hamlin and Valencia, 7.7 ˚Brix). Valencia had the lowest pH (3.1) however, pH did not vary significantly between season for each variety except for Hamlin. Vitamin C content was higher during the dry season led by Valencia (57.6 mg/100g) and Hamlin (57.4 mg/100g). Sugar to acid ratio was highest during the wet season (Washington navel, 41.5) and lowest in the dry season (Valencia, 17.1). Overall, dry season fruits and more especially Valencia showed versatility in meeting most of the quality requirements for both industrial juice processing and the fresh market. However, there is need to improve the available orange varieties with regard to juice content and optimal sugar: acid ratio regardless of season.展开更多
[Objectives]This study was conducted to improve the water use efficiency and fruit quality of citrus,and realize the automatic irrigation and standardized production in citrus orchards.[Methods]With Orah as the resear...[Objectives]This study was conducted to improve the water use efficiency and fruit quality of citrus,and realize the automatic irrigation and standardized production in citrus orchards.[Methods]With Orah as the research object,the effects of intelligent irrigation management in citrus orchards on citrus leaf chlorophyll content,photosynthetic characteristics and fruit quality were investigated by comparing with conventional farmer management.[Results]The smart irrigation measure in citrus orchards significantly increased the SPAD value of leaves at the maturation stage of citrus,and simultaneously significantly improved the photosynthetic rate,transpiration rate and stomatal conductance at the flower bud differentiation stage,as well as the photosynthetic rate,transpiration rate,stomatal conductance and intercellular CO_(2) concentration at the maturation stage.However,the effects on the photosynthetic characteristic indexes in the rainy season were not significant.Compared with conventional experience management,the smart irrigation management measure of citrus orchards increased the edible rate and juice rate of citrus by 4.53 and 3.69 percentage points,respectively,and increased soluble solids,total sugar,vitamin C and sugar-acid ratio by 16.75%,20.86%,24.10%and 13.17%,respectively.[Conclusions]The smart irrigation management fully met the water demand for citrus growth due to timely irrigation,significantly improved the photosynthesis indicators of citrus leaves during drought,and significantly improved the quality of citrus.展开更多
文摘Teso subregion in Eastern Uganda is a leading production hub for citrus in Uganda. However, information on fruit quality profile of the three major varieties (Hamlin, Valencia and Washington navel) grown in this region was limited and/or unreported, partly resulting in their limited use for industrial processing. The current study sought to understand the seasonal quality profile of these varieties during the wet and dry seasons for the years 2019, 2022 and 2023. The study was conducted with farmers in the districts of Kumi, Ngora, Soroti and Kalaki. Mature green oranges were periodically harvested and analysed for physical and chemical properties. The results showed that the quality of oranges varied depending on the season at harvest and the variety with significant differences (p ≤ 0.05). Mean weight per fruit was highest in wet season Washington navel (277.5 g) and lowest in dry season Hamlin (149.3 g). Similarly, fruit size varied in the wet season where Washington navel (81.2 mm) had the biggest fruits while dry season Hamlin were smallest (66.6 mm). Dry season Washington navel had had the thickest peel (7.9 mm). Valencia from the wet season had the highest juice content (36.9%) compared to Washington navel (26.5%) from the dry season with the lowest. Titratable acidity was higher in the dry season Valencia (0.9%) compared to the wet season Washington navel and Hamlin (0.3%). Similarly, Total soluble solids (TSS) was higher in the dry season (Washington navel, 10.1 ˚Brix) in contrast to the wet season (Hamlin and Valencia, 7.7 ˚Brix). Valencia had the lowest pH (3.1) however, pH did not vary significantly between season for each variety except for Hamlin. Vitamin C content was higher during the dry season led by Valencia (57.6 mg/100g) and Hamlin (57.4 mg/100g). Sugar to acid ratio was highest during the wet season (Washington navel, 41.5) and lowest in the dry season (Valencia, 17.1). Overall, dry season fruits and more especially Valencia showed versatility in meeting most of the quality requirements for both industrial juice processing and the fresh market. However, there is need to improve the available orange varieties with regard to juice content and optimal sugar: acid ratio regardless of season.
基金Supported by Guangxi Key Research and Development Project(GK AB1850024)。
文摘[Objectives]This study was conducted to improve the water use efficiency and fruit quality of citrus,and realize the automatic irrigation and standardized production in citrus orchards.[Methods]With Orah as the research object,the effects of intelligent irrigation management in citrus orchards on citrus leaf chlorophyll content,photosynthetic characteristics and fruit quality were investigated by comparing with conventional farmer management.[Results]The smart irrigation measure in citrus orchards significantly increased the SPAD value of leaves at the maturation stage of citrus,and simultaneously significantly improved the photosynthetic rate,transpiration rate and stomatal conductance at the flower bud differentiation stage,as well as the photosynthetic rate,transpiration rate,stomatal conductance and intercellular CO_(2) concentration at the maturation stage.However,the effects on the photosynthetic characteristic indexes in the rainy season were not significant.Compared with conventional experience management,the smart irrigation management measure of citrus orchards increased the edible rate and juice rate of citrus by 4.53 and 3.69 percentage points,respectively,and increased soluble solids,total sugar,vitamin C and sugar-acid ratio by 16.75%,20.86%,24.10%and 13.17%,respectively.[Conclusions]The smart irrigation management fully met the water demand for citrus growth due to timely irrigation,significantly improved the photosynthesis indicators of citrus leaves during drought,and significantly improved the quality of citrus.
