Purified endo-β-1,4-mannanase from Bacillus sp. enhances fruit juice clarity and yield with minimal effect on antioxidant properties

The effects of 2 consecutive years of annual defoliation during the harvest season on fruit size, yield, juice quality, leaf size and number were examined in trees of the midseason cultivar `Hamlin' and the late-season cultivar `Valencia' orange [Citrus sinensis (L.) Osb.]. In `Hamlin', removal of up to 50% of the leaves in late November had no effect on fruit yield, fruit number, fruit size, soluble solids yield, juice °Brix, and °Brix to acid ratio of juice the following year. In `Valencia', removal of 50% of the leaves in late March decreased fruit yield and soluble solids yield but did not affect Brix or the Brix to acid ratio of the juice. Leaf size of new flush was reduced by removal of 50% of the leaves in both cultivars but there was little effect on total canopy size. There were no measured effects of removing 25% of leaves from tree canopies. Thus, canopy growth, fruit yield, fruit quality, and leaf size were not negatively impacted when annual defoliations did not exceed 25% of the total canopy leaf area in `Valencia' and `Hamlin' orange trees for two consecutive years. Overall, fruit weight increased linearly with increasing ratio of leaf area to fruit number, suggesting that fruit enlargement can be limited by leaf area.

The interactive effects of CO2 elevation, N fertilization, and reduced irrigation regimes on fruit yield (FY) and quality in tomato (Solanum lycopersicum L.) were investigated in a split-root pot experiment. The plants were grown in two separate climate-controlled greenhouse cells at atmospheric [CO2] of 400 and 800 ppm, respectively. In each cell, the plants were fertilized at either 100 or 200 mg N kg-1 soil and were either irrigated to full water holding capacity [i.e., a volumetric soil water content of 18%; full irrigation (FI)], or using 70% water of FI to the whole pot [deficit irrigation (DI)] or alternately to only half of the pot [partial root-zone irrigation (PRI)]. The yield and fruit quality attributes mainly from sugars (sucrose, fructose, and glucose) and organic acids (OAs; citric acid and malic acid) to various ionic (NH4+, K+, Mg2+, Ca2+, NO3-, SO42-, and PO43-) concentrations in fruit juice were determined. The results indicated that lower N supply reduced fruit number and yield, whereas it enhanced some of the quality attributes of fruit as indicated by greater firmness and higher concentrations of sugars and OAs. Elevated [CO2] (e[CO2]) attenuated the negative influence of reduced irrigation (DI and PRI) on FY. Principal component analysis revealed that the reduced irrigation regimes, especially PRI, in combination with e[CO2] could synergistically improve the comprehensive quality of tomato fruits at high N supply. These findings provide useful knowledge for sustaining tomato FY and quality in a future drier and CO2-enriched environment.

Peach fruit is enriched with natural antioxidants but oxidation caused by biotic and abiotic stresses, reduce these antioxidants and consequently effect the quality and yield of the fruit. Therefore, an experiment was conducted to investigate the role of ascorbic acid to sustain the natural antioxidant activity, improve the fruit quality and yield of peach cultivars (Early Grand and Florida King). The peach cultivars, Early Grand and Florida King were tested against four levels of ascorbic acid (200, 400, 600 and 800 ppm) and compared with control as water spray. The foliar application of ascorbic acid significantly influenced anti-oxidant activity and physico-chemical attributes of peach cultivars. However, the foliar application of ascorbic acid @ 800 ppm significantly increased the fruit weight, fruit yield, fruit firmness, total soluble solids, titratable acidity, antioxidant activity of fruit peel, with least percent infected fruits and fruit juice pH as compared to the rest of the treatments. Similarly, significant variation was recorded for peach cultivars regarding anti-oxidant activity and various physico-chemical attributes. The maximum fruit weight, fruit yield, fruit firmness, total soluble solids, titratable acidity and TSS/TA ratio were noted in fruit of cultivar Florida King. On other side the foliar treated fruit of peach cultivar Early Grand had the highest percent infected fruits, fruit juice pH and antioxidant activity of fruit peel. It is concluded from the significant findings of present research that the peach cultivar Florida King performed better in terms of maximum fruit yield, whereas the cultivar Early Grand produced better quality fruits with high anti-oxidant activity when treated with 800 ppm of ascorbic acid as foliar spray.

1. Field experiments were carried out to study about the influence of irrigation on the fruit yield, quality and the content of mineral nutrients in spring leaves of mature Satsuma orange trees grown in steeply sloping citrus groves during seven years from 1965 to 1971.2. The effects of irrigation on the fruit growth and yield were greatly varied by year, and were especially remarkable in 1967 because of long drought, that is, fruit growth was much superior and the number of L, M fruits was greatly increased in the irrigated trees.The average increase during seven years by irrigation were 30.6 percent in yield, 6.7 percent in fruit weight and 19.2 percent in fruit size.3. The contents of soluble solids and citric acid of fruit juice were greatly changed by year both in the irrigated and non-irrigated trees, but generally those in the irrigated trees were lower than in the non-irrigated trees. While the ratio of soluble solids to acid was higher in the irrigated trees.In the average of seven years′ results, the contents of soluble solids and citric acid in the irrigated trees were lower by 0.8 percent and 0.21 percent than the non-irrigated trees, respectively.4. Only in 1967, phosphorous and calcium contents of spring leaves were increased by irrigation, while potassium content was decreased. In the average of seven years′ result, magnesium content was found to be lower in the irrigated trees.

The partial loss or reduction of leaf area is a wide-spread occurrence in the plant life cycle, caused e.g. by herbivory, stress or pathogen attack. The objective of the study was to evaluate the effect of partial defoliation on fruit production and quality in strawberry (Fragaria ×ananassa Duch. cv. Chandler). Plants were grown in a greenhouse in Tunja, Colombia, in hydroponics with an aerated nutrient solution. As leaves emerged, one or two leaflets were removed from each compound leaf, to attain 38 % and 67 % reduction of leaf area. Control plants grew intact, without defoliation. Fruit yield and fruit quality characteristics were evaluated for each plant. The pH, total soluble solids, ratio of total soluble solids to fruit juice acidity, fruit yield, fruit mass and size, and the ratio of leaf area/fruit yield were reduced drastically in defoliated plants. Leaf area reduction in excess of 38 % adversely affected physical and chemical characteristics of strawberry fruit, which did not meet marketing criteria.

چکیده به منظور بررسی تاثیر مقادیر مختلف نیتروژن، منگنز و روی بر عملکرد و کیفیت میوه انار، آزمایشی به صورت فاکتوریل بر پایه طرح بلوکهای کامل تصادفی با 3 تکرار و 18تیمار در یک مزرعه آزمایشی در شهرستان بهشهر در سال زراعی 1388 به مرحله اجرا گذاشته شد. تیمارهای مورد بررسی عبارت بودند از: نیتروژن (N)، منگنز (Mn) و روی (Zn). نیتروژن از منبع کودی اوره در سه سطح (صفر،544 و 1087گرم اوره) و منگنز از منبع کودی سولفات منگنز در سه سطح (صفر،100و200گرم سولفات منگنز) و روی از منبع کودی سولفات روی در دو سطح (صفر و 150گرم سولفات روی) برای هر درخت در نظر گرفته شد. تمامی کودهای سولفات منگنز و سولفات روی همراه با کود اوره در اسفند ماه قبل از بازشدن جوانه های گل به صورت خاکی مصرف گردید. اوره باقیمانده در دو نوبت دیگر در مرحله ریزش گلبرگها و یک ماه بعد از مرحله دوم مصرف شد. صفات مورد اندازه گیری در این تحقیق عبارت بودند از: عملکرد میوه، تعداد میوه، میانگین وزن تک میوه، درصد اسیدیته قابل تیتراسیون و نسبت وزن گوشت به آب میوه. نتایج تجزیه واریانس نشان داد که با مصرف اوره تفاوت معنی داری در عملکرد، تعداد میوه در هر درخت، میانگین وزن تک میوه، درصد اسیدیته قابل تیتراسیون و نسبت وزن گوشت به آب مشاهده شد. ولی با مصرف سولفات منگنز به جز در نسبت وزن گوشت به آب میوه تاثیر معنی داری بر بقیه صفات مشاهده نشد. اثر اصلی سطوح مختلف روی بر عملکرد، تعداد میوه و درصد اسیدیته قابل تیتراسیون معنی دار بود. بیشترین میزان عملکرد میوه به میزان 93/53 کیلوگرم در هر درخت با مصرف 1087گرم اوره برای هر درخت حاصل گردید. با کاربرد 150گرم سولفات روی، حداکثر تعداد میوه به میزان 445 عدد و با مصرف 200گرم سولفات منگنز بیشترین نسبت وزن گوشت به آب میوه به میزان 3/1بدست آمد. با مصرف اوره و سولفات روی وزن تک میوه نسبت به شاهد کاهش یافت ولی بر تعداد میوه در هر درخت افزوده شد. اثر متقابل فاکتور نیتروژن و منگنز و نیتروژن و روی بر تمام صفات به جز میزان اسیدیته قابل تیتراسیون معنی دار بود. حداکثر نسبت وزن گوشت به آب میوه با مصرف توام 200 گرم سولفات منگنز و 150 گرم سولفات روی بدست آمد. ولی اثر متقابل منگنز و روی فقط بر نسبت وزن گوشت به آب میوه در سطح احتمال یک درصد معنی دار بود. بالاترین میزان عملکرد و تعداد میوه به ترتیب به میزان 43/63 کیلوگرم در هر درخت و 500 عدد با مصرف توأم 1087 گرم اوره و 100 گرم سولفات منگنز بدست آمد. بهترین تیمار برای بدست آوردن بالاترین عملکرد و تعداد میوه 1087 گرم اوره، 100 گرم سولفات منگنز و 150 گرم سولفات روی برای هر درخت بود. واژه های کلیدی: انار، اوره، سولفات منگنز، سولفات روی، عملکرد، کیفیت میوه

Introduction: North of the Khouzestan is one of the most important citrus production center. Usually border irrigation is used to irrigate citrus in this area. This system has generally low application efficiency. Several investigations in other arid region have demonstrated in addition to improved irrigation efficiency with low-volume pressurized irrigation systems, citrus trees have adapted with these new irrigation systems. However limited information exists on the performance of mature orchards converted from border surface irrigation to pressurized irrigation systems. Therefore, the current research was conducted to evaluate the feasibility of converting surface irrigation to pressurized irrigation systems on mature citrus trees in climate conditions of North Khouzestan. Materials and Methods: This study was conducted during three years at Safiabad Agricultural Research Center to evaluate the yield of citrus trees and the quality of fruits for two Marss and Valencia varieties which grow 7 years previously with surface irrigation and converted to pressurized irrigation systems. The treatments consisted of six irrigation methods including Overhead sprinkle irrigation (OHSI), Under tree sprinkle irrigation(UTSI), Trickle irrigation(TI)(six 8 L/h Netafim emitters), Microjet irrigation (MI)(two 180 microjet were located under canopy near of the trunk at opposite sides of trunk),Bubbler irrigation(BI)(a single located under the canopy of each tree)andSurface irrigation(SI) method.Soil texture was clay loam well drained without salinity(ECe=0.69ds m-1), with 1.25 percent organic carbon. The experimental design was completely randomized design. The trees were irrigated during spring and summer seasons. For calculating irrigation water depth in TI, MI and BI systems, daily evaporation from a class A evaporation pan of the Safiabad weather station (nearby the experimental field) was collected, and evapotranspiration of the citrus trees was calculated applying a pan coefficient of 0.8. During the growth season, soil moisture content was measured before irrigation in root zone depth using weighing method at two points of the beginning and the end of the garden to obtain an average showing changes of the field moisture content. Applied water were measured with flow meter for OHSI, UTSI,TI, MI and BI methods and WSC flume for SI treatment. In middle January after fruit ripening, fruit yield was determined by harvesting all the fruits from six trees located in the center of each plot. Weight of fruits from every tree was recorded. Then, 3kilogram fruits per tree were randomly separated and peel thickness, diameter, weight, juice solid percent, total dissolved solids(TSS) and Citric acid were measured. Results Discussion: The annual precipitation was 385,345, and 336 mm for 2004, 2005, and 2006 years, respectively. The mean temperature of June, July and August (the warmest months) for 2004, 2005, and 2006 was 45.6, 45.2 and 45.8°C. Higher temperature in third year caused to increase heat stress, so fruit yield decreased. Irrigation water consumption in OHSI and UTSI were among 15000 to 17000 m3ha-1. Continues contact of irrigation water contacting with leaves in OHSI causes the accumulation of salts on the leaf surface and leaf drop in harvest season. Consumed water in BI, MI and TI compared with SI method reduced by as much as 48.6%, 57.2%, and 58.4%, respectively. Because soil wetted area in BI, MI and TI methods were low and about 30 to 50 percent of soil area. There were significant differences in citrus yield, water use efficiency (WUE) and quality in 1% and 5%, so that comparison of means in Mars variety showed that the yield of trees in TI and SI methods were significantly higher than UTSI method. On the other hand, fruit yield was similar in OHSI, MI, TI and SI methods. Valencia variety fruit yield was similar for in BI, MI, TI and SI methods in all 3 years, and significantly more than OHSI and UTSI although BI, MI, TI used only 48% to 58% of irrigation water compared with SI method. WUE under BI, MI and TI methods was enhanced by 2 to 3 times more than SI,OHSI and UTSI methods because consumed water decreased in BI, MI and TI about 50%. Fruit size and fruit weight of Marss variety in the OHSI and fruit size and fruit weight of Valencia variety in the OHSI, MI and SI were better than other systems and had a significant difference in 1% probability. Conclusion: Overall results of this study indicated that it is possible to convert SI to BI, MI and TI methods in northern khouzestan orchards without decreasing in fruit yield and quality of citrus trees. Salt accumulation on leaf surface in OHSI method was caused to drop leaves in harvest season.

Deficit irrigation effect on fruit yield, quality and water use efficiency: A long-term study on Pêra-IAC sweet orange

A large number of biotic and abiotic factors are responsible for decline and low fruit yield both in quantity and quality observed in the citrus across the YSR district, hence the present study was conducted to determine the effect of soil physicochemical properties on fruit yield and quality of sweet orange (Citrus sinensis (L.) Osbeck) in YSR district of Andhra Pradesh, India. To carry out this investigation 50 sweet orange orchards aged between 12 to 13 years were selected. Soil samples were collected from 0–30 and 3060 cm depth of the orchards, and analyzed for physicochemical properties. Determined soil parameters like pH, free CaCO3, sodium adsorption ratio (SAR), exchangeable sodium percentage (ESP), organic C, and assessed the impact of these properties on fruit yield and quality of sweet orange. Results indicated that soil pH (r = -0.512**), free CaCO3 (r = -0.329*), SAR (r = -0.424**) and ESP (r = -0.522**) were influenced the fruit yield negatively significantly. Fruit yield (r = 0.360*) and fruit weight (r = 0.330*) was positively and significantly influenced by soil organic C content. Soil pH, SAR and ESP showed a significant negative relation with per cent fruit juice and vitamin C, whereas soil CEC had significant positive correlation with total soluble solids (r = 0.366**) and vitamin C (r = 0.364**) content of the fruit juice.

Peach fruit and trees are prone to various issues, regarding yield, quality and pest attack. Calcium plays several roles in plant and fruit development. Therefore the current study was conducted to evaluate the response of peach fruit to foliar application. The experiment was laid out in Randomized Complete Block Design with two factors factorial arrangement and three replicates. Calcium chloride was applied at the rate of 0, 1, 2 and 3%. The foliar application of calcium was done at pink bud stage, berry size fruit stage, and then at pit hardening stage of peach. The obtained resulted indicated that foliar application of calcium significantly improved peach fruit quality and yield. The highest fruit weight (142.6 g), yield tree–1 (15.6 kg), ascorbic acid content (6.67 mg‧100 g–1), total soluble solids (11.0°Bx), fruit juice pH (3.98), sugar to acid ratio (45.1), fruit firmness (3.90 kg‧cm–2) and fruit volume (155.6 cm3) was obtained with the application of 3% solution of calcium chloride at pit hardening stage but it significantly reduced the percent titratable acidity (0.3%) and disease incidence (5.8%). It was concluded that 3% calcium chloride applied at the pit hardening stage significantly boosted peach quality and fruit yield.

Water and nutrient-useefficiency, both are considered as pre-requisites for sustained citrus productivity. The interactive effect of irrigation and fertigation levels on growth, yield and quality of 11-year-old Nagpur mandarin (Citrus reticulata Blanco) was studied through a field experiment during 2010-13 at ICAR-Central Citrus Research Institute (Formerly NRCC), Nagpur under AICRP Fruits. The experiment was laid out in split-plot design with nine treatment combinations, comprising three irrigation levels (70 %, 80 % and 90 % of daily evaporation replenishment) and three fertigation levels (60 %, 70 % and 80 % RDF based NPK doses) replicated six times. Canopy volume (74.9 m3) and fruit yield (19.2 tonnes/ha) were observed maximum with the drip irrigation scheduled at 80 % ER combined with 80 % RDF fertigation. The fruit quality parameters, such as fruit weight (129.2 g), juice percentage (45.05 %), TSS (10.27o Brix) and lowest acidity (0.81) were observed favorable with irrigation at 80% and fertigation at 80% RDF, in addition to maximum nutrient concentration in index leaves ( 2.38 % N, 0.12 % P and 1.50 % K) duly supported by changes in available pool of nutrients in soil (123.8 mg/kg N, 14.8 mg/kg P2O5 and 261.2 mg/kg K2O). Interestingly yield efficiency computed as fruit yield per unit canopy volume was also observed maximum (0.26) with treatment carrying irrigation at 80% ER and fertigation with 80% RDF. The sustained productivity of Nagpur mandarin can be achieved with irrigation scheduled at 80 % ER along with fertigation technology at 80 % RDF without any potential nutrient mining.

The effect of annual defoliation over two consecutive years on fruit yield, juice quality, leaf size, and number was examined in 11-year-old `Hamlin' and 13-year-old `Valencia' orange [Citrus sinensis (L.) Osb.] trees. Removal of up to 50% of the leaves in late November had no effect on fruit number, fruit weight, fruit yield, soluble solids yield, juice °Brix, and °Brix: acid ratio of juice in `Hamlin' oranges. In `Valencia' oranges, removal of up to 50% of the leaves in late March also did not affect °Brix or the °Brix: acid ratio of the juice, but decreased fruit yield and soluble solids yield. Leaf size was reduced by removal of 50% of the leaves in both cultivars. Removal of up to 50% leaves in late November had no significant influence on net CO2 assimilation (aCO2) of the subsequent spring flush leaves in early May in `Hamlin' oranges, whereas aCO2 of `Valencia' spring flush leaves in early May increased linearly with increasing levels of defoliation in late March. The results indicate that fruit yield, fruit quality, leaf size, and number were not negatively impacted when annual defoliations did not exceed 25% of the total canopy leaf area for `Valencia' and `Hamlin' oranges for two consecutive years. Overall, in whole `Hamlin' or `Valencia' orange trees, fruit weight increased linearly with increasing ratio of leaf area to fruit, suggesting that fruit enlargement depends on available photosynthate and can be limited by leaf area.

Pruning is an essential practice that helps control branch growth, optimize fruit size, and enhance fruit tree productivity. This study focused on ‘Valencia’ orange trees, which had experienced a decline in productivity after being cultivated on reclaimed lands for several years. The aim was to explore the impact of pruning intensity on vegetation growth, fruit yield, productivity, and fruit quality in these orange trees. The study involved 35-year-old ‘Valencia’ orange trees, which were subjected to four different levels of pruning. The pruning treatments included: T1—no pruning (control group), T2—light pruning (removal of 25% of main branches), T3—moderate pruning (removal of 50% of main branches), and T4—heavy pruning (removal of 75% of main branches). Each season, these pruning measures were consistently carried out on 15 February. The results indicated that the severity of pruning directly influenced vegetative growth parameters, such as shoot length and leaf area. As the pruning intensity increased, so did the growth of the vegetation. However, the overall volume of the tree’s canopy decreased compared to the control group. These findings provide insights into the relationship between pruning practices and the growth and productivity of ‘Valencia’ orange trees. The highest fruit yields were observed when pruning was carried out at a severity level of 75%, followed by 50 and 25%. These pruning treatments had a positive impact on various aspects of fruit quality, including weight, size, firmness, juice content, TSS (°Brix), TSS/acid ratio, and vitamin C content. Additionally, pruning contributed to a greater fruit yield per tree and an overall increase in the yield percentage. In essence, the findings suggest that pruning performed at different severity levels in February effectively promotes vegetation growth and enhances the physical and chemical properties of ‘Valencia’ orange trees. Notably, it resulted in a nearly 20% rise in fruit yield compared to the control group.

The experiment on N. P and K requirements for pineapple growing were conducted duing the periods of 1955 to 1957 at Chiayi and Fengshan and 1960 to 1961 at Changhua. The results of the experients have summerized as follows: (1) Effects on the yield of pineapple fruits Nitrogen has significant effect on the yield of the fruit in generall, The yield of the fruit has been increased as much as 32~440% at changhua and Fengshan where Nitragen seems to have more significant effect. Potassium and Phosphorous have no significant effects in increasing the yield of the fruit. (2) Effects on quality of the fruits The application of Nitrogen has increased the contents of reducing sugar and total sugar in the fruit as well as promoted the color of the flesh. Nitrogen seems to reduce the acidity of the juice and improve the taste of the flesh. Potassium application tends to increase the content of total sugar in the fruit but the application of phosphorous lose flavor of the flesh. It has been considered that the application of proper amounts of N and K is needed for improving quality of pineapple fruit. (3) Optimum requirements of N. P and K for pineapple growing Based on the results of the experients. the following aptimum requirements of N. P. and K has been suggested. (The form abridges)

ABSTRACTHigher demands for improved fruit yield and processing qualities for Tomato (Solanum lycopersicum L.) could be met through heterosis breeding. It is important to identify the parental line combination performing better for economically important quality traits. The experiment was composed of seven tomato inbred lines (two processing and five fresh market) and 21 F1 hybrids produced by crossing of them in a 7 × 7 half-diallel fashion. The nature and type of gene actions were analyzed to determine how they were involved in inheritance of fruit per plant, yield per plant, average fruit weight, total soluble solids, fruit juice pH, titratable acidity, sugar acid ratio, fruit juice content, shape index, and pericarp thickness. Most characters were predominantly controlled by nonadditive gene actions. Employing hybrid breeding for improving characters could be effective. The crosses ‘Metadel × Marglobe’, ‘Bishola × CLN2037E’, ‘Roma VF × ARP Tomato d2’, ‘Roma VF × CLN2037E’, ‘ARP Tomato d2 × Marglobe’, and ‘Eshete × CLN2037E’ showed positive and highly significant specific combining ability (SCA) effects for number of fruit per plant and fruit yield per plant. This indicated that the crosses could be used for developing high-yielding varieties. The crosses ‘Metadel × Roma VF’, ‘Bishola × Roma VF’, ‘Roma VF × Eshete’, and ‘ARP Tomato d2 × Marglobe’ exhibited positive, significant SCA effects for total soluble solids and negative, significant SCA effects for fruit juice pH. These crosses could be utilized as hybrids with better processing qualities. The crosses ‘Metadel × Marglobe’, ‘Bishola × Eshete’, ‘ARP Tomato d2 × CLN2037E’, and ‘Eshete × Marglobe’ exhibited positive, highly significant SCA effects for sugar-to-acid ratio, indicating that they could be used in hybridization for developing lines with better fruit flavor.