Fruit Physical Properties Research Articles

IMPROVING FRUIT QUALITY OF WONDERFUL POMEGRANATE BY USING FOLIAR APPLICATION OF POTASSIUM, IRON AND BORON

This study was carried out during 2017 and 2018 seasons, in order to investigate the effect of single and combined application of potassium sulphate (K2SO4), ferrous sulphate (FeSO4) and boric acid (H3BO3) on fruit physical, chemical properties and maturation of Wonderful pomegranate trees grown in sandy soil under Minia Governorate conditions. Results showed that increasing the concentration of K2SO4 from 0.5 to 1.5%, FeSO4 from 100 to 200 ppm or/and H3BO3 was very effective in fruit weight (g). While, the three examined compounds significantly decreased fruit cracked (%) and fruit sunburned (%) during the two experimental season. Application of the three examined compounds together significantly surpassed than untreated control or each compound alone terms of improved fruit physical and chemical properties, while, juice total acidity was significantly decreased. For producing favorable fruit physical properties of Wonderful pomegranate grown under sandy soil, it is necessary to spray the trees with mixture of potassium sulphate at 1.5%, ferrous sulphate at 200 ppm and boric acid at 100 ppm three times yearly during the fruit growth cycle.

Application of Arabic Gum and Essential Oils as the Postharvest Treatments of Le Conte Pear Fruits during Cold Storage

The present study was conducted during 2015 and 2016 seasons on Le Conte pear fruits harvested at mature stage, to investigate the application of (10% w/v) Arabic Gum (AG), Jojoba oil (JO) and Moringa oil (MO) at the rate (100 %) alone on physical and chemical properties. Fruits stored at 0 ± 1°C and 85-90 % relative humidity (RH) for 105 days. A fruit sample of each treatment was taken out at the end of cold storage period and left at room temperature (23 ± 2°C) and 47% (RH) up to 7 days was examined for quality Assessments. Fruit physical properties (weight loss, decay percentages and fruit firmness "Lb/inch2") and fruit chemical properties (total soluble solids percentage and total acidity percentage were evaluated. The results obtained that, all treatments including control succeeded in preventing fruit decay percentage up to 30 days in the two seasons. It is worth mentioning that, Le Conte pear fruits were coated with MO with stands free from deterioration up to 75 days of cold storage period. Beside, fruits coated MO progress in reducing the percentages of weight loss and decay throw cold storage periods for 105 day. The rate of softening increased in fruits with increasing the storage time in both fruits coated and uncoated, but it was significantly declined in uncoated treatments. Moreover, JO coating was more effective in firmness retention compared to the other treatments. Followed by pear fruits was coating with MO and AG in this respect. Furthermore, all coated fruits enhancement fruit quality during storage periods. Finally, it can be concluded that coating Le Conte fruits by Moringa oil recorded successfully reduction in fruit weight loss, decay percentages, improving fruit quality and extended storage fruit life as well as stimulate marketing period (shelf life), also safe on environmental and human health.

Impact of Sharka disease on tree growth, productivity and fruit quality of apricot (Prunus armeniaca L.)

In this study, the influence of Sharka disease, caused by Plum pox virus (PPV), on tree growth, yield attributes, financial losses, fruit physical properties, nutritive compounds, phenolic and flavonoid contents and antioxidant power was evaluated in a susceptible apricot (Prunus armeniaca L.) genotype. The results showed that Sharka significantly reduced tree growth, yield and economic results in PPV infected trees in comparison with PPV uninfected trees. The Sharka did not change fruit and stone weight and fruit shape, but significantly decreased flesh rate and flesh firmness. Soluble solids content (SSC) and titratable acidity (TA) were higher in symptomatic fruits, whereas ripening and sweetness index, sucrose and total sugars contents were smaller in fruits from PPV infected trees. Differences in content of invert sugars were not significant. Finally, PPV significantly reduced total phenolic (TPC) and total flavonoid contents (TFC) and total antioxidant capacity (TAC) in comparison with their contents in fruits from PPV uninfected trees.

Effect of Foliar Application some Plant Growth Regulators on Growth and Productivity of Olive Trees under South Egypt Conditions

This study was carried out through three successive seasons 2014 , 2015 and 2016 to study the effect of Salicylic acid at (200 &400 ppm) and Naphthalene acetic acid at (50& 100 ppm) as a foliar application on flowering, fruiting, yield and fruit quality of Picual and Manzanillo cvs olive trees (9 years old). Planted 6x6 apart at Horticultural Station Orchard at Shandaweel region, Sohag Governorate. The results indicated that foliar spray of salicylic acid at 200 ppm is recommended for improving productivity attributed to increase flowering percentage and density, as well as percentage of sex expression. Moreover, treatments reduced the alternative bearing and enhanced the fruit physical properties. Furthermore, each of two Salicylic acid concentration (200 & 400 ppm) improved fruit oil content.

Cultivar and fruit size influence bruise susceptibility and some physical properties of apple fruit.

ABSTRACT- For most fruit types, including apples, bruising is the most common type of postharvest mechanical injury. Bruise susceptibility was investigated in 3 commercial cultivars (‘JazzTM’, ‘Granny Smith’ and ‘Fuji’) and among a range of 4 different fruit sizes (commercial counts of 135, 120, 100, and 88) in each cultivar. Bruising was carried out by dropping a uniform round steel ball (110g) from a height of 30 cm through a vertical hollow PVC pipe onto the apples. Fruit physical properties and bruise assessments were evaluated. The results showed that ‘JazzTM’ and‘Granny Smith’ apples had the lowest and highest bruise susceptibility, respectively, indicating that ‘Granny Smith’ apple would be more likely to be bruised during harvest and post-harvest handling. Results also showed that smaller fruits were less susceptible to bruising. There was a positive significant correlation between fruit bruising and fruit volume; but, there were significant negative correlations between fruit bruising and fruit density, fruit firmness and fruit dry mater. These findings will be very useful to reduce the incidence of fruit damage of studied apple cultivars, which is of interest to both growers and operators of postharvest handling and marketing facilities.

Role of apple clonal rootstocks on yield, fruit size, nutritional value and antioxidant activity of ‘Red Chief ® Camspur’ cultivar

Abstract From 2007 to 2015 we investigated impact of three clonal rootstocks for apple (M.9 T337, M.4 and MM.106) on productivity, fruit physical and chemical properties of ‘Red Chief® Camspur’ cultivar under pedo-climatic conditions of Cacak (western Serbia). Results showed that tree vigour, yield per tree and per unit area, cumulative yield (CY) and yield efficiency (YE) significantly varied among rootstock. These parameters, with exception of YE were lower on M.9T337, and higher on M.4 and/or MM.106. YE was the lowest in M.4. Regarding fruit physical properties, we observed that all evaluated, except L/D ratio, significantly changed through rootstocks. Fruit weight and fruit linear dimensions (length and diameter), of above cultivar were higher and similar on M.4 and MM.106 then on M.9 T337. The MM.106 induced firmer fruits as compared with other both rootstocks. Soluble solids content (SSC) was the highest in whole fruits (pulp + peel) on M.4, and the lowest on M.9T337. In contrast, M.9 T337 induced higher titratable acidity (TA), total phenolic (TPC) and total flavonoid contents (TFC) and antioxidant power (TAC) in both pulp and peel than M.4 and MM.106 rootstocks, respectively. Ripening index (RI) was the highest on MM.106, and the lowest on M.9 T337. Otherwise, peel of this cultivar was better source of above compounds than pulp. Beside malic acid, in both pulp and peel, with exception of p-hidroxybenzoic and chlorogenic acids in peel, we detected other organic acids such as gallic, protocatechuic, p-hydroxybenzoic, caffeic and chlorogenic as a major and/or minor component.

Türkiye Muz Yetiştiriciliği İçin Yeni Bir Ekoloji

This study was conducted under the farmer greenhouses at Hassa province of Hatay where has being new production area with at Anamur province of Mersin where has been produced banana since long years. The cultivar of ‘Azman’ was used which knows more resistant to cold than other cultivars. The yield was founded by multiplying the bunch weight and the number of plant at each unit area. The analyses of mature fruit that belong to ‘Azman’ were done as fruit diameter, length, and weight, total soluble solid (TSS) content and peel color (L* C and Hueo). As a result, the yield was determined approximately 2 tones higher at Hassa condition for one decare. At the same experiment field, fruit physical properties such as fruit diameter, length, weight and TSS content were clearly found higher than the Anamur condition. Beside of cultivar practices, the higher economical yield and quality could be explained by doesn’t being soil exhaustion at Hassa where started newly production and does not reach the level which could being the problem aspect of special banana diseases and pest in here. The preliminary results were obtained positive about banana cultivation in this region, and it is needed to study more detailed with different cultivars.

A Comparative Study on Fertilization of Washington Navel Orange Trees

The effects of different soil application levels of Natural Elements Compound( NEC) either alone or in combination with EM soil application rates on Washington navel orange trees budded on sour orange rootstock grown under ''KarKashnda'' region, Qalyubeia Governorate condition to study their effects on some fruiting parameters and physical and chemical of fruit characteristics during the two successive seasons of 2013 and 2014. The obtained results revealed that all investigated treatments under study resulted in significantly increased in the most fruiting parameters and fruit characteristics as compared to the control treatment during the first and second seasons of experimental study. Moreover, data indicated that all studied treatments exhibited significantly increased fruit set % , yields either tree yield in kgs or yield expressed as tons per feddan. Furthermore, results displayed clearly that both studied fruit physical properties ( fruit weight, volume, height and diameter ) and fruit chemical characters such as TSS %, total acidity %, total sugers % and fruit juice vitamin C. contents were improved by subjected trees to different investigated treatments as compared with the control in the two experimental seasons of study. Generally, it could be concluded that , all investigated treatments under the study (NEC and EM ) either alone or in combination with them resulted in a significant and positive effects for increasing all fruiting parameters and improving most studied fruit quality. However, the treatment of (NEC4 x EM2) i.e. (6.0 kgs of NEC x 900 ml3/l of EM /tree /year) exhibited statistically the best and the most effect for increasing and improving all investigated fruiting parameters and fruit characteristics of Washington navel orange trees.

Associative learning of color and firmness of oviposition substrates in Drosophila suzukii

AbstractDrosophila suzukii Matsumura (Diptera: Drosophilidae), also known as the spotted‐wing drosophila, is a global pest fly. The degree of infestation of D. suzukii varies greatly among host plants, possibly depending on the physical properties of the fruits. Because some of the physical properties of fruits can only be judged by touching them, D. suzukii may choose to oviposit based on the physical properties of fruits and remote sensory information such as visual cues. Here, we conducted associative learning experiments with artificial substrates consisting of water, cornmeal, fructose, and agarose with different colors and firmness. We assessed associative learning by conditioning flies with combinations of two colors (purple or green) and degrees of firmness (firm or soft), and comparing their choice between the conditioned color and the other color afterward. We demonstrated that D. suzukii had an associative learning ability but it was limited to the association between green and soft. Drosophila suzukii conditioned with green and soft substrate preferred green as the first choice in the test phase. The proximate cause of this asymmetrical associative learning ability is completely unknown, but the pattern of learning coincides with D. suzukii's preference for immature fruits on the tree in nature, possibly to avoid competition with other fruit flies. The associative learning ability of D. suzukii was found to be limited to a certain combination of color and firmness. It suggests that the asymmetrical association of the natural fruit color and physical properties played a role in the evolution of color‐specific associative learning ability of D. suzukii.

Investigation of bound and free water in plant-based food material using NMR T 2 relaxometry

Plant-based food materials are porous and hygroscopic in nature; therefore, it contains three water environments, namely, intercellular, intracellular water and cell wall water. The intercellular water is known as capillary water or free water which is less constrained than intracellular water, considered as loosely bound water (LBW), and cell wall water, which is recognised as strongly bound (SBW). During food processing such as drying, frying, heating and cooking, optimisation of heat and mass transfer is crucial. The existing heat and mass transfer models for food processing are developed based on the concept that all of the water inside the food material is bulk water, which can act as free water that can be easily transported. This simplistic assumption has been made due to a lack of sufficient data to enable consideration of the proportion of free and bound water in plant-based food materials. Therefore, the aim of the present study is to investigate the proportion of different types of water such as free, LBW and SBW in 11 different plant-based food materials. The water proportion was investigated using 1H NMR T2 relaxometry. The experimental results uncovers that plant-based food materials contain about 80 to 92% LBW, 6 to 16% free water and only about 1 to 6% SBW. This investigation also confirms that among the five different fruits, kiwi contains the lowest percentage of LBW while Apple contains the highest percentage of LBW. Among the vegetables, eggplant comprises the largest amount of LBW while cucumber contains least amount of SBW. An attempt was made to establish a relationship between physical properties of fruits and vegetables and the proportion of the different types of water. Interestingly, it was found that SBW strongly depends on the proportion of solid in the sample tissue whereas FW depends on the porosity of the material.

ナス果実の調理前後の物性の品種・系統間差

ナス果実の調理前後の物性の品種・系統間差

Foliar Applications of Zinc and Boron on Fruit Set and Some Fruit Quality of Olive

The impact of foliar application of zinc and boron solutions on fruit set percentage, fruit physical properties and intake rate of the elements by leaf and fruit of three olive cultivars (‘Keylet’, ‘Coronaiki’ and ‘Mission’) were assessed. The spraying carried out twice at full bloom and 15 days later with zinc sulphate (2.5 kgm-3), boric acid (2.5 kgm-3) and the combination of these chemicals. The result indicated that the boric acid spray increased the initial fruit set (76.9%) while spraying with zinc sulphate + boric acid caused significant increase of final fruit set and number of fruit during the harvest (8.2% and 8%, respectively). The highest fruit length (2.08×10-2 m) was resulted from zinc sulphate application. No significant difference was observed between treatments on the fruit and pit length/diameter, length, diameter and weight of pit. Nutrient solution spraying significantly increased B and Zn concentration in leaf and fruit.

Foliar Applications of Zinc and Boron on Fruit Set and Some Fruit Quality of Olive

Foliar Applications of Zinc and Boron on Fruit Set and Some Fruit Quality of Olive The impact of foliar application of zinc and boron solutions on fruit set percentage, fruit physical properties and intake rate of the elements by leaf and fruit of three olive cultivars (‘Keylet’, ‘Coronaiki’ and ‘Mission’) were assessed. The spraying carried out twice at full bloom and 15 days later with zinc sulphate (2.5 kgm-3), boric acid (2.5 kgm-3) and the combination of these chemicals. The result indicated that the boric acid spray increased the initial fruit set (76.9%) while spraying with zinc sulphate + boric acid caused significant increase of final fruit set and number of fruit during the harvest (8.2% and 8%, respectively). The highest fruit length (2.08×10-2 m) was resulted from zinc sulphate application. No significant difference was observed between treatments on the fruit and pit length/diameter, length, diameter and weight of pit. Nutrient solution spraying significantly increased B and Zn concentration in leaf and fruit.. .

مدل سازی جرم و حجم لیمو ترش و بررسی روابط بین خصوصیات فیزیکی با استفاده از روش تحلیل مولفه اصلی (PCA)

مدل سازی ریاضی به منظور تخمین جرم لیموترش با استفاده از خصوصیات هندسی (ایعاد، حجم) و سطح تصویری صورت پذیرفت. مدل ها به صورت تک و چند پارامتری ایجاد شدند. همچنین خصوصیات فیزیکی لیموترش شامل ایعاد هندسی، جرم، حجم، دانسیته میوه و توده، ضریب اصطکاک و سطح تصویری میوه اندازه گیری شدند. سطح تصویری لیموترش با استفاده از تکنیک پردازش تصویر و در 3 بعد محاسبه گردید. در میان مدل های ساخته شده، مدلی بر مبنای3 بعد میوه، حجم محاسبه شده با استفاده از فرمول محاسبه حجم کره دوکی شکل و سطح سوم تصویری لیموترش با ضریب تبیین 909/.، 958/.، 942/. و خطای استاندارد تخمین 52/1، 19/1، 14/1 به ترتیب به عنوان مدلهایی مناسب جهت پیشگویی جرم لیموترش و مدلی بر مبنای 3 بعد میوه و سطح تصویری سوم لیمو ترش با ضریب تبیین 951/0 و 942/0 و خطای استاندارد 32/1 و 41/1 به ترتیب به عنوان مدلهای مناسب جهت تخمین حجم لیموترش پیشنهاد گردید. به منظور بررسی خصوصیات فیزیکی لیموترش و روابط بین آنها از روش تحلیل مولفه اصلی استفاده گردید. نتایج نشان دهنده وجود رابطه نزدیک میان سطوح اصطکاکی با یکدیگر و پارامتر های رنگی لیموترش می باشد.

Huanglongbing modifies quality components and flavonoid content of 'Valencia' oranges.

In order to evaluate the effect of citrus greening disease, or Huanglongbing (HLB), on quality components and flavonoid contents of 'Valencia' oranges, fruit from non-infected trees (control), from infected trees but symptom-less (asymptomatic) and from infected trees and showing clear HLB symptoms (symptomatic) were harvested in March and in May, 2013. Fruit peel, pulp and juice were separated, the main quality components were determined, and hesperidin, nobiletin, tangeretin, narirutin and didymin were quantified using liquid chromatography. Peel colour, total soluble solids and citric acid were similar in control and asymptomatic fruits. Symptomatic fruits were smaller, yielded less juice, had higher acidity and lower sugar and peel colour than control fruits. In the peel, hesperidin, nobiletin, tangeretin, narirutin and didymin were higher in symptomatic than in asymptomatic and control fruits. Peel flavonoids decreased with fruit maturation. Also, in pulp and juice, flavonoid content was higher in symptomatic than in asymptomatic and control fruits. These results show that asymptomatic fruits are similar to control fruits more than to symptomatic fruits, suggesting that secondary metabolism and physical properties of fruits are only affected at a later and more advanced stage of HLB infection. Despite the significant loss of quality, fruit with clear HLB symptoms accumulate high quantities of flavonoids in peel and pulp.

Model-Assisted Analysis of Spatial and Temporal Variations in Fruit Temperature and Transpiration Highlighting the Role of Fruit Development

Fruit physiology is strongly affected by both fruit temperature and water losses through transpiration. Fruit temperature and its transpiration vary with environmental factors and fruit characteristics. In line with previous studies, measurements of physical and thermal fruit properties were found to significantly vary between fruit tissues and maturity stages. To study the impact of these variations on fruit temperature and transpiration, a modelling approach was used. A physical model was developed to predict the spatial and temporal variations of fruit temperature and transpiration according to the spatial and temporal variations of environmental factors and thermal and physical fruit properties. Model predictions compared well to temperature measurements on mango fruits, making it possible to accurately simulate the daily temperature variations of the sunny and shaded sides of fruits. Model simulations indicated that fruit development induced an increase in both the temperature gradient within the fruit and fruit water losses, mainly due to fruit expansion. However, the evolution of fruit characteristics has only a very slight impact on the average temperature and the transpiration per surface unit. The importance of temperature and transpiration gradients highlighted in this study made it necessary to take spatial and temporal variations of environmental factors and fruit characteristics into account to model fruit physiology.

Physical properties of Rhus tripartium (Ucria) Grande fruits and seeds, indigenous of drylands Tunisia

In this study, some physical properties of fruit and seeds of R. tripartitum were determined in different provenances to know this species and see their morphological variations in arid regions of Tunisia. A highly significant difference between and within the site (0,000 <0,05 %) was found on the results of the ANOVA. Dimensions fruits vary from 4,892 (BH) to 6,705 (MM) mm long; 4,020 (BH) to 5,486 (MM) mm wide and 3,745 (BKH ) to 3,56 (BH ) thick. Sphericity ( ɸfr ) and area (Sfr) range from 0,842 (BH) 0,020 (MM) and 53,303 (BH) to 75,636 (MM ) mm ² respectively. Fruits from Matmata are heavier, while Djerba presented the lighter fruits. For seed sizes ranging from 3,750 (DJ) to 4,449 (MM) mm long, 2,676 (DJ) to 3,214 (MM) mm wide (lsmc) and 1,646 mm (BKH) to 0,970 (DJ) mm thickness (Esmc). Sphericity ( ɸsmc ) and area ( Ssmc ) range from 0,629 ( BKH ) to 0,569 (DJ) and 24,416 (BKH) to 14,267 (DJ) mm ² respectively. Drupes and seeds of R. tripartitum present the most important dimensions to mountain resorts (Matmata and Beni khedache) implying that this species favors high altitudes.

EFFECT OF FOLIAR SPRAY WITH GIBBERELLIC ACID AND AMCOTONE ON FRUIT SET, DROPPING, COMPONENT YIELD AND FRUIT QUALITY OF WASHINGTON NAVEL ORANGE TREES

The present study was carried out during 2007 and 2008 on 15 years old Washington navel orange trees (C. sinensis Osbeck) grafted on sour orange (C. aurantium L.) rootstocks. Trees were grown under north delta conditions. The results could be summarized in the following points: 1) The trees which sprayed with 100 g amcotone /100 L+ 20 ppm (GA3) gave the highest initial and final fruit set % and the lowest (June drop% and preharvest drop%) followed by the trees which sprayed with 50 g amcotone /100 L+ 20 ppm (GA3) which obtained the second order in this regard in both studied seasons. Also, there are no significant effects on number sprayed doses in this respect. 2) The trees which sprayed with 100 g amcotone /100 L+ 20 ppm (GA3) gave the highest {fruits number and yield (kg) /tree} followed by the trees which sprayed with 50 g amcotone /100 L+ 20 ppm (GA3) which possessed the second order in this regard in both seasons. Also, the trees which sprayed with three doses (mid-March, late April and the beginning of August) obtained the highest {fruits number and yield (kg) /tree}. 3) Fruit shape (H/D ratio) was the highest in trees which sprayed with100 g amcotone /100 L+ 20 ppm (GA3) followed by trees which sprayed with 100 g amcotone /100 L+ 15 ppm (GA3) with insignificant effect of three treatments. Whereas, non- significant effects of the number of doses . 4) Physical properties of fruits under this study as { fruit weight (g), fruit size (cm3) and fruit juice weight (g) } the highest values obtained in trees which sprayed with100 g amcotone /100 L+ 20 ppm (GA3) followed by 50 g amcotone /100 L+ 20 ppm (GA3).Moreover, trees which sprayed with three doses (mid-March, late April and the beginning of August) gave the highest values in this respect. 5) Regarding to the chemical properties of fruits which studied as ( T.S.S. %, total acidity % and Vitamin C mg/100 ml juice) the treatments which sprayed with100 g amcotone/100 L+ 20 ppm (GA3) gave the highest values followed by the trees which sprayed with 50 g amcotone /100 L+ 20 ppm (GA3) . Also, the trees which sprayed with three doses (mid-March, late April and the beginning of August) gave the highest values in this respect . 6) Trees which sprayed with Amcotone/100L+20 ppm GA3 treatment gave the highest values of T.S.S. /acid ratio with insignificant effect when compared with other treatments under this study. Moreover, trees which sprayed with three doses (mid-March, late April and the beginning of August) gave the highest T.S.S. / acid ratio. The recommendations: It could be recommended that spraying “Washington” navel orange trees with100 g amcotone /100 L+ 20 ppm (GA3) three times at (mid-March, late April and the beginning of August) gave the highest values of initial and final fruit set %, decrease of June and preharvest drop %, increase of yield as fruit number and weight (kg) /tree, improvement fruit physical and chemical properties as {fruit weight (g) and size (cm3) and fruit juice weight (g),TSS% , total acidity % ,Vitamin C. and TSS/Acid ratio }.

Basic physical properties of fruits in loquat (Eriobotrya Japonica (Thunb. Lindl.) cultivars and genotypes determined by both classical method and digital image processing

In this study, dimensions, mass and shape characteristics of five commercial loquat cultivars (‘Akko XIII’, ‘Champagne de Grasse’, ‘Guzelyurt 6’, ‘Hafifcukurgobek’ and ‘Sayda’) and two genotypes (‘KKTC3’ and ‘KKTC4’) were determined. Physical properties such as dimension and shape were determined both by digital caliper and image processing to compare each other. Among the cultivars and genotypes tested, ‘KKTC4’ (58.88 mm) had the highest length while ‘KKTC3’ had the highest major diameter, minor diameter, mass, geometric mean diameter, surface area and volume, with a mean of 46.31 mm, 43.61 mm, 60.12 g, 48.69 mm, 74.82 cm2, and 61.25 cm3, respectively. The greatest value of elongation and the smallest value of sphericity were obtained from ‘Akko XII’ with 1.33, and ‘Akko XII’ was more oblong than the other cultivars and genotypes. The smallest value of elongation and the greatest value of sphericity were obtained from ‘Sayda’ with 1.12 and 91.16%, respectively. The results of comparison between the digital caliper and image processing showed that using the image processing method could potentially be rapid and alternative to the conventional measurement method. Key words: Eriobotrya japonica, image processing, loquat, physical properties.

Physical Properties of Fruit and Seeds Ingested by Primate Seed Predators with Emphasis on Sakis and Bearded Sakis

Several primate radiations exhibit dental adaptations that enable them to gain access to seeds embedded in well-protected fruit. To a database drawn from published sources in which hardness of fruit and seeds were tested in the field, we added an additional 100+ species of plants used as resources by pitheciin primates (specifically, South American white-faced sakis (Pithecia pithecia) and bearded sakis (Chiropotes spp.). This sample allowed us to compare hardness of fruit and seeds and deduce the relative incisive and masticatory capability of several primate taxa (New World monkeys, Old World monkeys, prosimians and chimpanzees). Pitheciins have very well developed and highly modified anterior dentition that they use in gaining access to mechanically-protected fruit. In addition, their molars bear thin, but decussated enamel that protects the tooth enamel from crack proliferation. The ability of sakis (Chiropotes spp. and Pithecia pithecia) to open fruit orally was comparable to larger-bodied Old World seed predators-Lophocebus and Cercocebus. But, baboons and chimpanzees masticate seeds that are two to three orders of magnitude harder than sakis or mangabeys. In spite of their puncture abilities, ∼40% of foods ingested by pitheciins were in the range of a ripe fruit eater (Ateles paniscus). This raises the possibility that pitheciins exemplify Liem's paradox, that is, "that phenotypic specialization [is] not accompanied by ecological specialization" (Robinson and Wilson, 1998:224). Last, we examined the possibility that seeds may serve as fallback resources for primate seed predators. While pericarp hardness may vary seasonally for some seed predators (e.g., mangabeys), our data on bearded sakis and white-faced sakis suggest that seeds are their primary resources year round and pericarp hardness is unrelated to seasonal variation in rainfall. Pitheciins evolved specialized dentition that affords them access to relatively abundant and high-quality resources, a feeding strategy that results in minimal variation in resource availability seasonally.