Small Fruits Research Articles

Improving postharvest life, quality and bioactive compounds of strawberry fruits using spermine and spermidine.

Small fruits such as strawberries, are a good source of natural antioxidants. In recent decades, many efforts have been made to increase the shelf life of strawberries and maintain its nutritional value in post-harvest conditions. In the present study, the effects of spermine (Spm) and spermidine (Spd) (0, 1.0 and 1.5 mM) on the post-harvest life and quality of strawberry fruits during the 3rd, 6th, and 12th days of storage, were investigated. Applications of Spm and Spd decreased the rate of weight loss, fruit decay, soluble solids content, fruit juice pH and taste index during the storage period in compared to the control. However, titratable acids and vitamin C contents, tissue stiffness, phenolic compounds and antioxidant activity increased in compared to the control. These growth regulators prevented the aging and loss of bioactive compounds of the fruit by increasing the antioxidant activity and preventing the destruction of the fruit tissue. Among the studied treatments, applications of 1.5 mM of Spm and Spd were the most effective treatments to enhance the storage life and quality characters of strawberry fruits.

NEW VARIETIES OF APPLES WITH GENETIC DISEASE RESISTANCE, OBTAINED AT VOINESTI DEVELOPMENT RESEARCH STATION FOR FRUIT GROWING

The research carried out at Voinesti research-development station for fruit growing, considered highlighting the performance characteristics of some apple varieties with genetic resistance to diseases, approved in the period 2004 - 2020.
 The vigour of growth in the 10th year of the trees, grafted on the M.9 rootstock, is well defined by the trunk circumference, which records values between 14.9cm for the Cezar variety and 18.4cm for the Redix variety. The volume of the crown calculated per surface unit, at the plot of 2,857 trees/ha, was 6,520 mc/ha for the Brumar variety, being of low-medium vigour, and 8,800 mc/ha for the Redix varieties, being more vigorous.
 The productivity during the full fruiting period of the 10 apple varieties with genetic resistance to diseases, cultivated in a high density system, was between 28 - 45t/ha, the most productive being the Iris, Real, Remar, Valery, Brumar and Cezar varieties with productions of over 35 t/ha. The biomass of the fruits was between 155 and 180g, smaller fruits being recorded in the varieties Iris, Inedit, Voinicel and Revidar and larger in the varieties Cezar, Valery, Remar and Redix with fruits over 170g that correspond to market requirements. The apple varieties approved at SCDP Voinesti between 2004 and 2020 meet the demands of the producer, sensitive to economic efficiency, with high production potential, with quality fruits, which will certainly meet the ever-growing consumer demands.

Uticaj distribucije veličine i zrelosti na neke fizičke i mehaničke osobine plodova voća Spondias mombin

The effect of size distribution and ripeness on some properties of Spondias mombin fruits was investigated in this study. The mean length of a ripe small, medium, and large Spondias mombin fruit is 27.3, 35.2, and 38.5 mm, respectively. Also, the width and thickness varied from 19.9 to 29.9 mm and 19.2 to 30.0 mm, respectively. In half-ripe fruits, the length, width, and thickness for small, medium, and large size distribution also varied from 28.2 to 38.7 mm; 20.9 to 28.9 mm and 19.6 to 28.7 mm, respectively. The length of the unripe small, medium, and large sized fruits was 28.1, 35.1, and 38.9 mm, respectively. The width and thickness increased from 21.8 to 29.2 mm and 20.6 to 29.2 mm, respectively. As the size increased from small to large, the moisture content increased in each case for the three conditions of ripeness. The sphericity and bulk density of the fruit increased with the sizes and ripeness of the fruits. The effect of size and degree of ripeness on physical properties was significant. An increase in size and change in orientation increased compressive strain, with the highest being 0.169 at the large size and longitudinal position. The highest compressive stress of the fruit was observed as 9.00 N/mm 2 when in a transverse position. The energy required for breaking the fruit was highest (2.5 J) in a longitudinal orientation. The effect of size, degree of ripeness, and orientation of the fruit on the compressive properties were significant.

Virusi i viroidi kruške

One of the most common fruit species in the world is the pears. Compared to stone and small fruit trees, pears and other pome fruits are infected by a lesser number of viruses and viroids. The majority of commercial pear cultivars do not exhibit symptoms on their leaves, fruits, or other plant parts due to viruses. Only foliage and fruits show symptoms in susceptible cultivars. Apple stem pitting virus (ASPV), apple stem grooving virus (ASGV), apple chlorotic leafspot virus (ACLSV), and apple mosaic virus (ApMV) are widespread and economically significant pear viruses. Pear blister canker viroid (PBCVd) and apple scar skin viroid (ASSVd) are the most dangerous viroids infecting pears.

Desempenho de cultivares de pimenta, baseado em caracteres de frutos, para consumo in natura

ABSTRACT Different studies report that pepper fruit cuticle and pericarp thickness vary among marked cultivars and these variations likely influence many fruit quality traits, especially water loss rates. Thus, the objectives of this work was to evaluate the fresh market performance of pepper cultivars based on fruit traits, and indicate the cultivars of Capsicum spp. with less probability of post harvest water loss. Pepper fruits, belonging to C. chinense, C. frutescens and C. baccatum species, were collected in an experimental area at Bonfim’s settlement, Alagoinha, Paraíba, Brazil. After harvest, fruits were taken to the laboratory of biotechnology at Centro de Ciências Agrárias of the Universidade Federal da Paraíba. Fruits were characterized according to pericarp thickness, fruit weight, and fruit length, larger and smaller fruit diameter. The experimental design was completely randomized with eight treatments and four repetitions. Analysis of variance, mean test, heritability, and ratio of coefficient of genetic variation by coefficient of environmental variation, genotypic and environmental correlation, and Tocher’s grouping method were performed. The cultivar habanero vermelha had better performance for fruit weight and larger and smaller fruit diameter. On the other hand ‘dedo de moça’ presented the longest fruits and major pericarp thickness. These two cultivars also belonged to different groups based on Tocher’s method. The genetic correlation between pericarp thickness and fruit weight was high (0.70) and highly significant. Fruit wall thickness also presented highly significant genotypic correlation with larger fruit diameter (0.93) and small fruit diameter. (0.93). Those finds indicate that indirect selection for pericarp thickness could be done based on larger fruit diameter. These correlations are trustworthy and important due to the high heritability values presented for these traits. Some authors suggest selecting fruits with higher cuticle thickness and fruit width values due to lower water loss. Thus, we suggest that small farmers cultivate ‘habanero vermelha’ and ‘dedo de moça’ in order to produce fruits with extended shelf life.

Primeiro relato de Cerchysiella insularis (Howard, 1897) (Hymenoptera: Encyrtidae) parasitando Lobiopainsularis (Castelnau, 1840) (Coleoptera: Nitidulidae) em morangueiro

ABSTRACT: Strawberry is one of the most socially and economically important small fruits in Brazil, with strong demand by the food industry driving high levels of production. However, phytosanitary problems, especially insect damage, can hamper strawberry cultivation. A pest of great concern is the strawberry sap beetle, Lobiopa insularis (Coleoptera: Nitidulidae), which damages the fruits. Chemical control has not been effective against L. insularis, as it makes harvesting and marketing the product unfeasible. Parasitoids have been effectively utilized to control various strawberry pests and support sustainable production. We report the occurrence of the wasp Cerchysiella insularis (Hymenoptera: Encyrtidae) as a parasite of L. insularis on strawberries in São José dos Pinhais, Paraná, Brazil. Samples of strawberries (San Andreas cultivar) attacked by L. insularis were collected from February to March, 2019. Lobiopa insularis larvae were individually placed in rearing pots, fed on San Andreas strawberries, and checked weekly for symptoms of parasitism or parasitoid emergence. Parasitism rates were 33.85% in March and 45.90% in February. The sex ratio varied between 0.88 and 0.86. All parasitized larvae were infested by C. insularis. The natural parasitism rate above 33% and high sex ratio of C. insularis in strawberry crops indicated that it may have the potential in the control of L. insularis.

CERCETĂRI EXPERIMENTALE PRIVIND REALIZAREA UNUI ECHIPAMENT DESTINAT TOCĂRII RESTURILOR VEGETALE LEMNOASE

This article presents the results obtained through experimental research carried out with a machine for shredding woody plant residues (twigs, vine ropes), residues obtained from dry or green cuttings, in fruit or wine plantations. The obtained shredding is intended for utilization in the form of compost or biofuel (pellet type). The machine was designed and made by a group of researchers from INMA Bucharest, with the aim of developing the machine system made available to farmers, for mechanized work in small and medium-sized fruit plantations. The sizes of the fractions of the wood fragments resulting from the chopping process, their humidity and volumetric weight were determined. Using as raw material greener or drier branches, with dimensions between 10-45 mm, with an adjustment of the chopping drum at an average speed of 1400 rpm and an average speed of the conveyor chain of 0.425 m/s, wood chips with different sizes between 4 and 16 mm were obtained, the proportions varying from 13% to 16%. The average working capacity of the equipment was approx. 14.2 mc/h. Research will continue to determine the energy indices of the machine designed and made at INMA Bucharest, and the results will be presented in another article.

Market potential and value-added opportunities of cold-hardy berries and small fruits in the Intermountain West, USA.

Novel cold-hardy berries and small fruits represent an opportunity for growers in the Intermountain West, USA, as the harsh environment is not suited for other common berries and small fruits. This study analyzed the fresh market and value-added potential of haskap berries (Lonicera caerulea), saskatoon berries (Amelenchier alnifolia), and dwarf sour cherry (DSC) fruit (Prunus x kerrasis) by instrumental and consumer studies. Fresh and 2-week stored haskap (cv. Aurora), saskatoon (Lee 3), and DSC (Romeo) were measured for fruit weight, flesh firmness, bulk titratable acidity, pH, and soluble solid content. Participants (n=115) in at-home sensory tests scored these fruits for overall liking (OL, 9-point hedonic scale), purchase intent (PI, 5-point scale), and willingness-to-pay (WTP, 5-point scale). Ten participants further shared insight on these fruits in focus groups. Instrumental testing found a significant decrease in flesh firmness for 2-week stored haskap, but the consumers' OL was still comparable to fresh haskap. The fresh and 2-week stored haskap received significantly higher OL, PI, and WTP scores (7.7±1.0, 3.8±1.0, and $3.7±1.0; 7.7±1.2, 3.8±1.1, and $3.7±1.0, respectively) compared to saskatoon (6.1±1.8, 2.8±1.1, and $3.0±0.9, respectively) and DSC (5.6±2.2, 2.5±1.2, and $3.1±1.0, respectively) (α=0.05). The focus groups indicated that participants want to support local produce. The participants expressed interest in fresh unprocessed haskap berries, but preferred saskatoon and DSC in different value-added formats. Hence, this study concluded that there is an untapped fresh-market potential for haskap berries and there are value-added opportunities to extend the sale season and improve the palatability of saskatoon and DSC. PRACTICAL APPLICATION: This research has examined consumer perception of three species of novel small fruits by determining fresh-market potential and linking this to the opportunity for value-added product development. For haskap berries, the study not only indicated fresh market potential, but for the cultivar Aurora, consumer liking was not meaningfully altered by 2 weeks of cold storage. These results are meaningful because they will assist growers in the Intermountain West with market planning, including the possibility of formulating products that utilize these novel crops. This study provides growers the opportunity to diversify their income stream by utilizing local produce.

Effect of additional pollen supplement on fruit setting in Moringa oleifera

Moringa oleifera Lam. is a woody species with hermaphrodite flowers cultivated for its fruits and seeds for oil production. The fruit production of the species remains below producers' expectations.The current study was carried out from July to October along two consecutive years (2019 and 2020) at Komsilga (12°18'48.2''N and 1°64'60.2''W ) and at the INERA experimental station in Ouagadougou (12°22'801''N and 1°30'295''W ) both located in the northern Sudanian zone of Burkina Faso. Our study aimed at testing whether additional pollen on the flower stigma could improve pod and seed yields. For this purpose, a sample of 10 flowering trees and 20 inflorescences/tree was randomly selected at each site. Per tree, 10 newly flowering inflorescences were left to open pollinated and 10 others received pollenmanually. Results show that hand-pollinated inflorescences produced an average of 0.19 and 0.17 fruits, compared to 0.16 and 0.14 for open-pollinated inflorescences at INERA and Komsilga respectively (p= 0.7720). The mean seed weight was 63 (±11.2) and 50 (±7.4) g for the manualand open pollinated treatment, respectively. The Kruskal-wallis test of mean seed weight shows that the smallest fruits were obtained in the open pollination which differed significantly from manual pollination (p< 0.0001). The addition of pollen significantly improved Moringa fruit production.

Jabuticaba (Plinia sp.) Peel as a Source of Pectin: Characterization and Effect of Different Extraction Methods

The peel of jabuticaba, a small fruit native to Brazil, has been shown to be a potential source of antioxidants and soluble dietary fibers. In this study, flours prepared from these peels were evaluated as a source of pectin. Different extraction methods were employed: ultrasound (US) extraction followed by low temperature heating (40 °C); in a microwave (MW) without (method 1) or with cellulase (method 2) or hemicellulase (method 3); or in a water bath (method 4). Pectin yields ranged from approximately 18% for methods 1 and 4 up to 22% for enzyme-assisted extractions (methods 2 and 3). Methods that did not employ enzymes resulted in low amounts of methoxyl pectins, as opposed to high amounts of methoxyl pectins obtained after enzyme treatment. Cyanidin-3-O-glucoside (C3G) and ellagic acid were the main phenolic compounds found in jabuticaba peel pectins, with higher C3G levels obtained with enzyme-free extraction (methods 1 and 4). All pectins from jabuticaba peel presented a reddish tone, good emulsifying properties and high swelling capacity. The pectin extracted using US+MW+cellulase (method 2) presented better emulsifying performance (higher values of emulsifying activity and emulsion stability), more effective than commercially available citrus pectin.

Artisanal extraction of native chili seeds (Capsicum sp.)

Objective: To establish a methodology for the artisanal extraction and benefit of chili pepper seed from native and wild chili pepper varieties. Design/Methodology/Approach: From 2016 to 2019, nine chili pepper ecotypes were evaluated. The ecotypes include: habanero (Capsicum chinense Jacq); Ixcat ik, Bobo, Sweet, Maax, Bolita, Green (with red ripening), green (with yellow ripening), all of which belong to the Capsicum annuum; and Pico Paloma (Capsicum frutescens). The aim of the evaluations was to determine the morphological characteristics and the degree of genetic diversity. The extraction and exploitation method of the seeds was also evaluated. Cutting knives were used to extract the seeds. The seeds were dried in the open air, sheltered in closed and ventilated places. Both glass and plastic containers were used to store the seeds; the jars were lined with kitchen foil. Results: Two seed extraction procedures were used. Medium and large ecotype fruits were subject to circular and longitudinal cuts. For their part, small fruits were macerated. In order to dry the seeds, they were placed on metal trays or in perforated plastic baskets. The trays or bags were placed in ventilated and cool places (<40°C) for 8 to 10 days. Afterwards, they were stored at 5°C with low moisture and without light. Findings/Conclusions: The proposed methodology to obtain and exploit seeds in humid tropic conditions will support the conservation of the Capsicum resource, in the state of Campeche and the Yucatan Peninsula.

Evaluation of Open Tomato Cultivars for Adaptation and Yield Attributes in Central Mid-hills of Nepal

Tomato seedlings of nine tomato cultivars with Pusa Ruby as check were transplanted on March first to second week,2018 and 2019 at Khumaltar. Crop geometry was maintained with the 60X60 cm in three replications and fertilized with 150:120:100 NPK kg + 20-ton FYM per hectare. The main objective of this study was to evaluate and select high yielding, insect pest and disease tolerant cultivars with preferred characters at open field conditions for central mid-hills. The observation was recorded on vegetative, insect pest and disease, yield attributing parametersand response of consumers & farmers. Among the tested cultivars,HRD109showed superior performance onseptoria leafspottolerant (3.5), early days to flowering (21.8), higher number of fruits per plant (121), yield (58.80 t/ha) and 2289 gm per plant, consumers (4.5) and farmers preferred(4.1), and small fruit size (32.6 g). The next superior cultivar wasHRD7 which has late blight (4.1), days to flowering (22), the higher number of fruits per cluster (7.4) and per plant (119), superior yield (54.00 t/ha) and 2158 gm per plant, consumers (4.1) and farmers preferred (4.3), small fruit size (30.3 g). These two cultivars are recommended for cultivation in the central mid-hills of Bagmati Pradesh underopen field conditions.

Genomic Characterization of a Wild-Like Tomato Accession from Arizona

Abstract— Tomato domestication history has been revealed to be a highly complex story. A major contributor to this complexity is an evolutionary intermediate group (Solanum lycopersicum var. cerasiforme; SLC) between the cultivated tomato (Solanum lycopersicum var. lycopersicum; SLL) and its wild relative (Solanum pimpinellifolium; SP). SLC includes accessions with a broad spectrum of genomic and phenotypic characteristics. Some of the SLC accessions were previously hypothesized to be spreading northward from South America into Mesoamerica and that migration probably entailed reversal to wild-like phenotypes such as smaller fruits. Prior to this study, the northernmost confirmed extension of the SLC was limited to northern Mexico. In this study, we employed genomic methods to investigate the origin of a wild-like tomato found in a garden in Scottsdale, Arizona, USA. The so-called “Arizona tomato” featured a vigorous growth habit and carried small fruits weighing 2‐3 g. Our phylogenomic analyses revealed the identity of the Arizona tomato as a member of the Mexican SLC population (SLC MEX). To our knowledge, this is the first report of an SLC accession, confirmed using genomics, growing spontaneously in Arizona. This finding could have implications for conservation biology as well as agriculture.

Opportunities to Improve Effectiveness of Pollination of Blueberry CV. ‘Bluecrop’

In the production of blueberries, pollination is a key factor determining high quality yield. Problems with the process of pollination in blueberries occurs frequently. Lack of the effective pollination results in a lower yield and production of small fruits with low commercial value. The experiment described in this paper was carried out to test the effect of titanium organic complex (TOC) on the pollination and fertilization processes, seed formation, fruit setting and fruit development of blueberry in two consecutive years. The experiment consisted of two experimental factors: pollination type (self or open pollination) and application of TOC or lack of it. The presented study proves that TOC stimulates pollen adhesion and germination on the stigma, fruit setting, seed setting and fruit development. In self-pollinated flowers, the use of TOC increased the mass of each berry by 28% (in the first year) and 26% (in the second year), compared to non-treated plants. In open pollinated flowers, the application of TOC increased fruit mass by 38% (in the first year) and 29% (in the second year), compared to non-treated plants. Therefore, TOC may be treated as a substance stimulating the total fruit yield and mass of individual fruit.

Honey Bee Exposure to the Fungicide Propiconazole in Lowbush Blueberry Fields

The fungicide propiconazole is a commonly used fungicide in small fruit and tree fruit production in the U.S.A. In Maine wild blueberry production, it is used almost exclusively for mummy berry disease control. The goal of this study is to assess the risk of exposure to honey bee colonies deployed in wild blueberry fields for pollination. The study was conducted over a six-year period (2009–2014) in both the field and laboratory. Field surveys (2009–2011) measured the residues on blueberry flowers in 41 commercial fields across the blueberry growing region. A two-year study (2010–2011) determined the decay rate of propiconazole in blueberry fields after application. A laboratory study determined the contact LD50 of propiconazole to honey bee workers (2013). A field exposure/effect study was conducted over three years (2011–2013). In this study, 8–18 previously unexposed colonies were randomly assigned to one of two treatments, (1) isolated fields that were treated prior to bloom with the fungicide, propiconazole, but no other pesticides, or (2) isolated fields that were not treated with propiconazole or any other pesticides. The measures taken to evaluate effects of exposure monitored each year were (1) estimation of the exposure to colonies, measured as residues on flowers, workers, and in pollen brought back to hives; (2) colony population size (workers and brood); (3) queen status and presence; (4) queen oviposition rate; (5) supersedure rate; (6) egg hatch success; (7) mortality of developing larvae and pupae; (8) royal jelly deposition in wax comb cells; (9) worker longevity; (10) foraging activity; (11) treated bloom repellency to foragers; (12) colony overwintering success; (13) worker hypopharyngeal gland acini size; and (14) pathogen and parasite incidence and intensity. The results of these experiments and surveys showed that the propiconazole contact LD50 was 24,747 ppb. Residues of propiconazole were found to be commonly abundant on flowers in treated commercial fields after application with a mean concentration of 2083.8 ± 851.3 (se). The decay of propiconazole to non-detectable levels took about 40 days after application. The three-year hive deployment study showed that residues in treated fields were detected on flowers, pollen, and worker bees, demonstrating that exposure to this fungicide occurs even though it is applied before bloom. Also in the hive deployment study, evidence of reduced colony populations, increased supersedure, decreased queen oviposition rate, increased pathogen or parasite incidence and intensity, and increased overwintering colony loss due to propiconazole exposure was not found. However, propiconazole exposed colonies exhibited reduced worker longevity (17.3%), hypertrophy of 5 d old nurse bee hypopharyngeal acini (8.3%), and a 3.5 h repellency of foragers to treated bloom.

Identification Of Bioactive Phytochemicals By GC-MS Profiling, Phytochemical Screening, And TLC Using Methanolic Extract Of Carissa Carandas Linn Leaf

Background Carissa carandas (Apocynaceae) is a thorny evergreen shrub known as Karonda. It has small berry-shaped fruits, used as an additive in many pickles or spices in northern India. Objective The objective was to identify the phytochemical constituents, gas chromatography-mass spectrometry (GC-MS), and TLC screening by using a methanolic extract from the leaves of Carissa carandas. Methods and materials Leaves of C. carandas were collected, shade dried, pulverized, and extracted successively with methanol by the Soxhlet technique. The crude extracts were later exposed to phytochemical screening for secondary metabolites, thin-layer chromatography, and GC-MS analysis. Result The phytochemical screening revealed the presence of alkaloids, saponin, tannin, flavonoid, phenol, steroid, carbohydrate, glycosides, and terpenoids. TLC analysis was performed, and the Rf value was calculated. The GC-MS analysis determined the presence of 6 main phytochemical compounds in the methanolic extract of Carissa carandas leaf, showing that there were different types of high and low molecular weight compounds. Conclusion The results of the present study pave the invention of herbal medicines for several ailments by using the Carissa carandas plant, which may lead to the development of novel drugs.

Nonnutritive Sugars for Spotted-Wing Drosophila (Diptera: Drosophilidae) Control Have Minimal Nontarget Effects on Honey Bee Larvae, a Pupal Parasitoid, and Yellow Jackets.

Drosophila suzukii Matsumura, spotted-wing drosophila, is a major pest of small fruits and cherries and often managed with conventional insecticides. Our previous work found that erythritol, a nonnutritive polyol, has insecticidal properties to D. suzukii. Two formulations of erythritol (1.5M), with 0.5M sucrose or 0.1M sucralose, are most effective at killing D. suzukii. In this study, we investigated the nontarget effects of these erythritol formulations on honey bee Apis mellifera Linnaeus larvae, a pupal parasitoid of D. suzukii, Pachycrepoideus vindemiae Rondani, and western yellow jacket, Vespula pensylvanica Saussure. We directly exposed honey bee larvae by adding a high dose (2 µl) to larval cells and found no significant mortality from either formulation compared to the water control. Pachycrepoideus vindemiae may encounter erythritol in field settings when host plants of D. suzukii are sprayed. The erythritol+sucralose formulation was more detrimental than erythritol+sucrose to P. vindemiae, however, this effect was greatly reduced within a 21-d period when a floral source was present. Since yellow jackets are a nuisance pest and were attracted to the erythritol formulations in recent field trials, we tested adult V. pensylvanica survival with continuous consumption of these formulations in the laboratory. We found no detectable detriment from either formulation, compared to the sucrose control. Overall, both erythritol formulations caused minimal nontarget effects on honey bee larvae, P. vindemiae parasitoids, and western yellow jackets.

Environmental stress influences Malesian Lamiaceae distributions.

Dual effects of spatial distance and environment shape archipelagic floras. In Malesia, there are multiple environmental stressors associated with increasing uplands, drought, and metal-rich ultramafic soils. Here, we examine the contrasting impacts of multifactorial environmental stress and spatial distance upon Lamiaceae species distributions. We used a phylogenetic generalized mixed effects model of species occurrence across Malesia's taxonomic database working group areas from Peninsular Malaysia to New Guinea. Predictor variables were environmental stress, spatial distance between areas and two trait principal component axes responsible for increasing fruit and leaf size and a negative correlation between flower size and plant height. We found that Lamiaceae species with smaller fruits and leaves are more likely to tolerate environmental stress and become widely distributed across megadiverse Malesian islands. How global species distribution and diversification are shaped by multifactorial environmental stress requires further examination.

Discrimination Abilities and Parasitism Success of Pupal Parasitoids Towards Spotted-Wing Drosophila Pupae Previously Parasitized by the Larval Parasitoid Ganaspis brasiliensis (Hymenoptera: Figitidae).

Pachycrepoideus vindemiae (Rondani) (Hymenoptera: Pteromalidae) and Trichopria drosophilae (Perkins) (Hymenoptera: Diapriidae) are two cosmopolitan and generalist pupal parasitoids that are among a few of the resident parasitoids in North America capable of attacking Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), an invasive pest of small and soft fruit crops worldwide. Ganaspis brasiliensis (Ihering) is a specialist larval parasitoid of D. suzukii that was recently approved for biological control introduction against D. suzukii in the USA. As a solitary koinobiont species, G. brasiliensis oviposits in the host larva but emerges as an adult from the host puparium. This study investigated the discrimination ability and parasitism success by the pupal parasitoids towards D. suzukii pupae previously parasitized by G. brasiliensis, to examine whether interactions with resident parasitoids will affect G. brasiliensis after it is released in the USA. We found preliminary evidence that neither pupal parasitoid could discriminate towards D. suzukii pupae parasitized by early instars of G. brasiliensis. Pachycrepoideus vindemiae was able to successfully develop on D. suzukii pupae containing all preimaginal stages of G. brasiliensis, although parasitism success was significantly higher on those bearing later rather than early stages of G. brasiliensis. Trichopria drosophilae was only able to successfully develop on D. suzukii puparia containing early instars of G. brasiliensis. These results suggest that D. suzukii parasitized by the larval parasitoid could be subsequently attacked by the pupal parasitoids, possibly affecting the success of G. brasiliensis releases.

Fruit Yield in Sweet Orange Trees under Huanglongbing (HLB) Conditions Is Influenced by Reproductive Phenological Characteristics of the Scion-Rootstock Combination

Since greening (aka HLB), the most economically devastating disease of citrus worldwide was detected in Florida in 2005, citrus acreage and fruit production has reduced by more than 70%. Transmitted by the insect vector Asian citrus psyllid, the disease results in exacerbated preharvest drop, smaller fruit, and a rapid decline of trees leading to a significant reduction of yield. Currently, there is no cure for the disease. A strategy to cope with the disease relies on identifying tolerant or more productive varieties, and understanding factors that make them more productive. Under these circumstances, a combination of rootstock and scion that results in better fruit yield is highly desirable. In this paper we investigated phenological attributes of the main sweet orange varieties planted in Florida, Hamlin and Valencia, grafted on Swingle and US-942 rootstocks, two of the most used rootstocks by Florida citrus growers. Our goal was to better understand the phenology associated with the consistently higher yields of trees grafted on US-942. We assessed fruiting characteristics and abscission dynamics of fruit and leaves. We found that trees on US-942 rootstock, especially from Valencia scion, significantly set more terminals than cluster fruit; terminal fruit is larger and experiences less drop resulting in better yields. In general, rootstock did not have a significant influence on the fruit-bearing characteristics in Hamlin. Similarly, we found that fruit detachment force was not significantly influenced by rootstock. Our results show that in an HLB endemic situation, fruiting characteristics should be considered when selecting rootstocks and rootstock–scion combinations, so genetics resulting in larger, single fruits per fruiting branch should be favored.