Peach Orchards Research Articles

First Report of Mume Virus A Infection of Prunus persica in China

Mume virus A, belonging to Capillovirus in the family Betaflexiviridae, was discovered recently from Japanese apricot (Prunus mume) and exhibited diffuse chlorotic spots on leaves (Marais et al. 2018). To date, Japanese apricot is the only known host of Mume virus A (MuVA) (Maliogka et al. 2018). Peach (Prunus persica) is a delicious and healthy summer fruit grown in most temperate regions of the world. More than 20 different viruses infecting peach trees have been reported (Jo et al. 2018). In April 2019, the leaves from four peach trees showing severe yellow mosaic and leaf curling were collected from peach orchards in Xinjiang, China. The pooled total RNA was extracted from these four trees leaves with TRIzol reagent (Life Technologies Corporation, Carlsbad, CA) and subjected to high-throughput sequencing (HTS) using a PE150 sequence strategy on an Illumina HiSeq2000 (Novogene Corporation, Tianjin, China). Approximately 39.3 million of 150-bp paired-end reads were obtained and used for de novo transcriptome assembly by SPAdes Genome Assembler (Bankevich et al. 2012). A total of 89,163 contigs with N50 of 866 bp were obtained and then were annotated by BLASTX analysis against the NCBI nr virus database (Altschul et al. 1997). Six known viruses (apple chlorotic leaf spot virus, Asian prunus virus 2, cherry green ring mottle virus, nectarine stem pitting-associated virus, peach associated luteovirus, and plum bark necrosis stem pitting-associated virus) and one known viroid (hop stunt viroid) were identified. Moreover, a 7,623-bp contig with a coverage of 84.4-fold was identified as capillovirus-related sequence. To classify the capillovirus accurately, pairwise genome alignments analysis was performed between all members of the Capillovirus genus using PASC online tool (Bao et al. 2014). The closest match was the genome of MuVA (NC_040568.1), sharing 78.36% nucleotide identity, followed by those of some isolates of cherry virus A, sharing less than 58.5% nucleotide identity. This result suggests that the capillovirus from peach belongs to the same species with the MuVA from apricot but should be a different isolate. We designated it as isolate pp, and its HTS-derived viral genome sequence was deposited in GenBank (accession no. MN412555). To confirm the HTS experiment results, from the same peach orchards, 23 peach leaf samples from different trees were collected, and total RNA was extracted with TRIzol reagent with standard procedures following the instructions. The RNA was subsequently used to test for pp isolate by reverse transcription polymerase chain reaction (PCR) using specific primers DT-MVAF5716 (5′-CTTCACATCGGAGCTGTCCT-3′) and DT-MVAR6277 (5′-TGCTGATTGCTTCAGACCCT-3′), targeting a portion of the open reading frame 2 (putative movement protein). Eleven samples produced the expected 560-bp PCR fragment. Three PCR products randomly selected were cloned into pMD19-T Vector (TaKaRa) for Sanger sequencing. All sequences of amplicons shared nearly 100% sequence identity with the corresponding region of the HTS-derived viral genome sequence. However, at least the other two viruses and viroid had been detected in all 11 MuVA-positive samples, so the symptoms of the initial sample cannot be explained by MuVA infection. To our knowledge, this is the first report of MuVA infecting peach trees. This report suggests that MuVA may have a broad host range in the genus Prunus.

Integrated Weed Management in High Density Fruit Orchards

Despite the productivity, achieving long-term sustainability and maintaining plant biodiversity have become the pivotal goals in orchard floor management, especially along tree rows. Thus, the paradigm of eradicating weeds in the tree row using chemical herbicide or repeated soil tillage needs to be substituted with more sustainable alternatives. This study was conducted in two commercial apple and peach orchards in Marche region (Italy). Two integrated mechanical approaches, integrated mowing (mower and brush or disc) and integrated tillage (blade weeder and integrated mowing), were compared with the standard herbicide system in a 2-year trial. Weed species diversity, soil coverage, and weed biomass production, including, gas exchange parameters, trunk cross-sectional area (TCSA), fruit yield and quality were measured. Overall, both integrated practices demonstrated approximately 82%, 91% and 113% more species diversity, soil coverage, and weed biomass production, respectively, than herbicide systems. No significant differences were found in terms of tree gas exchange parameters, growth and fruit yield. However, a few fruit quality parameters such as fruit firmness, soluble solids content (SSC) and dry matter content responded positively to the integrated practices. These results suggest that the integrated mechanical approaches of weed management increased orchard biodiversity, and had no adverse effects on tree growth, fruit yield, and quality. The average costs per hectare associated with chemical weed control were 66.5% and 72% lower, respectively, compared to integrated tillage and integrated mowing. However, the government subsidies provided to the orchardists to encourage sustainable management practices were able to offset such additional costs.

Comparison of Mating Disruption and Insecticide Application for Control of Peachtree Borer and Lesser Peachtree Borer (Lepidoptera: Sesiidae) in Peach.

Simple SummaryThe peachtree borer and lesser peachtree borer are destructive insect pests of peach and other stone fruit. Damage is caused by larval feeding on the vascular cambium, which reduces tree health and vigor and can lead to tree death. The traditional method to control these pests is with directed trunk sprays of the organophosphate insecticide, chlorpyrifos. However, the ongoing review of pesticide tolerances mandated by the United States Environmental Protection Agency (US-EPA) makes the option of future long-term use of chlorpyrifos uncertain. Mating disruption is an alternative method of control that uses synthetic sex pheromones to disrupt male mate-finding behavior and prevent mating. We conducted field studies to compare the efficacy of mating disruption and application of chlorpyrifos insecticide for control of this pest complex. Although our data indicated that mating disruption can provide growers with an effective non-chemical alternative to chlorpyrifos trunk sprays, several variables may affect its long-term success in West Virginia peach orchards; most notably the presence of high population densities of the pest species, problems with maintaining adequate pheromone coverage in orchards, and the need for area-wide implementation.The peachtree borer, Synanthedon exitiosa, and lesser peachtree borer, S. pictipes, are economically important indirect pests of peach in West Virginia. The purpose of this 3-year study was to compare the efficacy of mating disruption and post-harvest trunk sprays of chlorpyrifos insecticide for control of this pest complex in a commercial peach orchard. Overall, Isomate PTB-Dual disruption dispensers applied at a rate of 371/ha significantly disrupted the male mate-finding behavior of S. exitiosa and S. pictipes. In addition, the infestation of peach trees by S. exitiosa larvae did not vary significantly between mating disruption and insecticide treated plots. Hot-spot maps of S. exitiosa infestation showed significant spatial clusters of infestation predominately near the perimeter of all orchard plots, or where trees were missing within and/or between rows. The generation of standard deviational ellipses revelated that the location of S. exitiosa infestations in orchard plots remained relatively constant between years, and were generally oriented in a north and easterly direction, which coincided with the prevailing wind direction. Although our data indicated that mating disruption can provide growers with an effective non-chemical alternative to chlorpyrifos trunk sprays, several variables may affect its long-term success in West Virginia peach orchards; most notably the presence of high population densities, problems with maintaining adequate pheromone coverage, and the need for area-wide implementation.

The performances of Linum usitatissimum on different organic manures and fertilizers under peach based horti medicinal system of agroforestry

Linum usitatissimum commonly known as Alsi is a medicinal plant. Mid Himalayas are the bowl of stone fruits and peach is one of the important stone fruit of Himachal Pradesh Farmers are raising the orchards, hence keeping in view the importance of medicinal and aromatic plants under peach orchard is very good option. Farmers of many states in India have made the choice of cultivating medicinal plants and making profits by cultivating it. The use of FYM @ (2t/ha and 4t/ha), vermicompost @ (2t/ha and 4t/ha) and jeevamrutha @ (500l/ha) at appropriate doses was found beneficial minimizing competition for critical resources. The most beneficial treatment is fertilizers T6(NPK) under peach base Linum usitatissimum crop. Maximum plant height (54.15 cm) at harvesting stage was observed with NPK 120:60:30 kg/ha + peach. The maximum numbers of branches per plant (4.85) were recorded in T6. Maximum fresh aerial biomass per plant (11.98 g/plant) and estimated fresh aerial biomass per hectare (39.93 q/ha) was recorded as T6. Maximum dry aerial biomass per plant (8.22 g/plant) and estimated dry aerial biomass per hectare (27.40 q/ha) was observed as T6. Maximum seed yield (10.16 q/ha) was found in T6. The highest gross return (Rs. 1,01,600) for Linum usitatissimum was recorded under T6. The maximum total net return (Rs. 1,25,026) was recorded in T6. Benefit cost ratio of Linum usitatissimum plants was best result (2.13) in T5. All over all characteristics maximum were observed in T6 as compare to other treatments. The intercropping of Linum usitatissimum with peach was found more beneficial as compared to sole crop.

Soil fertility of peach orchards at installation and first year plant growth

Soil fertility of peach orchards at installation and first year plant growth

Comparison among chemical thinners applied to ‘Maciel’ and ‘Sensação’ peach trees

Peach tree thinning, which aims at reducing plant load so as to ensure productivity and fruit quality, has been manually carried out within a short period of time in the stage of fruit development. Due to the need and shortage of qualified man power, chemical thinning is one of the alternatives that can solve these difficulties found in manual thinning. This study aimed at evaluating the effect of different products which have been applied – either alone or in combination – to fruit thinning of peach tree cultivars ‘Sensação’ and ‘Maciel’ in Pelotas, Rio Grande do Sul (RS) state, Brazil. The experiment was conducted in the 2015/2016 crop in a commercial peach orchard located in Morro Redondo, RS, Brazil. The following seven treatments were carried out 40 days after full bloom (DAFB): plants with no thinning, manual thinning, metamitron, benzyladenine, benzyladenine + metamitron, ethephon, ethephon + metamitron. Fruit abscission, effective fructification, number of fruits and production per plant, mean mass and fruit classification into caliber classes, epidermis color, pulp firmness and soluble solids were evaluated. Production and number of fruits per plant decreased excessively, whereas fruits placed in categories of higher caliber increased when ethephon was either used alone or in combination with metamitron. When both metamitron and benzyladenine were applied, either alone or in combination, they led to fruit abscission and resulted in mean fruit size and weight, at harvest time, similar to those found in manual thinning. Application of chemical products – either alone or in combination – may be an alternative of peach tree thinning in orchard management.

First Report of Pre-Harvest Soft Rot of Peach Fruit (Prunus persica) Caused by Enterobacter mori in China.

Peach (Prunus persica L. Batsch) is one of the major fruit crops of China and a rich source of vital nutrients and fibers. In July 2019, a peach orchard was visited at Pinggu District, Beijing, China. The average temperature and relative humidity at the sampling site were 28±2 °C and 75±2 % respectively. In the orchard, unripe and near to ripe peach fruits cv. 'China Pearl' were observed with soft brown patches (3-4×2-3cm) on the surface. The samples (n=25) were collected based on typical symptoms. When the rotten part of the fruit was pressed, a liquid oozed out of the fruit emitting an unpleasant odor. The disease incidence of fruit soft rot was 22 %. The percent incidence was calculated based on total number of infected fruits divided by total number of fruits examined. Infected fruit tissues were excised into small pieces (5mm) and surface disinfested with 1% NaClO for 25s and rinsed twice with sterilized distilled water (SDW). These pieces (4-5 pieces per sample) were macerated with 1.5 ml SDW in a 2 ml tube. Later, 5 µl supernatant was streaked on Luria Bertani (LB) agar plates and incubated at 28 ºC for 3 days. Oozing liquid (50 µl) was also inoculated on 100ml LB broth and incubated for 24 h and 5 µl was streaked on LB agar medium and incubated at 28 ºC. Purified colonies were obtained by re-streaking 3 times. The isolate formed creamy to light yellowish, irregular, round, rough or smooth-looking colonies on LB medium and pink colonies on Eosin Methylene blue. The bacterium was rod shaped, measuring 0.8 to 1.4 μm in length and 0.2 to 0.5 μm in width (Fig 1) observed using a scanning electron microscope (Hitachi-SU8010). Morphological characteristics were similar to previously described characteristics of Enterobacter spp. (Zhu et al. 2011; Nishijima et al. 1987). Genomic DNA was extracted from all twenty-five isolates by using TIANamp Bacteria DNA Kit (Tiangen-Biotech, Beijing, China) according to the manufacturer's instructions. The 16S ribosomal RNA gene of 25 isolates was amplified by using universal primers (27F:5'-AGAGTTTGATCCTGGCTCAG-3',/1492R:5'-CTACGGCTACCTTGTTACGA-3'), and rpoB gene (F2: 5'-AACCAGTTCCGCGTTGGCCTGG-3', R2: 5'-CCTGAACAACACGCTCGGA-3') (Mollet et al., 1997). Sequences for EPT-1 were submitted to GenBank (accessions MN548761 (16S rRNA), MN594495 (rpoB)). Accessions MN548761 and MN594495 had 99.35 and 99.77% sequence identity with E. mori (GenBank accessions KF747680, GQ406571). Maximum Likelihood phylogenetic tree constructed (1000 replicates) using Mega X (Kumar et al. 2018) indicated that isolate EPT-1 clustered with E. mori sequences. To confirm the pathogenicity, medium-sized (n=60) surface disinfested ripe peach fruits cv. 'China Pearl' were wound inoculated with 5 µl suspension of EPT-1 (107cfu/ml) and the control fruit were treated with 5 µl sterilized water. The fruit were kept in sterilized plastic box and incubated at 28 ºC for 7 days at 70% relative humidity, and the pathogenicity test was repeated 3 times. Symptoms similar to the original fruit samples were observed on all inoculated fruit (Fig 2). The pathogen was re-isolated, the colonies obtained from the oozing liquid were similar to those of infected fruit tissues and identified as E. mori based on morphological and sequencing analysis. Previously, E. mori has been reported to cause bacterial wilt on Morus alba L. in China (Zhu et al. 2011). To our knowledge, this is the first report of E. mori causing soft rot of peaches in China.

Peach volatile emission and attractiveness of different host plant volatiles blends to Cydia molesta in adjacent peach and pear orchards

The oriental fruit moth (OFM), Cydia (= Grapholitha) molesta, is a highly damaging pest; peaches are its primary host, and pears serve as post-peach secondary hosts during the late season in China. We collected volatiles from detached peach shoots and fruits, and identified them with gas chromatography–mass spectrometry (GC–MS). Antennally active compounds were identified by gas chromatography-electroantennogram detection (GC-EAD), and these were further tested in the laboratory and field. We detected consistent electroantennographic activity was for ten compounds. Significantly more C. molesta females were caught with a mixture of female EAD-active compounds identified from the detached matured peach fruits (nonanal, butyl acetate, 3-methylbutyl acetate, hexyl acetate, (Z)-3-hexenyl acetate, linalool and farnesene) than other mixtures mimicking the volatile profile from detached matured fruits or shoots. We identified a new GC-EAD active mixture from intact peach shoots composed of nonanal, (Z)-3-hexenyl acetate, (E)-β-ocimene, and 6-methyl-5-hepten-2-one. In the field test, the background odour of orchards could affect trap catches, and two peach-derived blends together with two previously known pear-derived blends were proven to be able to monitor the seasonal OFM population dispersal in adjacent orchards. These host plant blends will be effective for further designing candidate attractants for season-long C. molesta population dynamic monitoring.

Scion × Rootstock Response on Production, Mineral Composition and Fruit Quality under Heavy-Calcareous Soil and Hot Climate

Since there are many different factors which affect peach orchard profitability, it is necessary to conduct long-term studies to find the best scion/rootstock combination within the constraints imposed by local climate and economic conditions. The influence of six peach-almond hybrids (“Adafuel”, “Adarcias”, Garnem”, “GF 677”, “PADAC 9902-01” and “Rootpac 70”); one P. persica × P. davidiana hybrid: “Cadaman”; five hexaploid plums (“Adesoto 101”, “PM 44 AD”, “PM 105 AD”, “PM 150 AD”, and “Penta”); three plum × peach-almond hybrids (“PADAC 04-01”, “PADAC 04-03” and “PADAC 99-05”), and one plum x almond hybrid (“Rootpac R”) on agronomic, basic fruit quality parameters, and flower and leaf mineral nutrients of the “Big Top” nectarine was tested. The highest vigor was induced by “Adafuel”, while the lowest vigor was exhibited by “PM 105 AD”, although the latter did not differ from the rest of the rootstocks. Yield efficiency was higher for “Adesoto 101” and lower for “Adafuel”. Regarding the soluble solids content (SSC), “PADAC 04-01” rootstock induced the highest average content, although it did not differ from “Adarcias”, “Adesoto 101”, “PADAC 99-05”, “PM 105 AD”, and “Rootpac R”. In addition, significant effect of rootstock was found on the flower and leaf mineral analysis traits evaluated. The medium (“Adarcias”, “Adesoto 101”, “PM 105 AD”) to high vigorous plum based hybrid rootstocks (“PADAC 04-01”, “PADAC 99-05” and “Rootpac R”) showed the tendency to induce a better fruit quality, based on higher concentration of SSC, and other yield attributes, demonstrating their commercial interest as new rootstocks for peaches. Considering its overall performance, “PADAC 04-01” appears as a new promising rootstock alternative to peach-almond hybrids on heavy and calcareous textured soils.

Influence of peach (Prunus persica Batsch) phenological stage on the short-term changes in oxidizable and labile pools of soil organic carbon and activities of carbon-cycle enzymes in the North-Western Himalayas

The labile organic carbon (C) and C-related enzymes are sensitive indicators capturing alterations of soil organic matter (SOM), even in a short-time scale. Although the effects of crop husbandry and land use change on these attributes have been well studied, there is no consensus about how plant phenology may impact them. This study aimed to determine the short-term effect of six distinct phenological stages (PS-1: full bloom; PS-2: fruit set; PS-3: pit hardening; PS-4: physiological maturity; PS-5: 60 d after physiological maturity; and PS-6: fall) of peach on the changes in soil organic carbon (SOC) fractions of different oxidizability, labile C pools, and C-cycle enzyme activities in soils, for two consecutive years (2015 and 2016) in the North-Western Himalayas (NWH). Peach rhizosphere soils were sampled at the topsoil (0–15 cm) and subsoil (16–30 cm) layers, along with rhizosphere soils from adjacent perennial grasses, which served as a control. Values for most of the assessed parameters, including very labile C, labile C, microbial biomass C, permanganate oxidizable C, dissolved organic C, mineralizable C, amylase activity, and carboxymethyl-cellulase activity, were significantly (P ≤ 0.05) higher at PS-3 than at other phenological stages of peach. Conversely, a sudden decline in these soil variables was recorded at PS-5, followed by a slight buildup at PS-6, particularly in the topsoil of the peach orchard. Short-term changes in organic C fractions of different oxidizability, influenced by peach phenological stage, significantly (P ≤ 0.05) affected C management index, C pool index, and lability index. Both the C management index and lability index showed their highest values at PS-3 and their lowest values at PS-5, clearly indicating short-term accretion and depletion of SOC, in tandem with the peach phenological events. Principal component analysis suggested that a composite of soil indicators, including microbial biomass C, dissolved organic C, amylase, and invertase, could help detect short-term changes in SOC content. It is concluded that peach phenological events had a major impact on the short-term variations of the studied soil variables, which could be attributed to changes in the above- and belowground plant residues, as well as the extent of nutrients and water acquisition.

IDENTIFICATION OF PEACH TREE TRUNKS FROM LASER SCANNING DATA OBTAINED WITH SMALL UNMANNED AERIAL SYSTEM

Abstract. Agricultural robotics rely on digital tools and sensor integration in order to improve efficiency and sustainability of cultivations. One part of orchard inventory is the identification of a tree trunk i.e. localization and diameter determination. However, this is a challenging task, due to thin trunks, presence of leaves and low branches. In this paper we present a case study for determining these parameters using the example of peach orchard, for which a high-density LiDAR data (over 3000 points/m2) was obtained with a small unmanned aerial system (UAS) during a leafy and leafless season. We applied point thresholding by height and by components of normal vector, in order to identify points reflected from trunks. Alpha-shape algorithm was used to aggregate together points, that belong to the same trunk and their centroid determined the trunk location. Trunk diameters were calculated using two alternative approaches: the Principal Component Analysis (PCA) and circle fit. For the leafy season trunk identification is challenging. Omission errors were caused due to few reflections from trunks and commission errors occurred because of the unfiltered reflections from low branches and young twigs oriented towards the ground. All 194 trunks were identified from data collected during the leafless season. The accuracy of tree location was 0.27 m and the accuracy of diameter determination using PCA was 0.03 m.

Innovative Soil Management and Micro-Climate Modulation for Saving Water in Peach Orchards

Microclimatic and soil management studies emphasize that roofing above the canopy or soil mulching contributes to reduce water losses from horticultural cropping systems and, at the same time, to increase water use efficiency. The aim of this 2-year on-farm study, carried out on a late ripening peach (cv. California) orchard, was to investigate the combined effect of water supply (full or deficit irrigation, DI), incoming light (hail or shading net), and soil management (tilling or mulching) on: microclimate; fruit growth; yield; irrigation water use productivity (WPI); and soil water stress coefficient (Ks). Shading hail net reduced air temperature (−1°C), wind speed (−57%), solar radiation (−32%), while increased relative air humidity (+9.5%). Compared to the control treatment (hail net coverage, soil tillage, and full irrigation), the innovative management (DI + shading hail net + mulching) reduced seasonal volumes of irrigation water (−25%) and increased both final yield (+36%) and WPI (+53%). Saving water resources without losing yield is an achievable goal by peach orchards growing under the Mediterranean climate if the DI agro-technique is adopted conjointly with shading hail net and soil mulching.

A Decision Support System Based on Degree-Days to Initiate Fungicide Spray Programs for Peach Powdery Mildew in Catalonia, Spain.

The incidence of peach powdery mildew (PPM) on fruit was monitored in commercial peach orchards to i) describe the disease progress in relation to several environmental parameters and ii) establish an operating threshold to initiate a fungicide spray program based on accumulated degree-day (ADD) data. A beta-regression model for disease incidence showed a substantial contribution of the random effects orchard and year, whereas relevant fixed effects corresponded to ADD, wetness duration, and ADD considering vapor pressure deficit and rain. When beta-regression models were fitted for each orchard and year considering only ADD, disease onset was observed at 242 ± 13 ADD and symptoms did not develop further after 484 ± 42 ADD. An operating threshold to initiate fungicide applications was established at 220 ADD, coinciding with a PPM incidence in fruit around 0.05. A validation was further conducted by comparing PPM incidence in i) a standard, calendar-based program, ii) a program with applications initiated at 220 ADD, and iii) a nontreated control. A statistically relevant reduction in disease incidence in fruit was obtained with both fungicide programs, from 0.244 recorded in the control to 0.073 with the 220-ADD alert program, and 0.049 with the standard program. The 220-ADD alert program resulted in 33% reduction in fungicide applications.

Improved Monitoring of Grapholita molesta (Lepidoptera: Tortricidae) in Stone Fruit Orchards with a Pheromone-Kairomone Combination Lure.

Monitoring oriental fruit moth Grapholita molesta Busck (Lepidoptera: Tortricidae), populations based on counts in sex pheromone-baited traps within sex pheromone-treated orchards for mating disruption (MD) is challenging since male orientation to traps is disrupted. In this study, we evaluated a new commercial pheromone–kairomone combination lure for G. molesta (Pherocon® OFM Combo™ Dual™), which combines the G. molesta and Cydia pomonella L. sex pheromones with a blend of acetic acid and terpinyl acetate. Trap comparisons were performed in 33 trials in peach and nectarine orchards under MD (24) or non-MD (9) during the 2018–2019 period in Italy. Male and total moth captures in traps baited with the combination lure were significantly greater than in traps with G. molesta pheromone in both years and across both pheromone treatments. The proportion of females in the total moth captures using the combination lure averaged ca. 7% across all trials. The by-catch of non-targets, i.e., Apis mellifera L., was low in traps baited either with the combination and the sex pheromone lure, while trap color (white) affected the capture of beneficials but not of the target pest. Our study proves that this combination lure can improve the monitoring and management for G. molesta in stone fruits. New studies are needed to define action thresholds to trigger supplemental control methods to MD. Secondly, female-based monitoring lures should be further developed to improve management strategies.

Effects of disruption of Grapholita molesta (Lepidoptera: Tortricidae) using sex pheromone on moth pests and insect communities in orchards

Mating disruption and mass trapping based on insect sex pheromones have been used to effectively control Grapholita molesta (Busck) (Lepidoptera: Tortricidae). However, due to the different disruption intensities of these two approaches, few reports have evaluated the differences in their ecological recovery in orchards. We investigated the dynamics of major Lepidopteran pests; infestation patterns of G. molesta in shoots and fruits; composition of the orchard insect community; and diversity, similarity, and stability indices, from 2015 to 2017, in peach orchards in northern China. Three orchards were considered, each subjected to either mating disruption, mass-trapping, or pesticides (control), from 2010 to 2013. Our results showed that moth pests and insect communities inhabiting these orchards responded differently to the two approaches. Mating disruption and mass trapping mainly affected the major and secondary non-target pests, respectively. Mating disruption had a greater effect on delaying the recovery of G. molesta than mass trapping. Mating disruption resulted in higher dominance index values and dominance concentration index values, and reduced the community stability while improving the community recovery. Mass trapping resulted in higher diversity index values, and the community exhibited contrasting effects. These results indicate that mating disruption may be more suitable than mass trapping for managing G. molesta in orchards.

Suitability and Profitability of a Cereal Aphid for the Parasitoid Aphidius platensis in the Context of Conservation Biological Control of Myzus persicae in Orchards.

The use of cover crops can promote the abundance and early arrival of populations of natural enemies. Cereal cover crops between orchards rows could encourage the early arrival of the parasitoid Aphidius platensis, as they offer alternative winter hosts (e.g., Rhopalosiphum padi), enhancing the control of Myzus persicae in spring. However, the preference for and suitability of the alternative host must be addressed beforehand. To evaluate the potential of this strategy, we assessed host preference using behavioural choice tests, as well as no-choice tests measuring fitness traits, when developing on both host species. One source field for each aphid population from the above hosts was chosen. There was a clear choice for R. padi compared to M persicae, independently of the source, probably due to more defensive behaviours of M. persicae (i.e., kicks and escapes). Nevertheless, both aphid species were suitable for parasitoids’ development. The female progeny developed on R. padi were larger in size, irrespective of their origin. According to our results, in peach orchards with cereals sown between peach trees during the autumn, where we expect when R. padi populations will no longer be available during spring, A. platensis should be able to switch to M. persicae.

Species diversity, mating type assays and aggressiveness patterns of Monilinia pathogens causing brown rot of peach fruit in Turkey

Brown rot disease caused by fungal species from the Monilinia genus has recently been observed as one of the most important limiting factors for yield and quality of peach fruits in Turkey. During June and July of 2018, field trips to different peach orchards were performed in six provinces located in four different geographical regions of Turkey. One hundred and twenty-nine isolates were obtained from the diseased fruits, and of those, 109 were identified as Monilinia fructicola, whereas 20 were M. laxa according to the species-specific molecular markers. Mating types of the isolates were detected by PCR assays using primers designed in this study. Each isolate represented only one of the mating type genes. Overall data sets presented 1:1 ratio of mating types for both species, indicating a possible sexual reproduction. No polymorphisms were detected in partial sequences of mating type genes. The isolates were in vitro tested for their pathogenicity using apple fruits as a host and aggressiveness were evaluated at different time points using lesion sizes. Monilinia laxa was found more aggressive than M. fructicola. Moreover, M. fructicola isolates displayed larger colony growth compared to M. laxa isolates. However, no significant correlation was detected between the colony growth rates and virulence. This study is the first to demonstrate brown rot pathogens of peach fruit in Turkey and identifies different aspects of the pathogens, which would be useful in containment of pathogen spread and comparison with other populations of these pathogens worldwide, and suggests a new set of mating type markers for these species.

Deficit Irrigation in Peach Orchards under Water Scarcity Conditions

The irrigation patterns in two peach orchards, located in the central eastern region of Portugal, called “Beira Interior”, and the effect of different amounts of irrigation on the total production and fruit quality were evaluated. The experiment was conducted in 2016, in two different orchards, and included three treatments correspondent to three different flow rates per tree: 8, 12 and 16 l/hour. The water balance, which included the water supplied by rain and irrigation and the crop evapotranspiration, was developed. At harvest, crop production, pulp firmness and percentage of the total soluble solids were evaluated. There were no significant differences between treatments in the average production per tree. However, in one of the orchards production increased with the volume of irrigation. In the same orchard, fruit firmness decreased with the increasing water supply. Total soluble solids had decreased with the increasing water supply in both orchards, probably as a consequence of the dilution effect due, directly, to the water incorporated in the fruits, or, indirectly, to the larger fruits produced by the trees that were irrigated more. In general, the treatments used in this study as well as in the farmers’ practices, the supplied water was in deficit, but the farmers tend empirically to follow closely the evolution of evapotranspiration.
 Keywords: Deficit irrigation, Peach tree, Production, Total soluble solids, Fruit firmness

Are horticulture-based land uses benign for fertility and health of soils in mid to high hills of the north-western Himalayan region?

ABSTRACT Soil fertility in many parts of the north‒western Himalayan region (NWHR) has declined owing to accelerated nutrient mining under existing crop regime. Therefore, this study aimed to assess effect of the predominant horticulture‒based land uses on soil fertility and health in mid and high hills of NWHR. Soil samples (0‒20 cm) were collected, analyzed for different soil chemical attributes (pH, electrical conductivity, organic C, available primary-, secondary-, and micro-nutrients), and compared across five key land uses: perennial grass (PG), peach orchard (PO), apple orchard (AO), field vegetable farming (VF), and protected vegetable farming (PV). Soils of the investigated land uses were neutral to near neutral in soil reaction (6.3‒6.8) except field vegetable and protected vegetable farming. Amount of soil organic C and labile organic C was significantly higher (p ≤ 0.05) in soils of apple orchards (18.6 g kg‒1 and 687.3 mg kg‒1, respectively) and peach orchards (20.4 g kg‒1 and 731.3 mg kg‒1, respectively) over others. An abrupt and significant increase in Olsen-P was recorded in soils of field vegetable farming (17.1 mg kg‒1) and protected vegetable farming (13.0 mg kg‒1), which shifted their nutrient index (NI) of P in to high category (≥ 2.33). The concentration of mineralizable-N in soil was statistically at par in soils under perennial grass and fruit orchards, while protected vegetable farming showed maximum soil mineralizable-N content (115.5 mg kg‒1) and NI of nitrogen (1.83). The NI was in high category (≥ 2.33) for copper, iron, and manganese in majority of the land uses. In view of the results, temperate fruit‒tree based land uses are benign in up‒keeping soil fertility and soil health, and needs promotion on large scale. Additionally, policies to create incentives for the build-up of soil organic matter and replenishment of the depleted soil macro and micro nutrients in vegetable-farmed lands are warranted.

Identification, Characterization, and Pathogenicity of Colletotrichum Species Causing Anthracnose of Peach in Korea

Peach (Prunus persica L.) is one of the major fruit crops in South Korea, along with apple, persimmon, and Asian pears. Peach anthracnose is a continuing threat to growers and is accountable for enormous economic loss. In July 2018, anthracnose of peach appeared at different peach orchards in Gyeongsangbuk-do region, Korea. The typical anthracnose symptoms (brown, circular, and necrotic lesions) were observed on the fruits. Anthracnose of peach was surveyed in different peach orchards of Gyeongsangbuk-do, and 20 fungal isolates from 19 diseased fruits were collected. Multigene phylogenetic analyses coupled with morphological characteristic analysis approaches were used for identifying the fungal species isolated from diseased fruits. This study confirmed three Colletotrichum species. Based on the results, Colletotrichum siamense are reported for the first time as causal agents of peach anthracnose alongside C. fructicola and C. fioriniae, which has been reported previously. Pathogenicity assays were performed for the three isolates representing all the species identified, and Koch’s postulates on detached healthy peach fruits were verified. All the identified species were pathogenic on peach fruits as the typical anthracnose symptoms were reproduced. Significant variations in the virulence were observed among fungal species on peach fruit.