Orchards Research Articles

Performance of BSMRAU-developed vegetables under fruit tree-based agroforestry systems

Many field crop lands are being transformed to fruit orchards in different locations of Bangladesh. There is an ample scope to cultivate intercrops in the orchards following scientific manner and proper technology including suitable varieties. In this study, mango and orange orchards were transformed to agroforestry system in Kotchandpur upazila under Jhenaidah district to investigate the performances of selected vegetable varieties (bottle gourd, stem amaranth, papaya, cauliflower, and country bean) developed by the Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU). Randomized complete block design was used to compare agroforestry (mango and orange orchards) and non-agroforestry (open field) treatments for identifying suitable tree-vegetable combinations. The results indicated that yields of the tested vegetables were higher in the non-agroforestry system (crop field without trees) compared to the agroforestry system. Yields of bottle gourd stem amaranth, cauliflower, and country bean in agroforestry systems decreased by 21, 7, 18, and 19%, respectively, compared to non-agroforestry system. On the contrary, yield reductions were 7.9, 15.7, 3.9 and 4.6% in mango-based agroforestry than orange-based agroforestry for bottle gourd, stem amaranth, cauliflower, and country bean, respectively. The findings suggested that although all the tested vegetables can be grown in agroforestry, but creeping type vegetables are less suitable. Despite the observed reduction in yields, the fruit tree-based agroforestry system demonstrated its potential as a viable alternative, offering to reduce crop failure risk to the farmers and optimizing land utilization. The order of the suitability of the tested vegetables are stem amaranth > cauliflower > country bean > bottle gourd in agroforestry systems. Ann. Bangladesh Agric. 27(2):191-199

Digital transformation of fruit farming in Germany: Digital tool development, stakeholder perceptions, adoption, and barriers

Digital transformation of fruit farming in Germany: Digital tool development, stakeholder perceptions, adoption, and barriers

Irrigation Targeted to Provoke Ejection of Ascospores of Venturia inaequalis Shortens the Season for Ascospore Release and Results in Less Apple Scab.

Trials were carried out in apple orchards of Emilia-Romagna and Trentino-Alto Adige in northern Italy to investigate the effects of sprinkler irrigation on possible reduction in inoculum and subsequent disease pressure of Venturia inaequalis, the ascomycete causing apple scab. In spring, volumetric spore traps were placed above apple leaf litter containing pseudothecia with ascospores of the fungus. Pseudothecia matured more rapidly in irrigated plots, and 95% of the total number of spores trapped in a season was reached on average 164 degree days (base temperature 0°C) earlier in irrigated compared with nonirrigated plots. On average for seven location/year combinations, more than 50% of the ascospores were trapped following irrigations carried out for 2 h on sunny days before a forecasted rainfall. Subsequently, a much lower number of spores were trapped on rainy days following irrigation. Field trials with scab-susceptible apple cultivars were carried out in the two regions to evaluate the efficacy of sprinkler irrigation on disease. Irrigated and nonirrigated plots were either treated with different fungicide control strategies or not treated. Irrigation significantly reduced the incidence of apple scab at both sites, and the overall number of infected leaves and fruit was reduced by more than 50%. Midday sprinkler irrigation can significantly reduce the inoculum pressure of V. inaequalis in apple orchards. This may be a sustainable management strategy, especially in areas with extended dry periods.

Tracing the contribution and fate of synthetic nitrogen fertilizer in young apple orchard agrosystems

Excessive synthetic nitrogen (N) inputs in intensive orchard agrosystems of developing countries are a growing concern regarding their adverse impacts on fruit production and the environment. Quantifying the distribution and contribution of fertilizer N is essential for increasing N use efficiency and minimizing N loss in orchards. A 15N tracer experiment was performed in a young dwarf apple orchard over two growing seasons to determine the fertilizer N transformation and fate. Fertilizer N primarily contributed to 25 % to 75 % of soil nitrate in the top 60 cm, but the contribution to soil microbial biomass N and fixed ammonium was <8 %, with the contribution to plant N ranging from 9 % to 19 %. In most growth periods, soil nitrate and fixed ammonium contents derived from native soil with N fertilization were higher than those not receiving N fertilizer. The N use efficiency of plants was only 2.6 % and 4.9 % in the first and second seasons, respectively, in contrast to 56.6 % and 54.0 % of N recovered in soil. Meanwhile, N assimilated into microbial biomass accounted for 0.8 %, and the proportion fixed by clay minerals was 3.5 %–5.2 %. One season after N fertilization, the nitrate below the 1 m soil layers accounted for 4.6 % of the applied N fertilizer, and the proportion increased to 22.5 % after two seasons. The N loss rate via N2O emission was 0.4 % over two years. The application of N fertilizer facilitated indigenous soil N mineralization, and abiotic ammonium fixation more efficiently retained synthetic N than microbial immobilization. These findings provide new insight into orchard N cycling, and attention should be given to the improvement of soil N retention and turnover capacity regulated by soil microbial and abiotic processes, as well as the potential environmental impacts of additional soil N mineralization resulting from prolonged chemical N fertilization.

First Report of Alternaria gossypina Causing Stem Base Rot on Passilora edulis in Guangxi, China.

Passion fruit (Passilora edulis), known as the "king of fruit juices", is popular in southern China (Yuan et al. 2019). Stem base rot is a devastating disease of passion fruit commonly caused by several Fusarium spp. (Zakaria, 2022). In July 2022, typical symptoms of stem base rot were observed in a poorly managed "Qinmi No. 9" Golden passion fruit orchard in Jingxi (23°13'10"N, 106°5'23"E). The disease incidence had reached 40% (n=200) in the survey. Symptoms included ulceration and mutilation at the stem base, making the plants prone to breakage when pulled, wilting and drooping leaves above ground, and severe cases leading to the entire plant withering and dying. Fourteen plants with obvious symptoms were collected. Thin sections of plant tissue were cut from junction of sickness and health of stem, sterilized with ethanol and sodium hypochlorite, and placed on PDA medium at 28°C. Sixty fungal strains were obtained, 90% of which was identified as Fusarium based on morphology. 80% of Fusarium were F. oxysporum species complex (FOSC), but pathogenicity experiment showed all FOSC were weakly pathogenic. However, two severely pathogenic fungi with similar morphology but distinct from Fusarium were identified from the same plant. The representative strain C11 was selected for further study. C11 demonstrated a rapid growth rate, reaching a 90 mm diameter colony on PDA cultured at 25°C for 7 days. The colony displaced a round, flat shape with an overall light brown front, and cottony gray or light brown mycelium, while the reverse side was dark brown. Conidia production was observed as typically occurred in multiple chains after 14 days culture on OA medium, with round, oval or straight rod-like brown conidia ranging in size from 5.74-23.42×14.67-67.22, featuring 1-8 transverse septa and 0-3 mediastinum (Figure S1). For molecular identification, the internal transcribed spacer (ITS, OR616614), translation elongation factor 1-alpha (TEF, OR633298), alternaria major allergen (Alt a1, OR633294) gene, glyceraldehyde 3-phosphate dehydrogenase (GAPDH, OR633295), RNA polymerase subunit II gene (RPB2, OR633297), 18S Small subunit rDNA (SSU, OR616608) , 28S Large Subunit rDNA (LSU, OR616615), the KOG1058 gene regions (OR633296) and an approximately segment of the anonymous noncoding region (OPA10-2, OR633299) were amplified from C11 (Liu et al. 1999, Li et al. 2023, Andrew et al. 2009), and deposited in GenBank with accession number shown in the brackets. Phylogenetic trees were constructed in MEGA11 after splicing by BioEdit (Figure S3). Combining morphology and molecular analyses, C11 was identified as Alternaria gossypina (Woudenberg et al. 2015). To test the pathogenicity, the base of the seedling stem (20cm in height) of 50 healthy "Tainong No. 1" variety of purple passion fruit, which was more susceptible to stem-base rot, was puncture wound with needles, inoculated with 6 mm diameter colonies of fungi, and then wrapped in wet cotton (Ángel et al. 2018). Ten healthy seedlings inoculated with PDA were used as controls. These plants were cultured in an artificial greenhouse at 30±5℃with 80±5% humidity. After 15 days, the plants inoculated with C11 exhibited symptoms similar to those in the field, whereas the controls remained healthy. A. gossypina was reisolated from the diseased plant stems, with the morphology and GAPDH sequence consistent with the inoculated (Figure S1, S2). This is the first report of passion fruit stem rot caused by A. gossypina. This finding will aid in the prevention and control of stem rot in passion fruit.

Biologically active substances and safety of apples of different varieties of the Ural selection

Fresh apple fruits contain various components, including mono-, di- and polysaccharides, organic acids, triterpenoids, phytosterols, polyphenols, protein, vitamins, and macro- and microelements humans need. The purpose of the research was to study the biologically active substances and safety of apples of five varieties of winter and autumn ripening: Pervouralskaya, Krasa Sverdlovskaya, Blagovaya Vesti, Sverdlovchanin, Ekrannoe - to identify the most valuable fruits from the standpoint of modern nutritionology. The apple trees grew in equal climatic and agrotechnical (drip irrigation and fertigation) conditions IP GK(F) H Filippova A.A. (Chelyabinsk region, Kaslinsky district, Grigoryevka village). It was found that the content of insoluble dietary fiber in apples of the studied varieties did not have sharp fluctuations; the variability of the indicator was 14.3%. On the contrary, the amounts of vitamin C, pectin, polyphenols, and flavonoids had significant variability - up to 275, 100, 61, and 50%, respectively, depending on the variety. Safety indicators (content of Hg, Pb, patulin, HCH, DDT) in apples did not exceed the standards of TR CU 021/20H. The nitrate content in fruits was typical for the products of intensive apple orchards. At the same time, Pb levels varied from 0.036 to 0.103 mg/kg, nitrates - from 23.4 to 35.4 mg/kg. Increased amounts of studied biologically active substances and low levels of contaminants make it possible to classify apples of the Pervouralskaya and Krasa Sverdlovsk varieties as the best fruits of this apple orchard.

Effectiveness of sod and humus soil maintenance and biologized protection in intensive apple orchards (Malus domestica Borkh.) in the south of Russia

Application of intensive technologies in horticulture with a high mechanical and chemical load on soils and fruit plants leads to deterioration of soil properties, environmental pollution, and development of resistance among pathogens and phytophages. In this study, we aim to developing a biologized technology for apple tree cultivation using a sod and humus system of inter-row maintenance and biopreparations based on active strains of microorganisms, entomoacariphages, and pheromones. The research was conducted in 2019-2023 in intensive apple orchards of the central plain-steppe region of Crimea by the methods conventionally used in soil science, agrochemistry, horticulture, and plant protection. The use of a mixture of cereal-legume grasses in combination with microbiological fertilizers based on nitrogen-fixing microorganisms was found to increase apple yields by 11–12 t/ha, or 64 % compared to the control, by increasing the number of fruits and the average weight of one fruit. A positive balance of nutrition elements in soil with an intensity of 135-270 % was established. The efficiency of controlling the number of phytophages and pathogen harmfulness through the integrated use of biological and biotechnical methods was shown. Thus, the “attract-and-kill” method for Cydia pomonella L. pheromones demonstrated a 98 % efficiency along with a reduction in pesticide load to 7.7 kg/ha season by the preparation. Release of phitoseiid mites for control of tetranychus mites by the method of seasonal colonization provides for a reduction and retention of phytophagous population at the economic threshold of harmfulness during the entire vegetation period. The use of fungicides based on pathogenic bacteria of the Bacillus genus and antagonist fungi of the Trichoderma genus against scab is eff ective only in the years unfavorable for the development of the disease. The results obtained form the basis for a biologized resource-saving technology for exploitation of intensive apple orchards. This technology contributes to increased soil fertility, reduced chemical and pesticide load, and increased productivity of horticultural agrocenosis under the conditions of the Crimea and southern Russia.

Alleviation of Apple Replant Disease in Sandy Soils by Clay Amendments

Abstract Purpose The production of apple fruits in orchards or plants in tree nurseries is negatively affected by apple replant disease (ARD), worldwide. Our objective was to develop a method to counteract ARD without applying chemical soil disinfection. We tested if an addition of clays with high release of plant available silicon reduces ARD symptoms and a biochemical effect of silicon on the plant defence reaction occurs. Methods In a greenhouse experiment, apple rootstocks ‘M26’ were grown for 8 weeks in a sandy replant soil, a heat disinfected control and a grassland soil (Grass) with and without amendment by bentonite and the clay blend Florisol®TM Profi (6 and 18%). The micromorphology of silica bodies (phytoliths) in roots and the phytoalexin concentration as a measure of the defence reaction of roots were analysed. In a second approach, the gene expression of ARD biomarkers involved in phytoalexin biosynthesis was determined after two weeks. Results Normalised gene expression was significantly higher for the ARD soil with clay amendments compared to the ARD variant whereas phytoalexin concentrations were similar. Significantly lower phytoalexin levels were found in the heat disinfected and Grass variant, indicating less defence reaction than in the ARD variant. Clay amendment increased soluble silicon in the substrates and consequently silicon in the epidermis and vascular bundles, indicating high silicon accumulation. Plants grown in ARD and Grass with amendments showed improved growth compared to plants grown in the respective soils without amendments. Conclusion The amendment of soil by clays rich in plant available silicon may counteract ARD symptoms.

Variations in Soil Organic Carbon after Farmland Conversion to Apple Orchard

The Chinese Loess Plateau has undergone extensive revegetation to restore degraded land and enhance carbon sequestration. However, soil organic carbon (SOC) sequestrated in the soil profiles of deep-rooted plants has not been fully studied. Here, we investigated the SOC within a 0–23 m profile in farmlands and apple orchards converted from farmlands with different ages (A5, &lt;5 years; A10, ~10 years; A15, ~15 years; A20, &gt;20 years) and the controlling factors on three loess tablelands (Changwu, Qingyang, and Luochuan). The results show that SOC stocks among farmlands and orchards showed no significant difference (p = 0.88); however, SOC stocks showed a trend with tree ages, i.e., a decrease for A5 and A10 but an increase for A15 and A20. For the vertical variability, the SOC stock was the highest within 0–1 m, regardless of the standing age; however, the SOC stock in this layer only accounted for 8.8% of the total SOC stock (97.93 ± 9.18 kg m−2). Climate accounted for 82% of the variations and controlled the changes in SOC in the 0–1 m range, while soil texture dominated the SOC in the soil below 1 m, accounting for 57% of the SOC variations. The variations in SOC in the thick, unsaturated zones provide implications for future land use management and the sustainability of apple orchards in arid regions.

Experimental quantification of mating disruption for false codling moth, Thaumatotibia leucotreta (Lepidoptera: Tortricidae), in stone fruit and table grape cultivation

Mating disruption is the broadcasting of female pheromones within an agricultural system to interfere with, or decrease, the reproductive potential of the pest insect. Seen as a sustainable, nonchemical management method, it is used in citrus orchards against false codling moth (FCM), Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae). Research to support its efficacy against FCM is limited, especially in stone fruit and table grapes. Previous efforts to quantify mating disruption against FCM have yielded inconsistent results, highlighting the necessity for additional investigation. In the present study, an experimental design that provides reliable results was evaluated. Following their release in a stone fruit orchard and a table grape vineyard, sterile males were recaptured with a trapping grid every 24 h, for five days. Trapping efficiency, trap interference and recaptures of wild and sterile moths were compared. Factors that improved the reliability of results included the use of mark-release-recapture experiments, using a nine-trap layout and a paired control, which ensured that only one variable was changed. Experimental blocks were then either treated with 400 or zero pheromone dispensers/ha. The current study reports the first experimental evidence that mating disruption is an effective control method against FCM in stone fruit and table grapes. Mating disruption was calculated at 86% in stone fruit and 93% in table grapes, with less than the field dose, indicating that mating disruption shows promise as a control technique against FCM, in both stone fruit and table grapes. The present study, therefore, sets a solid foundation for further research into the mechanistic understanding of how the pest is disrupted, as well as into calculating the dosage causing the highest level disruption with the smallest amount of pheromone.

Insights into Nipah Virus: A Review of Epidemiology, Pathogenesis, and Therapeutic Advances

Emerging as a WHO priority pathogen, Nipah virus (NiV) – an RNA virus within the Paramyxoviridae family – first ignited outbreaks in 1998 Malaysia. Closely related to Hendra virus, NiV continues to threaten South and Southeast Asia. A zoonotic threat, Nipah virus (NiV) jumps from its natural reservoir, fruit bats, to pigs and then humans. This BSL-4 threat, with no cure or shield, compels us to harmonise the voices of humans, animals, and the environment in a One Health symphony to prevent future outbreaks. A 2018 Chinese study identified populations at high risk for Nipah virus infection are Fruit farmers, traders, palm wine brewers, Cattle herders, especially pig farmers and Tourists. Nipah virus exhibits remarkable zoonotic versatility, with transmission pathways between humans and animals varying based on geography. Factors such as diverse livestock breeding practices, local eating habits, and the interplay with the natural reservoir - fruit bats - contribute to this fascinating mosaic of infection routes. Unravelling these complexities is crucial for designing effective control strategies tailored to specific regions. Following exposure to the Nipah virus (NiV), symptoms typically appear within two weeks, ranging from 4 days to 2 months. Fever, headache, dizziness, and vomiting are common initial signs, potentially progressing to severe encephalitis. A promising development in the fight against Nipah virus emerges as the National Institute of Allergy and Infectious Diseases (NIAID) initiates an early-phase clinical trial for an investigational vaccine.

Tuning the Proportional-Integral-Derivative Control Parameters of Unmanned Aerial Vehicles Using Artificial Neural Networks for Point-to-Point Trajectory Approach.

Nowadays, trajectory control is a significant issue for unmanned micro aerial vehicles (MAVs) due to large disturbances such as wind and storms. Trajectory control is typically implemented using a proportional-integral-derivative (PID) controller. In order to achieve high accuracy in trajectory tracking, it is essential to set the PID gain parameters to optimum values. For this reason, separate gain values are set for roll, pitch and yaw movements before autonomous flight in quadrotor systems. Traditionally, this adjustment is performed manually or automatically in autotune mode. Given the constraints of narrow orchard corridors, the use of manual or autotune mode is neither practical nor effective, as the quadrotor system has to fly in narrow apple orchard corridors covered with hail nets. These reasons require the development of an innovative solution specific to quadrotor vehicles designed for constrained areas such as apple orchards. This paper recognizes the need for effective trajectory control in quadrotors and proposes a novel neural network-based approach to tuning the optimal PID control parameters. This new approach not only improves trajectory control efficiency but also addresses the unique challenges posed by environments with constrained locational characteristics. Flight simulations using the proposed neural network models have demonstrated successful trajectory tracking performance and highlighted the superiority of the feed-forward back propagation network (FFBPN), especially in latitude tracking within 7.52745 × 10-5 RMSE trajectory error. Simulation results support the high performance of the proposed approach for the development of automatic flight capabilities in challenging environments.

Good agricultural practices (GAP) adoption intensity and production constraints in apple orchards of western Nepal

The declaration of ‘Fruits Decade 2016/17–2026/27’ and the enaction of the ‘NepalGAP Scheme’ by the Government of Nepal has redirected increased public investments to promote apple production and marketability in the western high hills of Nepal. This study explores major good agricultural practices (GAP) related to orchard management, factors influencing their adoption intensity, and key underlying constraints to production using cross-sectional survey data from apple growers in Dolpa district, Nepal. The results showed that farmers mostly adopted GAP such as frequent weeding, intercropping, and nutrient management in apple orchards. Based on the negative binomial regression estimates, household characteristics such as gender of the orchard owner, experience, and number of literate household members were found influential in determining the GAP adoption intensity. The analysis of the problem severity index implied that apple production is mostly constrained by limited access to production inputs and transportation. The findings provide useful insights to the farmers and policymakers regarding the current scenario of GAP adoption along with the diversity of barriers that severely limits the realization of apple production potential in western Nepal.

On the Interplay Between Duration of Employment, Relational Quality and Wages—Results About Non-Family Farm Workers in Switzerland

Our knowledge on non-family farm workers has been hampered by a lack of reliable and relevant data. This study tackled this problem by asking Swiss managers of fruit, wine and vegetable farms about their employees. Using a dataset of 921 employees, we explain the duration of the labour contract, the level of wages and the relational quality between employers and workers. The level of wages and other resources like shelter are linked to employment duration but also to social factors like joint social events or the perception of relational quality by employers. Workers with the liberty to allocate their labour time have better relationships with their employers. The best wages are paid to full-time male employees with agricultural education residing in Switzerland. The fact that Swiss citizens receive a significant reduction in their payment compared to foreigners may point to a grey zone between unpaid family labour and market-based employment relations.

Pesticide risk during commercial apple pollination is greater for honeybees than other managed and wild bees

Abstract Most pesticide research has focussed on risk to managed honeybees, but other managed and wild bees are also exposed to pesticides. Critically, we know little about the magnitude and sources of risk to honeybees compared with other bees during crop pollination. To compare pesticide exposure and risk across wild and managed bees, we sampled the main bee groups present during bloom in 20 apple orchards, including managed honeybees (Apis mellifera), managed bumblebee workers (Bombus impatiens), wild mining bees (Andrena spp. and Andrena [Melandrena] spp.), bumblebee foundress queens (Bombus impatiens) and eastern carpenter bees (Xylocopa virginica). We screened all bees for 92 pesticides and computed a Risk Quotient using available toxicity data (honeybee LD50s), adjusting for differences in toxicity known to scale with body mass. To gain insight into exposure origin, we compared residues in bees to those in focal orchard apple and dandelion flowers. Nearly all bee samples contained pesticides (95%), with the average contamination level ranging from 7.1 ± 2.8 parts per billion (ppb) in B. impatiens workers to 388.4 ± 146.2 ppb in Andrena. Exposure profiles were similar for all bees except A. mellifera, whose unique exposure profile included high levels of the neonicotinoid insecticide thiamethoxam. All bee groups except wild B. impatiens queens had at least one sample exceeding a US Environmental Protection Agency or European Food Safety Authority exposure level of concern. Apis mellifera experienced significantly greater risk than other bee groups, with 63% and 81% of samples exceeding an acute or chronic exposure level of concern, respectively. Risk to honeybees was driven primarily by high thiamethoxam levels not found in focal orchard flowers and likely originating outside the orchard. Synthesis and applications: We find that pesticide exposure and risk differ between honeybees and other managed and wild bees during apple pollination. Furthermore, pesticide exposure is a landscape‐scale phenomenon and therefore measures to reduce exposure must consider the surroundings beyond focal farms. Limiting orchard sprays, while reducing on‐farm exposures, will not protect far‐foraging bees from off‐farm exposures such as thiamethoxam, which we hypothesize is coming from nearby seed‐treated corn fields planted during apple bloom.

Nitrogen-fixing bacterial communities differ between perennial agroecosystem crops.

Biocrusts, common in natural ecosystems, are specific assemblages of microorganisms at or on the soil surface with associated microorganisms extending into the top centimeter of soil. Agroecosystem biocrusts have similar rates of nitrogen (N) fixation as those in natural ecosystems, but it is unclear how agricultural management influences their composition and function. This study examined the total bacterial and diazotrophic communities of biocrusts in a citrus orchard and a vineyard that shared similar climate and soil type but differed in management. To contrast climate and soil type, these biocrusts were also compared to those from an apple orchard. Unlike natural ecosystem biocrusts, these agroecosystem biocrusts were dominated by proteobacteria and had a lower abundance of cyanobacteria. All examined agroecosystem biocrust diazotroph communities were dominated by N-fixing cyanobacteria from the Nostocales order, similar to natural ecosystem cyanobacterial biocrusts. Lower irrigation and fertilizer in the vineyard compared to the citrus orchard could have contributed to biocrust microbial composition, whereas soil type and climate could have differentiated the apple orchard biocrust. Season did not influence bacterial and diazotrophic community composition of any these agroecosystem biocrusts. Overall, agricultural management and climatic and edaphic factors potentially influenced community composition and function of these biocrusts.

Combination of functional plants conserves predators, repels pests, and enhances biological control of Aphis spiraecola in apple orchards

Functional plants possess the ability to attract natural enemies or repel pests, and they play an important role in ecological regulation. While most studies have focused on the impacts of individual plants or plant combinations with similar functions on pests, there is a scarcity of research on the effects of combining plants with different functions, particularly in the case of orchard pests. In this study, we combined plants (Cnidium monnieri (L.) or Brassica napus L.) that attract predators with plants (Ocimum basilicum L. or Mentha haplocalyx Briq.) that repel pests to determine if these combinations can enhance biocontrol of Aphis spiraecola Patch on apple trees. All four combinations reduced the A. spiraecola population on apple trees. B. napus & M. haplocalyx achieved the highest reduction rate (88.58%), followed by C. monnieri & O. basilicum (88.06%), B. napus & O. basilicum (86.11%), and C. monnieri & M. haplocalyx (79.41%). Cage exclusion tests on 29 June and 4 July 2023 showed that biocontrol services index of all combinations was significantly higher than that of the control. Rubidium marking test showed that 61.90%–71.43% of Chrysoperla sinica (Tjeder) individuals in trees had transferred from functional plants. Behavioral responses and field trapping indicated that compounds such as cis-citral, nepetalactone, caryophyllene, beta-pinene, and eugenol, which are present in repellent plants, had significant repellency against A. spiraecola. The use of functional plant combinations in apple orchards can enhance biocontrol of A. spiraecola by promoting predators and by repelling aphid. This supports the potential of functional plant combinations in agroforestry ecosystems for pest biocontrol.

Effects of cultivar, planting density and rootstock on long-term economic performance of apple orchards in the Northeastern U.S.

An economic analysis of profitability using Net Present Value (NPV) was conducted using data from two long-term training system × rootstock field trials conducted in New York State from 2006 to 2016 (Dressel Farm in southeastern New York State and VandeWalle Farm in Western, New York State). We used trial data for the first 11 years and estimated values for years 12–20 using average data from the last 4 years of field data. The field trials compared four training systems with different planting densities (Slender Pyramid, 840 trees ha−1; Vertical Axis, 1282 trees ha−1; Slender Axis, 2244 trees ha−1; and Tall Spindle, 3262 trees ha−1) each evaluated with several rootstocks in an incomplete factorial treatment list and with two cultivars at each location. By the end of the trial (11 years) all combinations of planting density, rootstock and cultivar were profitable (NPV positive) at the VandeWalle site but at the Dressel site seven combinations of rootstock and planting density with ‘Fuji’ and two combinations with ‘Gala’ were not profitable. Projected profitability over 20 years using estimated yields and fruit quality for years 12–20 showed that all combinations would be profitable by year 20. Estimated 20-year NPV was greatest with the Tall Spindle system with the highest planting density compared to the other lower density systems. Economic performance was mostly driven by planting density, regardless of the rootstock selection. Among cultivars, ‘Honeycrisp’ had significantly higher profitability largely due to high fruit price). ‘Gala’ had intermediate profitability due to high yields and medium fruit price while ‘Fuji’ which had low fruit price had significantly lower profitability than ‘Gala’. Among rootstocks, there was a significant interaction with training system and cultivar, so the same rootstock was not the most profitable with every cultivar and system. With ‘Fuji’ the most profitable combination was on G.16 rootstock planted at the highest density, however, it was not significantly better than with G.11 or M.9. With ‘Gala’ at Dressel farm the most profitable combination was on G.11 in the Tall Spindle system (planted at the highest density) but it was not significantly better than with G.16, G.41, M.9 or B.9. With ‘Gala’ at VandeWalle farm the most profitable combination was on G.41 planted at the highest density but it was not significantly better than on G.11, G.16, M.9 or B.9. With ‘Honeycrisp’ the most profitable combination was on M.9 planted at the highest density but it was not significantly better than G.11, G.16, G.41 or B.9. A sensitivity analysis showed that among economic parameters affecting the long-term profitability of an orchard, fruit price and yield were vastly more important than other factors. Of intermediate importance were the discount rate and labor costs while of much lesser importance were tree costs and land costs.

Assessment of satellite-based water requirements for a drip-irrigated apple orchard in Mediterranean agroclimatic conditions

Accurate assessment of evapotranspiration (ETa) and crop coefficient (Kc) is crucial for optimizing irrigation practices in water-scarce regions. While satellite-based surface energy balance models offer a promising solution, their application to sparse canopies like apple orchards requires specific validation. This study investigated the spatial and temporal dynamics of ETa and Kc in a drip-irrigated ‘Pink Lady’ apple orchard under Mediterranean conditions over three growing seasons (2012/13, 2013/14, 2014/15). The METRIC model, incorporating calibrated sub-models for leaf area index (LAI), surface roughness (Zom), and soil heat flux (G), was employed to estimate ETa and Kc. These estimates were validated against field-scale Eddy Covariance data. Results indicated that METRIC overpredicted Kc and ETa with errors less than 10 %. These findings highlight the potential of the calibrated METRIC model as a valuable decision-making tool for irrigation management in apple orchards.

A computer vision system for apple fruit sizing by means of low-cost depth camera and neural network application

AbstractFruit size is crucial for growers as it influences consumer willingness to buy and the price of the fruit. Fruit size and growth along the seasons are two parameters that can lead to more precise orchard management favoring production sustainability. In this study, a Python-based computer vision system (CVS) for sizing apples directly on the tree was developed to ease fruit sizing tasks. The system is made of a consumer-grade depth camera and was tested at two distances among 17 timings throughout the season, in a Fuji apple orchard. The CVS exploited a specifically trained YOLOv5 detection algorithm, a circle detection algorithm, and a trigonometric approach based on depth information to size the fruits. Comparisons with standard-trained YOLOv5 models and with spherical objects were carried out. The algorithm showed good fruit detection and circle detection performance, with a sizing rate of 92%. Good correlations (r &gt; 0.8) between estimated and actual fruit size were found. The sizing performance showed an overall mean error (mE) and RMSE of + 5.7 mm (9%) and 10 mm (15%). The best results of mE were always found at 1.0 m, compared to 1.5 m. Key factors for the presented methodology were: the fruit detectors customization; the HoughCircle parameters adaptability to object size, camera distance, and color; and the issue of field natural illumination. The study also highlighted the uncertainty of human operators in the reference data collection (5–6%) and the effect of random subsampling on the statistical analysis of fruit size estimation. Despite the high error values, the CVS shows potential for fruit sizing at the orchard scale. Future research will focus on improving and testing the CVS on a large scale, as well as investigating other image analysis methods and the ability to estimate fruit growth.