Fruit Rot Incidence Research Articles

Association of meteorological variables with leaf spot and fruit rot disease incidence in eggplant and YOLOv8-based disease classification

Eggplant is one of the major vegetables consumed worldwide. Several fungal, bacterial, and viral diseases challenge the yield and quality of eggplant. The incidence of plant diseases is strongly influenced by weather factors such as temperature, humidity, rainfall, and wind speed. Mattu Gulla (MG) is a GI-tagged traditional variety of eggplant grown in Mattu village of the Udupi district in Karnataka state, India, with a cultural legacy of more than four centuries. In this study, we investigated the relationships between weather parameters and disease incidence in Mattu Gulla. Leaf spot (LS) and fruit rot (FR) are the major diseases affecting this plant variety. The influence of plant age and weather parameters on the modulation of the disease incidence (%) [DI (%)] of leaf spot and fruit rot was recorded and analyzed via correlation and regression. Prediction equations for disease incidence was derived via regression. A significant negative correlation was observed between the leaf spot DI (%) and minimum temperature (Min. temp), and a positive correlation was observed between the DI (%) and fruit rot. In the case of FR, the DI (%) is also significantly positively correlated with wind speed (WS), temperature, maximum relative humidity (RH I), rainfall (RF), and wind speed (WS). An RH I of 86–87 % was favorable for the incidence of fruit rot in the field. Regression analysis revealed a significant association between Min. temp and leaf spot DI (%), and in the case of fruit rot DI (%), the association was with Min. temp and WS. An android application, “Leaf Guard,” has been developed for AI-based disease detection in eggplant. During testing, the accuracy of the trained model reached 98.2 %.

Assessment of Hast Bahar (Flowering Season) for Yield and Quality of Pomegranate at Farmer’s Field

An on-farm trail (OFT) on assessment of flowering season of pomegranate was tested. The experiment was conducted with three treatments comprising mrig bahar flowering as a control and hast bahar flowering with and without application of micronutrients and kaolin clay during June to February for three consecutive years from 2019–2022 in the different farmer fields at the Tharad taluka of Banskantha district, Gujarat, India. The treatment T1 Mrig bahar (June-July) flowering recorded the maximum total number of flowers (293.67) hermaphrodite flowers (108.9) and fruit setting (71.85%). Further, T1 exhibited the highest average number of fruits plant-1 (79.0) and maximum fruit yield (11.78 kg plant-1) followed by T3 and T2 treatments (10.14 kg plant-1 and 9.02 kg plant-1) respectively. In terms of total fruit yield, Treatment T1 exhibited the highest fruit yield of (9813 kg ha-1). Whereas, maximum individual fruit weight 179.44 g plant-1 and Total Soluble Solids (15.75°Brix) were found in Treatment T3. Moreover, treatment T3 Hast Bahar (Sept–Oct) flowering with foliar spray of micromix 0.2% and kaolin Clay 4.0%) has the lowest average fruit cracking (6.30%) and the lowest incidence of sunburn (8.80%) across the three years. However, treatment T1 recorded highest average fruit cracking (18.90%). Further, during the Mrig bahar season, incidence of leaf spots and fruit rot was observed higher compared to the Hast bahar flowering. In case of economics, treatment T3 obtained the highest average income of 411813 ha-1 as compared to treatment T2 and T3 ` 353074 ha-1 and 333425 ha-1, respectively.

First report of anthracnose fruit rot of papaya caused by Colletotrichum gigasporum in China.

Papaya (Carica papaya L.) belonging to the family Caricaceae is well known for its economic and nutritional value. Anthraconse caused by Colletotrichum spp. is a main postharvest disease of papaya fruit during storage (Cia et al., 2007). In July 2022, papaya fruits with anthracnose symptoms were collected in Changjiang County (108.996180E, 19.246560N), Hainan Province, China. The disease incidence of fruit rot reached 6.3%. Initial symptoms appeared as the watery lesions with tiny black spots, turning to dark brown, sunken necrotic lesions. The diseased tissues were cut into 18 pieces (5×5 mm) from 6 papaya fruits, disinfected with 2% sodium hypochlorite for 60 s, and rinsed three times with sterilized water. The pieces were air-dried and then placed on potato dextrose agar (PDA) at 28 ℃ for five days. Twelve isolates with similar morphology were obtained from 18 tissue pieces. Three isolates (FMG01, FMG02 and FMG03) were selected for morphological identification, molecular identification, and pathogenicity tests. Colonies were initially white, then gradually became dark grey on PDA. The ascospores were hyaline, fusoid, rounded at both ends, 37.43-84.32 (55.79±7.61) μm × 4.30-6.55 (5.36±0.60) μm (n=50). The conidia were hyaline, unicellular, long cylindrical, bluntly rounded at both ends, 11.59-25.54 (18.62±2.33) μm × 5.12-8.44 (7.19±0.62) μm (n=100). Appressoria were gray to dark brown, irregular, pyriform, or ovoid, 10.14-21.40 (13.81±2.25) μm × 6.05-11.85 (9.16±1.29) μm (n=50). Morphological features are similar to Colletotrichum gigasporum identified and described by Rakotoniriana et al (Rakotoniriana et al., 2013). In order to accurately identify the isolates, the internal transcribed spacer region (ITS) of the rDNA, the glyceraldehyde-3-phosphate dehydrogenase (GAPDH), the partial actin (ACT), the beta-tubulin (TUB2) and the calmodulin (CAL) genes were amplified and sequenced (Cannon et al., 2012). The nucleotide sequences were deposited into GenBank (accession numbers, ITS: OR017446 to OR017448, GAPDH: OR042810 to OR042812, ACT: OR042813 to OR042815, TUB2: OR042816 to OR042818, CAL: OR042819 to OR042821). Based on the BLASTn analysis, these sequences were more than 99% with the reference strain CBS 125476 of C. gigasporum sequences (ITS: MH863698, GAPDH: KF687833, ACT: KF687790, TUB2: KF687875, CAL: KF687814), respectively. The results of the multilocal phylogenetic analysis showed that the three isolates were C. gigasporum based on the Maximum Likelihood and Bayesian inference method. The pathogenicity test was performed by wounded with a sterile needle on the surface-sterilized papaya fruits. The mycelial discs (5 mm diameter) of three isolates were inoculated orderly on the same fruit, and the same inoculation was applied to non-wound papaya fruits. The control group were inoculated with sterilized PDA. Each treatment carried out with 9 fruits. The inoculated fruits were placed at 28 ℃ in plastic preservation boxes (32×22×11 cm) with sterilized distilled water to maintain high humidity. After 5 d of inoculation, typical anthracnose symptoms were observed on wound fruits and the non-wound fruits developed symptoms at 7 dpi, control fruits were symptomless. The fungi re-isolated from the inoculated fruits lesions after inoculation and identified by morphological characterization and molecular identification, fulfilling Koch's postulates. C. gigasporum has been reported causing leaf rot of Dalbergia odorifera in China (Wan et al., 2018). To our knowledge, this is the first report of anthracnose fruit rot of papaya caused by C. gigasporum in China.

The influence of the summer pruning on ‘Fuji’ apples storage under controlled atmosphere

This study aimed to evaluate the effect of the summer pruning time in ‘Fuji’ apple trees on the quality of fruit at harvest and after storage in controlled atmosphere with extremely low O2 (CA-ELO) (0.5 kPa O2). The treatments evaluated were summer pruning in December, January, and February, in addition to a control treatment (without summer pruning). The experiment was carried out in the 2018/2019 and 2019/2020 growing seasons. The fruit were evaluated at harvest and after eight months of CA-ELO (0.5 kPa O2 + <0.5 kPa CO2/1.5 ± 0.2°C/92 ± 2% RH) storage, at chamber opening, and after 7 days of shelf-life at 23 ± 3°C and 60 ± 5% RH. The quality of the fruit was evaluated through of soluble solids, flesh firmness, titratable acidity, fruit color, and physiological disorder incidence (sunburn and flesh browning), in addition to enzymatic activity and concentration of functional compounds. There was no significant effect of the summer pruning time on fruit flesh firmness, soluble solids, titratable acidity, and rot incidence after storage under CA-ELO plus 7 days of shelf life. Summer pruning in February resulted in fruit with higher peel red color development, which in general contains a higher concentration of functional compounds at harvest (total phenolic compounds and total antioxidant activity), and lower flesh browning incidence in ‘Fuji’ apples stored under CA-ELO. The nitrogen (N) concentration and nitrogen/calcium ratio (N/Ca) in the second growing season were lower in fruit from plants pruned in February, compared to no summer pruning or earlier pruning. The superoxide dismutase and peroxidase enzyme activity were lower in fruit from treatments with summer pruning in January and February, whereas the polyphenol oxidase enzyme activity was lower when summer pruning was conducted in February.

Prevalence and spatial distribution of cranberry fruit rot pathogens in British Columbia, Canada and potential fungicides for fruit rot management.

Twenty-eight cranberry farms in southwestern British Columbia were investigated for the prevalence and spatial distribution of fungal pathogens that contribute to fruit rot incidence. Farms were selected from six regions where most cranberry production is concentrated. Flowers, and green and ripe fruit (var. 'Stevens') samples, collected during two consecutive crop seasons, were analyzed for fruitrot pathogens. The most frequently isolated pathogens were identified asAllantophomopsis cytisporea, Botrytis cinerea, Coleophoma empetri, Colletotrichum fioriniae, Colletotrichum gloeosporioides, Fusicoccum putrefaciens, Glomerella sp., Phomopsis vaccinii, Phyllosticta elongata, Phyllosticta vaccinii and Physalospora vaccinii. The pathogens Allantophomopsis cytisporea, Phyllosticta spp., and Physalospora vaccinii were found at high incidence. These pathogens were present in all cranberry growing regions, although their mean percentage incidence varied from farm-to-farm and region-to-region. Amongst the pathogens from three phenological stages of cranberry crop examined, ripe fruit had the highest percentage incidence of fruit rot pathogens compared to that of flowers or green fruit; thus, indicating their presence at the early stages of crop development. The efficacy to inhibit the mycelial growth and spore germination of the fruit rot pathogens by twenty six fungicides, belonging to nine different modes of actions, were evaluated in vitro. The copper-based fungicides and captan of group M, flutriafol, triforine, difenoconazole, prothioconazole and propiconazole of group 3, benzovindiflupyr of group 7, and fosetyl-Al of group 33 demonstrated a high degree of efficacy in inhibiting the mycelial growth of all fruit rot pathogens. The fungicides chlorothalonil of group M, fenbuconazole of group 3, pyrimethanil and cyprodinil of group 9, and fludioxonil of group 12 also demonstrated activity against most fruit rot pathogens. The copper-based fungicides, chlorothalonil, captan, flutriafol, triforine, difenoconazole, prothioconazole, propiconazole, benzovindiflupyr, and fosetyl-Al effectively prevented the spore germination of most fruit rot pathogens. This demonstrated activity of the fungicides towards cranberry fruit rot pathogens should be assessed for efficacy in planta under field conditions. The current study identified the most critical fungal pathogens causing fruit rot of cranberry in British Columbia and potential fungicides that could be used in the management of fruit rot and to improve fruit quality and yield.

Peroxyacetic acid and hydrogen peroxide crop sanitizer efficacy against fungi and Drosophila suzukii in blackberries

Beyond their post-harvest disinfestation of produce, crop sanitizers show promise as broad-spectrum pre-harvest pesticides that could simultaneously target plant pathogens and insect pests. Fruit rots and spotted-wing drosophila damage blackberries globally and are difficult to manage, especially in organic production systems. An Organic Materials Review Institute (OMRI) approved peroxyacetic acid (PAA) and hydrogen peroxide (HP) crop sanitizer was evaluated in blackberries for its impact on fruit fungal communities and spotted-wing drosophila infestation in a two-year field experiment with a commercial sprayer. To better understand PAA-HP's efficacy against specific fungal isolates and communities, we also performed laboratory agar plug diffusion as well as fruit dip assays. Few previous studies have characterized blackberry yeast and non-yeast fungal communities. Over two years at one site, twenty-five yeast-like genera were isolated, with Curvibasidium spp., Hanseniaspora spp., and Aureobasidium spp. occurring most frequently. Cladosporium spp. consistently occurred most frequently out of the thirteen non-yeast fungal genera that were isolated. PAA-HP occasionally reduced fruit yeast and non-yeast fungal abundance in the field, but did not impact spotted-wing drosophila infestation or fruit rot incidence. In the laboratory, PAA-HP prevented and inhibited growth of multiple fruit rot fungi in agar plug diffusion assays, and also reduced yeast and fruit rot abundance in fruit dip assays. In all cases in the field and laboratory live fungi remained on the fruit. This crop sanitizer product does not provide sufficient standalone control of fruit rots or spotted-wing drosophila in blackberries, which experience relatively heavy pest pressure.

Fungitoxic role of endogenous eugenol in the hybrid grapevine cultivar Baco blanc resistant to <i>Botrytis cinerea</i>

Eugenol (2-methoxy-4-(2-propenyl)-phenol), widely spread in various plants, notably clove, basil and bay, is a well-known antifungal and antibiotic molecule that is abundant in the hybrid grapevine cultivar Baco blanc (Vitis vinifera × Vitis riparia × Vitis labrusca). This variety, created by François Baco (19th century), is confirmed in this study as highly resistant to Botrytis cinerea by comparing fruit rot incidence and severity with two Vitis vinifera cultivars: Folle Blanche and Ugni Blanc. According to two major antibiosis modes of action, i.e., direct or volatile, this study demonstrated the efficiency of eugenol in vitro by also investigating precisely the effect on B. cinerea of small concentrations of eugenol, 3 to 4 ppm, corresponding to IC10. Moreover, the vapour-inhibiting effect was shown to be highly powerful. The total eugenol concentration peaked at the veraison stage, exceeding 1000 μg×kg-1 in the skin of Baco blanc berry under our conditions. At this point, leaf removal in the bunch zone induced a significant increase in eugenol (32 %), from 1118 to 1478 μg×kg-1, which was also associated with a significant decrease in B. cinerea infection in the vineyard. Thus, for the first time, eugenol, as an endogenous molecule of Baco blanc, was clearly demonstrated to be an inducible compound in the vineyard. Furthermore, significant intravarietal variability in eugenol concentrations according to the Baco blanc clone was demonstrated to be associated with significant differences in fruit susceptibility to the plant pathogen assessed in biotests. Interestingly, in keeping with fruit ontogenic resistance, a significant negative correlation was established between the technological maturity of berries and the total eugenol content in the berry skin. Finally, the time-progress study of the two biochemical forms of eugenol (bound vs. free eugenol) allowed us to hypothesise the effectiveness against the plant pathogen of some precursor forms of eugenol, and the corresponding biochemical structures are currently being investigated. Thus, eugenol appears to be a key biochemical marker of ontogenic resistance in the hybrid cultivar Baco blanc.

First Report of Fruit Rot Caused by Diaporthe amygdali on Papaya in Punjab, Pakistan.

Papaya (Carica papaya L.) is grown widely in tropical and sub-tropical regions (Ahmed et al. 2008). In Pakistan, papaya production and consumption are increasing due to its medicinal, nutritional, pharmacological properties and a rich source of antioxidant, vitamin B, potassium, and magnesium. In November 2021, 26 to 35% incidence of fruit rot was observed in 15 fields of Lahore, a district of Punjab, Pakistan. Affected fruit developed circular, gray-to-brown lesions (8 to 10 mm in diameter) with white mycelia forming on the surface of lesions. In advanced stages of the disease, the lesions enlarged in size and led to the rot of entire fruit. To isolate the causal agent, small tissue segments (1 to 2 cm) were excised from 15 symptomatic fruit, surface disinfected with 1% NaClO for 30 s, rinsed with sterile distilled water three times, air dried in laminar flow hood, aseptically transferred onto petri dishes containing potato dextrose agar (PDA) and incubated at 25℃ for 5 days with a 12-h photoperiod. Eleven isolates were obtained that produced white mycelia on PDA. Flask-shaped, dark-pigmented pycnidia formed on PDA after 18 days of incubation at 25°C, which produced α-conidia measuring 4.1 to 7.2 × 1.5 to 3.0 μm and β-conidia measuring 16.4 to 25.5 × 1.0 to 1.6 μm (n = 40). α-conidia were hyaline, fusiform, and single-celled, whereas β-conidia were one-celled, hyaline, and filiform. The morphological characteristics of the fungus were compatible with a Diaporthe species (Gomes et al. 2013). The internal transcribed spacer region (ITS) (OM865414 and OM865415), translation elongation factor 1-alpha (tef1) (OM831226 and OM831229), and histone H3 (HIS) (OM831227 and OM831228) of two representative isolates (UO02 and UO03) were amplified and sequenced using primers ITS1/ITS4 (White et al. 1990), EF1-728F/EF1-986R (Carbone and Kohn 1999), and CYLH3F/H3-1b (Chaisiri et al. 2021), respectively. Blast searches showed 99 to 100% nucleotide identity with reference sequences of several Diaporthe amygdali deposited in NCBI GenBank, including the ex-type strain CBS 126679. A pathogenicity test was also performed on harvested fruit of papaya cv. Bombay using isolates UO02 and UO03. Ten mature and healthy papaya fruit were surface disinfected with 1% NaClO solution for 1 min, rinsed with sterile water and dried. Each fruit was wounded twice with a sterile scalpel (4 to 5 mm incision on the peel) and a 5-mm agar disc with mycelia of each isolate was separately placed in each wound. The wounds were wrapped with Parafilm following inoculation. Sterile PDA plugs were used in separate inoculated controls. All wounds were sealed with parafilm. All fruit were maintained in plastic boxes at 25°C with 80% relative humidity. After 6 days of incubation, rot symptoms similar to those appearing on naturally-infected fruit were observed on inoculated fruits while controls remained asymptomatic. The experiment was repeated twice with similar findings. Diaporthe amygdali was re-isolated (100%) from inoculated fruit and the pathogen identification was confirmed by morphological and molecular analysis, thus fulfilling Koch's postulates. Previously, the pathogen has been reported as a causal agent of canker and shoot blight disease in other countries (Ko and Sun, 2003; Beluzan et al. 2021). To our knowledge, this is the first report of D. amygdali on papaya in Punjab Province of Pakistan. Papaya is an emerging fruit crop in Punjab Province and it is important to further investigate the presence of this pathogen in other papaya orchards of the province since D. amygdali may cause rapid disease outbreaks resulting in severe losses.

Assessment of seed quality parameters in fruit rot infected seeds of brinjal caused by Phomopsis vexans and development of eco-friendly management for quality seed production

Phomopsis vexans is an important seed-borne pathogen and it is highly detrimental to brinjal crop. Among seventeen brinjal genotypes studied for the effect of fruit rot on the seed quality parameters using infected and healthy seeds, the germination percentage of infected seeds is relatively lower than the healthy seeds. The reduction in germination percentage of diseased seeds varied between 14 to 67%. Seed quality parameters like germination and vigour were negatively correlated and the electrical conductivity was positively correlated with fruit rot incidence. This shows that a higher incidence of pathogens will lower the viability and vigour of seeds and the infection level is also dependent on genotype and the environmental condition. The three known biocontrol agents were analyzed by using the dual culture technique for the antagonistic effect on the pathogens. The results showed that out of three biocontrol agents, Trichoderma harzianum showed maximum antagonistic effect followed by Pseudomonas fluorescence and Bacillus subtilis. Different modes of action like mycoparasitism, competition, antibiosis and production of antibiotics and secondary metabolites like harzianiol may act as inhibitors against Phomopsis vexans.

First Report of Fruit Rot of Cherry and Its Control Using Fe2O3 Nanoparticles Synthesized in Calotropis procera.

Cherry is a fleshy drupe, and it is grown in temperate regions of the world. It is perishable, and several biotic and abiotic factors affect its yield. During April–May 2021, a severe fruit rot of cherry was observed in Swat and adjacent areas. Diseased fruit samples were collected, and the disease-causing pathogen was isolated on PDA. Subsequent morphological, microscopic, and molecular analyses identified the isolated pathogen as Aspergillus flavus. For the control of the fruit rot disease of cherry, iron oxide nanoparticles (Fe2O3 NPs) were synthesized in the leaf extract of Calotropis procera and characterized. Fourier transform infrared (FTIR) spectroscopy of synthesized Fe2O3 NPs showed the presence of capping and stabilizing agents such as alcohols, aldehydes, and halo compounds. X-ray diffraction (XRD) analysis verified the form and size (32 nm) of Fe2O3 NPs. Scanning electron microscopy (SEM) revealed the spinal-shaped morphology of synthesized Fe2O3 NPs while X-ray diffraction (EDX) analysis displayed the occurrence of main elements in the samples. After successful preparation and characterization of NPs, their antifungal activity against A. flavus was determined by poison technique. Based on in vitro and in vivo antifungal activity analyses, it was observed that 1.0 mg/mL concentration of Fe2O3 can effectively inhibit the growth of fungal mycelia and decrease the incidence of fruit rot of cherry. The results confirmed ecofriendly fungicidal role of Fe2O3 and suggested that their large-scale application in the field to replace toxic chemical fungicides.

Characterization of Colletotrichum strains associated with olive anthracnose in Sicily

Anthracnose caused by Colletotrichum spp. is the most damaging olive fruit disease in many countries, including Italy. This disease has been sporadically detected in Sicily, but new agronomic practices can increase risk of olive anthracnose in this region. An etiological study of the disease focused on local olive cultivars growing at the International Olive Germplasm Collection (IOGC) in Villa Zagaria, Enna, Sicily has been undertaken. During 2018 and 2019, 137 Colletotrichum strains were isolated from olives. Colony morphology, conidium characteristics, and multilocus sequence analyses aided identification of three species: C. acutatum (affecting 70% of symptomatic olives), C. gloeosporioides, and C. cigarro. Three C. acutatum strains (B13-16, P77, and P185), and one strain of each C. gloeosporioides (C2.1) and C. cigarro (Perg6B) were evaluated for pathogenicity on olive fruits from 11 Sicilian cultivars, known for their high-quality oil. Differences in virulence were detected among strains and their pathogenicity to the cultivars. The C. acutatum isolates were more virulent than those of C. gloeosporioides or C. cigarro. The Sicilian olive cultivars Cavaliera, Carolea, Calatina, and Nocellara del Belice were the most susceptible to the pathogen, while the cultivars Biancolilla and Nocellara Etnea were the most tolerant. Cultivar response under field conditions showed that anthracnose severity and fruit-rot incidence were positively correlated. This is the first report of C. acutatum and C. cigarro affecting olive trees in Sicily. Control measures for anthracnose depend on accurate characterization of the etiological agents and host cultivar resistance.

Control of Apple Fruit Rot Caused by Alternaria porri and Alternaria mali by Using Hot Water Treatment and Some Inorganic Salts

Apple rot is one of the most important apple diseases worldwide. The disease causes significant losses in both the quantity and quality of apple fruits. In this study, the antifungal activity of hot water treatment and salts were investigated against apple fruit rots caused by Alternaria porri and Alternaria mali. Linear growth of tested fungi was inhibited at 5ºC, however, growth was increased by increasing storage temperature degree from 15ºC to 25ºC and decreased at 35ºC. On the other hand, hot water treatment at 55ºC significantly reduced the decay index and severity of infection. When salts such as potassium bicarbonate (KCO3), calcium chloride (CaCl2), sodium bicarbonate (NaHCO3) and ammonium bicarbonate (NH4CO3) was applied, a significant reduction in linear growth and fruit rot incidence was noticed using potassium bicarbonate. Calcium chloride, ammonium bicarbonate and sodium bicarbonate greatly inhibited growth of A. porri and A. mali. The most effective inhibitor of fruit decay was potassium bicarbonate and calcium chloride.

Applying antagonist yeast strains to control mango decay caused by Lasiodiplodia theobromae and Neofusicoccum parvum

Successfully inserting a biocontrol agent (BCA) in the integrated management of mango fruit decay can be affected by several factors, including BCA inoculum density and the timing of its application. This study focused on improving biocontrol efficacy by adjusting doses of a BCA formulation and the timing for the substitution of synthetic fungicides sprays. Technical grade formulations containing increasing doses (104 – 108) of the yeast strains Saccharomyces sp. ESA45, S. boulardii ESA46, Saccharomyces sp. ESA47, and Pichia kudriavzeviii CMIAT171 were applied to mango fruits, followed by the inoculation of Lasiodiplodia theobromae and Neofusicoccum parvum in artificial wounds. Non-linear regression analysis of increasing doses of the BCAs against severity data and curve slopes comparison showed a significant difference in control efficiency among yeast strains. A log-linear regression model showed that ESA45 and CMIAT171 exhibited lower doses to achieve 90% control. Two field experiments were conducted in commercial mango orchards cultivated with the cultivars ‘Kent’ and ‘Palmer’. Starting the substitution of fungicides by BCA in fruit onset and when fruits achieved egg size resulted in lower fruit rot incidence and severity during cold storage and shelf life. The complete substitution of fungicides during fruit development did not show consistent performance. Similarly, applying BCA formulation only at the end of fruit development did not hinder the establishment of quiescent infections.

Potential of Near-Infrared (NIR) spectroscopy technique for early detection of Insidious Fruit Rot (IFR) disease in Harumanis mango

Harumanis mango ‘Insidious Fruit Rot’(IFR), is one of the common issues that hampered the fruit quality and consequently lowered the premium value of Harumanis Mango. Physically and visually the affected fruit does not show any attributes that indicates the presence of IFR on any part of the fruit until it has been cut open. This paper investigates the feasibility of a non-destructive method to screen the Harumanis mango from IFR using near-infra red light and artificial neural network. A common NIR light emitting diodes of 1000nm wavelength was used as the light source to emit NIR light while a photodiode was used to measure the intensity of the reflected NIR light from Harumanis mango. Early detection of IFR were done manually by local expert using acoustic method by flicking fingers to detect any abnormality inside the fruit. Sample data on NIR Spectroscopy reflectance results of 120 samples were used to classify the presence of IFR using neural network. Mean value of NIR reflectance of RBG for Harumanis mango with an incidence of Insidious Fruit Rot are R=0.651, G=0.465 and B=0.458, while without IFR are R = 0.211, G=0.15 and B=0.146. Using MATLAB’s neural network training tool, a training set regression was obtained with an accuracy value of 0.9805 for prediction of IFR, thus this value is very high in accuracy.

Efficacy of Certain Essential Oils, Copper Oxide, Copper Oxide Nanoparticle, Imazalil and Bacillus subtilis to Control Fruit Rot of Avocado

Disease incidence and disease severity of avocado fruit rot were assessed on cv. Hass and cv. Fuerte during 2019 and 2020 growing seasons. The highest percentages of disease incidence and disease severity were recorded in cv. fuerte in the market at El-Qanater El-Khayria, Qaliobia Governorate. On the other hand, the lowest percentages of disease incidence and disease severity were recorded in cv. Hass in the field at El- Rahawy, Giza Governorate during the two growing seasons. Four different fungi, i.e., Colletotrichum gloeosporioides, Lasiodiplodia theobromae, Fusarium moniliforme and Penicillium expansum were isolated from the naturally infected avocado fruits in the surveyed regions. Pathogenicity tests showed that the maximum percentage of disease severity on cv. Hass and cv. Fuerte resulted from infection by L. theobromae, followed by C. gloeosporioides, while the lowest percentage of disease severity was incited byP. expansum. The efficacy of alternative products namely essential oils of Lemongrass (Cymbopogon citratus L.), Rosemary (Rosmarinus officinalis L.) and Thyme (Thymus vulgaris L.) and Serenade ASO (Bacillus subtilis QST713) was evaluated in in vitro and in vivo as well as under field conditions for controlling fruit rot of avocado comparing with Imazalil, Copper oxide and Copper oxide nanoparticles. Complete inhibition of colony growth and protection from fruit rot was recorded with essential oils and Copper oxide at concentration of 3 ml or g/L of each. Meanwhile, the same effect was recorded at concentration of 1 ml/ L in case of Imazalil, Copper oxide nanoparticles and Serenade ASO. However, under field conditions, Copper oxide nanoparticles and Imazalil gave the highest efficacy for controlling avocado fruit rot disease, followed by Serenade ASO, Copper oxide and Thyme, while the lowest efficacy was recorded when trees sprayed with Lemongrass and Rosemary, respectively. The results indicated that avocado fruit rot disease could be controlled using suitable concentration of the tested treatments.

EVALUATION OF MANUAL FRUIT HARVESTERS AND STORABILITY CHARACTERISTICS OF HARVESTED SWEET ORANGE UNDER ORDINARY ROOM STORAGE CONDITION

Harvesting is considered as one of the crucial and critical activities in fruit production, handling and storage and market cycle. Traditional harvesting and post-harvest technique are responsible for deteriorating the fruit quality and shortening the postharvest shelf-life. Hand-picking by climbing tree, tree shaking and stick biting are most common practices for majority of the fruit orchards in Nepal that is risky, labour and time-intensive practices as well as affects market quality and nutritive value of the fruits. Therefore, there is a need for simple manual fruit harvesting tools suitable for smallholder farmers to replace the manual picking of citrus. Hence, a study was conducted to evaluate the performance of different available models of manual fruit harvester along with the evaluation of post-harvest quality (physiological loss of weight, fruit firmness, total soluble solids, acidity and rot incidence) and shelf-life assessment of those harvested fruits during storage under ordinary room condition for 26 days. Nine harvesting treatments were investigated as follows: a) Farmer practice-hand-picking (FPground), b) Farmer practice tree climbing (FPclimb), c) Hand-shaking of the tree branch (TS), d) Secateurs (SEground), e) Secateur + tree climb (SEClimb), f) Pole mounted cut and hold type picking shears (CH), g) Telescopic Long reach fruit picker (LRF), h) Fruit picker harvester with basket and cushion (PHB), i) Metal fruit picker with cotton bag (PC). The harvesting capacity of FPground, FPclimb, SEground, SEClimb, LRF, CH, PHB, PC and TS methods were 98.4±5.84, 57.52±12.43, 94.7±38.14, 49.05±5.73, 79.14±6.15, 75.08±12.44, 49.88±17.48, 52.27±11.47 and 63.12±22.27 kg/hr, respectively.. The harvesting output of CH and LRF type harvester was 29.03 (591 nos/hr) and 15.93% (531 nos/hr) higher than FPclimb practice (458 nos/hr) and that of PHB and PC method was 20.96 (362 nos/hr) and 6.11% (430 nos/hr) lower than FPclimb. Regarding storability characteristics, shelf-life was found better in SEground, SEClimb, CH, LRF than TS and FP practices.SE and CH method found effective in prolonging the average shelf-life and maintaining the quality of sweet orange compared to TS and FP. The button or calyx on the harvested fruit in SE, CH and LRF method help to control and delay the sap oozing, physiological loss of weight and lateral infection that maintain fruit firmness, prolong the shelf-life and minimize the fruit damage and rot incidence during ordinary storage. Based on our findings, hand-held secateur, cut and hold type harvester and long reach fruit picker (twist and turn) are recommended as appropriate harvesting tools for sweet orange fruit picking.

Effect of mulching and planting density on production of sweet banana pepper (Capsicum annuum L.)

The present experiment was carried out at Dr Y S Parmer University of Horticulture and Forestry, Nauni, Solan (HP) during Kharif 2019 to study the effect of mulching and planting density on production of Sweet Banana pepper in mid hills of Himachal Pradesh. The experiment was laid out in Randomized Complete Block Design (Factorial) with three replications. The twelve treatment combinations comprised of combination of four different mulches (M) viz., no mulch (M0), pine needle mulch (M1) black-plastic mulch (M2), silver-black plastic mulch (M3) with three planting densities (P) viz., 60 cm×60 cm (P1) 60 cm×45 cm (P2) and 60 cm×30 cm (P3). The observations were recorded on growth yield and quality traits, fruit rot incidence (%), weed count, fresh and dry weight of weeds, soil moisture and temperature. The treatment combination silver-black plastic mulch with plant spacing of 60 cm×30 cm (M3P3) was found superior over all other treatment combinations for most of the growth and yield parameters, quality traits, fruit rot incidence and weed control as well as performed well in improving soil moisture and temperature. This treatment combination also had maximum benefit: cost ratio of 4.21:1. Hence silver-black mulch in combination with 60 cm×30 cm spacing can be recommended for commercial cultivation of Sweet Banana pepper in North Western Himalayan regions after multi-locational testing.

Systematic review of defense responses against Phytophthora and strategies to manage Phytophthora diseases in citrus.

Phytophthora spp. are the causal agents of gummosis or foot rot, fibrous root rot, and fruit brown rot diseases that affect the roots, trunk, and fruits of citrus trees, causing severe economic losses. This work presents an updated systematic review addressing the defence responses in citrus against Phytophthora and the strategies to manage Phytophthora diseases. Applying a new method of search based on an explicit, rigorous, and transparent methodology. For this purpose, a systematic literature review was conducted using the databases available for academic research. The main plant defence mechanisms reported in the cited papers are the hypersensitivity response, cell wall reinforcement, production of pathogenesis-related proteins, and expression of defence-related genes. Moreover, the main strategies to manage Phytophthora root rot are organic compounds in the soil and biological control with fungi and bacteria. In addition, inhibition of Phytophthora gummosis or canker by applying new oomycota fungicides and reducing the incidence of brown fruit rot through the application of potassium phosphite have also been reported. Moreover, modern plant biotechnology techniques can help to accelerate the selection of resistant rootstocks in breeding programs, as controlled crossings for the generation of hybrids, somatic hybridisation, transgenic citrus plants, mapped genomic regions of Quantitative Trait Loci (QTLs), candidate genes, metabolic markers and comparative transcriptomic. These innovative techniques represent a suitable tool to breed new Phytophthora resistant rootstocks, which is widely recognised as the best strategy to face gummosis or foot rot, fibrous root rot and ultimately minimise the expensive use of pesticides in crop protection.

Corrigendum to: Systematic review of defense responses against Phytophthora and strategies to manage Phytophthora diseases in citrus.

Phytophthora spp. are the causal agents of gummosis or foot rot, fibrous root rot, and fruit brown rot diseases that affect the roots, trunk, and fruits of citrus trees, causing severe economic losses. This work presents an updated systematic review addressing the defence responses in citrus against Phytophthora and the strategies to manage Phytophthora diseases. Applying a new method of search based on an explicit, rigorous, and transparent methodology. For this purpose, a systematic literature review was conducted using the databases available for academic research. The main plant defence mechanisms reported in the cited papers are the hypersensitivity response, cell wall reinforcement, production of pathogenesis-related proteins, and expression of defence-related genes. Moreover, the main strategies to manage Phytophthora root rot are organic compounds in the soil and biological control with fungi and bacteria. In addition, inhibition of Phytophthora gummosis or canker by applying new oomycota fungicides and reducing the incidence of brown fruit rot through the application of potassium phosphite have also been reported. Moreover, modern plant biotechnology techniques can help to accelerate the selection of resistant rootstocks in breeding programs, as controlled crossings for the generation of hybrids, somatic hybridisation, transgenic citrus plants, mapped genomic regions of Quantitative Trait Loci (QTLs), candidate genes, metabolic markers and comparative transcriptomic. These innovative techniques represent a suitable tool to breed new Phytophthora resistant rootstocks, which is widely recognised as the best strategy to face gummosis or foot rot, fibrous root rot and ultimately minimise the expensive use of pesticides in crop protection.

Prevalence of Bacterial Leaf Spot of Bottle Gourd and Pumpkin in Subtropical Zone of Himachal Pradesh

To assess the prevalence and severity of bacterial leaf spot on bottle gourd and pumpkin, a survey was conducted in Hamirpur, Una and Bilaspur districts of sub tropical zone of Himachal Pradesh, India during the years 2018 and 2019. Data were recorded in terms of disease severity and fruit rot incidence. The associated pathogen from bottle gourd and pumpkin was isolated on nutrient sodium chloride agar medium and identified on the basis of morphological, biochemical and pathogenicity tests on bottle gourd and pumpkin seedlings. Disease was found to be prevalent at all the locations surveyed exhibiting a mean disease severity from 24.70 to 87.55 and 5.30 to 52.92 per cent in bottle gourd and pumpkin, respectively. Fruits of bottle gourd were recorded to be affected badly exhibiting a mean fruit rot incidence of 10.23 to 95.32 to per cent, while, no fruit rot incidence was recorded in pumpkin fruits. The colonies of the isolated bacterium were mucoid, circular, smooth textured and yellow in colour having a diameter of 2-4 mm. The pathogen was found to be Gram–ve and tested positive for esculin hydrolysis as well as protein digestion test. During pathogenicity tests, incubation period of 2 and 4 days was recorded on bottle gourd and pumpkin, respectively. Based on these studies, the identity of the pathogen was confirmed to be Xanthomonas cucurbitae(ex Bryan) Vauterin et al.