Incidence Of Postharvest Diseases Research Articles

Effect of Chemical Pesticides on the Growth and Yield of Two Industrial Potato Varieties (Asterix and Courage) in Bangladesh

Experiments were conducted to find out suitable disease management practices to produce quality potato seeds in processing the varieties of Asterix and Courage in Bangladesh. A set of two field experiments was conducted in two different Agroecological zones of Bangladesh. A Factorial Randomized Completely Block Design with 2 potato varieties, 4 treatments, and 4 replications for each were used. A significant difference was found in the plant height and number of tubers per hill. In contrast, days to tuberization and the number of stems per hill of both varieties in response to pesticide application were insignificant. The highest tuber yield and better A and B-grade tubers were recorded, in which fungicides and insecticides were applied. The primary viral infection had been identified in the control and fungicide-treated plots only while there was no viral disease incidence was observed in the insecticide-treated plots. The incidence of post-harvest disease and disorder was found to be negligible. J. Bio-Sci. 32(2): 13-22, 2024

Carvacrol Treatment Reduces Decay and Maintains the Postharvest Quality of Red Grape Fruits (Vitis vinifera L.) Inoculated with Alternaria alternata.

In this study, we isolated and identified pathogenic fungi from the naturally occurring fruits of red grapes, studied their biological characteristics, screened fifteen essential oil components to find the best natural antibacterial agent with the strongest inhibitory effect, and then compared the incidence of postharvest diseases and storage potential of red grapes treated with two concentrations (0.5 EC50/EC50) of essential oil components (inoculated with pathogenic fungi) during storage for 12 d at room temperature. In our research, Alternaria alternata was the primary pathogenic fungus of red grapes. Specifically, red grapes became infected which caused diseases, regardless of whether they were inoculated with Alternaria alternata in an injured or uninjured state. Our findings demonstrated that the following conditions were ideal for Alternaria alternata mycelial development and spore germination: BSA medium, D-maltose, ammonium nitrate, 28 °C, pH 6, and exposure to light. For the best Alternaria alternata spore production, OA medium, mannitol, urea, 34 °C, pH 9, and dark conditions were advised. Furthermore, with an EC50 value of 36.71 μg/mL, carvacrol demonstrated the highest inhibitory impact on Alternaria alternata among the 15 components of essential oils. In the meantime, treatment with EC50 concentration of carvacrol was found to be more effective than 0.5 EC50 concentration for controlling Alternaria alternata-induced decay disease of red grapes. The fruits exhibited remarkable improvements in the activity of defense-related enzymes, preservation of the greatest hardness and total soluble solids content, reduction in membrane lipid peroxidation in the peel, and preservation of the structural integrity of peel cells. Consequently, carvacrol was able to prevent the Alternaria alternata infestation disease that affects red grapes, and its EC50 concentration produced the greatest outcomes.

Molecular Aspects Revealed by Omics Technologies Related to the Defense System Activation in Fruits in Response to Elicitors: A Review

Fruit losses and wastage are mainly due to postharvest diseases; their control is reduced with pesticides. The excessive use of synthetic fungicides has caused harmful effects on human health and the environment, so it is therefore necessary to reduce their use. The development of new innocuous strategies has led to the use of compounds of natural or biological origin with the capacity to induce the plant defense system, which improves the fruit’s response against future pathogen attacks in addition to reducing the incidence of postharvest diseases. These compounds are known as “elicitors”. Although the use of molecular tools such as RT-qPCR or the measurement of the enzymatic activity of molecular markers makes it possible to determine the activation of the plant defense system in response to the application of an elicitor compound, in recent years, omics technologies such as the transcriptome, proteome, or metabolome have provided new and interesting information that helps to elucidate the molecular aspects involved in the activation of the plant defense system in response to the application of elicitors. This review summarizes recent advances in molecular aspects, highlighting the contribution of omics technologies to a better understanding of fruit defense mechanisms induced by different elicitors.

Effects of thymol concentration on postharvest diseases and quality of blueberry fruit

In this study, we compared the incidence of postharvest disease and the storage potential of blueberry fruit treated with thymol (inoculated with Aspergillus niger) with those in the control fruit during storage for 42 d at 2 °C. Treatment with 10–30 mg/L thymol was found to be more effective than treatment with higher thymol concentrations of 40–50 mg/L in terms of controlling Aspergillus niger-induced decay. In the thymol-treated blueberry fruit peel, the activities of the disease resistance-related enzymes were significantly enhanced. Furthermore, the 20 mg/L thymol-treated blueberry fruit retained the highest firmness, total soluble solids content, and acceptability score, and it also maintained an unimpaired cell wall structure of pericarp quality. Thus, low-dose thymol-treatment could be a suitable biocontrol agent for controlling postharvest disease and prolonging the storage life of blueberry fruit.

Effect of Spacing and Mulch on Post Harvest Disease Incidence and Sensory Evaluation in Strawberry

Aims: To study the response of plant spacing and mulch material on post harvest disease incidence and sensory evaluation in Strawberry.
 Study Design: The investigation was laid in a factorial randomized block design.
 Place and Duration of Study: Sample: Farmer’s field in Dhankhuloi village of Jorhat district,Assam and Department of Horticulture,Assam Agricultural University,Jorhat,India, during November-April of two consecutive years 2019-20 and 2020-21.
 Methodology: We included twenty treatments which were the combination of five spacings viz. 20 cm x 30 cm, 30 cm x 30 cm, 30 cm x 40 cm, 40 cm x 40 cm and 40 cm x 60 cm with four mulch materials i.e. paddy straw,red mulch,silver black mulch and no mulch. Evaluation of percent post harvest disease incidence and organoleptic qualities was conducted.
 Results: Out of 20 treatments, the treatment combination of widest spacing 40 cm x 60 cm along with silver black mulch showed least percent postharvest disease incidence (18.90%) while maximum incidence (42.82%) was obtained in no mulch applied plots with 20 cm x 30 cm spacing. Sensory evaluation showed treatment combination of 40 cm x 40 cm spacing with silver black mulch exhibited better organoleptic qualities.
 Conclusion: Positive effects of wider spacing and silver black mulch material might have contributed to least post harvest disease incidence in strawberry. Fruits of strawberry mulched with silver black plastic and wider spacing owing to favourable microclimate may have contributed to a sweeter taste and, consequently, better consumer acceptance.

Effect of Storage Conditions on Storability and Antioxidant Potential of Pears cv. ‘Conference’

Late pear cultivars, such as ‘Conference’, can be stored for a long period if kept in good storage conditions. A three-year study (2011–2013) compared the impact of six-month storage using four technologies—normal atmosphere, normal atmosphere + 1-methylcyclopropene (1-MCP), controlled atmosphere, and controlled atmosphere + 1-MCP—on the quality parameters of ‘Conference’ pears, such as mass loss, firmness, total soluble solids, acidity, antioxidant capacity, and the incidence of diseases and disorders. Additionally, the study analysed different storage conditions in terms of profitability, based on the market prices for pears in the seasons during which the pears were stored. The storage conditions had a very strong influence on the fruit quality parameters, and were found to affect most visibly the mass loss and the incidence of postharvest diseases and disorders. The storage of ‘Conference’ pears for 180 days in normal atmosphere is not economically viable, even if the fruit is subjected to 1-MCP treatment; at the same time, it is profitable to store ‘Conference’ pears in controlled atmosphere for the same period, no matter whether 1-MCP was applied or not.

Use of modified atmosphere packaging combined with essential oils for prolonging post-harvest shelf life of mango (cv. Banganapalli and cv. Totapuri)

This study aimed to evaluate the combined application of modified atmosphere packaging (MAP) with essential oil (EO) vapours (Thyme, Clove, and Cinnamon) on the shelf life extension of cv. Banganapalli and cv. Totapuri mango fruit. The fruit quality was evaluated in terms of postharvest disease incidence and severity, physicochemical and sensory parameters. Also, the antioxidant enzyme activities, total phenolic, and flavonoid contents, DPPH radical scavenging activity, weight loss, and CO2 evolution were studied. Our results demonstrated that MAP + thyme oil vapour (TO) treatment significantly (p < 0.05) reduced the incidence and severity of anthracnose, and loss of fruit firmness. The MAP + TO treatment enhanced the shelf life of cv. Banganapalli up to 26 ± 2 days and cv. Totapuri up to 23 ± 2 days. MAP + Cinnamon EO treated fruits exhibited a shelf life of 22 ± 2 and 19 ± 1 days for cv. Banganapalli and cv. Totapuri, respectively whereas MAP + Clove EO prolonged the shelf life of mango up to 21 ± 2 days for cv. Banganapalli and 20 ± 1 days for cv. Totapuri fruits. The results of this study showed that a MAP + EO treatment could effectively control postharvest decay and preserve the physicochemical quality of mango fruits, extending their shelf life.

Blue Light Does Not Affect Fruit Quality or Disease Development on Ripe Blueberry Fruit During Postharvest Cold Storage

Blueberry fruit are perishable after harvesting due to fruit softening, water loss and susceptibility to pathogens. Light, especially blue light, increases the accumulation of anthocyanins and reduces postharvest decay in some fruits, but the effect of blue light on postharvest fruit quality attributes in blueberries is unknown. In this study, we evaluated the effect of blue light on fruit quality, anthocyanin accumulation and disease development during postharvest cold storage (2 °C–4 °C) in two experiments with southern highbush blueberry ‘Star’ and rabbiteye blueberry ‘Alapaha’. Overall, diurnal blue light did not affect postharvest fruit quality attributes, such as visual defects, fruit compression, skin puncture, total soluble solid content and titratable acidity, in the two cultivars compared with their respective controls (diurnal white light or continuous darkness). Further, there was no effect of blue light on fruit color and anthocyanin accumulation. Fruit disease incidence in ‘Star’ ranged from 19.0% to 27.3% after 21 days and in ‘Alapaha’ from 44.9% to 56.2% after 24 days in postharvest storage, followed by 4 days at room temperature, but blue light had no consistent effect on postharvest disease incidence for either cultivar. Disease progression following artificial inoculations with Alternaria tenuissima and Colletotrichum acutatum in ‘Star’ was not influenced by light treatment prior to inoculation and during fruit storage. In a separate experiment, we tested the effect of blue light on color development in ‘Farthing’, a southern highbush blueberry cultivar with fruit prone to non-uniform ripening, whereby the stem-end remains green as the rest of the fruit turns blue. Although green stem-end spots turned blue over time, there was no statistically significant effect of the blue light treatment. Overall, these data indicate that blue light does not affect fruit quality attributes or disease development in ripe blueberry fruit during postharvest storage in the conditions investigated here.

Preharvest Detection and Postharvest Incidence of Phlyctema vagabunda on 'Cripps Pink' Apples in South Africa.

Phlyctema vagabunda is responsible for significant postharvest losses in 'Cripps Pink' apples in South Africa. The first objective of this study was to determine the presence and incidence of P. vagabunda on stored commercial 'Cripps Pink' apple in five major pome fruit growing regions in the Western Cape. As the fungus remains latent until postharvest, the second objective was to develop a rapid molecular detection tool to determine the presence of P. vagabunda on asymptomatic 'Cripps Pink' apples from two commercial orchards. Postharvest disease incidence in 'Cripps Pink' apples in the Western Cape ranged from 0 to 73% in the 2010/2011, 0 to 6% in 2011/2012, and 0 to 30% in 2012/2013 seasons. P. vagabunda spores were also detected on 'Cripps Pink' fruit from December to February and from March to April. In December and January, P. vagabunda spores were detected on the 'Hillieri' crab apple pollinator. The knowledge that P. vagabunda conidia are present on the surface of 'Cripps Pink' apples and 'Hillieri' crab apples during the growing season could be applied to improving current management practices in the orchards.

Detection and epidemiological progress of quiescent avocado diseases

ABSTRACT: One of the major problems in the commercialization of avocados is the incidence of postharvest diseases, especially anthracnose (Colletotrichum spp.) and stem-end rot (Lasiodiplodia theobromae, Fusicoccum aesculi and Neofusicoccum spp.). As there is a lack of epidemiological information on these pathosystems, the objective of this study was to establish a method to detect quiescent infections and characterize their temporal progression and spatial pattern in a commercial orchard. Detection of quiescent infections was evaluated in flowers and fruits that were immature and in commercial harvest stage, treated with paraquat, ethrel or water. Treatment of flowers and immature fruits with paraquat led to rapid detection of Colletotrichum spp. In two seasons of a ‘Hass’ avocado orchard, the incidence of diseases was evaluated from open flowers to fruit harvest, totaling 11 evaluations at biweekly intervals. When fruits reached the harvest stage, the spatial distribution of diseased fruits in the trees was evaluated by means of dispersion index and modified Taylor’s law. Considering the evaluation of temporal disease progression, anthracnose was the most important disease, presenting a high initial incidence of 60 and 86% diseased flowers in the two seasons, respectively, while fruits showed an average disease incidence of 70 and 87%, respectively. Stem-end rot was observed only in fruits since the beginning of their development and presented low incidence (&lt;8% fruits), significantly inferior to that of anthracnose. The diseases showed random dispersion within the trees, indicating that their initial inoculum is evenly distributed in the plants.

Peach brown rot control and the relationship of latent infection with postharvest disease

ABSTRACT The peach brown rot, caused by Monilinia fructicola, is the main disease of the crop, causing significant losses during preharvest and postharvest. This study aimed to evaluate the performance of preharvest fungicide application on brown rot control and verify the role of latent infection and external contamination in postharvest disease. An experiment was carried out in the years 2014 and 2015 in order to evaluate the performance of six active ingredients (captan, iprodione, iminoctadine, tebuconazole, difenoconazole and azoxystrobin) during preharvest on brown rot control and the effect on latent infection. A second experiment was carried out to monitor the latent infection during growth and ripening of the fruit and in order to correlate it with the postharvest disease incidence. The data were submitted to analysis of variance (Anova) and the means were grouped by the Scott-Knott test (p &lt; 0.05), using statistical software Sisvar. The active ingredients iprodione, tebuconazole and difenoconazole were the most efficient in controlling brown rot on the field, while iminoctadine has higher efficiency during postharvest control, acting on latent infections. The incidence of latent infections during fruit growth and ripening has a positive correlation with brown rot incidence at postharvest. The highest disease incidence after storage is due to the latent infections manifestation. Effective chemical control in the field, throughout the growing and ripening of fruit, is an important approach to postharvest brown rot control, even after cold storage and during shelf life at 20 °C.

Effect of Burkholderia contaminans on Postharvest Diseases and Induced Resistance of Strawberry Fruits.

This study takes strawberry-fruits as the test material and discusses the effect of Burkholderia contaminans B-1 on preventing postharvest diseases and inducing resistance-related substances in strawberry-fruits. Soaking and wound inoculating is performed to analyze the inhibitory effects of different treatment solutions on the gray mold of postharvest strawberry-fruits. The count of antagonistic bacteria colonies in the wound is found, and the dynamic growth of antagonistic bacteria and the pathogenic fungus is observed by electron microscopy. The results indicated that, either by soaking/wound-inoculating, the fermentation and suspension of antagonistic bacteria significantly reduced the incidence of postharvest diseases of strawberry-fruits. With wound inoculation, the inhibition rate of antagonist fermentation and suspension (1 × 1010 cfu/ml) respectively reached 77.4% and 66.7%. It also led to a significant increase in the activity of resistance-related enzymes, i.e., phenylalanine ammonia lyase (PAL), 4-coumarate coenzyme A ligase (4CL), cinnamate-4-hydroxylase (C4H) and chalcone isomerase (CHI). On 1 d and 2 d post-treatment, the activity of 4CL was respectively 3.78 and 6.1 times of the control, and on 5 d, the activity of PAL was increased by 4.47 times the control. The treatment of antagonistic bacteria delayed the peaking of cinnamyl-alcohol dehydrogenase (CAD) activity and promoted the accumulation of lignin and total phenols. The antagonistic bacteria could be well colonized in the wounds. On 4–5 d post-inoculation, the count of colonies was 108 times of that upon inoculation. Electronmicroscopy indicated that the antagonistic bacteria delayed the germination of pathogenic spores in the wounds, and inhibited further elongations of the mycelia.

Effect of Electronic Cold-PasteurizationTM (ECPTM) on Fruit Quality and Postharvest Diseases during Blueberry Storage

With the growing popularity of blueberries and the associated increase in blueberry imports and exports worldwide, delivering fruit with high quality, longer shelf-life, and meeting phytosanitary requirements has become increasingly important. The objective of this study was to determine the effects of electron beam irradiation using a new Electronic Cold-PasteurizationTM (ECPTM) technology on fruit quality, microbial safety, and postharvest disease development in two southern highbush blueberry cultivars, ‘Farthing’ and ‘Rebel’. Fruit packed in clamshells were subjected to four levels of ECPTM irradiation (0, 0.15, 0.5, and 1.0 kGy) and evaluated for fruit quality attributes, surface microbial load, and postharvest disease incidence during various storage times after treatment and cold storage. Overall, there was no effect of irradiation on visual fruit quality in either cultivar. Fruit firmness and skin toughness in ‘Farthing’ was reduced following irradiation at 1.0 kGy, but no such effect was observed in ‘Rebel’. Other fruit quality characteristics such as fruit weight, total soluble solids content, or titratable acidity were not affected. Irradiation at 1.0 kGy significantly reduced total aerobic bacteria and yeast on the fruit surface, and in the case of ‘Rebel’, also levels of total coliform bacteria. There was no significant effect of irradiation on postharvest disease incidence in these trials. Overall, data from this study suggests that an irradiation dose lower than 1.0 kGy using ECPTM can be useful for phytosanitary treatment in blueberry fruit while avoiding undesirable effects on fruit quality in a cultivar-dependent manner.

Photoprotector adjuvants to enhance UV tolerance of yeast strains for controlling mango decay using pre-harvest spraying

ABSTRACTPost-harvest mango decay is caused by multiple pathogens in tropical conditions but concerns regarding the risk of food contamination by fungicides established biocontrol as a promising alternative. However, occurrence of quiescent infections requires pre-harvest applications of biocontrol agents (BCA), exposing them to harmful UV radiation effects. The objective of this work was to evaluate UV sensitivity of yeast BCA strains previously selected against multiple pathogens that cause mango decay and evaluate suitable UV protectants. In a first bioassay conducted exposing yeast suspensions sprayed on glass plates, it was verified that Saccharomyces sp. ESA47 and Pichia kudriavzevii CMIAT171 were highly sensitive to UV, while Saccharomyces cerevisiae ESA45 had a slightly lower mortality. A bioassay using fragments of mango peels evaluated UV protection from increasing concentrations of starch, dextrin, casein, benzophenone, and cinnamic acid derivative compounds. Results showed that starch and isoamyl p-methoxycinnamate (NHE-1000) resulted in higher survival for yeast strains in doses of 10.0 and 1.0 g kg−1, respectively. Application of the yeast BCA in a semi-commercial mango orchard resulted in a significant reduction of post-harvest disease incidence and severity. Field application of the yeasts in technical grade preparations containing both UV protectants enhanced the control efficiency by 52.5, 31.9, and 37.7% for ESA45, ESA47, and CMIAT171, respectively.

Do soil applications of fulvic acid applied with potassium sulphate influence mango fruit quality?

The effects of fulvic acid as a supplement to potassium (K) applications on mango fruit quality, flower synchronisation and yield were investigated in an 8-year-old 'Kensington Pride' (KP) orchard over two seasons, at Southedge Research Station in Far North Queensland, Australia. The aim of the trial was to determine whether fulvic acid (FA) improved the efficiency of potassium uptake. Experimental treatments included i) nil K + nil FA, ii) 800 g K tree-1, and iii) 800 g K + 300 mL FA tree-1. Treatments were applied approximately every 3 weeks, after fruit set and during the fruit filling stage through to harvest. Treatment effects were assessed by measuring tree yield, fruit weight, length, depth and width, the incidence of post-harvest disease, ground skin colour at eating-ripe stage, as well as the proportion of canopy flowering in different stages in the following season. Results indicated that neither K fertiliser nor FA increased average fruit number or yield. In the first year, K combined with FA significantly increased the proportion of fruit with no lenticel spotting and the lightness of the ground skin colour of eating-ripe mangoes. By the second season, K with or without FA significantly increased the average fruit length and foliar dry-matter K concentration, while fruit weight was only marginally increased when compared to the nil K treatment. In summary, the addition of K applied during fruit development led to improved fruit size and maintenance of foliar K concentrations 2 years after application. However, although the addition of FA with K fertiliser reduced the proportion of fruit with lenticel spotting, this result was only observed in the first season of the trial and hence would require further research to confirm.

Mango value chain improvement through postharvest research and development: a developing country case study

Pakistan is one of the major mango-producing and -exporting countries in the world. During 2007-15, significant postharvest research and development (R&D) work was conducted under the Australian-funded ASLP mango supply chain management/value chain improvement projects (two phases). The project started by laying a postharvest foundation R&D infrastructure in 2007. Fruit quality losses in supply chains were documented. Protocols were developed for maturity testing, de-sapping, storage/sea-freighting, and ripening and postharvest disease management of major mango cultivars. Quantity loss (unmarketable fruit) was around 20% while quality loss (affecting price) was 65 and 70% in Sindhri and Samar Bahisht Chaunsa mango, respectively. Sap burn and postharvest diseases were the most important fruit quality issues at retail. Cultivars differed in terms of fruit harvest maturity indicators, postharvest treatment response, controlled atmosphere conditions and temperatures for storage and ripening. Besides physical de-sapping (on racks), lime wash (de-stemming and dipping fruit in 0.5% lime solution for 2-3 min) was also found to be effective, with morning being the best time for fruit picking. Significant relationships of production locality, orchard management, nutrition (Ca, B and K) and pre-cooling were found with postharvest disease incidence. Postharvest hot-water fungicidal dip of Scholar (active ingredient (a.i.) fludioxonil), Amistar (a.i. azoxystrobin) and Sportak (a.i. procholaz) gave significant fruit disease control. An integrated approach of good production practices, right maturity, correct postharvest fungicidal treatments and pre-cooling was an effective strategy for reducing disease incidence and maintaining better shelf-life at retail. On the basis of R&D and interventions, significant improvement was brought to the local mango industry and export. Sindhri mangoes were sea-freighted commercially to the EU and UK with good fruit quality outturn and overall postharvest life of 40-45 days.

Prevalence and incidence of postharvest diseases of blueberries in California

Recent establishment of low-chill southern highbush blueberry cultivars in California's warm climate has significantly increased the acreage of blueberry production in the Central Valley of California, which is now a major southern highbush blueberry production region in the United States. The vast majority of blueberries grown in California are destined for the fresh market. As the production continues to grow, the blueberry industry has a need to prolong the storage life of blueberry in order to extend the marketing period. However, the postharvest life of blueberry fruit is limited by fruit rots caused by fungal pathogens. To determine what are the major postharvest diseases affecting blueberries in the region, blueberry fruit were collected at harvest from 42 (27 conventional and 15 organic) and 62 grower lots (49 conventional and 13 organic) in 2013 and 2014, respectively; stored at 0-2°C for 5 weeks; and then evaluated for the presence of fruit rots. Causal agents of rots were isolated from decayed fruit and identified. Incidence of decay ranged from 23 to 74% in 2013 and from 3 to 74% in 2014. One or more than one fungi were isolated from each decayed fruit. On average, Botrytis spp. (mainly B. cinerea), Cladosporium spp., Alternaria spp. (mainly A. alternata and A. arborescens), Aureobasidium pullulans, Rhizopus stolonifer, and Penicillium spp. were isolated from 21-46, 6-13, 25-38, 12-29, 2-26 and 2-8% of the decayed fruit sampled from conventional grower lots, respectively; and from 20-73, 5-18, 11-46, 7-19, 5-25, and 3-4% of the decayed fruit sampled from organic grower lots, respectively. Our results indicated that B. cinerea, Alternaria spp., Aureobasidium pullulans and Cladosporium spp. were the major pathogens as they were consistently isolated from decayed fruit from most grower lots during the 2-year survey and that control measures should target these pathogens.

Pre-harvest sprays of hexanal formulation for extending retention and shelf-life of mango (Mangifera indica L.) fruits

Field experiments were conducted to study the response of mango (var. Alphonso and Banganapalli) to pre-harvest sprays of a nano-emulsion of hexanal (Enhanced Freshness Formulation) in extending retention and shelf-life of fruits. Hexanal, a naturally occurring plant derived compound is known to inhibit phospholipase-D and facilitates extension of shelf-life of fruits during storage. Pre-harvest sprays of EFF (1.6mM) on 30 and 15 days before harvest were done and the observations on fruit retention, incidence of post-harvest diseases and net fruit yield were recorded. After harvest, the fruits were kept under ambient (25±2°C; 70–75% RH) and cold (14±2°C; 85–90% RH) storage conditions and the physiological and biochemical parameters were measured regularly till the end of the shelf-life. The data clearly indicated that pre-harvest sprays of EFF significantly reduced the post-harvest diseases such as anthracnose, stem end rot and other infestations which minimized the post-harvest losses while increasing the net fruit yield by 4–5kg per tree. The sprayed trees retained the fruits in the tree by 3–4 weeks longer than control. Further, the fruits harvested from the sprayed trees remained fresh for a longer period of time under both ambient (24–25 days) and cold (36–40 days) storage conditions in comparison to their respective controls (16–18 days; 20–22 days). The physiological loss in weight was registered lower while other quality attributes such as firmness, total sugars, acidity of treated fruits were higher than their respective controls regardless of storage conditions. Overall, the results suggested that pre-harvest sprays of EFF assisted in retention fruits for 3–4 weeks longer in the orchard itself besides extending shelf-life under storage conditions without the loss of quality of fruits.

Adubação nitrogenada sobre a ocorrência de doenças em pós-colheita do morango

RESUMO Avaliou-se o efeito de doses de nitrogênio, aplicadas em campo, sobre as doenças pós-colheita nos cultivares de morango Camino Real, Festival e Oso Grande. O nitrogênio, tendo como fonte a ureia, foi avaliado na dose recomendada total (100%), com base na recomendação oficial para a cultura, e mais 3 doses inferiores (83, 67 e 50% do recomendado), tanto no plantio como em cobertura. Os frutos foram colhidos e pesados com 75% da superfície de cor vermelho-brilhante. Doze frutos por parcela foram amostrados em 3 coletas a partir da segunda florada e avaliados quanto à incidência das doenças durante 5 dias de armazenamento a 25°C e 85% de umidade relativa. A identificação das doenças foi feita diariamente com base nos sintomas e sinais dos patógenos. Não foi observado efeito das doses de nitrogênio na produção de frutos e na incidência das doenças, expressa em área abaixo da curva de progresso da doença (AACPD). A maior produção foi observada nos cultivares Festival e Oso Grande. A incidência total de doenças não diferiu significativamente entre os cultivares. O mofo cinzento foi a principal doença, com incidência superior a 30%, seguido da podridão mole de Rhizopus e podridão de levedura.

Influence of Growth Regulators Combined with Chemicals to Improve Postharvest Fruit Quality in Banana cv. Nendran (Musa AAB)

A study was undertaken at TNAU, Coimbatore to envisage the effect of different chemicals and growth regulators in combination with Thiabendazole (Fungicide) on post-harvest quality and shelf life of banana cv. Nendran (French Plantain Musa AAB). Various concentration of, GA3, BA, CaCl2 and Hot water treatment either alone or in combination with Thiabendazole was applied to fruits after harvest to study their impact on post-harvest quality and shelf life. Exogenous application of chemicals, growth regulators in combination with Thiabendazole significantly decreased post-harvest disease incidence leading to increase in post- harvest fruit quality and shelf life. Among the treatments, post-harvest dipping of fruits in 150 ppm GA3 + 200 ppm Thiabendazole significantly increased firmness (3.70 kg/cm2) titrable acidity (0.09%) and storage life of fruits (18.00 days). While the parameters like PLW (13.53%), TSS (25.45oB), total sugars (18.88%), reducing sugars (17.11%) and percent disease incidence (5.55) was observed minimum in the same treatment after 12th day of storage.