Fruit Physiological Disorders Research Articles

Reprint of: A convolutional neural network approach to detecting fruit physiological disorders and maturity in ‘Abbé Fétel’ pears

Image processing through the implementation of manually coded algorithms has been adopted to detect fruit damage during post-harvest operations. This study tested convolution neural networks with “You Only Look Once” (YOLO) architecture using a commercial online platform to detect physiological disorders and ripening stage in ‘Abbé Fétel’ pear. Disorders such as superficial scald and the starch pattern index (SPI) were assessed. Three different models were trained to detect: I) individual fruit within the boxes; II) superficial scald or senescence scald on pear skin; III) the SPI value of pears was assessed using the Lugol solution. Preliminary statistics show that the model to count the fruit inside the boxes reached 64.70% of true positives with 0.5 intersection over union. The second had less accuracy (up to 20% of true positives) but maintained a good average precision (60%) with different confidence thresholds (40% and 20%). The third showed good performances compared to the Ctifl and Laimburg scales, with an F1 score of 0.36 and 0.59, respectively. The effectiveness of the transfer learning method was demonstrated. However, further image labelling and modelling research is needed to improve the accuracy of the simulations and to develop an application for portable devices for pre- and post-harvest factor mapping. These results could lead to improvements in the management of fruit boxes and thus help ensure good fruit quality for consumers. • Artificial intelligence allows to count fruit, to detect disorders and starch index. • Model for pear detection to estimate number of fruit gets F1 score of 0.84 • Model for superficial scald to detect early storage disorders gets an F1 score of 0.28 • Model for starch index to evaluate fruit ripening gets an F1 score of 0.59 • Neural networks applied to food production chain ensure good quality for consumers.

A convolutional neural network approach to detecting fruit physiological disorders and maturity in ‘Abbé Fétel’ pears

Image processing through the implementation of manually coded algorithms has been adopted to detect fruit damage during post-harvest operations. This study tested convolution neural networks with “You Only Look Once” (YOLO) architecture using a commercial online platform to detect physiological disorders and ripening stage in ‘Abbé Fétel’ pear. Disorders such as superficial scald and the starch pattern index (SPI) were assessed. Three different models were trained to detect: I) individual fruit within the boxes; II) superficial scald or senescence scald on pear skin; III) the SPI value of pears was assessed using the Lugol solution. Preliminary statistics show that the model to count the fruit inside the boxes reached 64.70% of true positives with 0.5 intersection over union. The second had less accuracy (up to 20% of true positives) but maintained a good average precision (60%) with different confidence thresholds (40% and 20%). The third showed good performances compared to the Ctifl and Laimburg scales, with an F1 score of 0.36 and 0.59, respectively. The effectiveness of the transfer learning method was demonstrated. However, further image labelling and modelling research is needed to improve the accuracy of the simulations and to develop an application for portable devices for pre- and post-harvest factor mapping. These results could lead to improvements in the management of fruit boxes and thus help ensure good fruit quality for consumers. • Artificial intelligence allows to count fruit, to detect disorders and starch index. • Model for pear detection to estimate number of fruit gets F1 score of 0.84 • Model for superficial scald to detect early storage disorders gets an F1 score of 0.28 • Model for starch index to evaluate fruit ripening gets an F1 score of 0.59 • Neural networks applied to food production chain ensure good quality for consumers.

Differences between ethylene emission characteristics of tomato cultivars in tomato production at plant factory

Ethylene is not only well known as a unique gaseous hormone, which has various impacts on plant growth, but also considered to be closely related to tomato productivity and occurrence of fruit physiological disorders. On the other hand, the different tomato cultivars were also considered as key factors influencing tomato productivity and quality. In this study, we examined the differences between ethylene emission characteristics of different tomato cultivars. Our results confirmed that the Dutch tomato cultivar ‘Endeavour’ emitted less ethylene compared to other Japanese tomato cultivars, whereas ethylene emission in ‘Rinnka409’ was significantly higher than that in other cultivars. We observed that the wounding treatment resulted in rapid increase in ethylene emission in tomato, and the increase in ethylene emission was much higher in the ‘Momotarou Youku’ cultivar than that in the ‘Endeavour’ cultivar. The results will be useful to maximize tomato productivity and reduce the occurrence of fruit physiological disorders in tomato production at plant factories.

I. Mineral nutrient profiles and relationships of ‘Honeycrisp’ grown on a genetically diverse set of rootstocks under Western New York climatic conditions

We measured mineral nutrient concentrations in leaves, fruit flesh and fruit peel from field grown apple trees grown on a genetically diverse group of rootstocks from year 5 through year 8 of planting (2014–2017) and identified relationships between nutrients in leaves and fruit of ‘Honeycrisp’ apple. We also evaluated the constancy of rootstock influence on scion nutrient profiles over the four years. Boron concentration in both leaf and fruit was consistent in different seasons, with rootstocks M.9 (several clones), B.9, M.26EMLA, PiAu51-11 and B.71-7-22 resulting in consistently low boron levels, while G.935, CG.2034, CG.4004, G.222 and CG.5087 provided consistently high boron levels. Unlike boron, calcium concentration in scion tissues was somewhat variable in different seasons suggesting a role for climate and perhaps management factors in the rootstock induced absorption and translocation of calcium. We identified a group of rootstocks that yielded high calcium levels in scion tissues (G.214, B.10, G.41, B.9, G.935, G.11, CG.4003) while another group yielded low calcium levels (M.26, M.9-T337, G.202, CG.4004, G.814). We also identified a group of rootstocks that induced low potassium values in scion tissues (CG.4003, G.935, G.222, and G.202), whereas B.70-20-21, B.67-5-32, B.70-20-20 yielded consistently higher values. Rootstock B.10 and CG.2034 induced consistently higher potassium values in fruit tissues. The ratio of K/Ca in leaves and fruit was the best predictor of bitter pit in ‘Honeycrisp’ apples, suggesting that rootstock induced levels for both nutrients play a role in this disorder and that the addition of potassium fertilizers on potassium-efficient rootstocks might increase the susceptibility to bitter pit. Rootstocks CG.4003, B.10, G.41 N, and G.214 seemed to produce fruit with lower levels of bitter pit. Our data indicates that some rootstocks are more efficient at absorbing nutrients than others, which implies that fertilizer recommendations developed using one rootstock, such as M.26 or M.9, might be too high for other rootstocks which are more efficient and could thus be causing tree and fruit physiological disorders. Newer rootstocks might be already supplying the needed amounts of minerals to scion tissues.

Proteomic Studies on Fruit Ripening and Senescence

ABSTRACTFruits containing beneficial nutrients are of significant economic importance. Due to the rapid development of “omic” technologies and strategies, the proteomic approach, in addition to genomics, transcriptomics, and metabolomics, has attracted the attention of scientists to cover the comprehensive analysis of plant physiology and biology. The implementation of quantitative proteomic approach contributed to elucidating the molecular mechanism underlying fruit development, senescence, physiological disorders, and response to exogenous treatments. During the last decade, the isotope-labeled/label-free proteomic strategies have been applied in fruit science to obtain the near-complete investigations of quantifications and functions of fruit proteomes. Additionally, the recent implementation of mass spectrometry (MS)-based selected/multiple reaction monitoring (SRM/MRM) technology in targeted proteomics introduced the possibility of quantitative follow-up of specific protein targets in hypothesis-driven experiments. This review presents a comprehensive and up-dated overview of the application of proteomics in fruit ripening and development, fruit senescence, fruit physiological disorders, and oxidative stress, as well as the fruit proteomic response to postharvest exogenous treatment. The proteomic technologies and strategies in fruit science are summarized, and the panoramic views of differentially expressed proteins are discussed.

High-density planting of tomato cultivar's with early decapitation of growing point increased yield in a closed hydroponic system

Decapitation of tomato growing point's results in a shortened growth season with no new flower trusses initiated thereafter. Since less flower trusses could lead to reduced yield, this study was conducted to investigate whether increased plant density could contribute to increase yield per unit area. The response of nine tomato cultivars with early decapitation of growing points at different plant densities (10, 16, 20 and 25 plants/m2) was investigated in a closed hydroponic system under a 40% white shadenet structure. The growing points of all plants were removed between the second and third inflorescence, with two leaves remaining above the second inflorescence. Fruit physiological disorders, number of fruits, as well as total and marketable yield were recorded. Cultivar ‘Miramar’, gave the highest marketable and total yield, followed by cultivars ‘Rodade’ and ‘Alfar’. Cultivars ‘Alexis’, ‘Star9006’ and ‘Zeal’ produced highest average fruit mass compared to other cultivars. There was no significant interaction effect between cultivars and plant densities on tomato yield. Fruit cracking was significantly higher for ‘Linares’ and ‘Star9006’, while raincheck was higher for cultivars ‘Alexis’ and ‘FA593’. ‘Rodade’ showed high incidence of zippering. Plant densities of 20 or 25 plants/m2 produced significantly higher marketable and total yield, while plant densities of 10 or 16 plants/m2 resulted in higher average fruit mass and highest incidence of fruit cracking. Nutrient uptake, as revealed in the mineral content of fruit, was not affected by plant density. Cultivar ‘Rodade’, an open-pollinated determinate cultivar, especially shows potential to compete with more expensive hybrid cultivars in such a production system in terms of yield. Results demonstrate that high-density planting of tomato with decapitated growing points increased yield per unit area in a closed hydroponic system.

EFFECT OF CALCIUM PROHEXADIONE AND NAPHTALENE ACETIC ACID SPRAYS ON POSTHARVEST QUALITY OF 'CASTLEBRIGHT' APRICOTS (PRUNUS ARMENIACA L.)

Generally, the orchard productivity is function of the vegetative-reproductive equilibrium of the trees. If this does not occur, excess of vegetative growth would reduce light penetration in the canopy, decreasing blooming, fruit set and fruit quality, and increasing fruit physiological disorders incidence. Pre-harvest application of Calcium prohexadione (Regalis@); Regalis® plus naphthalene acetic acid (NAA-800@) ; NAA-800® in a 'Castlebright' apricot orchard was evaluated. The objective of the study was to evaluate the quality of the fruit and its cold storage potential. The fruit was evaluated instrumentally and sensorially after 20 and 40 days of cold storage. In the treatment where Regalis® and NAA-800@ were sprayed singly, an increase of fruit size in comparison to the other treatments was observed. It was verified that fruits coming from trees treated with growth regulators kept their sensory quality unchanged during cold storage in comparison with the control.

(331) In Brazil, Preharvest Calcium Sprays Were Not Always Needed to Improve Fruit Quality of `Gala' Apples

Calcium sprays have improved quality and storage life of apples throughout the world as a result of Ca prevention of many fruit physiological disorders. The efficacy of Ca sprays, however, varies according to soil, cultivar/rootstock, orchard cultural practices, and weather conditions. This study was carried out from 1998 to 2004 in southern Brazil in order to assess the effect of Ca sprays on quality of `Gala' fruits in an orchard planted in 1988 on a density of 1234 trees/ha. Treatments consisted of 0, 4, 8, and 12 sprays of 0.5% CaCl2. Fruits of same size and maturity level were annually analyzed at harvest and after 5 months of cold storage. In five out of six seasons, fruits from all treatments were free of any physiological disorder, and Ca sprays had no effect on leaf composition and on fruit quality attributes (soluble solids, acidity, starch pattern index, flesh firmness, and concentrations of N, K, Ca, and Mg). In the 2000–01 season, however, when yield was 18 t·ha-1 and fruits had an average weight of 175 g, the incidence of bitter pit plus lenticel blotch pit on stored fruits decreased from 24% in the treatment with no calcium to 2% in that with 12 calcium sprays. Two seasons later, yield was also light (25 t·ha-1) and fruits were big in size (168 g), but they did not show any disorders regardless of Ca sprays. It seems that the incidence of Ca related disorders in `Gala' apples grown on limed soils in Brazil only occurs in seasons with a light crop load as a result of large fruits and a high leaf/fruit ratio, associated with some unknown climatic factor.

A Bioassay Investigation of Calcium Nutrition and Tomato Shoulder Check Cracking Defect

Fruit physiological disorders such as shoulder check crack defects in tomato fruits are frequently inconsistent in appearance. This poses a challenge to researchers and growers. The severity and incidence of crack defects depends largely on weather conditions and may vary from almost nondetectable to causing severe yields losses. A bioassay was developed to consistently induce fruit cracking and to evaluate the effect of calcium (Ca) treatments. Detached vine ripe and mature green fruits were either waxed or not waxed with paraffin on the stem end (calyx scar) and immersed into water and 90 mM CaCl2 solutions for 4–l6 days at 25°C incubation conditions. Mature green fruit was a more sensitive indicator than red ripe fruit, showing rapid water uptake within 2 h of treatment and having a consistent cracking response. Large cracks occurred on unwaxed fruits immersed in water. Unwaxed fruit took up water rapidly, as shown by gain in fresh weight. Fruits with wax on the stem end either did not show incidence of cracking or cracks were small and slow to appear. Fruits immersed in 90 mM CaCl2 solution took up reduced amounts of water and had limited cracking compared to water-treated fruits. In a field experiment, weekly 50 mM CaCl2 sprays consistently reduced fruit-cracking incidence to a moderate degree. The role of calcium in prevention of shoulder check cracking may be related to the osmotic potential of the Ca solution, which will tend to limit water uptake by the fruit, or to the enhancement of epidermal calcium nutrition. The symptoms of fruit cracks induced by the bioassay were similar to the shoulder check crack symptoms that occurred in the field. Field and bioassay results were generally consistent. A measure of protection against shoulder check cracks may be provided by spraying Ca on fruit.

Modified atmosphere packaging maintains postharvest quality of loquat fruit

Abstract The effects of modified atmosphere packaging (MAP) on the storage life of loquat fruit (Eriobotrya japonica Lindl. cv. Mogi) were investigated. Fruit in MAP had minimal water loss (0.9–1.5%), while perforated polyethylene (PE) packaged fruit had 8.9% water loss after storage for 60 days at 5 °C. MAP significantly retained loquat organic acid levels, although total sugars were not significantly affected. Lower gas permeance MAP increased fruit physiological disorders, including internal browning (or core-browning). Storage temperature was very important for loquat fruit in MAP conditions. Fruit stored at high temperature (20 °C) sustained severe decay, and MAP increased the incidence of decay. Bagging loquats with 20 μm thickness PE at 5 °C resulted in an in-bag atmosphere of approximately 4 kPa O2 with 5 kPa CO2, and in the highest scores for appearance and chemical compounds. Loquat fruit packaged under these atmosphere conditions could be stored for 2 months at 5 °C with a higher quality and minimal risk of disorder development.