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13Такое сравнение позволило бы выбрать наиболее оптимальный вариант сейсмически безопасного здания. Это представляется предметом дальнейших исследований.
Выводы и перспективы исследований. Преимуществом предложенного автором ранее и развитого в настоящей статье подвесного здания является факт существенного уменьшения сейсмических сил. Элементы несущей рамы могут быть изготовлены как из железобетона, так и из металла. Предложенная методика динамического расчета системы позволяет достаточно просто получить уравнения движения системы. Имея уравнения движения системы легко определить динамические усилия по выражению (2) и реакции в связях, а следовательно, усилия в несущей раме.
В перспективе предполагается исследование возможности упрощения численной реализации решения системы дифференциальных уравнений (4) и (6), анализ степени влияния учета вертикальных составляющих сил инерции, а также сравнение схемы с подвешенными по отдельности этажами и схемы с этажами, связанными между собой гибкими подвесками.
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EFFECT OF PROPICONAZOLE FUNGICIDE IN LEMON QUALITY: LEMON STORING EXPERIMENT WITH THE CHEMICAL METHOD
Jurakhonzoda R.
Faculty of Agribusiness, Food Quality and Safety Department, Tajik agrarian University named after Sh. Shotemur,
Dushanbe, Tajikistan
ABSTRACT
The aim of this study was to determine the advanced methods of preserving lemon and thus increase farmers' income by selling lemon in the off-season period in the Republic of Tajikistan. The article presents the influence and effect of fungicide Propiconazole in lemon storage. In fact, losses after harvesting and during storage can vary from 25% up to 40% depending on the level of developed countries. According to statistics, on average when the farmers store 35 kg in each box during the sale in April they would have 27 kg. Preventing these losses is one of the most important issues for producers, intermediaries, and exporters. Very often storage facilities have a structure in which fungal diseases can develop rapidly due to high moisture content and other dry substances. In this regard, the international practice of fungicides is widely used to protect the fruit against fungal diseases during storage. However, in Tajikistan for storing lemon fungicides are not applied properly. In this regard, an experiment was conducted on the use of fungicides in storage lemon. Fungicide Propiconazole, which is allowed for use in post-harvest practice, will be studied in Tajikistan. For the experiment were chosen two options: 1) control variant without treatment fungicides and 2) experimental variant-treated fungicides. The results showed that the experimental version which was treated with fungicides prolongs the shelf life of the fruits of lemon, thus fruit weight and quality losses are not negatively influenced.
Keywords: fungicide; pH; dry substances; shelf-Life; postharvest loss; lemon fruit
1. INTRODUCTION
With the development of agricultural structure adjustment, the areas and yields of fruits and vegetables in Tajikistan have increased substantially in recent years. The production of fruits has become the main part of agriculture as plant production and livestock breeding. Fruit production has been playing an im-
portant role in improving the farmer's income, agricultural efficiency, and peoples' living quality (S.M. Gulov., 2008). Thus, lemons have been cultivated in Tajikistan since as early as 1921. Tajik lemons are known to have thinner skin and richer flavor, which makes them highly popular abroad. Currently, lemon orchards occupy about 1500 hectares of land, with a
yield of more than 50,000 tons a year (http://taj ikproduct.com).
Lemon "Meyer" has been introduced in Tajikistan in 1940 and since then it has become one of the key crops and sources of income for thousands of farmers. This variety has a good aroma, is very juicy, and has good demand in neighboring markets. About 50% of production is exported to Kazakhstan and Russia, however, the market is becoming very demanding, and to maintain and further improve Tajik's lemons position in the market a lot needs to be done. One of the key problems of lemon producers is significant losses during the postharvest period which can reach up to 30% (A.F.Salimzoda., 2011). For the last few years, Chinese entrepreneurs buy a lemon in bulk from local farmers and treat it with a fungicide which prolongs shelf-life (S.M. Gulov., 2008).
Physiological and pathological disorders of lemons (Citrus limon) are the main causes of quality losses during shelf life leading to high economic losses. Combined post-harvest treatment is greatly reduced or even avoided physiological disorders (damage from injuries and red spots), reducing to a minimum the loss of mass, when the fruits of lemon in long-term storage and transportation, as well as in retail sales periods, prolonging its shelf life of lemons (B. Gines, et al., 2017). The most frequent kind of spoilage in citrus products is chemical and microbiological spoilage which includes nonenzy-matic browning, color change for other reasons, loss of ascorbic acid, deterioration of taste and aroma, and degradation of the bioactive principles (Zeki Berk., 2016).
Citrus is grown in over 100 countries on six continents, with a worldwide crop of about 70 billion kg in 2004 and its production exceeds that of any other fruit. It is essential to control postharvest diseases in order to maintain the quality and prolong the shelf life of citrus fruit, particularly in a market where transport from producer to consumer may take several weeks and storage in packinghouses can exceed 3 months. The green mould of citrus, caused by Penicillium digitatum (Pers.: Fr.) Sacc. is the most economically important posthar-vest disease of citrus in arid growing regions of the world (A.R.Helalia, et al., 2014).
Preservation of the natural qualities of fresh citrus after harvest, either for the domestic market or for export, is very important. Storage is the most important
operation during the marketing of fruit. All operations, including harvesting, pre-or post-harvest treatments, packaging, transportation, and temperature and humidity management during handling influence the storage life of fruits (S.Milind.,2008). Fungicides such as Imazalil, Pyremethianine, Thiabendazole, Propicona-zole are allowed for use in post-harvest practice in Europe and the Russian market. The shelf-life of a product begins from the time the food is prepared or manufactured. Its length is dependent on the following factors: types of ingredients; manufacturing process; type of packaging; storage conditions
(http://www.microchem.co). In South Africa, common application methods for postharvest fungicides include dip, wax coating, and drench application. A survey was done by Erasmus et al. (2015) to determine the most common parameters for these methods.
Products consist of biomaterial and after some times begin to deteriorate. Deterioration cannot be stopped but can be prevented by: high-quality raw material; appropriate technology; suitable packaging material; correct storage under transportation regimes (R. Steele., 2004). Future work should include the study of parameters that can improve the shelf life of lemon with less loss.
2. MATERIALS AND METHODS
The research was performed between March and April 2021 in the laboratory of the Food Quality and Safety Department of the Tajik Agrarian University named after Sh. Shotemur. Lemon (Citrus limon, Meyer cv) fruits without chemical treatments purchased from the supermarket and were used for the evaluation of weight loss, pH, and dry substances. Totally, all lemons fruit were washed first in 9:1 hypochlorite (NaOCl) solution then rinsed three times in sterile water.
For a further experiment lemons applied with a fungicide, was used 300 ml of Propiconazole 750 ppm and 100 liters of water. The study was conducted to assess the effect of fungicides in the composition of the lemon while maintaining. For the experiment were chosen two samples: 1) control variant - without treatment fungicides and 2) experimental variant - treated with fungicides, in each embodiment, four replications (pic.1).
Table 1.
Sample 1: Experimental with fungicides Sample 2: Control without fungicides
Repetition 1: experimental with fungicides for 35 days Repetition 1: control without fungicides for 35 days
Repetition 2: experimental with fungicides for 60 days Repetition 2: control without fungicides for 60 days
Repetition 3: experimental with fungicides and wax paper for the 35 days Repetition 3: control without fungicides in wax paper for the 35 days
Repetition 4: experimental with fungicides and wax paper for the 60 days Repetition 4: control without fungicides in wax paper for the 60 days
Within 60 days, the experimental and control variant will be observed in the following parameters: weight loss; acidity (pH); dry substances.
7iWI
y i
Picture 1. Experimental with fungicides and control without fungicides
3. RESULTS
3.1. Observing the effect of fungicide relative to the weight of Meyer lemon
Analysis of variance showed a significant interaction between different trials of preserving citrus fruit (trial). Significant interaction was observed between wax paper and without (Table 2). Protective treatment
fruit with 300 ml Propicanazol led to a significant improvement in the untreated lemon (Fig.1). In general, for each treatment combination in trials described above a small but significant improvement was observed after wax treatment. The best curative or protective control (19.6%) was achieved when processing fruits with the fungicide and wax paper.
Table 2.
The average weight samples of Meyer lemon and its modification during storage.
№ Samples Samples weight before Average weight of fruits before Samples weight after 60 days of Average after 100 days of Distinction of weight
storing, (g) storing (g), storing, (g) storing, (g) g %
1 Control 846,1 169,2 572,8 114,6 273,3 32,3
2 With wax paper 907,3 181,5 627,4 125,5 279,9 30,8
3 Treated fungicide 895,9 179,2 691,2 138,2 204,7 22,8
4 Fungicide and wax paper 795,5 159,1 639,5 127,9 156,0 19,6
Data tabulated in Table (2) indicated that fungicide Propiconazole exhibited high fungicidal effects against weight loss. The results showed that the fungicidal activity of the tested fungicide was increased by adding wax paper.
Correlation %
40
m
S
c
(U
a
u a.
30
10
Control With wax paper Treated fungicide Fungicide and wax
Samples paper
Fig.1. Variance between trial and experiment (%).
200 150 100 50 0
181 5
1 7Q 9
Before storing After storing
Control With wax Treated Fungicide and paper fungicide wax paper
0
Fig.2. Modification of weight during storing (g).
Conducted analysis for determining pH and dry substances showed that treating lemon with fungicide and wax paper can keep lemon with less modification. Similarly, there was generally a statistical difference for the resistant fungicide between the untreated and
treated fruit. In accordance with the results obtained from the experiment, using the fungicide might positively influence the structure of lemons.
3.2. Observing variance of pH of Meyer lemon and dry substances
Table 3.
pH and dry substances of Meyer lemon and its modification while storing.
Samples
Average Ph/dry substances indicator be-
Average Ph/dry substances indicator after
Distinction, Ph/dry substances indicator
Temperature of storing
Control 2,61 2,63 + 0,02 10 C
With wax paper 2,63 + 0,02
Treated fungicide 2,64 + 0,03
Fungicide and wax paper 2,57 - 0,04
Dry substances 7,16 10 C
Control 8,8 + 1,64
With wax paper 8,1 + 0,94
Treated fungicide 8,3 + 1,14
Fungicide and wax paper 8,1 + 0,94
4. DISCUSSION
The results clearly indicated that fungicide Pro-piconazole exhibited high fungicidal effects against the mycelia growth of P. digitatum. These results are in accordance with the previously recorded. Four fungicides (imazalil, thiabendazole, fludioxonil and azoxystrobin) and sodium bicarbonate were evaluated separately or in mixtures in the laboratory against P. digitatum causing green mould disease of an orange fruit (A.R.Helalia, et al., 2014). Sodium bicarbonate (NaHCO3), commonly known as baking soda, was selected for integration with the fungicides. It is a common food additive for pH adjustment, taste, texture modification, and spoilage control and has been shown to have antimicrobial activity against P. digitatum on citrus fruit (Zamani et al., 2008 and McKay et al., 2012). Also, the addition of sodium bicarbonate improved the performance of citrus post-harvest fungicides for the management of green mold decay.
Green mould is one of the main contributors to postharvest losses in the Tajikistan and export market due to decay. As a result of the long distances to markets, the time for South African fruit to reach export markets can be from 6 (for soft citrus) to 12 weeks (A. Erasmus., 2015). In addition, fungicides are used for postharvest disease control. Thiabendazole (TBZ), imazalil (IMZ), and guazatine (GZT) have been used for decades to control green mould over the world especially in South Africa.
5. CONCLUSIONS
Postharvest disease management is therefore of the utmost importance in order to assure the best possible quality fruit on the market. The results of this study
showed that fungicide Propiconazole has positive effects to protect fruits from deterioration. Our study clearly indicated that practices including sanitation and careful handling of fruit during harvesting are essential to control fruit from damage. In addition, we can say that it was an inception investigation about using fungicides afterward the whole sides are going to study in detail.
ACKNOWLEDGMENTS
The authors express their gratitude to the staff Food Quality and Safety Department of Tajik Agrarian University named after Sh. Shotemur for assistance and guidance.
References
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11. http://tajikproduct.com
12. http://www.microchem.co
