Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5327_Библиотеки_им_академика_М_И_Перельмана
.pdf
16 Thyme
https://t.me/medicina_free
47. Schroder, J., & Vollmer, H. (1932). The excretion of thymol, carvacrol, eugenol and guaiacol
and the distribution of these substances in the organism. Archiv fur Experimentelle Pathologie
und Pharmakologie, 168, 331–353.
48. Vasilatis, A.A. (2022). Inhibition of post-harvest pathogen gray mold (Botrytis cinerea) on
strawberry (Fragaria ananassa) with application of thyme (Thymus vulgaris) essential oil.
Rutgers University-School of Graduate Studies.
49. Sotelo, J.P., Oddino, C., Giordano, D.F., Carezzano, M.E., Oliva, M., & d. l. M. (2021).
Effect of Thymus vulgaris essential oil on soybeans seeds infected with Pseudomonas syringae. Physiological Molecular Plant Pathology, 116, 101735.
50. Rezatoghi, S.E., Seydabadi, A., & Nejad, S.M. S. (2014). Evaluating the efcacy of Achillea
millefolium and Thymus vulgaris extracts against Newcastle disease virus in Ovo. Jundishapur
Journal of Microbiology, 7(2).
51. Barros, F.A., Radünz, M., Scariot, M.A., Camargo, T.M., Nunes, C.F., de Souza, R.R., etal.
(2022). Efcacy of encapsulated and non-encapsulated thyme essential oil (Thymus vulgaris
L.) in the control of Sitophilus zeamais and its effects on the quality of corn grains throughout
storage. Crop Protection, 153, 105885.
52. Saltos-Rezabala, L.A., Silveira, P.R. D., Tavares, D.G., Moreira, S.I., Magalhães, T.A.,
Botelho, D.M. D.S., etal. (2022). Thyme essential oil reduces disease severity and induces
resistance against Alternaria linariae in tomato plants. Horticulturae, 8(10), 919.
53. Charalambous, M., Raftopoulos, V., Paikousis, L., Katodritis, N., Lambrinou, E., Vomvas, D.,
etal. (2018). The effect of the use of thyme honey in minimizing radiation-induced oral mucositis in head and neck cancer patients: A randomized controlled trial. European Journal of
Oncology Nursing, 34, 89–97.
54. Hashemian, F., Baghbanian, N., Majd, Z., Rouini, M.-R., Jahanshahi, J., & Hashemian,
F. (2015). The effect of thyme honey nasal spray on chronic rhinosinusitis: a double-blind
randomized controlled clinical trial. European Archives of Oto-Rhino-Laryngology, 272(6),
1429–1435.
55. Mehran, M., Hoseini, H., Hatami, A., Taghizade, M., & Safaie, A. (2016). Investigation of
components of seven Species of Thyme Essential oils and comparison of their antioxidant
properties.
429
Chapter 17
https://t.me/medicina_free
Onion
SaraZafar, NaziaAslam, AbidaKausar, ShaguftaPerveen,
andMuhammadRiaz
17.1 Introduction
Botanical Description
Kingdom: Plantae
Division: Magnoliophyta
Class: Liliopsida
Order: Asparagales
Family: Amaryllidaceae
Genus: Allium
Scientic name: Allium cepa
English/common name: Onion
Onion is an herb, which grows to about 80 cm in height. It is developed from a
pungent bulb. The bulb is almost of ovoid in shape, brownish in color, glossy, papery
and solitary. Different colored bulbs are found like yellow, white and red and avor
like sweet or pungent [1]. The leaves are simple, linear, stulose and entire. The
sheath part of the leaves forms a pseudostem, which hides a great part of the aboveground scape [2]. The scape is of about 1 m in length. Inorescence is of globose
umbels. Bracteoles are present at the bases of the pedicels. The spathe is short and the
owers are campanulate [2]. The parianth consists of 6 petals, which are white, ovate,
S. Zafar (*) · N. Aslam · S. Perveen
Botany Department, Government College University, Faisalabad, Pakistan
e-mail: sarazafar@gcuf.edu.pk
A. Kausar
Botany, Department, Government College Women University, Faisalabad, Pakistan
M. Riaz
Department of Pharmacy, Shaheed Benazir Bhutto University, Sheringal, Pakistan
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2023
M. Zia-Ul-Haq etal. (eds.), Essentials of Medicinal and Aromatic Crops,
https://doi.org/10.1007/978-3-031-35403-8_17
431
432
https://t.me/medicina_free
oblong and about 4mm in length. The androecium consists of 6 stamens. The ovary
is minute and sub-globose [3]. Allium show capitate stigmas. Ovary is trilocular with
septal nectaries having distinct nectariferous pores. Two ovules are present in each
locule, which develop into seeds [2]. Family is also known as Aliaceae [4].
S. Zafar etal.
17.1.1 Karyology
The basic chromosome numbers found in the onion plants are x=8 and x=7 with
polyploids [2].
17.1.2 Morphology ofOnion
17.1.2.1 Colors
The bulbs of onions are of different colors like yellow, red, brown, chartreuse
and white.
17.1.2.2 Size andShape
Bulbs are of variable shapes like at, elongated, pyriform and round. Height and
shape of the onion bulb has high inheritability as compared to the diameters
and weight.
17.1.2.3 Soluble Solids Content
Onions bulbs can accumulate signicant amount of carbohydrates called nonstructural carbohydrates or SSC [5]. Dehydrating industries use this higher SSC
content for producing onion powders or akes for seasoning. The main soluble content found in onion bulbs are sucrose, fructose, fructans of insulin neoseries and
insulin series. Fructans stored in the plants play important role in regrowth or
sprouting and help in protection of plant from low-temperature and drought [6].
17.1.3 Plant Characters
17.1.3.1 Premature Flowering
Bolting (Flowering during bulb production) creates somehow useless bulbs and
great loses for growers. After the emergence of true leaves, young onion plants are
subjected to cooler temperatures. There appear clear cut phenotypic differences
17 O n ion
https://t.me/medicina_free
from germplasm to bolt. It is important for the plants, grow in winter to resist bolting to bring out bulb in the harvest season of spring. Planting date is also important
for the plant, as the plants which are grown in the early season, faces long cold
temperatures and results in the increase in the bolting [7].
17.1.3.2 Seed Yield
Seed yield is dened as the “average quantity of seeds produced from a single plant”
or it can be the total number of owering scape or umbel produced by a single plant
or the number of perfect ower produced by a single umbel. Onion is considered as
the poor producer of seed as compared to the many of other crops. Normally, the
ovary of onion contains six carpels, expected to produce maximum six seeds per
ower. However, in order to meet the maximum seed production content, seed production must be excellent. The long day storage onions produced smaller umbels
and shorter scapes as compared to the short day onions. Level of inbreeding and
seed yield have a correlation [8]. Reduced seed yield often results in the loss of
vigor in the inbreeding results. Relatively good seeds are produced by the double
haploid varieties [8, 9]. Production of these variable seeds is due to the variability of
insects pollinated the plants. For example, the plants with high low sucrose content
in their nectar produced lower quantities of seeds as compared to the plants, producing higher amount of sucrose containing nectar as also reported by [10]. However,
no genetic basis was given for the attractiveness of insects in relation to the seed
production.
433
17.2 Onion Agronomy
Now a days the high yield of the onion can be achieved by the use of crop-protection
chemicals [11–13]. These chemicals control the weed effectively. It also works as a
constituent of the costly hand labour. Experiments were performed in Netherlands to
nd out the total inputs of all the pesticides which were about 23kgha−1 per crop
and 10.5kgha−1 of pesticide the post-transplant cropping season in Norway [14].
Along with these pesticides, onion also need some of the mineral quantities for
proper growth. Large number of pesticides and nitrogen are emitted from the onion
elds then from any other crop, which effect the on aquatic and soil organism [2, 15].
Integrated crop management (ICM) systems used some of the resources for the
production of onion crops which are less wasteful and rened then the older and
traditional crop production methods. This process deals with the usage of external
resources like water [16, 17], chemical input and fuel for the production of crop
along with using pesticides. Processors and consumers used onion in different forms
such as fresh bulbs after harvest, dry bulbs when fresh bulbs are not available, green
or salad onion with or without bulbs, some other used for pickling, freezing, for
dehydration as powder and akes, onion oils, fresh cut products etc. The distance
between the farm and the factory is of great economic importance [2, 18].
434
https://t.me/medicina_free
S. Zafar etal.
Table 17.1
different varieties of onion
Pungency of
Variety Pungency
Garlic
Spanish Mild
Southpart white Strong
Bessanovski V.Strong
Hysam Strong
Red Baron Strong
Purple intercross
Outer scales Mild
Inner scales Mild
17.2.1 Onion Pungency
Pungency of the onion is produced by the hydrolysis of S-alken/alknyl cysteine sulfoxide molecules [14, 19, 20] (Table17.1). This pungency is performed by the allinase enzyme right after cell disruption. The disruption of the cell produces substances
like, pyruvic acid, ammonia and sulfenic acid. Weston and Schwimmer method
proved that, the pyruvic acid is formed by the enzymatic cleavage of those molecules
which are the precursor of the avor forming substances [21–23] (Fig.17.1).
17.2.2 Ecology
The genus Allium shows diversication in distribution. Majority of the species grow
in open sunny areas. Areas inhabited by Allium species are Central Asian high
mountains, European subalpine pastures, alpine and sub-alpine grasslands of the
Himalayan, different types of forests and along the river banks as well. Some taxa
are able to tolerate saline and alkaline environments. Taxa with spring, summer and
autumn owering also exists. These are mostly short and long perennials, with one
to many cycles of leaf formation. Many ephemeroids species of genus Allium show
limited annual growth for a very short period of time in spring and early summer
which complete their life cycle from leaf sprouting to seed maturation in 2–3months.
A. cepa is a not ephmeroid. It’s leaves growth begins after the frost has ceased in the
spring and in the coming autumn and winter, growth limited [2].
17.2.3 Distribution
The specie cepa is known as petrophytes, which usually grows in open plant formations like rock cervices, river-banks, rocks, gravelly deposits, stony slopes and many
more like these. These sites mostly contain shallow soil layer. Their occurrence on
17 O n ion
https://t.me/medicina_free
435
Fig. 17.1 Flavor compounds of onion
these sites are not affected by pH of soil, plant-sociological associations, minerals
content or vegetation types. The distribution pattern often results in the formation of
small populations. However, large populations have also been reported by various
researchers [2].
17.2.4 Land Preparation andSoil Management
All the types of the soils are suitable for the cultivation of onion like heavy clay,
volcanic, sandy or peat organic soils. Stony heavy soil hindered the mechanical
harvesting. The homogenous, ne structured soil is required in the upper or surface
layer for growth. The best or suitable soils are found to be loamy or sandy loam soils
with good quantity of organic matter and soil structure [2].
436
https://t.me/medicina_free
S. Zafar etal.
17.2.5 Soil Preparation
Various methods are used for the preparation of soil for the cultivation of onion like
subsoiling plough, rotavator, mould-board plough and cultivator. Soil compaction is
mostly prevented in these methods. In sandy soil, after the completion of preparatory work, a roller may be used. For combating soil erosion, elevated beds of almost
15cm or higher are used to allow good drainage and can be constructed. Sometimes,
serpentine furrows are mostly set up inside large sized beds, whose purpose is to
allow water to supply to a limited area at one time [2]. One thing to be keep in mind
is that the land for the transplant production of onion should not have been used for
the Allium production or at least 3years. The sites with the onion disease and severe
weed problems history should be avoided [24].
On acidic soil with pH almost lesser then 6.0, 2–3months before preparation of
land, lime is applied to bring the soil pH to about 6.2–6.5 range. These applications
effect the storage and quality of bulb by reducing the percentage of bolting and
increasing the bulb rmness. Seedling emergence is mostly hindered by crust formation, making second sowing compulsory. In some countries, to prevent crusting,
onions are grown on organic or peaty soil, known as muck. Some of the other things
to prevent crust formation include, incorporation of organic matter, low intensity
irrigation or mulching helps to reduce the formation of crust [2–25]. For the sweet
onion production, sandy loam, loamy or sandy soils are preferred. These soils contain low Sulphur, one of the fact, which enhances the capability of soil to produce
sweet onions [24, 25].
Spraying of soil surface with 500× 10
4lm−2 and phosphogypsum (PG) spread after rainstorm, proved to be useful for the
crust formation and stimulating emergence of onions in loamy, non-sodic soils. In
some soil conditions, PG along with water of electrical conductivity of about 0.65
deci-siemens (dS) m−1 on average is proved to be useful for the improvement of
onion emergence. Vermiculite is a source of anti crustant which can be applied over
the seed row and then covered with a thin soil layer. It helps to prevent soil erosion.
H3PO4 is also found effective in controlling erosion when banded over the row. In
some cases, emulsied plastic gel is used on the soil which form the water stable
soil aggregates. This helps in increasing emergence of onions bunch and in decreasing soil cracking. Rice straw mulch is also in used in countries like Thialand [2].
Before sowing of onion, sterilization is performed by solarization. For killing
pathogens and weed seeds, moist soil is heated over 4weeks by mulching with
polyethylene. In some of the countries like Egypt and Florida, this method has successfully been practiced. This method results in the increase in the yield of jumbo
onions (>10cm). Onions show sensitivity to salinity and result in the decrease in the
−1
at about 1.4dS m
treatment solution. Therefore, the salinity of the soil is kept in
consideration while sowing onions. In some arid and sub humid areas, cropping of
onion is performed in saline soils. This is in turn, decrease the yield of the onions
even after adopting some of the preventive techniques just like planting of seedlings
on the ridges. Salinity effects increases with the increase in the temperature and
−6
gml−1 of polyacrylamide at a rate of
17 O n ion
https://t.me/medicina_free
decrease in the humidity. For avoiding salinity, adequate drainage system is required
[2, 11].
Onion storability is also affected by the soil characteristics. Onions sprouting
depends upon the presence of salts in the soil just like higher quantity of sodium
(more than 5.4mg, 100 per soil) showed highest storage aptitude, resulting in fewer
sprouts. In order to avoid toxicity, the soil salinity must be lower than 370mg of
salts 100g−1 of soil [2, 25].
437
17.3 Categories ofOnions
Onion is produced in three product segments. (1) Bulbs used for fresh market, these
bulbs have the greatest diversity. (2) Dehydrated onions which are used for food
processing. (3) Green salad onions used for fresh consumption. Bulbs of onion are
produced from sets, transplants or seeds. These can survive easily in low moisture
condition but still adequate supply of water is required for normal growth.
17.3.1 Green/Salad/Spring Onion
These are also known as scallions. These are immature onions grown very short
period of time, at high density. These are harvested and sold after a few days of
harvesting. These can be used both for salad and cooking.
17.3.2 Semi-bulbled Oninos
These onions provide larger amount of bulb tissues as compared to the scallions.
These also must be harvested before maturity and sold.
17.3.3 Bulb Onions
Bulb onion are specically produces for freezing, drying and dehydration. For
dehydration, specic onion verities are selected, whose dry matter content is up to
20% or more. This reduces the energy consumption of the dehydration process. The
onions growing in the high solar radiations areas are recommended for dehydration
[26]. As there are most chances to obtain the maximum dry matter. Onion is one of
the most traded plant, because of it’s durability and storage characteristics.
438
https://t.me/medicina_free
S. Zafar etal.
17.3.4 Storability
One of the best advantage of using onion as a crop is it’s storability. Upon reaching
at maturity, plants are lifted [27]. So that it’s roots, shoots and skin are completely
dry and keep well. The bulbs have the ability to remain dormant both in low and
high temperature regions. So, these are recommended both for temperate and tropical regions. In modern refrigerators, due to efcient storage ability, the onions can
be stored up to 9months [28–30].
17.4 Onion Production Methods
One of the best onion production method is direct sowing in humid temperate climates. The place should be where the irrigation can be managed well. For producing salad onions, a bed system with many rows is formed. While for bulb production,
other systems like furrows and ridges are adopted. On at surface, pneumatic seeders are used. Means or nal emergence of the onion plants depends upon the soil
moisture and eld temperature. The temperature being varies from 10 to 20°C and
water capacities from 40 to 80% for higher emergence. The depth for onion is found
to be about 1–2cm for optimal emergence while in the drier soils, depth of about
4–5cm is considered. A model was developed for the effect of water stress on germination of onion. According to this model, radicle growth can be initiated when
the difference between the virtual osmotic potential and ambient water potential
reach a certain threshold. Water potential is found to be in inverse relation with the
time of onion radicle growth and it’s emergence. Mechanical impedance decreases
the rate of onion root development then that of shoot. So, after recovery, onion
shoots develop better and elongate the non-impede seedlings [2].
Factors under consideration for the development of onions include water availability, season, price premium and soil types for early onions, jumbo (77–101mm)
and colossal (≥102mm) diameter bulbs. Level elds are mostly recommended for
irrigation layouts [2].
17.4.1 Timing
During the early part of the growing season, onions are mostly produced during
long cool season and there is also a variation in temperature year to year. Experiments
conducted for growing onion shows that sowing in February show high bolting in
almost all the cultivars. It is possible to control the inorescence induction by controlling the sowing date [2].
17 O n ion
https://t.me/medicina_free
439
17.4.2 Plant Density
Selection of population is a very important decision; high population decrease the
bulb while onion yield increase. It also increases the disease severity. Increase in the
density of the onion results in increase in the %age of bolting. Distances of sowing
or planting can be established according to mathematical calculations of grade and
size of onions [2–23, 25–31].
17.4.3 Seed Priming
Seed quality, it’s performance in the soil and its ability to pass through the difcult
chemical and physical conditions of soil. The usage of prime seeds increased the
rate of emergence and decrease the time spread. Seed priming is a process in which
seeds before sowing, are allowed to imbibe water in a well-controlled manner. In
some cases, re-drying of seeds is performed, which bring all the seeds to the same
stage of germination readiness, enhancing evenness in germination. But if the storage months’ increase from 6 to 12, the abnormal seedlings begin to increase, so the
priming seedlings should be done only one season depending upon the usage [2].
One of the priming methods include aerated salt solution, but it decreases the
%age of onions emergence, which is most probably due to non-tolerating behavior
of the onion seeds which reached their maximum stage of development before sowing. Other method is Solid matrix priming. In this method, priming is done by
mixing of seeds with known proportions of water and a solid material. Of all these,
successful method is Drum priming, a commercially used priming method. The
method includes the priming of seeds in bubble-columns in turn improved seeds and
seedling leek performance. Drum priming method is useful as in it controlled
amount of water is added to seed. The water revolves in drum, so that the seeds takes
only the required percentage of water, without becoming completely wet. The
imbibed seeds then dried with warm air and sown with a normal seed drill [2,
10, 32].
17.4.4 Seed Coatings
Onions seeds are coated with fungicides or insecticides, before sowing, which
results in the decrease in the chemical used per unit area of land. Usually colored
coating is applied. Then palletization is performed, which changes the shape and
size of the seed so that it can be sown easily with a drill [2, 33].
Соседние файлы в папке Библиотека им академика М.И. Перельмана