Information regarding the Avocado industry in Mexico.
Including, growing, packing, shipping, exporting to Asia, checking dry matter, ripening, and checking quality.
2. Introduction-Michoacan
This was when the cultivation area saw rapid expansion, up to approximately 50 000 ha in the
mid-1970s, and then to 100 000 ha in the 1980s, with Michoacรกn becoming the countryโs
number one production area. Faced with a massive influx of production and a saturated local
market, professionals sought to diversify their outlets, by developing the export sector from the
early 1980s. Avocados from Michoacรกn zones declared quarantine pest-free were authorized in
the US market in a limited number of non-avocado producer States from 1997, after nearly a
decade of joint efforts by the Mexican industry. The progressive opening up of this market,
complete by the end of January 2007, generated an exponential growth trend in the industry,
especially with the intense promotion campaigns for this fruit launched in the USA in the early
2000s
3. Introduction-Jalisco
Commercial scale cultivation of Hass in Jalisco is a recent phenomenon, dating
from the early 2000s, when land originally dedicated to livestock farming, the
staple crops (maize, sugar cane, etc.) or forests (pine) were converted to higher
added-value production such as the avocado, or more recently berries. The
avocado zone is packed into the southeast of the State, within a radius of
approximately 30 km around the city of Ciudad Guzmรกn. Its extension was
evaluated at 26,500 ha in mid-2019,
4. Geography - Michoacan - Growing Regions
Share of planting area HA in 2018
East: District of Patzcuaro 57,877 HA
Ario 16,031 HA
Salvador Escalante (Santa Clara) 16,293 HA
Tacambaro 17,000 HA
Center: District of Uruapan 60,168 HA
Tancitaro 23,650 HA
Uruapan 16,200 HA
West: District of Zamora 34,372 HA
Los Reyes 6,009 HA
Periban 12,560 HA
Others 14,185 HA
5. Geography - Jalisco - Growing Regions
โ Sierra del Tigre to the north-east of Ciudad
Guzmรกn (Main Region)
โ Gรณmez Farรญas
โ Concepciรณn de Buenos Aires
โ Zapotiltic
โ NE Ciudad Guzmรกn/ Zapotlรกn
2 Main Production Regions
โ Sierra de Tapalpa to the north-west of
Ciudad Guzmรกn
โ Tapalpa
โ Sayula Lagoon area
***Sierra del Tigre being favorable due to the soil type.
7. Geography - Jalisco Elevation
โ Plantations were originally set
up in the high-altitude parts at
1,700m to 2,300m
โ As demand grew, lower-altitude
zones were developed at
1,100m to 1,300m
11. Production- Planting /Land Preparation
Before planting the grounds should be treated if
pests such as weed if present.
Once pests have been eradicated, soil should be
disced or plowed and leveled.
A marker or in this case a black line is used to help
guide the producer on where to plant.
A trench or hole is dug to a depth suitable to fit the
rooted and to ease in the establishment of
Mycorrhiza.
Nursery trees are then planted at fixed intervals
that depend on the planting configuration.
12. Production- General Planting configuration
The most common planting
configurations:
Tresbolillo (staggered)
configuration
Real Frame (square/rectangle)
configuration.
This is the most common
configuration in Michoacan
Tree Spacing
(meters)
Trees per Hectare
Real Frame Tresbolillo
8 x 8 156 179
9 x 9 123 141
10 x 10 100 115
11 x 11 82 95
12 x 12 69 79
13. Production- Planting configuration (High Density)
An alternative for Hass avocado producers that offers the advantage of
recovering the investment between the third and fourth year after production
starts, compared to the traditional method in which it is recovered between
the eighth and ninth year, with little difference in the initial investment is the
establishment of the garden in a real setting with a high density of plants. In
this system, it is recommended to establish the orchard with a distance
between plants of 4.5 by 4.5 meters, with which an initial population of 493
trees per hectare is obtained, as opposed to the traditional densities of 123
plants per hectare. Between the sixth and seventh year after the plantation is
established, half of the trees are removed; thus, the distance between trees
increases to 9 by 4.5 meters, and there is a population of 246 plants in one
hectare. From the first year of harvest (at 4 or 5 years), the production of
fruits per plant is low, but the total amount per hectare is high as the number
of plants on the property is greater. At year 9, half the population is
eliminated again; only 123 trees remain per hectare, at a distance of 9 by 9
meters. With this, the capitalization of the producer is faster, since the
harvest volume is significant from the first years of production and the initial
investment is recovered in less time.
14. Production- Nursery Plants
Commercial Avocados trees are sourced from nurseries. The process
starts selecting seeds that will thrive in the soils they intend to planted in
and may have benefits such as being disease tolerant. After seed
selection, seeds are germinated by controlling humidity and temperature.
15. Production- Nursery Plants
Budwood or scions are
prepared from a carefully
selected mother tree. The
mother tree should show
vigorous growth and
consistent yields once the the
avocado sprouts reach a
certain maturity.
20. Variety - Origin of Mendez
In the 1980`s a Hass Avocado producer named
Carlos Mendez noticed one of his Hass trees
consistently bore 'out of season' flowers. It not only
had a loca crop every year, it regularly held the
fruitlets to full maturity, producing good quality fruit
at a time of year when the main Hass crop had yet
to start. Realizing its commercial importance he
propagated and multiplied the trees by grafting
them on trees in his orchard and supplying trees to
surrounding orchards. As the pattern continues
over the next decade enough blocks of trees were
established that the fruit began to be recognized
as a distinct form of Hass, and it became known
as the Mendez type.
21. Variety - Mendez vs Hass
Mendez and Hass
are a variation of the
same variety with the
only difference being
harvest timing.
Mendez can be
ready to harvest
about 1-2 months
earlier.
Seed Company Description of Each variety
Description Mendez Hass
Parentage Mexican Mostly Guatemalan
Flower Type Type-A Type-A
Fruit Shape Obovate Obovate
Skin Color When Ripe Black Black
Skin Thickness Medium to thick Medium to thick
Fruit Weight 6-14 oz. 6-14 oz.
Seed Size Medium to Large Medium to large
Oil Content 20% 20%
Tree Size Large Large
Hardiness Average to 28ยฐF Average to 28ยฐF
Flavor Excellent Excellent
23. Hass vs. Mendez
โ Obovate shape
โ Fairly Large Seed
โ Medium skin thickness
โ Hass look-alike
โ Obovate shape
โ Fairly Large Seed
โ Medium skin
thickness
24. Avocado yield comparison by year
Growing area
Proportions of
planted area
Yield (mt/ha)
Michoacan
Traditional
System 60% 9.25
High-tech system 40% 16
(Weighted)
Average Yield 100% 12
Jalisco 100% 15
Maturity of trees
4
Years
5
years
6
Years
7
years
8
years
Michoacan - avg yield (mt/ha) 0-0.3 1.3 4.2 8.4 12
Jalisco - avg yield (mt/ha) 1.6 5.3 10.5 15 15
25. Michoacรกn โ Survey of cultivation area in 2018
Michoacรกn โ Survey of cultivation area in 2018, and projected production of planted surface areas
Year of planting Age at the end
of 2018
Age at the
end of 2023
Planted Area
(HA)
2023 Yield
(MT/HA)
2023 Total
Production
before 2015 >=5 years >=10 years 131,400 HA 12.0 MT 1,576,800 MT
in 2015 4 years 9 years 13,500 HA 12.0 MT 162,000 MT
in 2016 3 years 8 years 10,400 HA 12.0 MT 124,800 MT
in 2017 2 years 7 years 7,800 HA 8.4 MT 65,520 MT
in 2018 1 year 6 years 8,400 HA 4.2 MT 35,280 MT
Total Production by 2023 171,500 HA 1,964,400 MT
* 5 years for Orchards in Michoacan to start becoming significant
26. Jalisco โ Survey of cultivation area in 2018
Year of planting Age at the end of
2018
Age at the end
of 2023 Planted Area (HA)
2023 Yield
(MT/HA)
2023 Total
Production
before 2016 >=4 years >=9 years 23,700 HA 15.0 MT 355,500 MT
in 2016 3 years 9 years 2,344 HA 15.0 MT 35,160 MT
in 2017 2 years 8 years 4,163 HA 15.0 MT 62,445 MT
in 2018 1 year 7 years 3,133 HA 10.5 MT 32,897 MT
Total Production by 2023 33,340 HA 486,002 MT
* 4 years for orchards in Jalisco to start becoming significant
27. Production of Orchards planted after 2019
Surface area expansion
Annual expansion (ha) Additional production
in 2023 (mt) Comment2019-2021 2021-2023
Hypothesis 1
Michoacan 5,000 HA 5,000 HA 6500 MT 5000 ha 5 years old producing 1.3MT /HA
Jalisco 3,000 HA 3,000 HA 20700 MT 3000 ha 4 years old, and 3000 ha 5 years old
Hypothesis 2
Michoacan 7,000 HA 7,000 HA 9100 MT 7000 ha 5 years old producing 1.3MT /HA
Jalisco 3,000 HA 3,000 HA 20700 MT 3000 ha 4 years old, and 3000 ha 5 years old
28. Projected production volume by 2023
Description
Hypothesis 1 Hypothesis 2
Michoacan Jaliso Michoacan Jalisco
Production prior to 2018 1,964,400 MT 486,002 MT 1,964,400 MT 486,002 MT
Production from 2019 6,500 MT 20,700 MT 9,100 MT 20,700 MT
Total per state 1,970,900 MT 506,702 MT 1,973,500 MT 506,702 MT
Total Michoacan + Jalisco 2,477,602 MT 2,480,202 MT
30. Bloom Calendar based on Elevation
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
1100
1200 Temporada
1300
1400 Marzena
1500
1600 Aventajado
1700
1800
Loca/
Aventajado
1900
2000 Aventajado
2100
2200
2300
2400
2500
31. Flowering Cycles
Avocado production in Mexico is defined by seasonal
blooms that grow into Avocados.
In Mexico there are 4 seasonal blooms per year, from July
to May.
It takes 7 to 12 months for an avocado to grow to maturity
from flower bloom.
Excessive rain or can damage the flower blooming and
affect the following year`s production.
Avocado Flowering Blooms:
โ Flor Loca
โ โcrazy flower" time of bloom is variable, small sized, as they are the first fruits
harvested, with a rounded shape and smooth skin.
โ Aventajada
โ Early flowering before main season, pear-shaped, granular fruits.
โ Temporada
โ Main season fruits similar to Aventajada.
โ Marzena
โ March bloom late flowering, fruits variable in appearance, small size, pear-
shaped with thick skin. But good taste quality, since their oil content is high
thanks to high sun exposure.
โFlora Locaโ
32. How Blooms work
The avocado flower has both functional male and female organs in the one flower, but opens and closes twice over a
two-day period
The first day as functionally female (left) and the next as functionally male (right).
Each opening stage only lasts about half a day.
First Day Second Day
Morning Afternoon Morning Afternoon
Female Male
1st / 2nd Day
Morning Afternoon
Female Male
But with hundreds of flowers opening in both stages day after day, the daily
situation appears with an equal ratio of male and female.
But, as the average temperature falls below about 70 F, the flower
parts function less well. Below about 60 F (15.5 C), there may be zero
set.
34. Pre Harvest
A Procurement Engineer records his visit to
the orchard the packhouse intends to
harvest
In case of not identifying prohibited
substances and verifying that the security
intervals of substance application are met
the sampling of the orchards is performed
and dry matter is tested.
Dry matter: samples are taken to determine
that the dry matter is adequate to be able to
harvest (Greater than 22%).
35. Dry matter
Dry Matter is defined
as the part of a
foodstuff or other
substance that
would remain if all of
its water content
were removed.
Dry matter of avocados shall be determined by weighing the fresh weight and dry weight of a sample of avocados. The testing procedures
and method of calculating the percent of dry matter shall be as follows:
(a) At the widest circumference of the avocado, remove a core from the entire width of the avocado. Discard the seed portion, and remove
the seed coat and skin to the depth of the edible portion from the remaining core pieces. Cut each core piece in half. The core sample
shall be removed with a coring device having an inside diameter of 5/8 inch, plus or minus 1/16 inch.
(b) Repeat the above for the number of sample fruit required.
(c) The cored pieces shall be immediately placed in a sealed plastic bag if there is a delay in completing the procedures below.
36. How to check Dry Matter
(d) Weigh a clean petri dish and record the weight (P).
(e) Place all cored pieces on the preweighed petri dish; reweigh the petri dish with the sample and record the weight (F).
(f) Place the petri dish with the sample in a 1,000 watt microwave oven and dry the sample at 50% power for 40 minutes, adjusting the power down as necessary to avoid charring the
tissue. Remove the sample from the microwave oven and note the weight. Place the sample back in microwave oven for 5 minutes. Remove the sample again and compare weight. If
weight is the same, record it as dry weight. Whenever there is a weight difference, repeat this step until there is no weight loss. After the sample reaches a constant weight, record the
weight (D).
37. Checking Dry Matter
(g) Calculate the percent of dry matter using the
following example:
D-P (/) F-P x 100 = _____ % dry matter
All weighings required by this section shall be
recorded to the nearest 0.01 gram.
38. Checking MRLs
If lab results comply with the MRLs according to the Mexican regulation and to the destined
country standards the orchard is added to the harvest schedule to be processed based on
the demand of the countries the avocados can be exported to.
Additionally, analysis must not exceed 30 days prior to harvest.
39. Harvest
Fruit is harvested according to size
and placed in small plastic bins
(Most packing houses use a
combination of their own harvest
crews with contracted independent
crews)
(Harvest in Michoacan)
(Harvest in Jalisco)
Since the orchards in Jalisco are trained to limit
their height eliminating the need for a ladder.
40. Harvest
The plastic bins are then taken to
a collection site in the field to be
picked up by a truck and take to
the packhouse
41. From Field to Storage
Plastic field bins are unloaded
from field truck and palletized.
The pallets are then moved to storage area of
the packhouse that is specific to export
destination. Each storage area is separated by
Mesh screen barriers to allow air circulation and
keeping strict control of traceability.
42. Storage to Pack
Palletized field bins are moved to packing area
Each bin is then
dumped on the packline
by either circular bin
dumper or by hand to
avoid shock to fruit.
43. Packline
Each Avocado is weighed and mechanically
sorted into the sizing area that corresponds to its
weight. Each roller has its own scale.
44. Packed by hand
Fruit is packed by hand into carton boxes.
Fruit with excessive scarring and dark color is
selected out and packed into black plastic
boxes.
46. Palletized
Each type of case is the
palletized and labeled
Fruit sorted out into black
plastic boxes is marketed
domestically in Mexico.
47. Cooling
Pallets are then moved
to a heat extraction
chamber.
Large fans in the
front of the chamber
pull air from the
bottom as fans on
top push cold air into
the pallets.From this point cold
chain is kept until
delivery
48. Cold Chain Management
Cooled pallets are then moved to cold
storage until loading. The area between
Extraction chamber and cold storage is
also refrigerated to maintain cold chain
Once the shipping container
arrives, the container must reach
the preset temperature before
loading. Once required
temperature is reached loading
begins.
49. Logistics
Port of Departure
Port of Arrival
Altamira Manzanillo
Lazaro
Cardenas
(Gulf of Mexico) (Colima) (Michoacan)
EU
Antwerp, Belgium 19 - 22 days 24 - 25 days 22 - 24 days
Rotterdam, Netherlands 21 - 24 days
Algeciras, Spain 21 - 25 days
Japan Yokohama 16 - 18 days 18 days
China Shanghai 20 - 28 days 24 - 32 days
50. Container (Reefer / Controlled Atmosphere)
Reefer is used to maintain cold
chain in the container. Holes in the
carton boxes and alignment of
cartons on the pallets are
designed to allow air circulation
Controlled Atmosphere (CA) is also used
to help maintain freshness of Avocados to
destination
51. Ripening Introduction
Fruit should not be ripened completely or excessive bruising will result. Fruit bruising is the most prominent cause of quality
reduction at retail level. The problems will start at repackers or ripeners if suitable precautions are not taken.
Because fruit from different origins, maturities, shipping temperatures and age after harvest will react differently, only uniform
groups of fruit should be treated together. The speed of ripening and therefore the number of days at which the fruit should be
let to ripen, is very dependent on the maturity of the fruit, notably indicated by the dry matter content.
52. Ripening process
Temperature
18.33 to 20ยฐC.
Higher temperatures - Increase the ripening rate Increase the risk of stem end rots which also increases risk of
vascular browning, body rots due to anthracnose and especially in the case of low maturity fruit, uneven ripening.
Lower temperatures - poor color development.
Ventilation
Required to prevent excess buildup of gases, especially CO2, is needed.
High levels of CO2 will inhibit ripening and increase risk of internal disorders grey pulp and anthracnose rots. During
the ripening of the fruit, high concentrations of CO2 will gradually develop. It is essential that the CO2 is not permitted
to rise above 2%, and preferably not above 1% otherwise ripening will be retarded and internal defects such as grey
pulp will occur. Ripening rooms must be vented every 8 hours for at least 20 minutes, with fans running to ensure air
change.During the ripening of the fruit, high concentrations of CO2 will gradually develop.
53. Ripening Process
Ethylene application.
Automatic ethylene control systems should be used to control the concentration.
Apply ethylene as a trickle system to maintain 10 ppm ethylene.
If intermittent application of ethylene is done, apply a shot to obtain a concentration of approximately 100 ppm. The concentration is
then allowed to slowly decrease over 6 to 8 hours.
Humidity
The relative humidity of the ripening room should be maintained at 90-95%.
Time Frame
Varies on maturity of the fruit, with approximate times of:
โข Dry matter <23% use 2 to 3 days
โข Dry matter 23-26% use 1 to 2 days
โข Dry matter >26% use 1 day
The treatment is designed to initiate fruit ripening, and the process should therefore be stopped before ripeness is actually reached.
The fruit should be checked regularly for indications of ripening by a change in softness.
Fruit should be ripened only until the point of breaking (sprung stage, where fruit neck is slightly soft).
54. Ripening
Repacking Ripened Fruit
Fruit can be packed in singles or multiples, and can be sorted, using the variability in ripening speed likely to be encountered, into
groups with different numbers of potential days to ripe, which is useful for retailers and consumers.
Fruit sorting can be done using in-line softness touch testing or acoustic equipment
Color changing ethylene determining sticker can be included in the pack to indicate to the consumer the stage of ripeness without
physical squeezing
Storage after ripening
Fruit must be transferred to a cold room set at 5ยฐC to 7ยฐF for holding before shipment to final destination. Ready to eat dates should be
applied
55. Ripening Rooms
โ Constructed with Puf Panels,vertical or sliding door.
โ Suits places with space constraint as two or three Tier
โ Side Curtains block air from flowing over Pallets and force air flow through boxes.
โ Absence of moving parts in rooms reduce maintenance
โ Plug-in type, ready to assemble and commission
โ Premium, uniform and quality ripening of fruits
โ Auto control of all criterias for fruit ripening
โ Microprocessor controlled compatible with computer
โ Pre-cooling and ripening functions
56. Stages of Ripeness
Ripe Stage 1 - Hard
Fresh off the tree, no
give, 5+ days until ripe
at room temp
Ripe Stage 2 - Pre Conditioned
Ripening has begun but, still very
firm, 4-5+ days until ripe at room
temp
Ripe Stage 3 - Breaking
Yields slightly to pressure
but, still firm, 2 days until
ripe at room temp
57. Stages of Ripeness
Ripe Stage 4 - Firm Ripe
Ripe, yields to slight
pressure. Best for slicing
and cubing
Ripe Stage 5 - Ripe
Ripe and yields easily to
pressure. Best for Mashing
and guacamole
59. Quality - External and Internal Defects
EXTERNAL DEFECTS
Fruit color has been used for many years as a marketing tool for Hass avocado fruit, indicating
to the final consumer when fruit is ripe and ready to eat. However, the degree of black
coloration and intensity of color does di"er within season and fruit origin, depending on maturity
and climatic conditions. Therefore, color is not a good determinant of fruit quality, and should
not be used.
INTERNAL DEFECTS
Where the fruit are evaluated for internal defects, the number of fruit within a 10-fruit sample
with the defect is reported. This can also be expressed as a percentage.
60. External Defect: Ridging
Ridging is usually due to some form of damage very early in fruit
development, possibly even during flower development. While it may be
weather or insect related, an extensive raised portion of the fruit may be
genetically linked. Ridges may be seen as a clearly raised portion normally
longitudinally down the fruit, of varying width, and the fruit may also be
misshapen. Ridges are prone to general abrasion while fruit is on the tree, by
for example leaves rubbing the area when fruit is very small. Additional
damage could occur during picking, transporting and packing. Internal quality
is not likely to be a"ected, but visually the fruit may be unattractive to buyers.
61. External Defect: Sunburn
Sunburn is most notable as an area of hard, corky or cracked skin that may
be of light yellow to reddish brown or even black in color, usually only on one
side of the fruit and often towards the stem end. The flesh below the
damaged area is usually also damaged and will not ripen normally. Sunburn
is most prominent on exposed fruit especially at the top of trees and notably
where leaf coverage is sparse.
62. External Defect: Lenticel Damage
Lenticels are the pores of outer plant tissue that provide a direct exchange of
gases between internal plant tissues and the atmosphere. Lenticel damage
is characterized by black and collapsed lenticels. After extended periods of
storage, particularly at low temperature, the initially small areas of damage
often enlarge as the cells around the lenticels dehydrate, become more
susceptible to low temperature damage and therefore also collapse and die.
Unless extensive, much of the lenticel damage becomes hidden by the dark
background color of ripe Hass fruit. Lenticel damage usually has little e"ect
on internal quality. Lenticel damage is primarily caused by abrasion during
handling, usually during picking and transport to the packing house, as well
as on the pack line. Fruit dumping onto the line, especially if dry dumped,
and the action of brushes during washing or cleaning are major causes of the
physical damage.
.
63. External Defect: Chilling Injury
Chilling injury is indicated by well defined areas of black, sunken lesions.
These may vary from small to large extensive areas of the fruit surface. O!en,
one side of the fruit is more extensively damaged, and the distal (bottom) end
of the fruit is o!en worse. The lesions do not penetrate into the fruit flesh,
although in severe cases internal chilling damage may also occur. In the
absence of internal damage, internal quality will not be affected, but the
external damage may encourage development of post harvest fungal
diseases. The primary cause of chilling damage is the use of initial cooling
as well as storage and shipping temperatures that are too low. Less mature
early season fruit is more susceptible, as is fruit from trees high in nitrogen
and low in calcium. In addition, the longer the shipping period, especially if
temperature is too low, the more extensive the damage. If initial cooling is
too fast, excessive air flow over fruit surfaces can result in enhanced
damage, especially if this also results in fruit water loss and if lenticel
damage is also present. The solution is careful use of the most appropriate
cooling and shipping protocols taking fruit maturity and origin into account.
64. External Defect: Thrip Damage
Thrip damage usually occurs early in fruit development, and is the result of
the insect removing the top layer of the fruit skin. Scar tissue forms in these
areas, resulting in areas of rough, corky brown scar tissue on the fruit surface
which will not color with ripening. Because the damage usually occurs early
in fruit development when fruit are small, the eventual result may be
extensive fruit surface damage. A good pest monitoring and control program
is essential. Internally, fruit are usually not a"ected, making the defect mainly
cosmetic.
65. External Defect: Limb Rubs (Scarring)
Lines of brown corky, scarred skin which will not color on ripening, are the
result of physical damage, most notably when the fruit is small. The fruit skin
can be damaged by leaves or branches rubbing against the fruit. The use of
windbreaks can substantially reduce the incidence. Generally, this is
confined to external blemish, with little to no e"ect on the internal quality of
the fruit.
66. External Defect: Copper Sulfate Residue
Copper sulfate is extensively used in many production areas to decrease
orchard fungi which cause post harvest diseases such as stem end rot and
anthracnose. This may leave visible bluegreen spray residue, which does not
in any way adversely a"ect internal quality or food safety, but may be
unacceptable to consumers. Fruit washing and brushing on the pack line will
help to remove this, but may not always be successful. Certain formulations
of copper sulfate which are easier to remove are available.
67. External Defect: Checkerboard Ripening
Checkerboard ripening refers to boxes of fruit where the fruit colors and
ripens at di"erent rates, such that the fruit within a box varies from green to
varying shades and intensity of black as well as variable so!ness. Some fruit
may never color entirely, resulting in a green to brown color even when fully
ripe. While the internal quality will not be seriously a"ected, it is a
considerable problem for fruit ripeners as it is di"icult to predict ripening rate
and shelf life within a consignment. The most likely cause is the packing of
variable maturity fruit, most likely where there are multiple fruit set periods in
a season and older, more mature fruit is mixed with younger less mature
fruit.
68. Internal Defect: Diffuse Flesh Discoloration
Diffuse flesh discoloration presents as a diffuse grey to black or sometimes
brown coloration of the fruit flesh, which may be visible in hard fruit which
has been stored or shipped but intensifies as fruit ripens.
The discoloration is due to the presence of dead fruit flesh tissue, which
affects taste in addition to appearance.
There are multiple potential causes for the disorder, which include internal
chilling injury, especially if the fruit is less mature, incorrect gas
concentrations during controlled atmosphere shipping (particularly low
oxygen or high carbon dioxide) or fruit that has been stored or shipped for
very long periods, especially late season fruit.
Fruit that starts ripening during shipping is especially prone to the disorder.
Fruit from trees high in nitrogen and low in calcium are also more sensitive to
the factors that cause the disorder.
69. Internal Defect: Flesh Bruising
Flesh bruising is shown by an area of grey to black flesh usually on one side
of the fruit extending from the seed towards the skin, and often around the
middle section of the fruit. The defect is most notable when the fruit is ripe.
There may be no other noticeable internal defect. Bruising is an indication of
rough handling, which may occur at any time from harvesting onwards.
Although hard, unripe fruit is susceptible, and only shows symptoms later
after ripening, the most sensitive stage for bruising occurs once ripening
begins, and is therefore particularly important in the retail sector. Rough
handling, stacking of fruit too high in displays and repeated customer
handling to test ripeness are important factors.
70. Internal Defect: Grey Pulp
Grey pulp is a more intense form of diffuse flesh discoloration. The grey to
black coloration of the flesh is particularly intense in the distal (bottom) area
of the fruit, but may also extend towards the stem end. Vascular discoloration
may sometimes accompany the symptom. There are a number of potential
causes, but the disorder is particularly noted in more mature fruit towards the
end of the harvest season. Length of storage plays a notable role, with
longer storage or shipping times significantly increasing the potential for the
disorder. The temperature of storage or shipping is also important. Especially
notable, is the effect of temperatures that are slightly too warm, allowing the
fruit to start ripening during the shipping or storage. The presence of
ethylene during a slow, low temperature fruit ripening, which would occur
under these conditions, is known to enhance the problem. Fruit from trees
high in nitrogen and low in calcium are more prone to the disorder.
71. Internal Defect: Flesh Adhered to Seed
When fruit is cut in half and pulled apart, sometimes a portion of the flesh
adheres to the seed. The cause is uneven ripening, where some of the fruit,
especially at the top of the seed, does not ripen properly, and remains hard
and rubbery, while other portions of the fruit ripen normally and therefore
separate from the seed easily. The disorder is more prevalent in early
season less mature fruit. Incorrect ripening temperature (temperature too
high) may enhance the problem. Fruit quality is a"ected, in that some of the
fruit ripens normally while other portions remain unripened.
72. Internal Defect: Stem End Rot
Stem end rot appears as translucent to brown discoloured area in the fruit
flesh, starting from the stem end and progressing downwards through the
fruit. Where severe, white fluffy or pinkish fungal mycelium may also be
present. Externally, a black clearly decaying zone around the stem end may
be present, although in early stages of development no external symptoms
may be seen. At early stages of development, there may or may not be
vascular discolouration accompanying the disorder. The cause is a group of
fungi present in the avocado trees in the field. Dead branches within the
trees are a particular source of the fungal spores which infect the fruit. Warm,
wet conditions also increase the presence of the pathogens. Fruit becomes
infected mainly at the time of harvest, the fungi entering through the cut fruit
pedicels. Picking wet fruit increases the chance of infection, and less mature
fruit are also more susceptible. Growth of the fungi tends to be suppressed
by low temperatures, but increases rapidly once fruit starts ripening. The
most common control measures involve preharvest fungicidal sprays (mostly
using copper formulations) to decrease fungal presence, and removal of
dead wood from trees. Postharvest fungicides are only partially effective.
73. Internal Defect: Vascular Browning
Vascular browning is indicated by distinctly visible dark brown to black
vascular tissue in cut fruit. The dark colored vascular tissue follows the
vascular tissue from the stem end through the fruit to the distal (bottom end)
of the fruit where it enters the seed. The disorder is o!en associated with an
internal chilling damage due to long storage periods at temperatures too low
for the maturity of the fruit (symptoms more noticeable around the distal end
of the fruit), or with stem end rot (symptoms extend more clearly from the
stem end).
74. Internal Defect: Stem End Rot & Vascular Browning
In many cases, fruit shows symptoms of both vascular discolouration and
stem end rot. This is particularly the case with advanced decay (with the
exception of stem end rot caused by one fungal group). The cause is a group
of fungi present in the avocado trees in the field. Dead branches within the
trees are a particular source of the fungal spores which infect the fruit. Warm,
wet conditions also increase the presence of the pathogens. Fruit becomes
infected mainly at the time of harvest, the fungi entering through the cut fruit
pedicels. Picking wet fruit increases the chance of infection, and less mature
fruit are also more susceptible. Growth of the fungi tends to be suppressed
by low temperatures, but increases rapidly once fruit starts ripening.
79. Annual market trend 2017
โ Super Bowl
โ Academy Awards
โ Cinco De Mayo
โ Mothers Day
โ Memorial Day
โ Fathers Day
โ 4th of July
โ Labor Day
โ Thanksgiving
โ Xmas
