Open sidebar Drying Preservation Tips Default (GPT-3.5) User Preservation of drying ChatGPT Preservation of drying typically involves storing dried food or materials in a way that prevents moisture from re-entering and spoiling them. Here are some general tips: Airtight Containers: Store dried items like food, herbs, or seeds in airtight containers to prevent moisture and air from getting in. Mason jars or vacuum-sealed bags work well. Cool, Dark Place: Keep the containers in a cool, dark place to avoid exposure to heat and light, which can degrade the quality of the dried items. Desiccants: Use desiccants like silica gel packets to absorb any residual moisture inside the containers. Labeling: Clearly label containers with the date of drying and the contents to help with organization and tracking freshness. Vacuum Sealing: Consider vacuum-sealing equipment for long-term preservation, as it removes air and seals items tightly. Humidity Control: If you live in a humid environment, consider using moisture-absorbing products or a dehumidifier in the storage area. Regular Inspection: Periodically check stored items for signs of moisture or spoilage and replace any compromised containers. By following these tips, you can extend the shelf life of dried items and ensure they remain in good condition. Send a message Free Research Preview. ChatGPT may produce inaccurate information about people, places, or facts. ChatGPT August 3 Version ChatGPT Open sidebar Drying Preservation Tips Default (GPT-3.5) User Preservation of drying ChatGPT Preservation of drying typically involves storing dried food or materials in a way that prevents moisture from re-entering and spoiling them. Here are some general tips: Airtight Containers: Store dried items like food, herbs, or seeds in airtight containers to prevent moisture and air from getting in. Mason jars or vacuum-sealed bags work well. Cool, Dark Place: Keep the containers in a cool, dark place to avoid exposure to heat and light, which can degrade the quality of the dried items. Desiccants: Use desiccants like silica gel packets to absorb any residual moisture inside the containers. Labeling: Clearly label containers with the date of drying and the contents to help with organization and tracking freshness. Vacuum Sealing: Consider vacuum-sealing equipment for long-term preservation, as it removes air and seals items tightly. Humidity Control: If you live in a humid environment, consider using moisture-absorbing products or a dehumidifier in the storage area. Regular Inspection: Periodically check stored items for signs of moisture or spoilage and replace any compromised containers. By following these tips, you can extend the shelf life of dried items and ensure they remain in good condition. Send a message Free Research Preview. ChatGPT may produce inaccurate information about people, places, or facts. ChatGPT August 3 Version ChatGPT Open sidebar Drying Preservation Tips Defau

1. Diseases of Field and Horticultural
crops and their management-II (2+1)
DR. SRUJANI BEHERA
ASST. PROF. (PLANT PATHOLOGY)
COLLEGE OF AGRICULTURE
BHAWANIPATNA, OUAT

2. Diseases of citrus
Canker :Xanthomonas axonopodis pv. Citri
Phytophthora Gummosis: Phytophthora nicotianae var.
parasitica, P. palmivora, P. citrophthora, P. hibernalis,
P.syringae, P. Cactorum.
Diplodia Gummosis: Diplodia natalensis
Dry root rot: Fungal complex (Fusarium sp., Diplodia.,
etc)
Scab : Elsinoe fawcetti
Tristeza: Citrus tristeza virus
Greening: Candidatus liberobacter asiaticus

3. • Disease : Citrus canker
• Pathogen : Xanthomonas axonopodis pv. Citri
• Host : Numerous species, cultivars, and hybrids of
citrus and citrus relatives including orange,
grapefruit, pummelo, mandarin, lemon, lime,
tangerine, tangelo, sour orange, rough lemon and
trifoliate orange.
1.Citrus canker

4. Economic importance
• In India, citrus canker occurs in all the citrus growing
areas.
• It is reported from Punjab, Tamil Nadu, Andhra
Pradesh, Karnataka, Rajasthan, Madhya Pradesh,
Assam, and Uttar Pradesh.
• Acid lime is highly susceptible to canker.

5. Symptoms
• Citrus canker is mostly a leaf-spotting and fruit rind-blemishing disease, but
when conditions are highly favorable for infection, infections cause defoliation,
shoot dieback, and fruit drop.
• The bacterium enters the plant tissue and causes the development of blister-like
formations (lesions).
• Lesions are usually raised, coloured tan to brown, surrounded by an oily, water-
soaked margin and a yellow ring or halo. Large or older lesions may have a
crater-like appearance.
• Leaf, fruit and stem tissue may be infected. Leaf tissue offers more opportunity
for infection and as such typically displays the most numerous lesions over time.
It is unusual to see multiple lesions on fruit or stems if lesions are not present on
leaves.

6. Symptoms
On leaves

7. On Fruit

8. Causal organism:
Xanthomonas axonopodis pv. citri
• The bacterium is a rod-shaped, gram-negative, and has a single
polar flagellum. Colonies on laboratory media are usually
yellow due to ‘xanthomonadin’ pigment production.
• The maximum and optimum temperature ranges for growth are
to 39°C (95 to 102°F) and 28 to 30°C (82 to 86°F),
respectively.

9. Epidemiology &Pre disposing
factors
Favourable conditions : Free moisture for 20
minutes, 20-30°C.
Mode of survival and spread :
• Wind and rain splashes.
• Survives in infected leaves for 6 months.
• Injury caused by citrus leaf miner (Phyllocnistis
citrella) helps the entry of the bacterium.

10. Management
• Prune out and burn all canker infected twigs before monsoon.
• Use canker tolerant varieties.
• Select seedlings free from canker for planting in main field.
• Spray Streptocycline (1g) + Copper oxy chloride (30g) in 10
litres of water at fortnightly intervals for effective management
of canker in citrus nurseries.
• Three sprayings of Streptocycline (1g) + Copper oxy chloride
(30g) in 10 litres of water at an interval of 20 days during rainy
season is effective for leaf canker.
• Fruit infection can be prevented by two sprays of Streptocycline
(1g) + Copper oxy chloride (30g) in 10 litres of water at marble
stage followed by another spray30 days later.
• Control leaf miner when young flush is produced.

11. 2.Gummosis
Economic importance
• Gummosis is widespread in Punjab and Assam.
• Lemons are highly susceptible compared to grapefruit, rough
lemons and sweet orange.
• In South India, it is common in the sweet orange

12. Symptoms

13. Sap oozing from trunk lesions is a symptom of
Phytophthora gummosis.

14. Causal organism- Phytophthora sp.

15. Disease cycle & Epidemiology
Mode of spread and survival
• Sporangia spread by splashing rain water, irrigation
water and wind.
Favourable conditions
• Prolonged contact of trunk with water as in flood
irrigation; water logged areas and heavy soils.

16. Management
• Selection of proper site with adequate drainage.
• Avoid irrigation water from coming in direct contact
with the trunk.
• Scrape the diseased portion with a sharp knife.
• Protect the cut surface with Bordeaux paste followed
by spraying of 0.3% fosetyl- AL reduces the spread.
• Soil drenching with 0.2% metalaxyl and 0.5%
Trichoderma viride commercial formulation is also
effective.

17. Diplodia gummosis
Economic Importance:
• It Occurs commonly in Andhra Pradesh, Tamil Nadu
and Uttar Pradesh.
• It is common on Sathgudi and Batavian oranges,
mandarins and lemons in A.P. and Tamil Nadu.

18. Gummy secretion at base of the dead twig

19. Symptoms

20. C.O: Diplodia natalensis
Perfect stage: (Physalospora rhodina)

21. Disease cycle &Epidemiology
Favourable conditions
• Reduced tree vigour, insect damage, malnutrition and old age
predispose the disease.
Mode of spread and survival
• Black pycnidial bodies appear on the diseased bark which gets
removed in flakes.
• The disease spreads through dissemination of pycnidio spores
or conidia by air, rain and insects.

22. Management

23. 4. Citrus Tristeza or quick decline
Economic Importance:
• This disease was first reported in Citrus aurantifolia and C.
sinensis from Italy and Florida in the U.S.A.
• In India, tristeza is present in Andhra Pradesh, Tamil Nadu,
Karnataka, Madhya Pradesh, Maharashtra, Punjab, Bihar, West
Bengal and Sikkim.
• The name “Tristeza” was suggested to describe the sad
appearance of the diseased citrus trees

24. Symptoms
• Citrus tristeza virus (CTV) causes different symptoms on citrus plants depending on the
virus strain, the variety of citrus.
• In Asia, various strains of CTV, generally referred to as seedling yellows (CTV-SY),
tristeza (CTV-T), stem pitting (CTV-SP).
• Tristeza affected trees look chlorotic and sickly in the early stages. Gradually the leaves
drop and the defoliated twigs show die-back. The declining trees die gradually but
sometimes apparently healthy trees die suddenly.
• Vein clearing or vein flecks (elongated translucent area) in young leaves of acid lime is
seen intermittently when viewed against light (characteristic symptom).
• In sweet orange, the specific symptom of tristeza is honeycombing, a fine pitting of
inner face of bark in the portion of trunk below the bud union.
• In acid lime which is highly susceptible to the disease, vermiform or linear pits appear
in the woody cylinder.
• Tristeza infected citrus trees on sour orange rootstocks cause phloem necrosis at the
graft union
• Diseased trees usually blossom heavily. Trees with stem pitting are stunted and set
less fruits. The fruits are of smaller size and of poor quality.
• As the fruits develop, the tree wilts partly or completely. Grapefruit and acid lime are
susceptible irrespective of root stock.

25. Yellowing and decline caused by CTV

26. Stem pitting induced by
CTV on a grapefruit trunk
Reduced fruit size for
Mexican lime

27. Causal organism- Citrus tristeza virus
The causal virus is a flexious
and thread-like rod, 2,000 nm in
length and 15 nm in width.
 The virus particles are located
in the phloem of the host plant,
and disturb its transportation
systems.
The optimum temperatures for
virus infection and multiplication
are 20°C - 25°C.
CTV is transmitted by some
species of aphids found on citrus
plants
Transmission electron micrograph of purified
Citrus tristeza virus particles.

28. • The disease primarily spreads through grafting and budding.
• Under field conditions, it is transmitted by the black citrus
aphid, Toxoptera citricida.
• The virus is not seed borne.

29. Management
• Strict quarantine measures to be enforced.
• Use certified bud wood free of CTV.
• Remove all diseased trees as and when the disease is
noticed. Fresh plantings to be taken with virus free
materials on tolerant rootstocks.
• For sweet orange and mandarin avoid susceptible root
stocks.
• Periodic sprays of insecticides.

30. 5. Greening or Huanglongbin
Economic importance
• The disease is more severe on sweet oranges than on
acid lime, mandarin and grapefruits.
• This disease affects almost all citrus varieties.
• In India Mosambi sweet orange and Darjeeling
orange (Citrus reticulata) are good indicator plants
for greening.

31. Leaf Symptoms
• Leaf symptoms include blotchy mottle, yellow veins, vein corking or green
islands.Yellow veins, vein corking or green islands are not diagnostic alone.
• Blotchy mottle is the best diagnostic leaf symptom of greening.
• Blotchy mottle: a random pattern of yellowing (chlorosis) on leaves that is
not the same on the right and left sides of the leaf.
• Yellow veins can be confused with other diseases (e.g. foot rot) or damage
(e.g. broken or girdled limb)
• Pen Test for Leaves
• A simple procedure to determine if symptoms are the same on both halves
of a leaf
• Draw two circles on opposite halves of the leaf
• Is the pattern the same in both circles?
• Nutrient deficiencies are often symmetrical on each side of the vein
whereas, citrus greening is asymmetrical.

32. Pen Test for Leaves
Nutrient Deficiency Greening

33. Fruit Symptoms
• Fruit external appearance may small green fruit.
• The fruit would taste salty and bitter.
• The internal appearance may have aborted seeds, yellow stain
beneath the calyx button and/or a curved central core.
Tree Appearance
• Yellow shoots
• Twig dieback
• Stunting
• Off-season bloom
• Overall tree decline

34. Fruit Symptoms

35. Causal organism-Candidatus Liberibacter spp
Electron micrograph of
Ca. Liberibacter cells in a sieve
tube of sweet orange leaf
Candidatus Liberibacter spp. are
phloem-limited plant pathogenic bacteria.
The bacterium is Gram nagative.

36. Transmission and Spread
The Asian Citrus Psyllid transmits the greening bacterium. The disease
can also be spread by grafting.

37. Management
• Select certified disease-free seedlings.
• Control psyllids with insecticides like dimethoate.
• Use pathogen free bud wood for propagation.
• Raise virus free plants through shoot tip grafting.