Mitigation strategies for abiotic stress situations in fruit crops

1. Mitigation Strategies For Abiotic Stress
Situation In Horticultural Crops
Presented by:
Mandeep Kaur
PhD Fruit Science
Presented to:
Dr J S Brar
Senior Horticulturist

2. ABIOTIC STRESS
• Abiotic stress is best defined as any factor exerted by the environment
on the optimal functioning of a plant.

3. Abiotic Stress Conditions
Edaphic (soil)
Water stress
Excess Deficit
Salt/Ion stress
Deficiency Toxicity
Atmospheric
Temperature stress
Heat stress Cold stress
Light stress

4. Mitigation Strategies
For Drought Stress Situations
In Fruit Crops

5. Tolerant Moderately tolerant Sensitive
Ber
Phalsa
Custard apple
Date palm
Pomegranate
Grafted citrus
Aonla
Cashew
Avocado
Passion fruit
Litchi
Longan
Carambola
Coconut
Guava
Sugar apple
Atemoya
Citrus
Papaya
Banana
Sapota
Carambola
Rambutan
Apple
Balerdi et al (2006)
• Under drought stress conditions, always grow drought tolerant fruit
crops.
• Fruit crops on the basis of drought tolerance is given below:

6. Fruits Cultivars Reference (s)
Apple Carola, Priscella, Golden Delicious, Golden
Resistant, Start, Yellow Spur, Stark Spur,
Cooper-6.
Tolstolik and Krasulya
(2001)
Babino, Strimka, Granny Smith. Khalin (1989)
Pear Starkrimson, Victoriya, Beurre Hardy, Clapp’s
Favorite.
Tolstolik and Krasulya
(2001)
Plum Nikita Early, Vitanova. Ryazanava (2002)
Olive Chemlali Ennajeh et al., (2006)
Citrus Orlando, Mortan, Swingle Figveiredo et al.,(2002)
Drought tolerant fruit cultivars

7. Drought tolerant rootstocks in fruit crops
Fruit crops Rootstocks Reference (s)
Apple M7, MM111 Fernandez et al (1994)
M 26 (Intermediate drought tolerant) Tatarinov (1992)
Pear Oregon 211 and 249, Oregon 260, 261,
264
Ananda (2001)
Quince A, Provence Quience Khalil (1999)
Plum Myrobalan 27, Mariana 4001, Peach-
Almond Hybrid GF 667 and GF 577
Ryazanova (2002)
Ananda (2001)
Peach GF 577, GF 667 Mannini and Galliana
(2001)
Cherry Victor, Sour Cherry, Gisela 5, Edadriz,
Maxma 14, and P. avium (intermediate
Resistant)
Goncalues et al (2000)
Citrus Sweet Orange, Sour Orange, Rough
Lemon, Sweet Lime, Mandrin
(Moderately tolerant) Rangpur Lime and
Cleopatra
Ananda (2001)

8. Drought tolerance in fruit plants are
characterized by the following features
Fruit crops Special features
Aonla, Karonda, Wood apple Reduction in no. and size of leaves
Phalsa and Fig Leaves densely pubescence
Date palm Leaf tips modified into spines
Ber Leaves modified into spines
Sapota, Cashew nut,
Pomegranate
Leaves has shining surface due to presence of
thicker cuticle
Mango, Ber, Deep and extensive root system
Ber, Bael, Wood apple, Fig Radiation reflected by the glittering leaves/ waxy
coating/ latex
Ber, Cashew Decrease in stomatal density and frequency
Ber Reduction in cell and stomatal size
Mango, Karonda , Cashew High degree of phenol, tannins and oil content
Sontakke (2006)

9. Survival strategies of citrus rootstocks subjected to drought
• To investigate survival strategies of two citrus rootstocks, Rangpur lime (RL)
and Sunki Maravilha mandarin (SM) with shoot scions of two varieties:
Valencia orange (VO) and Tahiti acid lime (TAL).
• Three water treatments : well-watered, severe drought and rehydration.
Santana et al (2016)
Brazilian_Agricultural_Research_Corporation_EMBRAPA

10. RL: Rangpur lime; SM: Sunki Maravilha mandarin; VO: Valencia orange; TAL: Tahiti acid lime.
Rootstocks can transfer their survival strategy to the grafted shoot scions.
DA

11. 2. Different Irrigation practices
• Drip irrigation: Water is given directly to the root zone, so high application
efficiency and distribution uniformity.
• Singh et al (2010) evaluated the performance of drip and conventional
surface (check basin) irrigation methods in banana in clay soils at Rahuri.
Higher fruit yield and WUE of banana was found under drip irrigation.
• Tab. Water use efficiency with drip irrigation
Crop Yield increase (%) Water saving (%) Increase in WUE (%)
Banana
Grape
Sweet lime
Pomegranate
52
23
50
45
45
48
61
45
176
136
289
167
Source: INCID (1994), Drip irrigation in India.

12. Deep drip irrigation
• The Deep Drip Stake is designed to water directly in the deeper root zone.
• It promotes root growth in deep root zone.
• 24" – Works well for fruit trees and palms
• 36" - For large established trees and palms
https://www.dripworks.com/deep-drip-tree-watering-stakes

13. Trees Buried diffuser
Buried Diffuser (15x15cm or 15x30 cm) can be installed in holes, 50 to 70 cm
below the topographic soil surface.
http://www.chahtech.com/diffusers/trees

14. How to install Trees Buried diffuser

15. • Can be installed before & after plantation.
• If before, diffuser should be 50 to 70 cm far from the axis of the tree.
• If after the trees plantation, they should be installed in the extremities of the canopies.
• It delivers water to plants at the root level.

16. • More advantageous than in terms of water and energy savings as well as drought
mitigation as compared to drip irrigation.
• Used for all kind of trees such as banana, mango, papaya, litchi, guava, avocado,
ficus indica, pomegranate, date palm, oil palm, apple, apricot, grape, olive, orange,
citrus, almond, nut, pear, fig, etc.
http://www.chahtech.com/diffusers/trees/

17. Partial root zone drying
• New method of irrigation based on Sub surface drip irrigation, derived from “Spilt-
plot principle”.
• The technique essentially involves irrigating approximately half of the root system of
a crop while the other half is left to dry.
• Water deficiency -> ABA production in roots -> ABA transporting to the leaves ->
Reducing aperture of the stomata -> Stomata closes -> Water saving.
• Regular alteration of water in soil enables the entire root system to be
maintained in a viable state.

18. Regulated Deficit Irrigation (DI)
• Full irrigation is supplied during the drought-sensitive phenological stages
(critical periods) of fruit trees and irrigation is limited if rainfall provides a
minimum supply of water during the drought-tolerant phenological stages
(non-critical periods).
• It is becoming popular in the areas where water supply is limited (Fereres and
Soriano, 2006).
• Helpful in saving water without compromising production.
• Several researchers have reported water savings from 43% to 65% under RDI
strategy with a small reduction in yield, but with higher quality of produce
(Mirás-Avalos et al., 2016).

19. Effect of Water Deficit on the Physiological & Morphological
Characteristics of Mango Rootstock Seedlings
• To investigate effect of water deficit on six month old Mango rootstock seedlings.
• Four different irrigation treatments namely watering daily, twice in a week, once
in a week and once in two weeks.
• Plant height increased by watering once in a week.
Luvaha and Ouma (2008)
Maseno University Botanic Garden, Kenya

20. Apple tree responses to deficit irrigation
combined with periodic applications of particle
film or abscisic acid
• To determine effect anti-transpirant application on physiological response of “Golden
Delicious” apple trees on MM 106 rootstock under water deficit stress conditions.
Two anti-transpirants applications:
• Kaolin particle film (6% w/v), abscisic acid (ABA 5 mM) & control at 0, 30 and 60 days.
Three deficit irrigation treatments:
• 30%, 60%, and 80% depletion of available water (DAW) before irrigation to runoff.
• WUE increased under water deficit stress conditions by kaolin application.
Al-Absi and Archbold (2016)
USA

21. 3. Moisture conservation practices
1. Soil management practices: Maintenance of soil cover: Through sod
culture, inter and cover cropping. This will help in slow seepage of water.
2. Pruning reduces leaf area, decreases transpirational loss of water, hence
conserve water under stress. Summer pruning can also be used in apple to
conserve moisture. Severe pruning of peach and pear has been found to
reduce transpiration.
3. Crop load: A heavy cropping exhaust metabolites and photosynthates and
tend to put less carbohydrates into root growth.
4. Green manuring: Improves soil moisture retention capacity.
5. Weeding: If irrigation is not possible, remove weed from young trees to reduce
competition for water and then the area should be mulched.
6. Plant shady trees, as shade will reduce water loss.
7. Rain water harvesting should be done. So, saved water can be utilized during
water stress conditions or critical growth phases.
8. Light cultivation only of top soil during summer to avoid the evaporative
losses.
9. Laser leveling

22. Hydrophilic polymers
• HPs are class of polymers which gets dissolved or swollen by water.
• They form three dimensional network of macromolecules carbon chain.
• Swells by absorbing solution as much 100 times their weight.
• Deswell to supply water to the plant based on its need.
• It plays a vital role in stress alleviation at appropriate time as needed by the plants.

23. HPs used in agriculture
• Aquasorb: Cross-linked copolymers of acrylamide and potassium
acrylate from SNF Floerger, France
• Agrihope: Gel-conditioner, cross-linked sodium polyacrylate, Nippon
Shokubai Co., Japan
• Broadleaf P4: High molecular weight, cross-linked PAM, Agric.
Polymers Ltd. UK
• Hydrogel: Starch copolymer, Potassium acrylate, Finn Corporation, USA
• Hydrosource: Cross-linked PAM, potassium or sodium acrylate
Advantages of HPs
• Improving nutritional and water status of the plant.
• Improving soil physical properties.
• Aiding seed germination and emergence and increasing seed survival
• Increases soil water holding capacity, yield and water use efficiency of plant
• Decreases the negative effect of soil salinity on plant
(Bhatt et al. 2009)

24. Cultivar dependent impact of soil amendment with water
retaining polymer on olive (Olea europaea L.) under two
water regimes
2 Olive tree cultivars
Chemlali
Chetoui
2 Irrigation regimes
Drought stress
Watering
Hydrogel “stockosorb-660” treatments
With hydrogel
Control (Without hydrogel)
M’barki et al (2019)
University of Monastir, Tunisia
Varieties Treatments RWC % Plant height (cm) Leaf dry weight (g)
Chemlali Control – Irrigated (I) 94.68 80 40.21
Control – Drought (D) 48.22 65 12.26
Chetoui Control – Irrigated (I) 59.88 65 13.96
Control – Drought (D) 36.90 65 14.75
Chemlali Stockosorb treatment – I 94.16 87.5 43.01
Stockosorb treatment – D 64.80 71.5 19.55
Chetoui Stockosorb treatment – I 80.40 105 17.41
Stockosorb treatment - D 52.62 64.5 15.66
Hydrogels can used to avoid dehydration damages of young olive plants.

25. Mulches
A. Organic mulches B. Synthetic mulches

26. Role of mulching in soil moisture conservation
• Soil water content: Li et al. (2001) reported that black plastic mulch helps to
maintain high soil water contents than control.
• Improve water use efficiency: Li and Zhao (1997) reported that plastic
mulches improves WUE, by reducing soil water evaporation.
• Vazquez et al. (2006) found that drip irrigation along with plastic mulch
increases the water and nutrient use efficiency and also control weeds.
Plastic mulch with drip line in
case of Mango tree
Black Plastic mulching
of guava

27. Plastic mulches installed in high tunnels and outdoors
The best yields were obtained with black plastic mulches
Medicago et al (2012)

28. 4. Spraying different chemicals
• Nutrient sprays :
1. Urea spray – Enhance drought tolerance by decreasing osmotic potential.
2. Calcium treatment: External Ca++ treatment increase activity of AEz such
as CAT, SOD and peroxidase. It also improves adaptation to drought by
mitigating oxidation stress.
• Growth regulators :
• Triazoles: Growth retardant, which improves plant survival under low soil
moisture conditions by interfering with biosynthesis of gibberellins, by
inhibiting the oxidation of ent - Kaurene to ent- Kaurenoic acid.
• Eg. Triazol compounds (Paclobutrazol, Triapenthenol, Uniconazol).

29. Anti-transpirants
• Materials or chemicals which decrease the water loss from plant
leaves by reducing the size and number of stomata.
• Nearly 99 per cent of the water absorbed by the plant is lost in
transpiration.
• Anti-transpirants are applied to transpiring plant surfaces for reducing
water loss from the plant.
Features of Anti-transpirants
1. Non toxicity
2. Non permanent damage to stomata mechanism.
3. Specific effects on gaurd cells and not to other cells.
4. Effect on stomata should persist at least for one week.
5. Chemical or material should be cheap and readily available.

30. Stomatal activity after application of stomatal regulating compound
• Stomatal closing type: Most of the anti - transpirant functions as stomatal closer
compound when it applied over leaves.
• Eg. Herbicides like 2, 4 – D, Phosphon D and Atrazine
• Fungicides like Phenyl Mercuric Acetate (PMA)

31. Film-forming anti-transpirant (polyvinyl chloride complex) was applied to the
entire leaf surface but only that portion of the film loosened by the needle is
visible in photo.
• Film forming type: Plastic and waxy material which form a thin film on the
leaf surface and result into physical barrier.
• Eg. Ethyl alcohol.

32. Reflectant type Kaolin spray coating
• Reflectance type: They are white materials which form a coating on the
leaves & increase the leaf reflectance (albedo).
• By reflecting the radiation, vapour pressure gradient reduces and thus reduce
transpiration.
• Application of 5 percent kaolin spray reduces transpiration losses.
• Eg. Kaoline, China Clay, Calcium bicarbonate, Lime water.

33. • To study effect of kaolin application on H2O2 damage & antioxidant activity.
• Grapevines were exposed to pulverised 5% kaolin (w/v)
Kaolin particle film application lowers oxidative damage on
grapevine (Vitis vinifera L.)
Bernardo et al (2017)
University of Trás-os-Montes e Alto Douro, Vila Real, Portugal

34. H2O2 Month Control Kaolin
Leaf July 5.63 5.72
August 4.88 5.66
September 5.20 3.66
Fruit August 2.40 1.66
September 1.79 0.83
Hydrogen peroxide (H2O2) concentration
Enzymatic activities in leaf and fruit extracts
A − Catalase (CAT) B − superoxide dismutase (SOD)

35. Comparing Kaolin and Pinolene to Improve
Sustainable Grapevine Production during Drought
• To Compare Kaolin and Pinolene application on grapevine cultivar.
• Three treatments:
• Untreated control
• Kaolin application (95% K) @ 6 Litre per hectoliter (L/hL).
• Pinolene application @ 2 Litre per hectoliter (L/hL).
• Results: Use of kaolin increased grapevine intrinsic WUE (+18% of average as compared to
control) without affecting berry and bunch weight and quantity, or sugar level as compared
to pinolene. Brillante et al (2016)
Università Cattolica del Sacro Cuore, Piacenza, Italy

36. The Possible Role of Foliar Application of Manganese
Sulfate on Mitigating Adverse Effects of Water Stress
in Grapevine
• To study physiological response of grapevine cultivars under manganese sulfate treatment
and water stress conditions.
• MnSO4 treatment @ 4 g/l @ very severe water stress increased growth
parameters such as plant height, dry weight of roots, root length, leaf surface area
and number of leaves.
• It also increased RWC in the grapevine leaves of Thompson seedless cultivar
by 10% as compared to control.
• Conclusion: Foliar MnSO4 application can be used as protective mechanism
against water stress in grapevine, especially in Thompson seedless cultivar.
4 Water stress conditions
WS 0 Field capacity (FC)
WS 1 moderate (−1 Mpa,)
WS 2 severe (−1.5 Mpa)
WS 3 Very severe (−2 Mpa)
3 Manganese sulfate
Concentrations
0 g/l
2 g/l
4 g/l
2 Grapevine cultivars
Rotabi Drought
tolerant
Thompson
seedless
semi-
sensitive
Ghorbani et al (2019)
Shiraz University, Shiraz, Iran.

37. Comparative effects of exogenous glycine betaine, kaolin
clay particles and Ambiol on photosynthesis, leaf
sclerophylly indexes and heat load of olive cv. Chondrolia
Chalkidikis under drought
• To investigate the effects of exogenous application of kaolin clay particles,
glycine betaine and Ambiol on olive cv. subjected to drought stress.
• Each tree was treated with a mean volume of 152 mL of spraying solution.
Application of 4 Ameliorating products
Glycine betaine BlueStim WP: GB 95% (w/w) 500 g 100 L−1
Kaolin clay particles Surround WP: K 95% (w/w) 5 kg 100 L−1
Ambiol Pure compound 10 mg L−1
Control Water spray -
Water treatments
Full Irrigation (W)
Drought condition (D) Denaxa et al (2012)
Agricultural University of Athens, Greece

38. Effects RWC WUEi Photosynthesis
Water Irrigation (W) 86.54 75.36 14.74
Drought condition (D) 65.39 45.22 4.30
Control (C) 72.35 64.19 9.91
Glycine betaine (GB) 78.88 56.81 9.22
Kaolin (K) 78.83 63.69 10.81
Ambiol (A) 73.81 56.47 8.13
C-W 85.28 84.34 16.27
C-D 59.43 44.03 3.55
GB-W 86..81 66.84 13.41
GB-D 70.94 46.79 5.04
K-W 89.75 78.06 16.55
K-D 67.91 49.31 5.09
A-W 84.31 72.19 12.73
A-D 63.30 40.74 3.53
Effects of irrigation regime and treatments on RWC, WUEi & Photosynthesis
Both, kaolin clay particles and glycine betaine proved to be the most effective,
among the applied products, on alleviating the negative effects of drought stress.

39. Effects Of Glycine Betaine Concentrations On The
Agronomic Characteristics Of Strawberry Grown Under
Deficit Irrigation Conditions
• To examine effects of different exogenous GB concentrations (0, 10 and 20 mM) to
deficit irrigation conditions (15% drainage) in Fortuna and Albion strawberry cultivars.
Adak (2019)
Akdeniz University, Antalya, Turkey
Glycine betaine concentration
(mM)
Cultivars
Fortuna Albion
TSS (%)
0 6.56 7.56
10 6.70 7.36
20 6.36 7.23
Overall 6.54 7.39
Yield (g/plant)
0 287.67 226.67
10 430.67 287.33
20 334.67 268.00
Overall 351.00 260.67

40. 5. Using Precision Farming to identify crop stress
• PF techniques have made it possible to assess crop stresses, yield estimations and
vegetation cover.
• Hyperspectral images can be taken by cameras mounted on drones or aircrafts.
• Reflected light is analyzed. Health of each crop can be estimated based on the relationship
and interaction between foliage and electromagnetic radiation.
• Helpful in Early detection of drought stress resulting from water insufficiency.
• Farmers can identify the specific areas to irrigate, before drought stress hits the crops.

41. 6. Transgenic approach
• Use of modern molecular biology tools for engineering stress tolerant
plants is based on the expression of specific stress-related genes.
• Involved manipulation of a single or a few genes involved in
signaling/ regulatory pathways or that encode enzymes involved in
these pathways for genetic improvement against environmental stress
resistance [Jewell et al., 2010].

42. Plant Gene Remarks Perform to abiotic
stress
References
Apple Osmyb4 Encoding a transcription factor belonging to
the Myb family, accumulation of several
compatible solutes
Drought and cold Pasquali et al. (2008)
MdNHX1 Tonoplast Na?/H? antiporters Salt Li et al. (2010)
PpCBF1), C-repeat binding factor (CBF/DREB
transcriptional activator genes
Cold Wisniewski et al.
(2011)
MdCIPK6L Encode a CBL-interacting protein kinase
(CIPK)
Salt, drought and
chilling
Wang et al. (2012)
Banana MusaDHN-1 Overexpression of dehydrin gene, belonging
to a broader class of LEA proteins
Drought and salt Shekhawat et al.
(2011a)
MusaWRKY71 Encodes a WRKY transcription factor
protein
Multiple abiotic
stress
Shekhawat et al.
(2011b)
MusaSAP1 i.e.
stress
Encodes a zinc finger protein associated
proteins (SAP)
Multiple abiotic
stress
Sreedharan et al.
(2012)
Citrus P5CSF129A Osmotic adjustment, protected against ROS
by modulating the antioxidant enzymes
activity
Water deficit de Campos et al. (2011)
AhBADH Overexpressing AhBADH gene regulates
accumulate higher level of glycinebetaine
Salt Fu et al. (2011)
Genes, mechanisms, and genetically modified fruit plant species implicated in plant responses to many abiotic stresses.

43. Grapevine DREB1b Dehydration response element binding
gene, a cold inducible transcription
factor
Cold Jin et al. (2009
VvCBF4 C-repeat binding factor gene, reduced
freezing-induced electrolyte leakage
Cold Tillet et al.
(2012)
Kiwifruit AtNHX1 Maintaining a relatively high K?/Na?ratio Salt Tian et al.
(2011)
Mulberry hva1 Encodes a group 3 LEA protein Salinity and
drought
Lal et al. (2008)
Osmotin Encoding osmotin and osmotin-like proteins
belonging to the plant PR-5 group of proteins
Salt, drought
and and variety
of fungal (biotic)
pathogen
Das et al. (2011
Papaya C-repeat
binding factor
(CBF)
Transcriptional activator genes Cold Dhekney et al.
(2007)
Pear SAMDC2 Encodes sadenosylmethionine decaboxylase,
transgenic plants expressing polyamines
Salt He et al. (2008)
SPDS1, SPDS Encodes spermidine synthase, transgenic
plants expressing polyamines
Salt, multiple
abiotic stress
Wen et al.
(2008, 2009)
Strawberry Osmotin Enhanced levels of proline, total soluble protei Salt) Husaini and
Abdin (2008
Genes, mechanisms, and genetically modified fruit plant species implicated in plant responses to many abiotic stresses.

44. Mitigation Strategies
For Salt Stress Situations
In Fruit Crops

46. Classification based on relative tolerance of fruit species to Salinity

47. Important Salt tolerant rootstocks

48. Important Salt tolerant rootstocks

49. Relative Salt Tolerance of Different Grape Rootstocks
to Different Chloride Salts
• Objective: To study the variability in salt tolerance of grape rootstocks (viz.,
Dogridge, Salt Creek, RS-19, SO4 and 1613-C) to different chloride salts viz.,
NaCl, KCl, MgCl2 and CaCl2 salts, applied at 4 meq, 8, 16 and 32 meq/lt
concentrations.
Saritha et al (2017)
Grape Research Station, Rajendranagar, Hyderabad
Chloride
content
(%)
• High chloride exclusion ability represents the salt tolerance.
• Significantly lowest chloride content was recorded with Dogridge (0.87%)
rootstock.

50. Effect of varying chloride salts on root parameters in different grape rootstocks
Results: Highest root growth parameters measured was recorded in Dogridge.
Due to low Cl‫־‬ content in leaves & high vigour, Dogridge is more tolerant to salinity
than other rootstocks.

51. Grape Rootstock Response to Salinity, Water and
Combined Salinity and Water Stresses
4 irrigation water
salinity levels
S 0 = 0.7 dS m−1 water
S 1 = 1.7 dS m−1 water
S 2 = 2.7 dS m−1 water
S 3 = 3.7 dS m−1 water
Cabernet Sauvignon scions
grafted onto
SC represents Salt Creek rootstock
Ru represents 140 Ruggeri rootstock
SG represents St. George rootstock
Three water treatments
D 0 = 100%
ETc
Two 1.0 L h−1 and one 0.5 L
drippers
D 1 = 80%
Etc
Two 1.0 L h−1 drippers
D 2 = 60%
ETc
One 1.0 L h−1 and one 0.5 L
h−1 drippers,
Suarez et al (2019)

52. Salt tolerance of mango grafted on rootstocks and
antioxidant enzyme responses
• To investigate salt tolerance of mango (Mangifera indica L.) rootstocks (Sukkary,
Zebda, 13/1 and Peach) grafted with the scion Keitt.
• 3 Saline treatments: 1000, 2000 and 3000 ppm & one untreated one (control)
• RESULTS
• Highly tolerant: Peach and 13/1
• Mild tolerant: Sukkary
• Least tolerant: Zebda
Fayek et al (2018)
Agriculture Research Center, Giza, Egypt
• Low tolerance of "Zebda"
rootstock was due to high
Na/K ratio in the leaves
& low AEz.

53. Evaluation of MM106 and Omara
apple rootstocks for salt tolerance in vitro
• To evaluate salt tolerance of two apple rootstocks (MM 106 and Omara).
• 5 NaCl Concentration (20, 40, 60, 80 and 100 mM) & control (no NaCl) for 8 weeks.
Abdel-Hussein (2006)
University of Kufa, Iraq
• More plantlet height & total chlorophyll content found in plantlets of MM 106
rootstock.
• MM106 rootstock appeared to be more salt tolerant as it is less damaged by salt
stress.

54. Improved salt-tolerance in Citrus macrophylla
mutant rootstocks
• To study ability of Five mutants of Citrus macrophylla to cope with salt stress.
• The mutants were submitted to different NaCl treatment.
• Cv. Alemow was kept untreated (CONTROL) to use as reference plant.
Jiménez and Tornero (2019)
Murcia, Spain
Starch & Proline act as a protector that is able to overcome abiotic stresses through the
balance of the osmotic potential.
MM2A, MM3A mutant shoot (80 mM NaCl)
MM3B, MM4B, MM5B mutant shoot (60 mM NaCl)

55. Tetraploid citrus rootstocks are more tolerant to salt
stress than diploid
• To investigate salt stress tolerance of three tetraploid rootstock genotypes along
with their corresponding diploid rootstocks (Poncirus trifoliata, Carrizo
citrange, Cleopatra mandarin).
Saleh et al (2008)

56. • Results: Less leaf sodium & chloride found in tetraploid rootstocks.
• Tetraploids: Thicker leaves, difference in the number and size of the stomata
and it synthesize more ABA.
• Tetraploid citrus rootstocks are more tolerant to salt stress than diploid.

57. 2. By using soil test reports
• In many cases, growers realize salinity problem in their field, only after yields
are decreased or crop quality is reduced. THAT IS TOO LATE.
• Soils should be tested periodically.
• Regular soil analysis gives better indication of the salt content in the soil.
• A practical approach in order to prevent salinity buildup early enough is
sampling the soil 5 times over a growing period of 8 months (a test every 6
weeks or so).
• It is recommended to do at least one water analysis as well.
• The test report will indicate any change in soil content, allowing the farmers
to adjust the fertilization and irrigation regimes as needed.
• This is the cheapest & most practical way to follow up on salinity status,
keeping crop quality and yield at optimal level.

58. 3. Leaching
• The salt concentration of the drainage water is normally 5 - 10 times higher
than normal irrigation water.
• Leaching is most effective procedure for removing salts from the root zone
of soils.
• It can be done by ponding fresh water on the soil surface and allowing it to
leach through the soil, be drained and discharged through an appropriate
drainage system.
• Should be according to leaching requirement of soil.
• Heavier soils require larger water applications than lighter soils, in order to
avoid salinity buildup.
• Best results during the summer months because this is the time when the
water table is deepest and the soil is dry.

59. 4. Different Irrigation Practices
• Improper irrigation management is the primary man-made cause of salinization.
1. Right intervals between two irrigations should be kept.
2. Irrigation regimes and intervals must be appropriately scheduled according to
the soil conditions and growth stage of the crop.
3. Frequent and shallow (superficial) applications result in salt accumulation in
the root zone.
4. River water or groundwater used in irrigation contains salts. After evaporation
of water, salt remains behind in the soil, leads to soil salinity in irrigated field.
So, irrigation by river water or groundwater should be avoided.
• Different Irrigation Methods to cope up with salinity stress
• .
1. With furrow irrigation, soluble salts in the soil move with the wetting front &
salts get more concentrated at the termination of wetting front.
2. Drip Irrigation
3. Subsurface drip irrigation (SSDI)

60. Subsurface drip irrigation (SSDI)
• SSDI refers to the application of water below the soil surface through
emitters in which Surface drip in tubes are buried in soil.
• Drip irrigation results in gradual downward movement of salts to the
root zone increasing osmotic stress and salt toxicity to the crops.
• But, in SSDI, salt front is partially driven down into the deeper soil
layers and damage to the main roots of the plants can be minimized by this
method.

61. Effects of winter irrigation on soil salinity and
jujube growth in arid regions
• To investigate the effects of different irrigation methods on growth rate of young
jujube trees under salinity stress.
• Total 13 treatments: Drip irrigation (DI) and flood irrigation (FI) with 6 irrigation
quotas (450, 1350, 2250, 3150, 4050, and 4950 Cubic meter per hour per square
metre: m3/hm2) & one control (without winter irrigation ).
• Winter drip irrigation significantly reduced soil salinity, changed the soil salt
distribution, created a good environment for the growth of jujube trees and
improved the survival rate of young jujube trees, especially under winter drip
irrigation with a quota of 3150 Cubic meter per hour per square metre: m³/hm².
Liu et al (2019)
Hohai University, Nanjing, Jiangsu, P.R. China,

62. Drip irrigation with organic fertilizer application improved
soil quality and fruit yield in Jujube
• Irrigation and fertilization management are important for controlling
agricultural soil salinity and increasing productivity in extremely arid regions.
• To evaluate the effects of long-term drip irrigation and organic fertilizer
application (FYM) on soil salinity, fruit quality and yield of jujube.
• Lower salt content in root zone was found in treatment: DIOF after 7 years.
• The yield of DIOF increased annually and reached an equilibrium level after the
4th year (15-17 Mega grams per hectare : Mg/ha).
• Long-term combination of drip irrigation and organic fertilizer application would
be an effective strategy maintaining productivity and improve fruit quality in
extremely arid areas.
Li et al (2019)
Xinjian, China
Six treatments
CK (conventional irrigation, no fertilizer)
CIMF (conventional irrigation, mineral fertilizer)
CIOF (conventional irrigation, organic fertilizer)
DI (drip irrigation, no fertilizer)
DIMF (drip irrigation, mineral fertilizer)
DIOF (drip irrigation, organic fertilizer).

63. 5. Fertilization & Fertigation
• Improper Crop fertilization is one of the sources of salinization of soils.
1. The fertilizers type and their quantities should coincide to the requirements of
the crop and with nutrients that are already present in the soil.
2. Excessive nutrient applications must be avoided.
3. High-purity, chloride-free (K2SO4 & CuSO4) & low-saline fertilizers (K2SO4 &
K2Mg2(SO4)3 should be selected.
4. Foliar or soil application of NO3‫־‬, Ca2+, K, P, SA and silicon (Si) also improves salt
tolerance of fruit crops.
• Fertigation reduces soil salinization.
• It mitigates salt stress effects as it improves the FUE by increasing nutrient
availability to plants and by controlling time of application, and the concentration of
fertilizers.

64. 6. Microbial bio-inoculants
• Arbuscular mycorrhizal (AM) fungi mitigates the detrimental effects of
salinity.
• It accumulates compatible solutes to avoid cell dehydration, regulates ion
and water uptake by roots, reduces oxidative stress by enhancing the
antioxidant capacity and stabilize photosynthesis for sustained growth
(Ruiz-Lozano et al., 2012).
• Rhizospheric and endophytic bacteria (CSR-G-1, CSR-B-2, and
CSR-B-3) have been found promising to enhance salinity tolerance in
different horticultural crops.

65. 7. Reclamation of alkaline soil
1. Gypsum, when slowly mixed with water, releases calcium ions, which replace
sodium ions from the soil into the downward moving water.
The term reclamation of saline soils refers to the methods used to
remove soluble salts from the root zone.
Types of alkaline soil
Saline soil <8.5
Sodic soil 8.5-10
Saline sodic soil >8.5

66. 8. Reclamation of acidic soil (pH <7)

67. Scrapping Flushing
9. Conventional methods of salt stress management
• Flushing: Washing away the
surface accumulated salts by
flushing water over the surface.
• Used to desalinize soils having
surface salt crusts.
• Small amt of salt is flushed out.
• Less practical significance.
• Scraping: Removing the salts that
have accumulated on the soil
surface by mechanical means.
• Limited success.
• Temporarily improve crop growth.

68. Mitigation Strategies
For High Temperature Stress Situations
In Fruit Crops

69. High temperature tolerant rootstocks
Apple M7, M 16, M25 and MM109
Pear Oregon 211, 249,260,261 and 264
1. By growing resistant rootstocks

70. 2. By use of anti transpirants
Efficacy of Kaolin and Screen Duo Spraying on Fruit Sunburn,
Yield and Fruit Quality of Keitt Mango Fruits
• To study the influence of kaolin and screen duo foliar application on fruit
sunburn, yield and fruit quality.
• Six years old Keitt mango trees grafted on Succary seedlings as rootstocks
were used.
Baiea et al (2018)
Benha University, Egypt

71. Treatment details Quantity Spray time
T 1 Control Tap water spray Sprayed once at
mid of June.
T 2 Koalin (aluminum silicate) 25 g/L
T 3 Koalin (aluminum silicate) 50 g/L
T 4 Koalin (aluminum silicate) 75 g/L
T 5 Screen duo 6 cm³/L
T 6 Screen duo 12 cm³/L
T 7 Screen duo 18 cm³/L
T 8 Control Tap water spray Sprayed twice at
mid of both June
and July
T 9 Koalin (aluminum silicate) 25 g/L
T 10 Koalin (aluminum silicate) 50 g/L
T 11 Koalin (aluminum silicate) 75 g/L
T 12 Screen duo 6 cm³/L
T 13 Screen duo 12 cm³/L
T 14 Screen duo 18 cm³/L

72. Treatments No. of sunburned fruits
2016 2017
Once Twice Mean Once Twice Mean
Control 5.67 4.67 5.17 6.00 6.00 6.00
K @ 25 g/L 3.67 1.33 2.50 4.00 1.00 2.50
K @ 50 g/L 3.33 1.00 2.17 3.33 0.67 2.00
K @ 75 g/L 2.33 0.67 1.50 2.33 1.00 1.67
Screen duo @ 6 cm³/L 1.67 0.33 1.00 2.00 0.67 1.33
Screen duo @ 12 cm³/L 1.00 0.33 0.67 1.33 0.00 0.67
Screen duo @ 18 cm³/L 1.00 0.00 0.50 1.67 0.00 0.83
Mean 2.67 1.19 - 2.95 1.33 -
• Least sun burned fruits were found in screen duo spray at 12 or 18 cm³/L
when it was sprayed in both summer months (at mid of both June and July).
• Screen duo had a positive effect to prevent fruit sunburn damage and
improved yield and fruit quality of Keitt mango fruits.

73. Foliar application of kaolin reduces the incidence of
sunburn in ‘Thompson Seedless’ grapevine
• To study effect of foliar application of kaolin in four concentrations for two
times on ‘Thompson Seedless’ grapevine cultivar.
Time Kaolin (%)
Mid June 0.00
2.50
5.00
7.50
Mid July 0.00
2.50
5.00
7.50
Hosseinabad and Khadivi (2019)
Arak University, Arak, Iran
A & B : Untreated berries: the presence of sunburn
C: Treated berries: no sunburn.

74. Time Kaolin
(%)
Berry length
(mm)
Berry weight
(g)
Leaf burn Berry sunburn
Mid June 0.00 13.40 1.30 2.33 2.33
2.50 13.24 1.40 0.00 0.07
5.00 13.99 1.45 0.00 0.00
7.50 35.59 1.41 0.00 0.00
Mid July 0.00 13.42 1.39 3.00 1.33
2.50 13.45 1.40 0.00 0.47
5.00 13.32 1.32 0.00 0.20
7.50 13.51 1.42 0.00 0.60
• Berry length & weight improved with kaolin application in both months i.e. mid
June and mid July.
• Leaf sunburn & berry sunburn was measured based on rating, scoring, and coding according
to the grape descriptor (IPGRI, 1997).
• There were no leaf burn & berry sunburn symptoms in the vines treated with
kaolin in mid-June.
• Spraying kaolin in mid-June is better option than mid July.

75. 3. Use of shade nets
• Shading can be a useful tool for controlling temperature.
• Lowers temperature by avoiding heat stress.
• Advantages of using shade nets against temperature differences:
1. Enhanced fruit size
2. Larger high-quality yield
3. Protection against sunburn
4. Increased WUE: Effective water consumption
5. Protection against natural and environmental damage
6. Especially used in apple orchards to have improved quality and
increased yield.
• Red and White: High productivity, yield and larger fruit size was found in
Golden Delicious apple variety which were covered with red & white shade
nets.

77. Red, blue and pearl netting hangs over a fourth-leaf Honeycrisp orchard owned by
McDougall and Sons near Quincy, Washington, on Aug. 17, 2016, as part of a
Washington State University research study into the benefits of netting.

78. Other control measures
1. White washing tree trunk: April & June-July. (Mixture slaked lime: 25Kg,
CuSo4: 500g, water: 100L).
2. Providing shelters: Erecting thatches made up of sarkanda, rice straw or
khajor (datepalm) leaves.
3. Quick growing shade plants: Jantar & Arhar.
4. Wrapping bark of tress: Old gunny bags or farm waste materials (rice starw or
paddy straw) in young tender fruit plants.
5. Wind breaks: Grow on western side of the orchards. Eg. Jamun, mulberry,
arjan, shisham.
6. Planting low headed trees: Low headed trees escape ill effects of hot sun. Fruit
trees should be trained low headed in hot-arid regions.
7. Frequent irrigation: More frequent irrigations during hot weather conditions.
It should be done at regular intervals.

79. Mitigation Strategies
For Low Temperature Stress Situations
In Fruit Crops

80. Cold hardy rootstocks
Apple B.490, B.491. B.9, 0.3, P.2, P.22, K.14_ Novate, Alnarp 2 and Robusta 5
Pear OH x F series
Peach Siberian C, GF-677, Marianna GF 8/1, Damas GF 1869
Plum St. Julien A, Marianna 2624, Marianna OF 8/1
Apricot Hoggith
Cherry CAB 6P, CAB II F, W 10, W 11, Wl3
Walnut J. Mandshurica, J. Cinerea, J. Nigra
Frost tolerant rootstocks
Apple MM106, M7, MM104
Pear Oregon 211, 249, 261, 264 and P. betulaefolia
Peach Rutger's red leaf, St. Julien Hybrid no. 1 and No. 2
Plum Marianna GF 8/1, Iarianna 2621, Damas GF 1869
Walnut J. nigra.
1. Grow cold hardy & frost tolerant rootstocks

81. 2. Use of Nutrients to alleviate low temperature tress
1. Organic manures: Poultry manure in banana to rise temperature.
2. Foyer et al (2002) reported that Potassium supply in high amounts can
provide protection against oxidative damage caused by chilling or frost.
3. Palta (2000) reported that Ca is necessary for recovery from low temperature
stress by activating the plasma membrane enzyme ATPase, which is required
to pump back the nutrients that were lost in cell damage.
4. Waraich et al (2011) observed that under low temperature stress, Magnesium
improves carbohydrates translocation by increasing phloem export and
reduces ROS generation and photo-oxidative damage to chloroplast.
5. Kang et al (2002) reported that SA application at lower concentrations
reduced electrolyte leakage due to low temperature stress in banana.

82. 3. Use of mulches to alleviate low temperature
tress
• Mulches rise soil temperature by 2-3 degree in winters.
• Lieten (1991) reported that plastic mulches stimulate growth of young
plants, increase soil temperature, reduce evapotranspiration and restrain
heat loss during cold nights.

83. Papaya plants covered by paddy straw mulch to
reduce frost damage

84. The Effect of Film Mulching on Soil Temperature
(double silver-black reflective film)
• Soil temperature increased by 2˚C - 3˚C by film mulching than control.
Zhang and Xie (2014)

85. Metalized-striped Plastic Mulch Reduces Root-zone
Temperatures during Establishment and Increases Early-
season Yields of Annual Winter Strawberry
• Performance of three mulches using two cultivars namely ‘Florida Radiance’ and
‘Florida Beauty’ over two seasons was evaluated.
Deschamps and Agehara (2019)
University of Florida, Wimauma, FL
1. Black mulch (left)
2. Metalized coatings: Fully metalized (middle)
3. Metalized-striped (right): Center metalized stripe was 51 cm wide.
On its both ends, 25 nm thick layer of aluminum was present.

86. Fig. Average hourly root-zone temperatures at a 10-cm depth for the bed center and
bed shoulder.

87. Cultivar Plastic mulch 2016-17 2017-18
Early Late Total Early Late Total
Florida Radiance Black 12.1 15.0 27.1 8.8 15.3 24.2
Fully metalized 13.2 16.4 29.6 11.8 15.9 27.7
Metalized striped 14.2 15.9 30.1 13.4 19.0 32.4
Florida Beauty Black 11.2 13.9 25.1 10.5 12.1 22.6
Fully metalized 12.9 14.9 27.8 11.7 11.9 23.7
Metalized striped 13.7 14.8 28.4 12.7 13.9 26.5
Effect of cultivar and mulch type on early, late, and total yield of strawberries in the
2016–17 and 2017–18 seasons.
• Maximum early, late, and total yield has found in metalized striped mulch.
• Metalized-striped mulch have the dual benefits of metalized and black-mulch films.
• It is well suited to optimize soil microenvironment conditions throughout the
dynamic environmental conditions.

88. 4. By use of organic chemical compound
.
Enhanced chilling tolerance of pomegranate fruit by edible
coatings combined with malic and oxalic acid treatments
• Influence of polysaccharide based edible coatings in combination with
organic acid treatments on CI of pomegranate cv. Rabbab-e-Neyriz during cold
storage was evaluated.
• Fruit were treated with carboxymethyl cellulose (CMC, 2% w/v) and chitosan
(CH, 1.5% w/v) edible coatings alone or in combination with oxalic acid (5 mM
OA and 10 mM OA) and malic acid (50 mM MA and 100 mM MA).
• Results showed that Chitosan combined with 5 mM Oxalic Acid and Chitosan
combined with 50 mM Malic Acid were the most effective treatments for
ameliorating chilling injury.
Ehteshami et al (2019)
University of Hormozgan, Bandar Abbas, Iran

89. Effect of Putrescine Treatment on Chilling Injury, Fatty
Acid Composition and Antioxidant System in Kiwifruit
• To investigate the effects of different concentrations of putrescine (0, 1, 2 and 4 mM)
on chilling injury, fruit quality & antioxidant system of cold-stored kiwifruit.
• Normal kiwi flesh & flesh damaged due CI.
• 2 mM putrescine reduced chilling injury during storage.
• Putrescine induced chilling tolerance by enhancing antioxidant activity and
inhibiting ethylene production.
Yang et al (2016)
Northwest A&F University, Province, China

90. 5. By use of synthetic PGR
.
1-Methylcyclopropene alleviates chilling injury by
regulating energy metabolism and fatty acid content in
‘Nanguo’ pears
• To investigate the effects of 1-methylcyclopropene (1-MCP) treatment on chilling
injury (CI) in harvested ‘Nanguo’ pears during the shelf life after cold storage at 0 C.
• 1-MCP @ 0.5 mL/L.
• 1-MCP treated fruit showed slower Chilling injury development, lower ion leakage
and malondialdehyde accumulation.
• 1-MCP enhanced energy metabolism related enzyme activities & helped in
lowering CI.
Cheng et al (2015)
Shenyang Agricultural University, Shenyang, People’s Republic of China

91. 6. Other temporary measures
1. Training of tress: Well trained & low headed trees.
2. Wrapping the lower portion tree trunk: Old gunny bags to avoid CI to bark.
3. Providing smoke screens: Dry leaves, grass or trash is ignited & allowed to
burn slowly. Rises temp & avoid frost injury.
4. Light winter irrigation: Rise temp by 2-3 degree. Most easy & Most practical
method.
5. Oil lamps: Installed in orchard earlier & ignited when there is forecast of
occurrence of frost.
6. Wind machines: Installed in orchard to produce violent movement of wind,
which in turns helps to keep away the frost.
7. Growers should remain alert & keep in touch with weather forecasts or frost
warnings. Use soil thermometers to check fall in temp.
8. When temp falls around zero degree & sky is clear, frost is sure to occur.
Time to preventive action against frost.
Fruit growing by JS Bal

92. Mitigation Strategies
For Strong Winds In Fruit Crops

93. Wind stress
• High winds are experienced in association with cyclones, depressions and
thunderstorms which damage crops.
• Wind affects the growth and development of horticultural crops by
following ways:
1. Loss of moisture through evaporation and results in water stress.
2. Mechanical damage to crops.
3. Light winds blowing from colder parts will bring about a drop in
temperature and create frosty conditions, which in turn damage the crop.
4. Less fruit is produced on trees under wind stress compared to those
protected from wind.
• Adaptations to wind stress
1. Wind‐exposed plants generally develop fewer, smaller leaves which contain a
higher proportion of mechanical tissues.
2. Most wind‐exposed plants also exhibit reduced shoot extension.

94. Mitigation strategies for wind stress conditions
1. Tree size control practices
2. Planting windbreaks
3. Protect plant from extremes of hot, dry winds and dust
4. Conserve moisture by reducing evaporation and transpiration

95. Mitigation Strategies
For Hail Storm In Fruit Crops

96. Hail is a form of solid precipitation.
It consists of balls or irregular lumps
of ice, each of which is called a hailstone.

98. Mitigation strategies for
Global Climate Change

99. Control
GROW LOW CHILLING FRUIT VARIETIES

105. Flowering in apple
Hand pollination in apple

106. Use of Greenhouse technology
• Provides a controlled & favourable environment for crop to grow & yield high in all seasons.
• Saves crop from excessive cold in winters, from heat in summers & from rains in monsoon
seasons.

107. Mitigation strategies for global climate change
Conventional Approaches:
1. Development of stress tolerant varieties and rootstocks.
2. Development of low chilling requirement varieties
3. Development of efficient climate forecasting systems
4. Development of weather based cropping systems
5. Development of eco-friendly water use efficiency systems.
6. Weather based pest management strategies.
7. In-situ and ex-situ conservation of genetic resources.
Biotechnological Approaches:
1. Transgenic - Engineering stress tolerance associated genes
2. Somaclonal variations.
3. Somatic hybridization
4. Meristem culture/shoot tip grafting
5. Molecular Marker