The germplasm repository
of Centre contains a total of 581 accessions
of citrus.
World Collection = 6000 acc
India About = 1505
acc
NRCC Total Collection
= 581
A = Exotic = 49
Scion = 30 (14
mandarin, 9 sweet orange, 7 grapefruit and
Pummelo)
(USA, France, Japan, Niger)
Rootstock = 19
(mostly from USA, few from other countries)
B = Endagered / threatened / Rare species
= 7
C. indica C. macroptra, C. megaloxycapa, C.
rugulosa, C. assamensis, C. latipes,
C. inchagesis.
C = Indigenous Collection = 532
Institute Collection = 108
NATP (PB) collection = 356
IPGRI / ADB Collection
Superior Clone Selected :
Acid lime = 12, Mosambi = 5
Nuceller seedling of Nagpur mandarin = 212
Irradiation seedling (Gamma rays) of Nagpur
mandarin = 320
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Variability in fruits of collected citrus germplasm |
Collected germplasm regenerated and maintained in screen house |
Promising clones of Nagpur mandarin, Acid lime, and sweet orange cultivar “Mosambi” have been identified for various desirable horticultural traits and later using them for mass multiplication.
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 |
N-2 (Early Maturing clone of Nagpur mandarin) |
N-4 (Seedless clone of Nagpur mandarin) |
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Disease free planting material of Nagpur mandarin, acid lime and Sweet orange (Mosambi) is being produced on large scale using various latest techniques like containerized nursery, soil solarization and indexing (biological) and serological) and distributed to user agencies as mother trees.
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Solarization |
Seed sowing in nursery |
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Germinated
seedling in primary
nursery |
Nagpur
Mandarin buddings ready
for sale |
1. STG in Citrus for disease free quality planting stock. (Citrus Sanitation)Realizing the principle means of spread of most citrus virus & virus like diseases in India occurred through infected nursery stock during propagation and further realizing there is absolutely no control once virus enters into the plant system, a comprehensive citrus improvement program through in vitro shoot tip grafting started at NRCC, Nagpur since 2001 to clean the selected mother trees through in vitro STG in order to produce and distribute certified disease free and quality bud grafts on large scale to the citrus growers/nursery men under various funding agencies.
Through shoot tip grafting technique so far around 57,000 certified elite ,healthy planting stock were distributed to the citrus growers /nurserymen and 212 hectars of healthy orchards were established in farmers field, predominantly in Central India .The performance of STG derived planting stock was found promising compared to commercially raised planting stock in farmers orchard.
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In vitro Shoot tip grafting |
Double grafting |
Disease Free Planting Stock Through STG |
2. STG based citrus quarantine.
A quarantine programme based on tissue culture procedure (in vitro bud stick culture and STG) is playing a spectacular role in Spanish citrus industry, which was also standardized at NRCC , Nagpur.It is technically superior and safer compared to traditional quarantine programme.The technique consists of culturing in vitro imported bud sticks at a constant 32o C day and 30o C night temperature for inductions of flushes from which shoot tips can be isolated and micro grafted in vitro.This technique helps as a post entry quarantine check for preventing entry of any virus and virus like diseases along with the introduced budwood.Through this technique so far cleaned 20 exotic citrus scion cultivars and 14 exotic scion cultivars were recommended for field evaluation after STG and indexing.
3. Micro-budding in Citrus
Standardized micro-budding a new propagation technique in Citrus on just 5 month old roughlemon and Rangpur lime rootstocks which saves growers time, money ,space and enables rapid and year round multiplication of planting stock.
The technique is standardized for collecting representative leaf samples for Ambia and Mrig flushes in both Nagpur mandarin and Acid lime.
Leaf Age
* 6-8 months old leaves for Ambia Flush
* 5-7 months old leaves for Mrig Flush
Leaf Position
* 2nd, 3rd and 4th leaf on a shoot
Leaf Sampling Size
* 30-70 leaves covering 2 to 10 % trees.
Time of Sampling : For Ambia : Aug. – Oct.
For Mrig : Dec. – Feb.
Leaf Age
* 3-5 months old leaves
Leaf Position
* 2nd, 3rd and 4th leaf on a shoot
Leaf Sampling Size
* 30-70 leaves covering 2 to 10 % trees
Time of Sampling : Sept. – Nov.
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Leaf nutrient indices (derived from DRIS based analysis) for different commercial citrus cultivars of India.
|
Indices |
Nutrient |
Deficient |
Low |
Optimum |
High |
Excess |
Nagpur mandarin (Citrus reticulata Blanco) |
N (%) |
< 1.12 |
1.12 – 1.69 |
1.70 – 2.81 |
2.82 – 3.38 |
> 3.38 |
P (%) |
< 0.06 |
0.06 – 0.08 |
0.09 – 0.15 |
0.16 – 0.19 |
> 0.19 |
K (%) |
< 0.22 |
0.22 – 1.01 |
1.02 – 2.59 |
2.60 – 3.38 |
> 3.38 |
Ca (%) |
< 1.1 |
1.1 – 1.79 |
1.80 – 3.28 |
3.29 – 4.02 |
> 4.02 |
Mg (%) |
< 0.31 |
0.31 – 0.42 |
0.43 – 0.92 |
0.93 – 1.38 |
> 1.38 |
Fe (ppm) |
< 55.6 |
55.6 – 74.8 |
74.9 – 113.4 |
113.5 – 132.7 |
> 132.7 |
Mn (ppm) |
< 40.2 |
40.2 – 54.7 |
54.8 – 84.6 |
84.2 – 98.7 |
> 98.7 |
Cu (ppm) |
< 5.9 |
5.9 – 9.7 |
9.8 – 17.6 |
17.7 – 21.5 |
> 21.5 |
Zn (ppm) |
< 5.5 |
5.5 – 13.5 |
13.6 – 29.6 |
29.7 – 37.7 |
> 37.7 |
Yield(kg/tree) |
< 12.9 |
12.9 – 47.6 |
47.7 – 117.2 |
117.3 – 152.1 |
> 152.1 |
Khasi mandarin (Citrus reticulata Blanco) |
|
N (%) |
< 1.67 |
1.67 – 1.96 |
1.97 –2.56 |
2.57 – 2.85 |
> 2.85 |
|
P (%) |
< 0.06 |
0.06 – 0.08 |
0.09 – 0.10 |
0.11 – 0.13 |
> 0.13 |
|
K (%) |
< 0.52 |
0.52 – 0.98 |
0.99 – 1.93 |
1.94 – 2.40 |
> 2.40 |
|
Ca (%) |
< 1.72 |
1.72 – 1.96 |
1.97 – 2.49 |
2.50 – 2.75 |
> 2.75 |
|
Mg (%) |
< 0.14 |
0.14 – 0.23 |
0.24 – 0.48 |
0.48 – 0.54 |
> 0.54 |
|
Fe (ppm) |
< 22.6 |
22.6 – 84.5 |
84.6 – 249.0 |
249.1 –331.3 |
> 331.3 |
|
Mn (ppm) |
< 18.6 |
18.6 – 41.5 |
41.6 – 87.6 |
87.7 – 110.6 |
> 110.6 |
|
Cu (ppm) |
< 1.83 |
1.83 – 2.12 |
2.13 – 14.4 |
14.5 – 20.6 |
> 20.6 |
|
Zn (ppm) |
< 11.1 |
11.1 – 16.2 |
16.3 – 26.6 |
26.7 – 31.8 |
> 31.8 |
|
Yield(kg/tree) |
< 19.1 |
19.1 – 31.5 |
31.6 – 56.3 |
56.4 – 68.8 |
> 68.8 |
Sweet orange ‘Mosambi’ (Citrus sinensis Osbeck) |
N (%) |
< 1.28 |
1.28-1.97 |
1.98-2.57 |
2.58-2.68 |
> 2.68 |
P (%) |
< 0.050 |
0.050-0.090 |
0.091-0.17 |
0.18-0.21 |
> 0.21 |
K (%) |
< 1.12 |
1.12-1.32 |
1.33-1.72 |
1.73-1.92 |
> 1.92 |
Ca (%) |
< 1.09 |
1.09-1.72 |
1.73-2.98 |
2.99-3.62 |
> 3.62 |
Mg (%) |
< 0.13 |
0.13-0.31 |
0.32-0.69 |
0.70-0.87 |
> 0.87 |
Fe (ppm) |
< 25.9 |
25.9-69.4 |
69.5-137.1 |
137.2-200.1 |
> 200.1 |
Mn (ppm) |
< 29.7 |
29.7-42.1 |
42.2-87.0 |
87.1-159.5 |
> 159.5 |
Cu (ppm) |
< 2.0 |
2.0-6.5 |
6.6-15.8 |
15.9-20.5 |
> 20.5 |
Zn (ppm) |
< 9.0 |
9.0-11.5 |
11.6-28.7 |
28.8-37.3 |
> 37.3 |
B (ppm) |
< 7.8 |
7.8-12.7 |
12.8-23.1 |
23.2-43.8 |
> 43.8 |
Mo (ppm) |
< 0.28 |
0.28-0.38 |
0.39-1.1 |
1.2-1.5 |
> 1.5 |
Yield(kg/tree) |
< 45.9 |
45.9-76.5 |
76.6-137.9 |
138.0-168.5 |
> 168.5 |
Unsuitable Soil
Suitable Soil
Comprehensive soil suitability
guidelines have been developed for the Nagpur
mandarin orchards grown in Vidarbha region
of Maharashtra and Chhindwara region of M.P.
Soil fertility guide (derived from DRIS based analysis) for different commercial citrus cultivars of India
|
Parameters |
Indices |
|
Deficient |
Low |
Optimum |
High |
Excess |
Nagpur mandarin (Citrus reticulata Blanco) |
|
pH |
< 7.2* |
7.2 – 7.5 |
7.6 – 8.2 |
8.3 – 8.6 |
> 8.6** |
|
Org. C (g/kg) |
< 0.26 |
0.26 – 0.37 |
0.38 – 0.62 |
0.63 – 0.74 |
> 0.74 |
|
N (mg/kg) |
< 64.7 |
64.7 – 94.7 |
94.8 – 154.8 |
154.9 – 184.9 |
> 184.9 |
|
P (mg/kg ) |
< 4.8 |
4.8 – 6.5 |
6.6 – 15.9 |
16.0 – 20.7 |
> 20.7 |
|
K (mg/kg) |
< 64.1 |
64.1 – 146.7 |
146.8 – 311.9 |
312.0 – 394.6 |
> 394.6 |
|
Ca (mg/kg)* |
< 306.1 |
306.1 -408.0 |
408.1 – 616.0 |
616.1-718.0 |
> 718.0 |
|
Mg (mg/kg)* |
< 43.3 |
43.3- 85.1 |
85.2-163.2 |
163.3-202.8 |
> 202.8 |
|
Fe(mg/kg) |
< 4.6 |
4.6-10.9 |
10.9-25.2 |
25.3-40.6 |
> 40.6 |
|
Mn(mg/kg) |
< 4.7 |
4.7 – 7.4 |
7.5- 23.2 |
23.3 – 31.1 |
> 31.1 |
|
Cu(mg/kg) |
< 1.1 |
1.1 – 2.4 |
2.5 – 5.1 |
5.2 – 6.5 |
> 6.5 |
|
Zn(mg/kg) |
< 0.33 |
0.33 – 0.58 |
0.59 – 1.26 |
1.27 – 1.73 |
> 152.1 |
|
Yield(kg/tree) |
< 12.9 |
12.9 – 47.6 |
47.7 – 117.2 |
117.3 – 152.1 |
> 152.1 |
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|
Khasi mandarin(Citrus reticulata Blanco) |
|
pH |
< 4.5 |
4.5 - 5.0 |
5.1-6.2 |
6.2-6.8 |
> 6.8 |
|
Organic C (g/kg) |
< 8.6 |
8.6 - 15.6 |
15.7-32.5 |
32.6-50.2 |
> 50.2 |
|
N (mg/kg) |
< 82.1 |
82.1 - 160.9 |
161.0 – 418.7 |
418.8 – 547.6 |
> 547.6 |
|
P (mg/kg) |
< 2.3 |
2.3 - 4.4 |
4.5 – 8.7 |
8.8 – 10.9 |
> 10.9 |
|
K (mg/kg) |
< 20.3 |
20.3 – 82.2 |
82.3 – 287.5 |
287.6 – 390.2 |
> 390.2 |
|
Ca (mg/kg) |
< 80.4 |
80.4 – 148.7 |
148.8 – 285.4 |
285.5 – 353.7 |
> 353.7 |
|
Mg (mg/kg) |
< 4.7 |
4.7 – 31.2 |
31.3 – 84.4 |
84.5 – 111.0 |
> 111.0 |
|
Fe (mg/kg) |
< 31.4 |
31.4 – 39.4 |
39.5 – 180.9 |
181.0 – 251.6 |
> 251.6 |
|
Mn (mg/kg) |
< 8.9 |
8.9 – 26.9 |
27.0 – 80.3 |
80.4 – 116.1 |
> 116.1 |
|
Cu (mg/kg) |
< 0.53 |
0.53 – 0.66 |
0.67 – 2.90 |
2.91 – 4.09 |
> 4.09 |
|
Zn (mg/kg) |
< 2.17 |
2.17 – 2.83 |
2.84 – 5.14 |
5.15 – 8.70 |
> 8.70 |
|
Yield (kg/tree) |
<19.1 |
19.1 31.5 |
31.6 – 56.3 |
56.4 – 68.8 |
> 68.8 |
|
Sweet orange (Citrus sinensis Osbeck) |
pH |
< 7.8 |
7.8-7.9 |
8.0-8.3 |
8.4-8.5 |
> 8.5 |
Org. C (g/kg) |
< 0.30 |
0.30-0.48 |
0.49-0.69 |
0.70-0.82 |
> 0.82 |
N (%) |
< 62.5 |
62.5-107.3 |
107.4-197.2 |
197.3-242.2 |
> 242.2 |
P (%) |
< 4.9 |
4.9-8.5 |
8.6-15.8 |
15.9-19.5 |
> 19.5 |
K (%) |
< 85.0 |
85.0-186.3 |
186.4-389.2 |
389.3-490.6 |
> 490.6 |
Fe (ppm) |
< 1.6 |
1.6-4.7 |
4.8-17.3 |
17.4-23.5 |
> 23.5 |
Mn (ppm) |
< 3.7 |
3.7 – 7.6 |
7.7 – 15.7 |
15.8 – 19.7 |
> 19.7 |
Cu (ppm) |
< 0.30 |
0.30-1.75 |
1.76-4.70 |
4.71-6.17 |
> 6.17 |
Zn (ppm) |
< 0.14 |
0.14-0.43 |
0.44-1.03 |
1.04-1.33 |
> 1.33 |
B (ppm) |
< 0.17 |
0.17-0.30 |
0.31-0.57 |
0.58-0.70 |
> 0.70 |
Mo (ppm) |
< 0.05 |
0.05-0.08 |
0.09-0.16 |
0.17-0.19 |
> 0.19 |
Yield (kg/tree) |
< 45.9 |
45.9-76.5 |
76.6-137.9 |
138.0-168.5 |
> 168.5 |
* Low, ** Very low
Go Top
Using multinational trials, a comprehensive fertilizer schedule from pre-bearing to bearing Nagpur mandarin and Acid lime orchards has been developed.
Fertilizer Schedule Development
Fertilizer
(g/tree) |
Age of the plant (in years) |
Ist |
IInd |
IIIrd |
VI & beyond |
Nagpur mandarin |
Urea |
325(150)* |
650(300) |
975(450) |
1300(600) |
Single super phosphate |
315(50)** |
630(100) |
945(150) |
1260(200) |
Muriate of potash |
45(25)*** |
90(50) |
130(75) |
180(100) |
Acid lime |
Urea |
325(200)* |
870(400) |
1300(600) |
1740(800) |
Single super phosphate |
315(50)* |
630(100) |
945(150) |
1260(200) |
Muriate of potash |
45(25)*** |
90(50) |
130(75) |
180(100) |
* N, ** P2O5 *** K2O
Considering the behavior of black clay soils,
drainage using bedding system (broad bed and
furrows) has proved very effective to avoid
water logging problem in Nagpur mandarin.
1. Losses from water and fertilizer used by weeds are undoubtedly substantial.
2. It is observed that 46.60 Kg N, 4.12 Kg P and 75.06 Kg K is removed by the weeds in Nagpur mandarin orchards in an area of one hectare if they are not removed.
3. 133.5 Kg/ha nitrogen and 2 Kg/ha Zn is removed by weeds in Jambhiri seedling plants if it is not removed.
Most commonly found weed species in citrus orchards in central India are Brachiaria septance, Chenopodium album, Cynodon dactylon, Cyperus rotundus, Euphorbia spp., Launia spp., Malvestrum tricuspidatum, Parthenium hysterophorus and Sonchus arvensis.
WEED CONTROL IN CITRUS NURSERIES
Hand weeding although most common, damages young roots and shoots, increases production cost. Chemicals Diuron 2 Kg/ha or Terbacil 2.5 Kg/ha effective for 5-6 months.
WEED CONTROL IN CITRUS ORCHARDS
Pre-emergence weed control : Diuron 3 Kg/ha or Simazine 4 Kg/ha give complete control of weeds beyond 300 days when applied two times as pre-emergence sprays, first before commencement of monsoon in the first week of June and second after 120 days of first spray in September.
Post-emergence weed control : Glyphosate @ 4 l/ha as post-emergence weedicide when used at the rate of 2 l/ha kills both monocot and dicot weeds but regrowth of weeds starts especially in Bermuda grass after 20 days.
TIPS FOR EFFICIENT WEED MANAGEMENT
1. Use well rotten FYM for manuring to avoid introduction of weed species in the orchard
2. Avoid grazing of animals in the orchard to reduce the incidence of weeds
3. Uproot Parthenium weed before it comes to flowering
4. Avoid contact of herbicides to the foliage of the orchard trees
5. Clean the area of application before pre-emergence weedicide applcation
6. Spray post-emergence weedicides preferably before the weeds come to flowering
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Diuron @ 3 kg a.i./ha |
Simazine @ 4 kg a.i./ha |
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Glyphosate 4 l/ha |
Paraquat 2 l a.i./ha |
Tips to manage fruit drop :
- Maintain balance of nutrients in the plants to develop sufficient foliage to support the developing fruits.
- Prune the plants after harvesting to minimize the incidence of diseases.
- Avoid stagnation of water in the field.
- Ensure supply of moisture to the plant at crucial stages.
- Dispose off the dropped fruits from the orchard immediately.
- For ensuring complete solubility, dissolve 2,4-D and GA3 first in 30 ml of alcohol.
Nature of fruit drop in Nagpur mandarin
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Physiological |
Pathological |
Entomogical |
Follow given schedule at crucial stages :
- Spray gibberellic acid 10 ppm + urea 1 % at the time of flowering.
- Spray 2,4-D 15 ppm + Benomyl/carbendazim 1000 ppm + Urea 1 % one month after fruit set (fruit size 8-10 mm).
- Spray gibberellic acid 10 ppm + potassium nitrate 1 % two months after fruit set (fruit size about 18-20 mm).
- Spray 2,4-D 15 ppm + Benomyl/carbendazim 1000 ppm + Urea 1 % in September.
- Spray gibberellic acid 10 ppm + potassium nitrate 1 % in October.
For Mrig crop the above spray schedule can be followed starting from flowering.
The entomological fruit drop can be controlled by
- Poison baiting for fruit sucking moths with 20 g malathion w.p.or 50ml diazinon + 200 g jaggery with some vinegar or fruit juice in 2 litres of water (two bottles containing poison bait per 25-30 trees are sufficient).
- Light traps can also be used for collecting moths.
- The fallen fruits should be collected and disposed off from the orchard because such fruits attract.
- fruit sucking moths.
- For control of fruit flies also bait containing malathion or trichlorofon or fenthion 0.05 % + 1 % crude sugar, about two months before fruit ripening followed by 10 days interval.
- Male attracting traps containing 0.1% methyl eugenol and 0.05 % malathion reduces pest population. Use 25 traps / ha starting from 60 days before fruit harvest and solution after every seven days.
Go Top
- The factors for induction of flowering in Nagpur mandarin were characterised. The soils with low coarse fragments, high clay (> 60%) and concretions of CaCO3 were found to be problematic in flowering.
- The magnitude of flowering was less in areas having deep and clayey soil types.
- Leaf NH3-NH4 accumulated during stress and reduced after the removal of stress.
- Leaf NH3-NH4 and C/N ratio showed no correlation with flowering intensity.
- No change in leaf carbohydrate was observed in regular and irregular flowering orchards.
- Flowering intensity had no relationship with C/N ratio during and after the water stress period.
- Quantum of water stress in excess of –3.5 MPa is optimum for inducing profuse flowering in Nagpur mandarin which is achievable by imposing a stress of 30 days in December for Ambia flush and of about 40 days in the month of May for Mrig flush.
- Paclobutrazol @ 18 g/plant was found promising in Nagpur mandarin for inducing flowering in problematic high clay soils.
- Paclobutrazol @ 18 g/plant was also found to be promising for inducing the Hasta bahar flowering and fruiting in acid lime
- In case of Ambia crop of Nagpur mandarin, the date of alleviation of stress seemed to have a definite relationship with final fruit retention; earlier the stress is alleviated (in first week of January) better is the fruit retention and final yield.
- Chlormequat chloride (CCC) @ 2000 ppm or stem girdling (0.3 cm) applied in the month of September induced Hasta flowering in the month of October.
Technologies developed:
- Leaf water potential in excess of –3.5 MPa was found effective in imposing water stress in Nagpur mandarin for inducing flowering.
- For inducing flowering in Nagpur mandarin planted in problematic high clay soils paclobutrazol @ 18 g/plant or stem girdling of scaffold branches (0.3 cm) is found effective
- Resuming irrigation early in first week of January ensures better retention of fruits and avoids failure of Ambia crop in Nagpur mandarin.
- Post fruit-set fruit drop: Two sprays at monthly interval in May and June of either 2,4-D, 15 ppm or GA3 15 ppm + Benomyl 1000 ppm + Urea 1 %.
- Pre-harvest fruit drop : Two sprays at monthly interval in September and October of 2,4-D, 15 ppm or GA3 15 ppm + Benomyl 1000 ppm + Urea 1 %.
- For taking Hasta bahar (October-November flowering ) crop in acid lime, foliar spray application of chlormequat chloride (2000 ppm) or stem girdling (0.3 cm) in the month of September is found effective.
- Treatment combinations with monopotassium phosphate 2 %, DAP 2 %, 2,4-D 10 ppm and GA3 10 ppm can be alternatively used for increasing the fruit size of Nagpur mandarin.
Go Top
Irrigation requirement in Nagpur mandarin and Acid lime is reduced by 40% in drip irrigation compared to flood irrigation method.
The fertigation requirement has been developed consisting of irrigation at 20% depletion of available water capacity in Nagpur mandarin and 30% depletion of available water capacity of Acid lime with 500 gm N+140 P.O. + 75g K.O.
Filter pump station of fertigation system
About a dozen of them attack this crop regularly right from nursery stage to the harvest with cognizable damage. But only a few are quiet serious of which effective and quality of the produce.
Citrus Blackfly
It is a very serious pest. Both nymphs and adults cause excessive desapping and the nymphs secrete honey dew on which sooty mould grows that leads to “KOLSHI” manifestation. General plant health, its productivity and quality of the produce is severely hampered.
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Citrus blackfly infestation |
Citrus blackfly adults |
Occurrence : The pest attacks the crop during all the three flushing periods viz., Ambia (Jun.-Feb.), Mrig (Jun.-July) and Hasta (Oct.-Nov.) bahar and completes three generations in a year.
Control:
- Spray monocrotophos @ 1.5 ml or pjosalone @ 1.5 ml dimethoate @ 2 ml inidacloprid of water on the lower side of leaves covering the entire tree canopy.
- Second spray should be given after 15 days with any of the above insecticides or neem oil @ 10ml/L of water.
Time of application :
Timing of spray is very vital as only first nymphal instar of the pest is vulnerable to insecticides. The stage of 50% eggs hatching is the most ideal timing for spray application. This needs regular watch on the pest population in the field. Following timing were found most suitable to initiate control measures. Spraying operation should be completed within 2-3 days during summer.
Flushing periods Period of 50% egg hatching
1. Ambia First fortnight of April
2. Mrig Second fortnight of July
3. Hasta First fortnight of December
Citrus psylla
Nymphs and adults damage buds and soft young leaves suck the cell sap that causes heavy droop of flush and drying of twigs. It secretes honey on which sooty mould grows. The pest also acts as the vector for the deadly disease known as “Greening”.
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Citrus psylla adult |
Citrus psylla infestation |
Control :
- Foliar spray of monocrotophos @ 0.7 ml/L indacloprid or phosphamidon @ 0.3 ml/L or quinalphos @ 1 ml/L of water should be given and when sprouts appear in June-July and January-February or when infestation is noticed.
- If necessary, second spray of any of the above insecticides should be given after 15 days.
Citrus leaf miner
Newly emerged larva mines the undersurface of the leaf in a zigzag way. This results in curling and drying of leaves, stunted plant growth and die-back in case of nursery plants.
|
|
Citrus leaf miner adult |
Leaf miner infestation |
Occurrence : The pest attacks the crop through out the year except during severe cold and hot summer having peaks in March and September.
Control :
- Spray monocrotophos @ 1.5 ml or quinalphos @ 2 ml or dimethoate @ 1.5 ml or fenvaterate 1 ml/L of water at the bud burst stage and/or as soon as infestation is noticed.
- Second spray should be given 10 days after the first with any of the above insecticides or neem oil @ 20ml/L of water
- Pruning of infested branches during rainy season is suggested in case of severe infestation and spray should be aimed at young flush only.
Citrus mites
Mottling of leaves, chlorotic appearance due to multitude of gray spots and leaf drop are the major maladies caused by this pest.
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|
Citrus Mites Adult |
Citrus Mites Infestation |
Occurrence : The pest attacks the crop from November to May having peaks in February and March.
Control : Foliar spray of dicofol @ 1.5 ml or wettable sulphur @ 3 g of monocrotophos @ 1.5 ml/L of water should be given when pest incidence is noticed. Second spray, if required, may be given after a week.
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The chrysopid and coccinellid predators and the eulophid and encyrtid parasitoids are found to be the key bio-agents of the important insect pests of citrus.
Predators:
The chrysopid, Mallada boninensis Okamoto (Neuroptera: Chrysopidae) and the coccinellid, Serangium parcesetosum Sicard (Coleoptera: Coccinellidae) are the important insect predators found in citrus eco system. Predatory activity was more in Ambia (January-March) (2.9 predators / tree) as compared to Mrig (June-July) (1.7 predators / tree) and Hasta (October-November) (1.6 predators/tree) seasons in central India.
Mallada boninensis is found to feed on citrus blackfly, Aleurocanthus woglumi Ashby, whitefly, Dialeurodes citri Ashmed, psylla, Diaphorina citri Kuwayama, leaf miner, Phyllocnistis citrella Stainton, Aphids, Toxoptera spp. and mealy bugs, Planococcus citri Risso which are responsible for the considerable loss of general growth of plant and also the poor fruit yield and low fruit quality.
Mass multiplication technique of Mallada boninensis has been standardised at NRC for Citrus, Nagpur using protinex 40gm + fructose 70gm in 250ml water as adult diet and eggs of C. cephalonica as larval diet. A modest culture of 200-300 adults, 1500-2000 larvae and 2000-3000 eggs is being maintained regularly by following this method. This technology has been included in the “Technologies from ICAR (For Industrial Liaison)”, ICAR, New Delhi on Page No. 5
Filed release of M. boninensis @ 30 larvae/ tree twice in each season effectively reduced citrus blackfly, psylla and leaf miner to the extent of 40-60% and 25-35% together under caged and open field condition, respectively.
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M. boninensis larva adult |
Egg laying by M. boninensis |
M. boninensis adult |
Parasitoids:
Encarsia sp. (Hymenoptera: Encyrtidae) on citrus blackfly, Tamarixia radiata Waterston (Hymenoptera: Eulophidae) on citrus psylla and Citrostichus phyllocnistoides and Cirrospilus quadristriatus (Hymenoptera: Eulophidae) on leaf miner were found to be predominant parasitoids in citrus eco system. T. radiata (35-64 % parasitism) and Encarsia sp. (8-26 % parasitism) in Ambia (Fab-March) and C. phyllocnistoides and C. quadristriatus (6-23 % parasitism) in Hasta (Oct-Nov) seasons were found to be active as compared to other flushing seasons. Temperature of 25 º + 1 ºC for adult parasitoids of C. phyllocnistoides, C. quadristriatus and Encarsia spp. and 30º + 1ºC for T. radiata was found to be favourable as compared to 8º, 10º, 35º and 40ºC. Honey 50% and Fructose 60% + Honey 40% were preferred by adult parasitoids of Encarsia spp. and eulophid parasitoids of leaf miner, respectively. Mass multiplication studies indicated that these parasitoids are highly host specific. Release of C. phyllocnistoides + C. quadristriatus each @ 10 adults / cage (32-41 % increase in parasitism) Tamarixia radiata @ 50 adults /cage (43-65% increase in parasitism) and Encarsia spp. @ 60 adults/cage (26-28 % increase in parasitism) recorded more parasitism of leaf miner, psylla and blackfly, respectively, under caged conditions. 200 adults of E. opulenta were collected from Punjab and released in blackfly-infested Nagpur mandarin orchards in central India. But the attempts to establish the parasitoids met with failure perhaphs due to non-synchronization of the life stages of the pest in central India with that of the parasitoids in Punjab. The temperature rose sharply during summer period in central India as compared to that of Punjab area.
Since these parasitoids are highly host specific, efforts are on to multiply under natural conditions by providing their respective host insects under cage house conditions where the citrus seedlings being maintained by staggered pruning.
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Tamarixia radiata attacking psylla nymph |
Citrostichus phyllocnistoides adult |
Cirrospilus quadristriatus adult |
Two sprays with drenching either by Fosetyl-Al (2.5g/L)or Metalaxyl MZ-72(2.75g/1 watercoverning the whole plant canopy and basin of affected plant at 40 days interval after onset of monsoon provided significant control .For the control of gummosis, scraping of the affected parts followed by apllication of Metalaxyl MZ-72 paste.
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Gummosis |
Pasting of Metalaxyl |
Drenching
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Pruning and destruction of infected twigs followed by three to four sprays with copper oxychloride (COC) 0.3% + streptocycline 100 ppm at monthly intervals after the onset of monsoon.
Considering ‘citrus decline’ as the most ominous problem of citrus industry in the form of a syndrome caused by one or more than one factors, multidisciplinary demonstrations using technologies developed at NRCC were undertaken at three locations viz., Kondhali, Chargaon, and Kalmeshwar to instill the confidence of citrus growers in the NRCC technologies meant for rejuvenating the declining citrus orchards.
Besides these efforts, Centre also conducted a “Workshop on Citrus Decline and its Management in North-Eastern Region” at Shillong, Meghalaya during September 4-5,2000, with the purpose to transmit NRCC technologies for rejuvenation of declining citrus orchards in the region.
Rejuvenation Technology (on one ha basis)
i. |
Pruning and burning of deadwood 10 labours for 10 days/ha @ Rs. 50/- day labour |
Rs. 5000/- |
ii. |
Providing drainage channels along the slopes around orchard and channels between rows |
Rs. 1000/- ha |
iii. |
Plant protection |
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- Bordeaux mixture; preventive fungicide (Twice)
June & Oct. Partly. Ridomil MZ- 72 @ OF 10g
- A fungicidal spray Bavistin @ 1 gm/lit of water
Ridomil / Alliete a. Spraying
- Pasting (only the infected trees)
iii. Bark eating catter pillar control 100 ml Nuvan + disposable syringe |
Rs. 3940/- per hectare
Rs. 4133/- ha
Rs. 200/- per hectare |
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Pesticides 2 sprays / season (total 3 spray)
(against insect pests) |
Rs. 3831/- ha |
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Fertilizers |
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i. FYM@ 25 kg/plant |
Rs. 1500/- per hectare |
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ii. Chemical fertilizers (NPK) |
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- Urea (N) @ 1350 g / plant costs Rs. 1832/- per ha
- SSP(P) @ 1250 g / plant costs Rs. 626/- per hectare
- MOP (K) @ 500 g / plant costs Rs. 626/- per hectare
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Rs. 3556/- per ha |
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iii. Micronutrient sprays
- ZnSo4 0.5% - 35 g/1/ plant costs Rs. 850/- per ha
- FeSO4 0.5% - 35 g/1/ plant costs Rs. 800/- per hectare
- MnSO4 0.5% - 35 G/1/ plant costs Rs. 800/- per hectare
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Rs. 2450/- per hectare |
iv. |
Labour charges for spraying |
Rs. 2000/- per hectare |
v. |
Labour charges for fertilizer application |
Rs. 2500/- per hectare |
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Total |
Rs. 30,160/- per hectare |
Chemical control of post-harvest losses in Nagpur mandarin to minimize the decay has been developed which includes three pre-harvest fungicidal (Carbendazim) spray at 15 days intervals.
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Citrus fruit physiology
1. Respiration rate at 25-300C: 40-45 mg CO2/kg/hr
2. Ethylene production : < 0.1 micro l/kg (25-300C)
3. Water loss (mandarin) : 12-13 mg/g/day under normal ambient conditions (22-240C, 40-45% RH)
Fruit needs infection for decay. Fruit without infection either pre-harvest or post-harvest) will not rot although it would shrivel or wilt and hence become unmarketable.
Storage under ambient conditions:
1. “Nagpur” mandarin :- Fruit retains natural qualities up to 3 weeks at 30 degree Celcius with mechanical wax coating and packing in vented polyethylene liner within 5-6 hrs after harvest without curing.
2. “Mosambi” Orange and “Kagzi” acid lime:-Fruits can be stored up to 30 days in acceptable condition after mechanical wax coating with fungicidal wax and packing in polyethylene liner.
Refrigerated storage:
1. “Nagpur”mandarin : At 6-7 degree Celcius temperature and 90-95% RH for storage up to 45 days. The temperature at 3-4 degree Celcius results in chilling damage.
2. “Kagzi” acid lime : The 8+1 degree Celcius temperature and 90-95% RH are optimum for long term storage up to 90 days. Fruits stored at 6+1 degree Celcius develop chilling injury while at 10+1 degree Celcius ageing of fruit is quite high.
3. “Mosambi” orange : The temperature at 6+1 degree Celcius with 90-95%RH are optimum for storage in vented polyethylene lined corrugated boxes up to 90 days. The shelf-life is up to 1 week.
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Nagpur mandarin fruits having minimum TSS of 10% and TSS/acidity ration of more than 4 days beam identified as optimum standards.
Degreening chamber with 1-ton fruit holding capacity has been designed.
1. Management of stem-end rots
2. Pruning of dead twigs
3. Removing fallen fruits
4. Three pre-harvest sprays of benzimidazoleat 15 day interval before harvest
Benefits:
1. Fruit drop reduced to 9.94% as against 22.26 in control and
2. Post harvest decay reduced > 70 %.
Mechanized packing line :
The mechanized processes of sorting, washing, was coating and size grading have been standardized on 1 ton per hour capacity packing line.
Pre-cooling unit with ½ ton fruit holding capacity has been developed for forced-air cooling.
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The chamber (7.5 ft length x 6 ft width x 7 ft height, inside ) having drip system for continuous watering the sand mixture filled in between two layers of bricks and exhaust fan for air movement has been developed for on field storage of fruits at temp. 13-14 C and RH 95-100% upto 25 days.
Packaging containers
1. Corrugated fiber board cartons (50x30x30 cm size) for “Nagpur” mandarin. These corrugated boxes are suitable for distant transport and have sufficient strength to withstand storage conditions at 90-95% RH.
2. Corrugated boxes (universal RSC type and telescopic type) from cotton plant stalks (CPS) Kraft paper have been developed.
Comparison of the number of corrugated boxes and wooden boxes transported in trucks in India
Pre-packing/Consumer packaging
Net bags and polyethylene bags are used for pre-packing or consumer packaging (These packages are used for direct retail marketing). These are small packages of 1-2 kg or 4 kg each.
Wrapping:-The control of moisture loss is more in wrapping with plastic films as compared to wax coating. The other advantages of wrapping of fruits are
1. Spread of decay is effectively reduced in plastic film wrapping of individual fruit.
2. Allows fruit to be stored at higher temperatures.
3. Seal-packing allows fruit transport at ambient conditions from weeks (Mandarins) to few months (oranges, grapefruit, pummelos)
Packaging with Permeable films (MAP): A sealed package in permeable film creates MAP
1. The individual fruit wrapping and tray-wrapping of “Nagpur” mandarin in “Cryovac” heat- shrinkable films (D-955 “Impact” 15 & 25 micron) and in cling film.
2. Shrink-film wrapping of “Mosambi” sweet orange (Individual and tray-wrap) also provides MAP.
The mature fruits of Nagpur mandarin having orange colour surface and recommended TSS and TSS/ acid ratio both for Ambia and Mrig fruits is selected to make quality value added products.
Juice extraction : The extraction of juice from Mandarin is important steps in processing as it turns bitter due to limonoate into limonoids a bitter compound are located in albedo portion and juice sacs. Which could be minimized in juice extracted from Nagpur mandarin fruit by using screw type of juice extractor where it was found better to obtained the minimal bitter juice.
Juice debitterness & its Optimisation : Glass column having 3.0 cm internal diameter filled with fresh XAD-16 resin to a bed height of 6.5 cm were used. The fraction of 50 ml to debittered juice were drawn for every column after 20 minutes retention time with a definite flow rate (10 ml/min). The drawn juice samples were analyzed for juice chemistry which showed the unalteration of juice quality excepts slight changes in color.
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Mature Fruits |
Fresh Juice |
Glass column (resin & juice) |
Single strength canned juice : Mandarin juice is canned in its original form. The juice contains 85% juice, natural TSS not less than 12%and acidity 0.5% without preservative. The juice is pasteurized at 88-90OC, filled hot in, AI tins cans, homefically sealed, inverted and kept for few minutes and cooled immediately in running water and stored in cool dry places. Natural TSS and 100% juice better retention of Vitamin C and colour was noticed when juice was canned in plain tin cans than that of bottled juice.
Juice concentrate : After screening, deaeration and pasteurization, the juice is evaporated under reduced pressure at 45 0C to 4 folds (4:1), 5 folds (5:1) , 6 fold (6:1) and 8 fold (8:1) i.e. 4-8 times increase in solids as compared with single strength natural juice. It is screened through 24 or 32 mesh screen to avoid gelaton during storage by reducing the pulp content. During evaporation process, recovered essence and essences oil is added back to concentrate is either pasteurized and chemically preserved and stored in glass containers. Sulphur dioxide concentration could be used not less than 350 ppm.
Squash: The syrup prepared from sugar in which citric acid and water is mixed along with juice for preparation of squash. Orange oil and orange red colour is added to improve Flavour and appearance of the product. potassium metabisulphite @ 350 ppm as an preservative is added and squash is then filled in sterilized bottles and closed with crown cork cap. Low methyl pectin or propylene glycol ester of organic acid is added for cloud stability. The filled bottles then are stored in cool and dry place upto 12 months.
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Single Strength canned juice |
Juice Concentrate |
Squash Bottles |
Honey based Nagpur mandarin health juice : The 18% honey based Nagpur mandarin health juice was prepared & stored under ambient and refrigerated condition (40C) for limonoids and its quality evaluation.The bitterness, TSS, acidity, pH, colour, viscosity and carotenoids content under both ambient and refrigerated storage were adjudged to be best upto 120 days without microbial population .
Ready-to-serve-beverage (RTS) : The RTS has minimum 10% juice, not less than 10% TSS and 0.5% acidity as anhydrous citric acid (w/w). Product is bottled prepared from fresh mandarin juice, permitted food colours and flavouring are added.
Juice blending : The blending of Nagpur mandarin juice and Mosambi juice in the 20 : 80 combination was adjudged to be the best over Nagpur mandarin juice alone with regard to Vit. C, viscosity, acidity, colour and bitterness acceptability in sensory property upto 60 days after storage. The other combination of Nagpur mandarin juice with Grapes and Aonla juice in proportion to 30G: 40N: 30A: were recorded to be the better than that of alone upto 120 days under storage at ambient temperature.
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Honey based Nagpur Mandarin juice |
RST |
Juice Blending |
D segment dehydration : The high concentration of 20g of KCO3 with 6 minutes dipping in dipping oil resulted in to better product within 13 days of dehydration without altering bitterness, attractive segments, colour, acidity and carotenoids etc. and increased the segment TSS to 26 % as end product under ambient temperature ranges between 42-440C during 13 days period of dehydration.
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D Segment Dehydration |
Peel essential oil |
Peel oil: The oil can be extracted by separated peel. peel is separated manually since mandarins are easy peelers, the separated peel is distilled in Clevenger apparatus peel to obtained higher yield. The oil content in peel of different citrus spp was found to ranged between 0.5 to 0.7% of which quality is given as under in tabular form:
Physicochemical Characteristics of Peel Essential Oil in Different Citrus Species
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Stage I - Marble size fruits, Stage II - Stage before colour break, Stage III - Colour break, Stage IV - Mature fruits |
Animal feed: The deoiled peel and pomace is shredded and mixed with calcium hydroxide (0.2 to 0.5%) and allowed to react for 30 minutes. The alkalinity of calcium oxide causes demethylation of pectin and helps in release of water. The water is pressed out which concentrated to yield molasses. The dried peel and pomace can be fed to cattle and poultry. Feed prepared from Nagpur mandarin processing waste at NRCC Nagpur contained nearly 8% protein, 20.57% Sugar and 7.8% fibre. Feed mixed in broilers diet @ 10%) by replacing maize with and without pellets reduced cost without affecting broilers' weight.
Centre has entered into a number of collaborative programmes, namely, USAID and NARP, World Bank funded project; Asian Development Bank (ADB) aided project; Ad-hoc schemes of ICAR, National Agricultural Technology Projects (NATP), National Horticulture Board (NHB) and National institutes like NBPGR, New Delhi; IIHR, Bangalore; CIRCOT, Mumbai and DRDO, Jodhpur and SAUs namely, dr. PDKV, Akola; JNKVV, Jabalpur etc.
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