Everything you need to learn about cultivating mangoes organically. Learn about:- 1. Introduction to Mango 2. Climate and Soil Required for Mango Cultivation 3. Propagation and Rootstock 4. Planting Density and Spacing 5. Training, Pruning and Canopy Management 6. Organic Nutrient Management 7. Intercropping 8. Rejuvenation Technique 9. Harvesting 10. Insect Pests and Diseases.
Contents:
- Introduction to Mango
- Climate and Soil Required for Mango Cultivation
- Propagation and Rootstock of Mango
- Planting Density and Spacing of Mango
- Training, Pruning and Canopy Management of Mango
- Organic Nutrient Management of Mango
- Intercropping of Mango
- Rejuvenation Technique of Mango
- Harvesting of Mango
- Insect Pests and Diseases of Mango
1. Introduction to Mango:
Mango (Mangifera indica), the king of fruits, is grown in India since time immemorial. The fruit is cultivated in India in the largest area i.e. 2,500 thousand ha and the production is around 18,002 thousand tons, contributing 44.14% of the total world production (2012-13). The main mango producing states in India are Andhra Pradesh (24.47%), Uttar Pradesh (24.36%), Karnataka (9.97%), Bihar (7.57%), Gujarat (5.57%), Odisha (4.18%), West Bengal (4.08%), Tamil Nadu (3.96%) and Maharashtra (3.51%).
Average productivity of mango is quite low compared to many developed countries. The main reasons for low productivity are seedling plantations, use of low yielding cultivars, low planting density, inadequate application of inputs and improper control of pests and diseases.
2. Climate and Soil Required for Mango Cultivation
Mango is grown in both tropical and subtropical regions. Commercial cultivation of mango can be done in areas up to 600 meters above sea level. However, it cannot stand severe frost especially when the trees are young. High temperatures in combination with low humidity and high wind velocity affect the trees adversely. Rain during flowering is harmful but it is beneficial during fruit setting. Rain at maturity time causes damage to fruits. Mango can be grown with success with rainfall of 750 to 2250 mm per year.
Loamy alluvial, well drained, aerated and deep soils are most suitable which are rich in organic matter. Soils with a pH range of 5.5 to 7.5 are ideal for mango cultivation. Extremely sandy, shallow, rocky, water logged, heavy textured, alkaline and calcareous soils are not suitable for mango cultivation. Even less fertile soils can be modified by appropriate management practices i.e. by growing green manure crops, etc.
3. Propagation and Rootstock of Mango:
Mango is usually propagated by inarching or by approach grafting. However, this method is very cumbersome and time consuming and only limited plant material can be multiplied. Lately, improved propagation practices have been standardized which are quite popular i.e. veneer grafting, epicotyl grafting and soft wood/wedge grafting.
Moreover, modern nursery practices comprising sterilized media, containers i.e. poly bags and advantage of modified atmospheric conditions in a greenhouse like misting etc., enable multiplication of healthy and disease free plant material quickly and all-round the year.
Locally available mango stones are gathered and their 1 year old seedlings are used as rootstocks. For this purpose, stones are sown in June-July in flat beds in open or greenhouse filled with sterilized organic medium.
One to two month old seedlings are used for preparing grafts through epicotyl grafting or planted in polybags filled with sterilized organic medium and later these seedlings are used for preparing grafts through veneer grafting or soft wood/wedge grafting. Thus grafts can be prepared all-round the year in a greenhouse depending upon availability of scion sticks.
4. Planting Density and Spacing of Mango:
For planting, field should be ploughed deeply, harrowed and levelled. Pits of the size 0.5m x 0.5m x 0.5m in loamy and deep soils and 1.0m x 1.0m x 1.0m in shallow, rocky, stony and other problem soils should be dug at appropriate distances suiting to planting density required to be adopted. Solarize the pits with white polythene (150 to 200 gauze) after sprinkling slight water into the pit. Even otherwise pits need to be dug in summer months and are required to be exposed to sun.
Normally, in deep alluvial soils mango is planted at a distance of 10m x 10m or 12m xl2m. However, recent results with regard to pruning and canopy management have shown that higher planting density is possible and beneficial as short statured plants help in better management of pests and diseases and ultimately producing high yields of quality fruits under conventional management systems.
But under organic management systems it is not possible to adopt high density planting as it leads to faster multiplication of pests and diseases. As appropriate air circulation and light penetration within plant canopies is a prerequisite of organic management, it can be achieved by the adoption of canopy management techniques comprising of thinning of branches, topping, hedging etc. even under little less wide spacing’s in most mango varieties.
A plant spacing of 10m x 5 m or 9m x 6m or 7.5m x 5m can be adopted for varieties like Langra, Banganapalli, Neelam etc. Similarly a spacing of 7.5 m x 5 m or 6 m x 5 m for Dashehari and 5m x 5m or 5m x 2.5m for Amrapali also can be adopted. With these plant to plant spacing planting densities of 200 to 800 plants/ha can be accommodated.
Multiple benefits of plant canopy management are as follows:
1. Canopy management allows higher planting density, which ensures higher yields.
2. Helps in better management of orchard practices including pests and diseases, because of short stature of plants.
3. Provides better air circulation and light penetration, thus less multiplication of insect pests and diseases.
4. Allows growing of intercrops in the additional space which help in creating diversity and promotes multiplication of natural enemies of insect pests.
5. Frequent, thinning and pruning helps in faster recycling of nutrients locked in branches and twigs.
Fill the pits with top soil mixed with 30-40 kg well rotten FYM per pit Pseudomonas fluorescens/Trichoderma viride @ 100 g/pit is also mixed with FYM. Take out the plant carefully by cutting the polythene and plant during monsoon period.
5. Training, Pruning and Canopy Management of Mango:
Proper control of vegetative growth is very important; otherwise excessive growth results in overcrowding, shading and lateral growth of canopy. Mango plant requires shaping, immediately after planting and allowing branching at a height between 70 to 80 cm is most appropriate.
A simple cut is made on the main stem of the graft which gives rise to multiple leafy branches from the buds just below the cut. Of these 3-4 horizontal shoots, spaced equally around the stem are allowed to grow. These selected horizontal shoots form the main scaffold limbs of the tree and should be allowed to grow about 40-50 cm long, which is generally reached in second growth flush of leaves.
At this time these shoots are pinched off with fingers or left to mature and then pruned. Then multiple shoots emerge from buds below the cut. These are allowed to grow to 40-50 cm in length and then again pruned. This procedure is continued in second year also. Short branches within tree canopy produce compact strong structure of fruiting shoots after three years. Fruiting should be allowed in initial years as it will minimize the tree size.
After fruiting and harvesting, plants are pruned and headed back to a length of 50 cm which will favour formation of horizontal shoots again. Thus tree canopy management starts early after planting and this process continues.
During life span of the tree, depending upon its growth, spread, congestion in the canopy, thinning of limbs, opening up of the canopy, topping and hedging are practiced as per requirement periodically. These practices will ensure tree size control of mango plants.
Water for irrigation must be of good quality, which means that pH should be in range of 6.5 to 7.5, electrical conductivity and salt content should be in normal range.
Irrigation schedule will vary with the type of soil, climatic conditions prevailing at that time and water requirements of a particular variety. There are several methods of irrigation, but basin method of irrigation is most common. Another method becoming quite popular is drip irrigation. Quantum of water to be applied varies with the method of irrigation. Following tentative schedule is given for irrigating mango orchards.
With this method of irrigation during first year, when plants are very young, they should be watered at 2-3 days interval in the dry season. Trees in the age group of 3-5 years should be irrigated at 4-5 days interval. The irrigation interval could be increased to 10-15 days for 5-8 years old during dry season.
When plants are in full bearing stage, 2- 3 irrigations are given after fruit set. First irrigation should be given just after fruit set, second 20 days later or at marble stage. Frequent irrigations, 2-3 months before flowering are not advisable as it affects flowering.
Drip Irrigation:
Due to water scarcity, drip irrigation has become quite popular. Animal/cow urine/Vermiwash can also be added in drip irrigation system. Schedule for drip irrigation from February to May months during fruit growth is given below in Table 47. The schedule is tentative and exact amount of water and frequency will depend upon evapo-transpiration rates of the location i.e. soil type and climatic conditions.
6. Organic Nutrient Management of Mango:
As organic farming systems are based on multi cropping systems, high density plantations and sole mango orchards with little interspaces are not sustainable. Therefore keeping plant-to-plant distance in such a way that adequate space is available for intercrops and cover crops is most essential and is the key to the success.
Thus wide spacing is most appropriate in large mango orchards. Planting of mango on borders or interspersed with other fruit trees or keeping one row of aonla, custard apple or any other climate suitable fruit tree between every two rows of mango or cultivating mango under silvi-pastoral system are typical examples of diversified systems
Although, mango is an evergreen tree and grows well round the year, growth of luxuriant intercrops/cover crops is possible with proper interspaces. One cycle of green manure crop (sunhemp, mung bean, urad bean, cowpea or Sesbania) and cover crops (clover and Trigonella) when incorporated into the soil adds about 50-80 kg nitrogen per ha during early years of planting while in later years it may add only about 30-40 kg of nitrogen.
Keeping the soil covered with green cover from July till February-March and frequent drenching of biomass with Jivamrit can ensure sustained biological activity in the soil. In rainfed areas where irrigation facilities are not available and taking intercrops during winter is difficult, ensure that soil remains covered with biomass mulch for moisture conservation, sustained microbial activity in the soil for adequate nutrient recycling and for effective weed control.
As mango bears fruits only once a year, nutrient requirement is high during flowering and fruit setting and after the harvest, just before the onset of monsoon. Therefore keeping all these situations in mind and keeping the likely nutrient release pattern from recycled biomass from green manures, cover crops and biomass mulch two different nutrient management protocols are proposed, one for rainfed dry areas, and second for irrigated humid areas.
Recommendations of fertilizers under conventional management systems at 1000g N, 500g P2O5 and 1000g K2O per plant for fully grown plants (10 years old and above) are also taken into account for calculating the need for nutrient through organic sources.
As application of organic manures in multiple split doses is difficult, nutrient requirement is met partly through FYM/compost and concentrated manure as soil application and partly through foliar feeding in the form of sprays.
For soil application FYM or compost is generally provided once (under rainfed conditions) or twice (under irrigated conditions) and concentrated manure mixture is provided twice or thrice. Treating FYM/compost with cow urine can further enrich their nutrient status.
Methods for preparation of enriched FYM/compost, concentrated manure mixture and foliar feeding solutions are as follow:
i. Making Cattle Urine Enriched FYM/Compost:
Spread the FYM/compost on the floor on bright sunny day and allow it to dry in sun for 6-8 hrs. In the evening spray 50 lit cattle urine per ton of compost and mix thoroughly. If available 1-2 kg of Cow pat pit per ton of compost may also be mixed with enriched FYM/compost.
ii. Concentrated Manure Mixture:
Mix 66 kg vermicompost/biodynamic compost with 5 kg de-oiled cakes (such as of castor, mahua, karanj etc.), 8 kg neem cake, 5 kg of poultry manure and 15 kg wood ash (In case if ash is not available then add 2.25 kg of sulphate of potash). In areas of phosphorus deficiency 2 kg of rock phosphate or bone meal may also be added to this mixture.
Add 200 gm each of Azotobacter, PSB and KMB bio-fertilizers and 500 gm each of Trichoderma viride and Pseudomonas fluorescens in 5 lit of water and mix with the above manure mixture. Keep the manure mixture covered in a heap for 48 hrs for incubation and use for soil application. Using this mixture within 5-8 days of preparation gives best results.
iii. Foliar Feed Solution:
Feeding plants through leaves is an important strategy in organic farming. Vermiwash (5%), Panchagavya (3%) and farm made protein hydrolysate (4-5 ml/lit of water) are ideal inputs. Any one or combination of two or all can be used depending upon the requirement.
Application Method of Manures as Soil Treatment:
Recommended doses of manures duly mixed and incubated with bio-fertilizers should be applied in the trench 1.0 to 1.5m away from trunk. After application of organic manure, trench should be covered with soil and dry biomass as mulch. Drench the area with 1-2 lit Jivamrit mixed with some water.
7. Intercropping of Mango:
In organic management system mixed cropping has been found to be very useful and profitable. In young mango orchards vacant spaces in between the two rows can be profitably used for growing intercrops. Most preferred crops are light vegetables, leguminous and green manure crops. For first 4-5 years kharif pulses such as green gram, black gram etc. in summer followed by vegetables like pea, tomato etc. in winter can be adopted.
Alternatively, green manure crops (sunhemp, cluster bean) can be taken in summer, which are ploughed in the soil and are followed by tomato, brinjal etc. in winter. Another sequence consisting of cucurbits in summer and pea, methi and Bengal gram in winter can also be adopted.
Apart from above crops, cover crops like clover or methi (Trigonella) can also be grown which not only fix nitrogen but also control the weeds. Nutritional and pest management requirements of intercrops need to be taken care properly to make mixed cropping a success.
Productivity of mango in some states is quite low because of poor cultivation practices, wide spacing and high proportion of old and unproductive orchards. Thus productivity of mango needs to be enhanced in order to be competitive and for better returns to the farmers. Mango trees after attaining 30-40 years of age or sometimes even at early age start declining and become non-remunerative.
Penetration of sunlight in such orchards is poor and thus trees attain upright growth. Trees are characterized by intermingling and overcrowding branches and pest and disease infested branches and are unsuitable to produce required yields. Therefore, for getting economical yields, these orchards should be rejuvenated.
8. Rejuvenation Technique of Mango:
The technique standardized by ICAR- CISH, Lucknow requires pruning of undesirable branches for inducing development of open canopy of healthy shoots, which ensures better light penetration and results in improved flowering and fruiting.
The steps involved are:
1. Remove completely from base the undesirable, criss crossed, overcrowded, dried and diseased branches in November- December months.
2. Pruning/heading back of main branches (3-4 numbers) which are to be retained at a height of 4 meters from ground in the month of November- December and are allowed to produce shoots and develop well distributed canopy.
3. Pruning must be done by saw and needs to be started from lower side of the branch to avoid cracking and bark splitting.
4. Apply Bordeaux paste to cut surfaces. Alternatively apply fresh cow dung + Pseudomonas @ 20 gm/kg of cow dung.
5. Judicious management of nutrition, irrigation, thinning of shoots and plant protection measures will lead to healthy vegetative growth.
6. The pruned trees develop umbrella like open canopy of healthy shoots with good bearing potential.
7. Rejuvenation technique gives old and senile trees new life of 25-30 years and makes such sick trees productive and economical.
Mango trees have the tendency to bear a heavy crop in one year (On year) and very little or no crop in the succeeding year (Off year). Some of the varieties like Dashehari and Langra are irregular or biennial bearers, while south Indian varieties like Bangalora (Totapuri) and Neelum are regular bearers. Amrapali is also a regular bearing variety.
For controlling or overcoming this tendency, de-blossoming and thinning, the fruit load on the tree is done in the “On” year, so that it is balanced in the “Off” year. Also soil application of 10 kg vermicompost twice in a year followed by 5% Vermiwash spray two times to break the alternative bearing cycle is suggested.
9. Harvesting of Mango:
Proper harvesting is very important as fruit must be harvested at appropriate maturity and method of harvesting should be such that it does not injure the fruit and that it must be transported safely to pack houses.
Different aspects of post- harvest handling are described in detail as below:
Harvesting Stage:
Maximum fruit quality is attained when fruits are harvested at optimum stage of maturity.
Fruits should be harvested at mature green stage when these have attained physiological maturity which can be judged by:
1. Fully developed cheeks with outgrown shoulders and formation of a depression at stem attachment point.
2. Change in skin colour from dark green to light green.
3. Visibility of lenticels.
4. Change in flesh colour from greenish white to light yellow.
5. Specific gravity is more than one.
Thus fruits, which have reached physiological maturity having outgrown shoulders, with a depression at the stalk end and are firm and green will ripen to excellent quality if harvested.
Time of Harvesting:
Mango fruits need to be harvested during early morning hours or evening hours but not during noon hours when the temperatures are high and it is difficult to remove the field heat. Do not harvest during rainy season and allow gap of 4- 5 days for harvesting after rain.
Method of Harvesting:
Fruits of mango must be harvested in a way that fruits are not damaged.
Therefore, fruits must not be harvested by:
i. Shaking the branches
ii. Pulling and twisting actions
iii. Beating by sticks
These methods harm the plants and the fruits are bruised. Moreover fruits must not fall on the ground. To avoid this damage, various Institutes have designed mango harvesters, which can be used. Moreover, fruits must be harvested with long pedicel (stem-end) and collected in a flat ventilated plastic crates. There should be no over filling in the crates.
Post-Harvest Handling and Management:
Post-harvest management of mango covers a series of steps like harvesting, transportation, desapping, sorting, cleaning, hot water treatment, grading and packing. It is very important that fruit is carefully handled during all the above- mentioned stages, so that the fruits are not bruised or injured which make them more vulnerable to attack of microbes and decay.
After this, either the fruit can be handled at farm itself in case of small farmers who have not joined other farmers or to take their produce for post- harvest handling treatments in a pack house with all the required facilities.
Pre-Harvest Fruit Drop:
This fruit drop is of physiological nature. Since the fruits are almost fully developed at pre-harvest stage, the fruit drop at this stage results in heavy losses to the farmers. To minimize these losses, foliar spray of Vermiwash (5%), or Panchagavya (3%) or cow urine (5%) needs to be given at an interval of 15 days starting from two months before harvest.
Post-Harvest Management at Farm:
Desapping of Fruits:
First step after harvest is to desap the fruits at farm itself. This can be done by keeping the fruits upside down in shade for 2-3 hours or so. Before keeping the fruits on desapping bench or specially prepared desapper, the stem end of the fruits need to be cut to 1 cm if not already done by a clipper. Desapping is done to avoid blemish on the fruit by oozing sap.
Sorting:
Mangoes are sorted out to remove immature, undersized, damaged, bruised and scarred fruits.
Washing or Wiping the Fruit with Wet Cloth:
Fruits having sooty mould or other stains need to be washed (if facilities are available at the farm) with water having mild detergent solution and then dried with dry muslin cloth. If fruits are already clean, then these can be wiped with wet cloth.
Grading and Packing:
After this, fruits are graded according to size to impart quality to the fruit and better appeal. Fruits then can be packed in a 4 kg cardboard fiber boxes. Cardboard fiber boxes are preferred over wooden boxes where damage to the fruits is minimum.
Post-Harvest Management in a Pack House:
This system of post-harvest management is applicable to farmers who individually or as a member of a group of farmers can take advantage of facilities of a pack house. A series of steps mentioned below serially are taken for the post-harvest handling of fruits. Following steps in post-harvest management of mango are required to be taken.
Transportation to Pack House:
Freshly harvested fruits are transported in plastic crates very carefully to a pack house. Utmost care is taken while loading, transporting and unloading the crates, so that no damage takes place to the fruits.
Desapping:
After receipt of the fruit in the pack house, the fruits are desapped. Stem end of the fruits is trimmed to retain only 1 cm at the attachment point and the fruits are kept upside down on desapping racks in the pack house. This is to avoid stains on the fruits due to spilling of sap oozing out of cut stem end. Desapping must be done under shade or in a hall for a period of 2-3 hours.
Sorting:
Mangoes after desapping need to be sorted out to eliminate immature, undersized, blemished, bruised, diseased and insect damaged fruits.
Cleaning and Washing:
Fruits are to be washed properly to remove any stains, spray residues, sooty mould etc. To eliminate all these, clean water solution having mild bleaching solution (75 to 100 ppm chlorine) with liquid soap @ 1ml/litre of water is used. After washing, the fruits are rinsed with clean water and then individual fruits are wiped with dry muslin cloth or surface moisture is eliminated through a mechanical device.
Hot Water Treatment:
In cases where mangoes are destined for distant shipping or long term storage and thus likely to be affected by anthracnose and stem end rot diseases, mango fruits are required to be treated with hot water at constant temperature of 52°C (maintained by thermostat control) for ten minutes.
Grading and Packing:
Grading can be done by weight of the fruits or by counts. Following counts can be followed for a 4 kg box.
Usually mango is packed in wooden boxes, which is not appropriate, as quite high losses occur when wooden boxes are used, mainly due to impact, compression, vibration etc. However, CFB boxes have been found more useful. Usually telescopic type CFB boxes of 4.0 kg capacity are preferred. Such boxes have been found safe, attractive and satisfactory for handling and transportation of the produce.
It is suggested that only sound and uniform fruits should be packed. Individual fruits may be wrapped to avoid bruising. Box must be lined with newspaper or with paper cuttings. In addition to above, provide required ventilation in the pack. There should be no under-filling or over-filling of fruits.
Pre-Cooling:
If mangoes are to be shipped to long distances or exported then pre-cooling is essential. Pre-cooling is usually done through forced air cooling at a temperature of 10-13°C and relative humidity of 90-95%. The process will take 4-6 hours.
Storage:
Optimum temperature for storing fruits is 13°C with RH 85-90%. The fruits can be stored for 3-4 weeks depending upon the variety.
10. Organic Management of Insect Pests and Diseases in Organic Mango:
Pest management in organic mango orchards is done through combination of approaches involving diversity, habitat management, adequate manuring, keeping appropriate planting distances allowing adequate aeration and sun shine as long term measure and adopting cultural, mechanical and biological strategies as medium term strategies. Botanical and organically acceptable chemicals are used only as short term immediate strategies as last resort.
First and foremost strategy for organic pest management in mango is creation and maintenance of diversity, which includes permanent diversity plantation on boundary and internal bunds, and seasonal diversity through cover crops, intercrops, flowering plants and trap crops.
Permanent diversity plantation includes, plantation of 2-3 varieties of mango between main variety, nitrogen fixing plants like Gliricidia, Leucaena leucocephala etc. or some other fruit plants like custard apple or ber etc. on borders and pesticidal value plants such Adathoda, Ipomea, Calotropis etc. randomly in between border plantation. Seasonal diversity includes intercrops and cover crops. Some flowering trap crops such as marigold and Hibiscus can also be planted along the borders.
Second strategy involves manipulation of cultural practices to ensure a balance in natural processes, which in turn keep the pests below the economical threshold limit.
Important cultural and ecological practices are:
i. Planting of disease free and resistant cultivars.
ii. Proper spacing, mulching and green manuring and adequate use of organic manures and proper irrigation. Do not follow high density planting.
iii. Frequent growing of legume cover crops and their mowing with soil.
iv. Keeping soil covered with living vegetation and or crop residue.
v. Adequate use of organic manures followed by biomass mulching and drenching with fermented dung-urine slurry (such as Jivamrit).
vi. Frequent application of bio-fertilizers especially the mycorrhiza and PGPRs.
vii. Frequent drenching of tree basins (at least once a year) with Trichoderma viride, T. harzianum, Pseudomonas fluorescens.
viii. Lime brushing of tree trunks helps in control of some soil borne pests.
ix. Smoking in low intensity during flowering time in the evening reduces the number of pests including hoppers.
x. Prophylactic spray of Pseudomonas fluorescens @ 10gm/lit on trees before flowering and at the time of flushing will be beneficial.
xi. Ensuring natural habitat and survival conditions for natural pest enemies such as pest predators, parasites and pathogens.
xii. Do not uproot weed plants those are growing naturally and act as nectar source for natural enemies.
xiii. Due to enhancement of biodiversity by the flowering plants, numbers of parasitoids and predators (natural enemies) also will increase due to availability of nectar, pollen and insects etc. The major predators are a wide variety of spiders, ladybird beetles, long horned grasshoppers, Chrysoperla, earwigs, etc.
xiv. Collect egg cards of beneficial insects for release such as Trichogramma, Chrysoperla, Telenomus etc. which are available from state Bio-control Labs.
xv. Install 4-5 pheromone traps for monitoring and 10-12 traps for mass trapping of moths.
xvi. Set up 10-15 yellow pan water trap/sticky traps 15 cm above the canopy for monitoring of pests.
xvii. Set up light traps 1 -2 trap/acre 15 cm above the crop canopy for monitoring and mass trapping insects. Light traps with exit option for natural enemies of smaller size should be installed and operate around the dusk time (6 pm to 10 pm).
xviii. Grow flowering plants along the orchard border by arranging small plants towards the crop and taller plants towards border. Important insectary plants that can be used as intercrops also include mustard, sunflower, alfalfa, marigold, carrot, coriander, french bean, cowpea, maize, spearmint, peppermint, Ocimum etc. After flowering these plants can be used as green manure/mulch.
Keep on enumerating pest- defender ratio. If pest defender ratio is 2:1 then no need to worry. If it increases above 2:1 then adopt necessary curative and control protocols.