Coconut Cultivation practices
1. Nursery management techniques comprising selection of garden, mother palm and seed nuts, planting and maintaining the nursery and the technique for raising polybag nursery were standardized.
2. Square system of planting at a spacing of 7.5 x 7.5 m with a plant density of 175 palms/ ha is recommended for monocrop and coconut based cropping system.
Nutrient management
3. Recommended dose of fertilizer for coconut palm is application of Organic Manure @50kg/palm or 30 kg green manure, 500 g N, 320 g P2O5 and 1200 g K2O/palm/year in two split doses during September and May. Application of magnesium @500 g MgO per palm was found to be advantageous in areas where palms show yellowing of leaves (Coconut root (wilt) affected gardens) through soil application. However, soil test based nutrient application is recommended for efficient utilization of resources. In acid soils, for soil test values of more than 20 ppm, P application can be skipped.
4. Fertilizer saving through drip fertigation i.e., 50% of the recommended dose of fertilizer when applied through drip fertigation is sufficient to give a yield equivalent to 100 % of the recommended dose of fertilizer. Fertilizers viz., 70 g Urea, 60 g DAP and 170 g Muriate of Potash is recommended for single application for one palm. A total of 7 applications is needed to apply recommended dose of fertilizer per palm through fertigation. For phosphorus application, commercial phosphoric acid can also be used.
5. The critical boron level in soil and coconut leaves was standardized through techniques such as Cate and Nelson graphical (CN) method, the Mistcherlich equation (ME), and the quadratic plateau response (QP) method and it was 0.87 mg/kg in soil and 13.27 mg/kg in leaves.
6. Application of 160 g borax per palm in four split doses along with husk burial in the basin and vermicompost application @ 20 kg per palm is recommended for correction of boron deficiency symptoms in coconut.
7. Two nutrient mixtures ‘KalpaPoshak’ and KalpaVardhini’ has been developed based on release pattern studies in the laboratory and evaluated in the field. KalpaPoshak @ 100g per palm per year in two splits can be applied to the juvenile palms for enhanced growth and earliness in bearing. KalpaVardhini@ 500g per palm in two splits can be applied in adult bearing palms.
8. A web based tool for computing soil test based nutrient recommendation was evolved and uploaded in CPCRI website :Go to site
9. Recommendation developed for dwarf palms under integrated management for root (wilt) affected area: 100% soil test based nutrient requirement (STBNR- 530: 150: 1200 g N:P2O5:K2O/palm/year) along with raising and incorporation of cowpea in coconut basin, application of vermicompost and neem cake (@15 kg and 5kg/palm/ year, respectively).This is ideal for dwarf palms meant for tender nut production.
10. A Longterm fertilizer cum manurial experiment of 43 years of coconut cultivation revealed that soil exchangeable, lattice and total potassium status was higher with the regular fertilizer application compared to no manurial treatments. Moreover, reduction in lattice potassium status in no manurial treatments and slight reduction in non exchangeable potassium in fertilized plots also reveals that it is imperative to apply potassium according to the removal in order to reduce potassium mining and to sustain soil fertility and productivity in a long run.
11. The technique for utilization of leguminous cover crops such as Puerariaphaseoloides, Mimosa invisa and Calopogonium species as green manures to supply biologically fixed nitrogen and easily decomposable biomass to coconut, to substitute 50 % nitrogen fertilizer, was standardized.
12. Growing Glyricidia as green manure crop and using the biomass as green manure was found to be ideal for management of littoral sandy soils.
13. Harvesting tender nuts at 25-day intervals throughout the year is identified as an improved production technology, resulting in significantly higher yield, nut weight, and net returns compared to harvesting mature nuts at 35–40-day intervals..
14. Fifty-three-year-old tall coconut varieties recorded the highest above-ground carbon sequestration potential (20.3 t/ha), followed by D × T (13.64 t/ha) and T × D (13.48 t/ha) hybrids, whereas dwarf varieties exhibited comparatively lower potential (8.4 t/ha).Gypsum@2kg/palm could ameliorate sub soil acidity and aluminium toxicity in laterite soils of coconut growing tracts. Magnesium sulphate application @ 1 kg/palm could effectively ameliorate aluminium toxicity and sub soil acidity in sandy soils.
15. Site specific management of soil constraints for enhancing the economic viability of coconut cultivation: Application of lime, dolomite, gypsum, and major, secondary, and micronutrients significantly improved soil properties in both AEU-3 (Onattukara Sandy Plain) and AEU-9 (South Central Laterite Soil). Application of magnesium sulphate at 1 kg per palm reduced exchangeable acidity caused by subsoil exchangeable aluminum in sandy soils.
Water management
16. Application of 200 litres of water once in four days was recommended for irrigating coconut palms by basin irrigation method.
17. Drip irrigation @ 66 % of the open pan evaporation (27 to 32 litres of water per palm per day under Kasaragod conditions) from December to May is ideally suited for coconut resulting in 34 per cent saving of water.
18. Sprinkler irrigation or perfo irrigation with 20 mm (IW / CPE = 1) water was found to be the best suited to inter or mixed cropping systems where the entire surface requires wetting.
19. Moisture conservation methods such as mulching with coconut husk, coir dust, coconut leaves, etc. in addition to application of organic manures or green manures, intercrop cultivation, bunding, terracing, etc. are recommended.
20. In sloppy terrains, trench filled with coconut husk, half moon bund, staggered catch pit reinforced with pineapple and growing CO3 grass across the slope, were proved successful in soil and water conservation.
21. Surface runoff water harvesting and Roof water harvesting were successfully implemented and harvested water was utilised for irrigation.
Cropping and farming systems
1. Coconut based cropping systems involving cultivation of compatible crops like tubers, flowers, medicinal and aromatic crops, fruits, vegetables, spice crops, in the interspaces of coconut is economically superior to coconut monocropping.
2. Coconut-based high-density multispecies cropping systems (HDMSCS) involving many crops like banana, pineapple, clove, and pepper was established.
3. Application of 2/3rd of recommended NPK along with recycling available biomass in the farm of vermicompost resulted in sustainable yield in the system. The system provided a net income of Rs.3,50,000/- per ha/annum.
4. Mixed farming system including coconut, dairy, poultry, rabbitry, sericulture, goats and pisciculture has been successfully demonstrated under Kasaragod condition. System provided organic manures for recycling, additional man power and additional income to a coconut farmer.
5. Mixed cropping with CO3, CO4,CO5 hybrid Napier fodder grass and multi cut fodder sorghum fodder provided sufficient green grass to feed 5 to 7 cows from one ha coconut garden.
6. Banana variety, Grand Naine, Elephant foot yarm (gajendra), pineapple, vegetables were found suitable intercrop for coconut gardens in littoral sandy soil with coir pith and husk as amendments.
7. In root (wilt)-affected areas, Hybrid Bajra Napier variety CO-3 can be successfully cultivated as an intercrop in coconut gardens (utilizing 60% of the area) under an integrated nutrient management system. The recommended practice includes a basal application of 90:30:24 NPK through fertilizers, followed by the recycling of organic inputs such as cow dung slurry (3750 L ha⁻¹) and vermicompost (2000 kg ha⁻¹) after each harvest, applied in two equal splits at fortnightly intervals (six times a year). In addition, liming at 400 kg ha⁻¹ yr⁻¹ and Azospirillum at 3.5 kg ha⁻¹ yr⁻¹ are advised to maintain soil health and productivity in a cost-effective manner.
8. Heliconiastricta ‘Iris’, H.bihai x H.caribaea ‘Kawauchi’, Heliconiastricta Sunrise and H. orthotropica ‘She’, are found to be suitable as intercrop in coconut plantations. A combination of varieties viz., ‘She’ and ‘Sunrise’ can be planted in 1:1 ratio for year round production of inflorescences. The coconut palms (Disease Early and Middle) 11-17 % increase in yield in three years time, wasmainly due to complimentary use of resources by both crops and improved microclimate.
9. Heliconiastricta ‘Iris’ can be recommended as an intercrop during early stage in coconut plantations where the light intensity is low (30 to 35%) for improving the livelihood of farmers.
10. Alpinia ‘Jungle King’ is suitable for intercropping in coconut gardens. It produces flower throughout the year except during April-May. The inflorescences produced in these plants were of marketable standards with more than 1 meter in length and spike circumference of 20cm.
11. Tagetus-Gomphrena sequential cropping (30% area) under coconut based farming system in coastal humid tropics fetches year-round income from the system with a BCR 2.6
12. Papaya (Carica papaya L.) is an ideal intercrop occupying 40% area, which can generate sufficient income to the farmer from very early stage of cultivation. At an average return of Rs.12/kg, the gross income from the system comes to Rs.3,60,000/- . The net return was about Rs. 2,34,000/- per hectare basis.
13. Different medicinal crops like Aloe vera, Asparagus, Swertia, Aswagandha, Mentha were planted as intercrop in coconut plantation to find out the total system productivity. It was found that cultivation of medicinal crops under these systems helped to increase the system productivity. Maximum system productivity (8.62 t copra/ha) was recorded in coconut and Asparagus system followed by coconut + Aloe vera and Coconut Rawalfia over coconut as monocrop 2.8 t copra/ha).
14. Gladiolus, China aster, Gomphrena, and marigold can be successfully cultivated as intercrops in coconut gardens using different soil moisture conservation materials such as coconut husk, coir pith, and shredded coconut leaves. Among these, shredded coconut leaves proved to be the most effective, resulting in significantly higher growth of flower crops due to superior moisture retention (6.7%) compared to the control (3.51%). (Fig.1)
Fig. 1 Growing of flower crops as intercrop in coconut under coastal sandy soil
15. Intercropping cinnamon with coconut using a pentagonal planting design (0.6 m × 1.2 m spacing) produced net returns of ₹3,56,792 per hectare with a B:C ratio of 1.93, highlighting its potential for efficient space utilization and high profitability (Fig.2)
Fig.2 High densityPentagonal planting of cinnamon as intercrop in coconut
16. Leguminous and grass fodder combinations for enhancing soil health and system productivity in coconut gardens of the humid tropics
Fodder crops are an essential component of coconut-based mixed farming systems. However, continuous cultivation of fodder in coconut gardens can gradually deplete soil fertility, particularly base nutrients such as potassium, calcium, and magnesium, which are in high demand by both coconut and fodder grasses. In nutrient-depleted sandy soils, this can reduce the productivity of both crops. Incorporating leguminous fodder crops, such as cowpea (var.) and Stylosanthes hamata, along with grass fodder (var. Suguna), is an effective management strategy to maintain soil fertility. This practice enhances soil health by improving organic carbon and the availability of K, Ca, and Mg. The complementary nutrient uptake patterns of grass and leguminous fodders help prevent nutrient depletion, thereby sustaining soil fertility and overall system productivity.
17. Bioresources management
1. The technology for vermicomposting of coconut palm wastes by using a local earthworm, Eudrilus sp., closely related to the African night crawler, was standardized.
2. Multiplication technique for the local Eudrilus sp. of earthworm using 1:1 cow dung-decayed leaves mixture was standardized and the earthworms are being distributed to the farmers to initiate vermicomposting.
3. Production of vermiwash from coconut leaf vermicompost has been standardized and its beneficial impact on crop growth is being assessed.
4. Utilization of coconut wastes for oyster mushroom cultivation (P. florida, P. sajorcaju, P. flabellatus, P. opuntia and P. eous) was found to be economically feasible.
5. Beijerinckiaindica, Azospirillum spp., Burkholderia sp., Azoarcus sp., etc. were effective bioinoculants for better establishment of nursery seedlings.
6. Four coconut PGPRS - P. putida KnSF 208, B. coagulans RSB 14, B. megaterium TSB 16 and B. megaterium TEB 2 and four cocoa PGPRs - P. putida KDSF 23, B. licheniformis KGEB 16, B. cereus ASB 3 and B. subtilis VEB 4 gave the highest increase in plant growth parameters. All the eight isolates have been identified using biochemical, BIOLOG and molecular based procedures.
7. Developed organic farming practices for coconut to achieve coconut yield of over 100 nuts per palm per year with recycling of farm wastes, application of nitrogen fixing legumes and biofertilizers.
8. A farmer-friendly methodology for mass-multiplication of bioinoculants was developed. The medium comprises of mature coconut water+rice gruel and minute quantities of coconut waste biochar. Using a pressure-cooker, the bioinoculant can be mass-multiplied using above liquid medium for immediate use by the farmers.
9. The efficiency of vermicomposting of coconut leaves can be enhanced by employing a bio-shredder for pulverizing coconut fronds including their hard petioles. Using this method, vermicomposting of pulverized substrate can be successfully completed in one cycle (90 days) with 80-85% conversion efficiency as compared to the conventional method of chopped leaves in basins as well as in large tanks.
10. A ‘push-pull’ strategy based simple and economical method for harvesting of earthworms from coconut leaf vermicomposting tanks has been developed. The method minimizes labour requirement and involves pushing of the earthworms by mustard solution and attracting them using cow dung mixed with other agro-wastes
11. A coconut leaf vermicompost + coir-pith compost +PGPR based soilless medium was successfully formulated for raising healthy seedlings of cocoa and arecanut. This technology will help sustainable nursery management for agri-horti agencies.
12. A next-generation sequencing based metagenomic analysis of the different stages of the unique coconut leaf vermicomposting process and the earthworm gut microbiota was analyzed. The complete bacterial diversity and its functional attributes were deciphered.
13. Adopting organic farming practices—including FYM at 12.5 t ha⁻¹, in situ green manuring (producing 15–20 t ha⁻¹ of green matter), crop residue incorporation (generating 3 t ha⁻¹ of dry biomass), and application of biofertilizers such as Azospirillum, phosphobacteria, and K solubilizer at 3 kg ha⁻¹ each—can increase cassava yield by 76%
Fig. 3 Organic management of cassava in coconut garden , compared to conventional farming methods
14. Adoption of organic farming practices for yams (Dioscorea spp.)—including FYM at 15 t/ha, green manure, neem cake at 1 t/ha, and ash at 1.5 t/ha—achieved 98.6% of the yield obtained under conventional farming methods. (Fig 4).
Fig. 4 Organic cultivation of yams as intercrop in coconut garden
Arecanut
Cultivation practices
• Nursery management techniques comprising selection of garden, mother palm and seed nuts, planting and maintaining the nursery, and the technique for raising polybag nursery were standardized.
• A spacing of 2.7 X 2.7 m is found to be optimum for the growth of arecanut crop.
• For planting in laterite soils, a pit size of 90 cm x 90 cm x 90 cm is recommended, while in red soils, a 75 cm x 75 cm x 75 cm pit size is ideal. For heavy soils or soils with high water tables, a pit size of 60 cm x 60 cm x 60 cm or 45 cm (depth) is suggested.
Nutrient management
• Recommended fertilizer dose for arecanut is 100g N, 40g P₂O₅ and 140g K₂O / palm / year, in addition to 12 kg each of FYM/compost and green leaf. However, soil test based nutrient application is recommended for efficient utilization of resources.
• With respect to optimization of fertigation dose and frequency, 50% and 75% of the standardized fertilizer dose is sufficient for pre-bearing and bearing arecanut palms, respectively through drip fertigation.
• Fertigation of 75% NPK at 10 days interval was highly profitable with highest net returns per rupee investment of 4.57 followed 75% NPK through fertigation at 20 days interval (4.44).
• Total uptake of macronutrients by arecanut was in the order of N > K > Ca > P > Mg. The order of total uptake of micronutrients was Fe >Mn> Cu > B > Zn.
• Optimum foliar concentrations for N, P, K, Ca and Mg were established as 2.70, 0.23, 1.12, 0.61 and 0.20%, respectively. Optimum micronutrient concentrations (mg kg-1) were estimated at 146 for Fe, 56.5 for Mn, 2.6 for Cu, 45.8 for Zn, 39.5 for B, 432 for Al and 63 for Na.
• Optimum soil nutrient limits were higher for laterite soils in arecanut tract than generalized guidelines for interpretation of soil analysis data. At 0-30cm soil depth, optimum nutrient concentration for P, K, Ca, Mg, Fe, Mn, Cu, Zn and B was established as 15, 192, 925, 179, 37, 88, 26, 5.5 and 1.4 mg kg-1, respectively.
• Nutritional disorders like crown choking, crown bending and oblique nodes in arecanut are due to deficiency of zinc. The zinc deficiency in arecanut may be the result of complex interactions between DTPA extractable Zn and other nutrients in soil.
• Deficiency symptoms for boron were reproduced in arecanut seedlings. Reduced leaf size, fused leaf tips and thicker leaf sheath were found to be the boron deficiency symptoms in arecanut.
• In 12 year old arecanut (cv. Sreemangala), total biomass production was significantly greater in high yielders (43.6 kg palm-1) than in low yielders (30.8 kg palm-1). Trunk biomass accounted for 69% of the total biomass in high yielders and 74% in low yielders indicating less partitioning to other parts.The biomass partitioning towards yield was 9.5 - 9.8 % in arecanut and cocoa.
• Developed nano-potassium intercalated composted coir pith fertilizer, a novel approach of using the composted coir pith as a carrier material for nano-fertilizer as it not only contains higher K than NZK but also releases K slowly for a longer period, making it an excellent carrier of nano-zeolite based K fertilizer.
• Soil test based nutrient management and plastic mulching during monsoon in YLD affected arecanut gardens was found to delay the symptom expression and increase the yield, especially when the initial disease index low. It also improved the soil physical properties and available P, K, Ca, Mg, and B in the soil, implying the significance of plastic mulching during monsoon in YLD-affected arecanut gardens.
Water management
• Irrigation with 200 litres of water per palm once in 6 days through hose is recommended.
• Drip irrigation @ 20 liters of water per palm per day results in 45% yield increase and 44% saving in water in arecanut.
Cropping and farming systems
• Sowing cover crops like Mimosa invisa (15 kg per ha), Stylosanthesgracilis (9 kg per ha), Calapogoniummuconoides (11 kg per ha), and Puerariajavanica (11 kg per ha) during May-June and its incorporation into soil during Octoberwill improve the soil fertility. Similarly, green manure crops like diancha and mucuna can also be grown in the arecanut plantations.
• Crops like banana, ginger, turmeric, elephant foot yam, lime, pineapple, ivy gourd, arrow root, tapioca, colocasia, dioscorea, French bean and chilliare found suitable for intercropping in young arecanut garden.
• In Assam condition, gladiolus, chrysanthemum and marigold; cauliflower, cabbage, radish, carrot, French bean, and spinach during winter; amaranthus, ridge guard, okra and chilli during summer can be intercropped with arecanut.
• Pineapple, turmeric, tomato, brinjal, chilli, capsicum, dolichus bean, French bean, pumpkin, ash gourd, bottle gourd, snake gourd, spinach, cabbage, knolkhol, radish, turnip, carrot,gladiolus, aster, helichrysum, calendula, anthurium, marigold, sunflower, and Salvia can be grown as intercrops in Sub-Himalayan tracts of India.
• Black pepper, cocoa, banana, coffee, lime, vanilla, nutmeg, and betel vine can be profitability grown in yielding arecanut plantations.
• Intercropping of medicinal and aromatic plants (MAPs) in arecanut increased the productivity per unit area by 272 to 1524 kg ha-1. This amounted to the total system productivity of arecanut + MAPs intercropping system to the tune of 2990 to 4144 kg ha-1 while the average sole arecanut yield was 2795 kg ha-1.
• The net return per rupee investment was highest in Cymbopogonflexuosus (4.25) followed by Bacopamonnieri (3.64), Ocimumbasilicum (3.46) and Artemisia pallens (3.12).
• On the basis of yield, quality and economic feasibility, recycling of gliricidiaprunings from standards and vermicompost application alone or in combination with husk mulching are better options for intercropped vanilla in arecanut.
• Growing of vanilla on gliricidia standards did not affect the arecanut yield and the average kernel yield of arecanut during the experimental period was 3114 kg ha-1.
• Different medicinal crops like Aloe vera, Asparagus, Swertia, Aswagandha, Mentha were planted as intercrop in arecanut and coconut plantation to find out the total system productivity. It was found that cultivation of medicinal crops under these systems helped to increase the system productivity. More system productivity was recorded in all combination. Maximum system productivity 8.77 t/ha chali was recorded in arecanut and Asparagas combination followed by arecanut and Aloe vera (7.22 t chali/ha) and arecanut and Rawalfia combination (6.22 t chali/ha) over arecanut as monocrop (3.82 t chali/ha).
• Different arecanut based cropping system models were tested to find out the total system productivity of the systems. It was found that Arecanut+ Black pepper+ Acid lime + turmeric had maximum total system productivity (10361 kg/ha) followed by Arecanut + Black pepper+ Acid lime + Banana with a total system productivity of 9355 kg/ha.
• Arecanut+ black pepper + cocoa + banana is an ideal multispecies cropping system in traditional arecanut growing regions of Karnataka and Kerala.
• Among the different inter/mixed crops it was found that black pepper contributed maximum (55-60%) on total system productivity where the main crop arecanut contributed only 29-36 % on total system productivity. Cultivation of inter/mixed crops in arecanut system is highly profitable as there was 224-334% increase of total system.
• An arecanut based mixed farming system (ABMFS) model comprising arecanut (0.7 ha), fodder grass (0.2 ha), dairy, and fishery units (0.1 ha) was developed which would be economically sustainable, especially for the small and marginal farmers and becoming nutrient positive, except for K.
• Replacing 10% of cattle feed with arecanut leaf sheath can be followed to reduce the feed cost.
17 Genetic Stock
18. The rhizosphere microbiome of arecanut in Yellow Leaf Disease (YLD) endemic regions has been characterized using 16S V3–V4 metagenome sequencing by ICAR-CPCRI. The data are available under SRA-NCBI BioProject PRJNA721704 with 18 SRA accessions: SRR14252056 to SRR14252061 and SRR14297298 to SRR14297309 (Ref: NCBI SRA PRJNA721704).Innovative Approaches and methodology aiding technology assessment:
Rhizosphere bacterial microbiome signatures of arecanut rhizosphere soils in Yellow Leaf Disease (YLD) endemic area
comprehensive analysis of the arecanut rhizosphere bacterial diversity was conducted using next-generation sequencing (NGS) technology, employing amplicon sequencing of the V3–V4 regions of the 16S rRNA gene on bulk soil and rhizosphere samples collected from Yellow Leaf Disease (YLD) endemic regions of Dakshina Kannada District, Karnataka, India. The study revealed that the dominant bacterial phyla in the arecanut rhizosphere include Proteobacteria, Bacteroidetes, Firmicutes, Acidobacteria, Planctomycetes, Patescibacteria, Chloroflexi, Actinobacteria, Fusobacteria, and Verrucomicrobia
19. The rhizosphere abundance of novel phylum Candidatus Patescibacteria in YLD healthy rhizosphere and their biological significance
For the first time, a higher abundance of the novel phylum Candidatus Patescibacteria has been observed in the rhizosphere of YLD-healthy arecanut palms.The arecanut palm selectively enriches Candidatus Moranbacteria, which ferments carbon compounds to acetate, thereby supporting the growth and metabolism of culturable microflora. Candidatus Kaiserbacteraceae exhibits hydrochemical preferences for ammonia-oxidizing bacteria, aligning with the high relative abundance of Betaproteobacteriales–Nitrosomonadaceae OTUs in the YLD-endemic arecanut rhizosphere. A significant abundance of Parcubacteria indicates their potential for degrading complex carbon substrates. Candidatus Magasanikibacterales shows associations with the iron-oxidizing Gallionella and thiosulfate-oxidizing Sulfuricella, suggesting co-localization with other key autotrophs. Overall, the classes ABY1 and Candidatus Gracilibacteria are highly enriched and co-occur with autotrophic organisms involved in nitrogen, sulfur, and iron cycling, representing predominant chemolithoautotrophs in the arecanut rhizosphere.
20. Rhizosphere bacterial microbiome signature of Yellow Leaf Disease (YLD) intensive rhizosphere and apparently healthy rhizosphere of arecanut in endemic area
A comprehensive analysis of the bacterial microbiome in the arecanut rhizosphere was conducted across YLD-endemic apparently healthy rhizosphere soil (YLD-AHR), disease-intensive rhizosphere soil (YLD-DIR), and non-rhizosphere soil (YLD-NR) using shotgun metagenomics to study microbial community structure and functional potential. The metagenomic data revealed that bacteria were the most dominant group, with Proteobacteria identified as the predominant phylum in the YLD-endemic arecanut rhizosphere. The most abundant bacterial families in these rhizosphere soils included Burkholderiaceae, Bradyrhizobiaceae, Anaeromyxobacteriaceae, Comamonadaceae, Streptomycetaceae, Pseudomonadaceae, Sphingomonadaceae, Zoogloeaceae, Micromonosporaceae, Rhodospirillaceae, Xanthomonadaceae, Gemmatimonadaceae, Nitrobacteraceae, Methylobacteriaceae, Myxococcaceae, Geobacteraceae, Acidobacteriaceae, and Nitrospiraceae.
• A defined starter/mother culture has been developed, consisting of a pure culture of an elite bacterial cellulose-producing bacterium selected from indigenous strains of Komagataeibacter spp., suitable for nata-de-coco, industrial bacterial cellulose, and vinegar production. The K. intermedius strain BC5, which produces high-quality bacterial cellulose pellicles, is technology-ready for the commercial production of nata-de-coco from mature coconut water The nutrient-solubilizing coconut rhizosphere bacterium Pseudomonas migulae strain K3HPSB2 has been identified as effective for biopriming coconut nursery seedlings and for field application, promoting growth and enhancing soil health in root (wilt)-affected areas
Bioresources management
• About 5.0 to 8.5 tons of leaf wastes are available from one hectare of areca garden, every year. This can be effectively recycled into fine, granular, and odorless vermicompost using earthworms (Eudriluseugeniae and Eiseniafoetida) with 80% recovery in within 60 days. Application of vermicompost at 100% N equivalent can meet the N and P demand of arecanut. Potassium must be added through other sources like MOP, wood ash or composted arecanut husk.
• The yield levels of arecanut can be sustained at around 2600 kg ha-1 due to organic waste recycling. However, the response of arecanut to chemical fertilizers was more pronounced as the yield increase was 73-85% with NPK application compared to VC application alone (48-59%) and integrated treatments (46-63%) over control.
• In arecanut based high density cropping systems having component crops like cocoa, pepper, banana and clove, comparatively similar yield levels and soil nutrient status was noticed with organic matter recycling (OMR), and integrated use of chemical fertilizers and OMR. The result emphasizes that the system can be self-sustainable over a long term period. Application of N and P through inorganic fertilizers could be reduced or skipped, while the system proved exhaustive with regard to the availability of K.
• Vermicompost maintained higher SOC, soil test levels of P, Ca, and Mg than chemical fertilizers. Depletion of soil available K and accumulation of micronutrients was noticed in arecanut basins with vermicompost.
• A coconut leaf vermicompost + coir-pith compost +PGPR based soilless medium was successfully formulated for raising healthy seedlings of cocoa and arecanut. This technology will help sustainable nursery management for agri-horti agencies.
Cocoa
• Softwood grafting is the most successful vegetativepropagation technique.
• Canopy architecture by pruning and planned cutting of branches have been standardized for canopy management under intercropping and in sole crop
• Cocoa is planted at a spacing of 2.7m x 5.4m in pits of 60 cm3 filled with compost in areca garden planted at a spacing of 2.7m x 2.7m.
• To adopt coconut + cocoa system, cocoa can be planted at 2.7 m apart in single hedge system and 2.5m apart in paired rows in double hedge system between two rows of coconut palms.
• The crop is to be irrigated once in a week during November-December, once in 6 days during January-March and once in 4-5 days during April-May with about 175 liters of water.
• Systematic study for 10 years on drip irrigation and fertilizer requirement of cocoa mixed cropped in arecanut revealed that drip irrigation at 1.0 Ep (20 liters of water per day per tree) and a fertilizer dose of 100: 40: 140 g of N, P2O5 and K2O per tree per year would be optimum for cocoa.
• The nutrient removal through yield tree-1 varied significantly among cocoa genotypes and it was in the order of K>N>Ca>Mg>P>Mn>Fe>Cu>B>Zn. It was estimated at 19-71 g N, 2.5-9.4 g P, 27-118 g K, 5.5-21.1 g Ca, 4.3-15.6 g Mg, 71-336 mg Fe, 182-1304 mg Mn, 29-152 mg Zn, 68-255 mg Cu, and 37-153 mg B. This indicates that, cocoa removes huge quantity of nutrients, especially potassium.
• The association of leaf mineral nutrient status and yield in cocoa was studied. Among different mineral nutrients, K and B had significantly positive influence and Mn had negative influence on the dry bean yield per tree (Y = -0.5410 + 0.411 K + 0.017 B - 0.0016 Mn; R2 = 0.53). It indicates, optimum K and B levels should be maintained for better cocoa yield.
• Micronutrients in the nibs of 20 cocoa genotypes were studied. Among them, the Upper Amazon genotype, VTLC 151, was found to have multiple special features. It was potassium (K) use efficient, K responsive, partitioned significantly more zinc (45.5% higher than mean value) and boron (141% higher than mean value) towards the nib. The iron concentration in the bean was also high.
• Potassium-use-efficient (VTLC 19A) and -inefficient (VTLC 150) genotypes were identified in cocoa. Released varieties VTLCS-1 and VTLCH-1 were identified as nitrogen use efficient.
• Transcriptome analysis of cocoa seedlings grown in contrasting K levels indicated that, K transporters were up-regulated, and the genes related to nitrate and magnesium were down-regulated in cocoa plants grown in high K. This resulted in lower N and Mg uptake with higher K in the nutrient solution. Transcriptome analysis also revealed a discernible upregulation in genes associated with potassium transport (Potassium transporter-TCM_042171) in potassium-use-efficient genotype, highlighting the genotype's heightened proficiency in managing potassium.
• Geographical variability of heavy metal contentsi.e., cadmium (Cd), chromium (Cr), mercury (Hg), lead (Pb), arsenic (As), nickel (Ni), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn), were studied in cocoa beans collected from across major cocoa-growing regions in India. Results showed regional variations in heavy metal content, and the cocoa beans grown in India have very low heavy metal content, making them safe and compliant with EU food safety standards.
• Grafts of cocoa variety Netra Centura were planted in five planting distances of 1.35 x 1.35 x 2.7 m, 1.35 x 2.7 m, 1.35 x 5.4 m, 2.7 x 2.7 m and 2.7 x 5.4 m with planting density ranging from 650 to 3712 plants ha-1. The result indicated that, high density planting of cocoa can give bolder bean and significantly higher productivity in the initial years.
• The total above ground dry biomass in high yielders was significantly higher (30.9 kg palm-1) than medium (22.2 kg palm-1) and low yielders (10.3 kg palm-1). The wood biomass was higher in medium (73.7%) and low yielders (73.4%) than high yielders (70%).
• Regression models for estimation of aboveground biomass of arecanut and cocoa was developed.
Use of artificial intelligence
• Deficiency symptoms for N, P, K, Ca, Mg, Fe, Mn, B, Zn and Mn were reproduced in cocoa plants by growing them in hydroponic system without the specific nutrient.
• The ConvNext model was utilized for detecting nutritional deficiencies, achieving an accuracy of 96% with a macro average precision, recall, and F1-score of 96%, 95%, and 95%, respectively, showcasing its robust performance.
• Severity levels—categorized as critical, moderate, and low—were predicted using the Random Forest Classifier, which achieved an overall accuracy of 91.61%. Precision values ranged from 0.88 to 0.95, and recall values ranged from 0.82 to 0.97, demonstrating the model's reliability in severity prediction.The results indicated that deep learning models, combined with color imaging, could provide a promising approach to timely monitor the deficiency of nutrients in cocoa, which allows for taking corrective measures and mitigating production losses.
• The standard operating procedures for the aerial spray of nutrients and pesticides in arecanut plantations using UAVwas standardized. The most desirable outcomes—in terms of droplet size, uniformity,canopy penetration, and reduced ground losses—were achieved using high spray volumes(75 L/ha), moderate flight speed (3 m/s), and moderate altitude (2.5m), tailored to cropstructure and target zone requirements. This integrated approach is crucial for maximizing spray efficacy while minimizing environmental impact.
Carbon sequestration potential
• Arecanut and cocoa are perennial crops with enormous potential to sequester atmospheric carbon. The carbon stock in arecanut - cocoa cropping system was estimated as 45.52 t/ha. The contribution of twenty-year old arecanut to the total carbon stock in the system was 84.25% (36.35 t ha-1), whereas, ten-year old cocoa trees accumulated 9.17 t carbon ha-1. Carbon sequestration in the arecanut-cocoa cropping system was estimated at 167 t CO2 ha-1, which is quite high.
• The carbon stock in different aged arecanut palms (var. Mohitnagar) was assessed, and it was found to be 14.8 C t ha-1, 23.2 C t ha-1, and 37.2 C t ha-1, in 10-year, 20-year and 40-year old plantations. It indicates that, arecanut can store >136 t CO2 ha-1 and long term storage is possible as C storage in stem accounts for 77% of the above ground C stock.
• The annual carbon sequestration potential of coconut, arecanut and cocoa were determined and the values were 8 to 32 t CO2/ ha/ year in coconut, 5.14 to 10.94 t CO2/ ha/ year in arecanut and 2.02 to 3.89 t CO2/ ha/ year in cocoa depending on cultivar, agro-climatic zone, soil type and management practices.Arecanut-cocoa cropping system can considerably accumulate atmospheric carbon, and this has a greater significance in the era of climate change.
Important
Notifications
Notifications 1