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Welcome to Agricultural Research Station, Kovilpatti




District :           Tuticorin

State    :           Tamil Nadu


Agro-ecosystem :  Rainfed


Research Territory

Rainfed black soil areas of southern district of Tamil Nadu viz., Tirunelveli, Tuticorin, Virudhunagar, Madurai  and Ramanathapuram dt.


Geo reference

            Latitude            :           09o12’N,

            Longitude          :           77o53’E

            MSL                  :           166.42m



            Rainfall (2001-02)          :           736.2

            Rainfall (normal)*          :           743.1

            PET (mm)                      :           21.5 to 36.5 mm


Annual Normal

            Max Temp         :           34.9o C

            Min Temp          :           22.8 o C

            Sunshine (Hrs)   :           7.083

            Wind speed       :           8.99 km/hr


Crop period Normal

            Max Temp         :           33.6o C

            Min Temp          :           21.3 o C

            Sunshine (Hrs)   :           7.3

            Wind speed       :           6.45 km/hr


Normal onset of monsoon

            Date / Week     :           2nd fort night of September
                                               (39th std week)


Cessation of monsoon

            Date / Week     :           2nd fort night of December



             Type                     :      Black soil

             AWC (%)                :      14 to 35

             pH                        :      7.8 to 8.2

             EC (dS / m)           :      < 1

             Depth (cm)            :      110 – 150

             Erosion status       :      Medium

             Drainage class       :      Moderate

             Surface texture     :      Clayey

             Prevailing slope     :      < 1 %

             Organic carbon      :      < 0.5 %



             Nitrogen      (Walkey & black)          < 180 kg/ha

             Phosphate    (olsen)                        < 11 kg/ha

             Potash         (ammonium acetate)    > 360 kg/ha

             Zn (< 12 mg/kg) Fe (< 3.67 mg/kg)

             Fine, Smectitic , Isohyperthermic  family of Typic


Background :

Established – 1901

Merged with Tamil Nadu Agricultural University – 1.4.1981


Mandate :

  • Research on dryland crops

  • Breeding High Yielding crop varieties

  • Crop weather models

  • Weekly weather forecasting

  • Integrated nutrient management

  • Agronomic technologies

  • Land management practices

  • Integrated plant protection measures


First crop specialist :

                    K. Kannaiyan (1962 - 1963)


First Professor and Head :
                    Dr. V. Ravi kumar  (1982-1985)


Research Activities

Rain Water Management:

In an experiment to find out suitable land treatment for moisture conservation, the land treatment tested were farmers practice, compartmental bunding, broad bed furrows and vegetative barrier with Vettiver.  From the runoff and yield data, it was observed that out of the runoff producing rainfall of 316.2 m3, only 9.5 m 3 of water was recorded as runoff in the compartmental bunding treatment which was seventy per cent less than the runoff recorded in the control treatment (32.56 m3).  Due to higher moisture stored in compartmental bunding treatment, the yield of cotton + blackgram was high which accounted for 608 kg/ha of cotton and 231 kg/ha of blackgram.  This was 21.7 and 29.7 per cent higher than the yield of cotton (476 kg/ha) and blackgram (178 kg/ha ) obtained in the control treatment.


The results of the experiment on low till farming strategies for resource conservation and soil quality for rainfed vertisols revealed that among the tillage treatment, conventional tillage i.e., disc ploughing once followed by harrowing twice has recorded a mean yield of 1262.88 kg/ha which was significantly superior to the low tillage treatments.  In the sub plot treatments of nutrient management, the treatment in which 50% FYM + 50% inorganic fertilizers (Urea) were applied has recorded a mean yield of 1126.88 kg/ha which was superior to the treatment in which 100% organic manure plus inorganic fertilizers were applied.  The interactive effect of tillage and nutrient supply revealed that conventional tillage + 50% nutrient as FYM + 50% nutrient as inorganic fertilizer recorded 1383.33 kg/ha of cumbu grain yield.


From a study on evaluation of production system for farmpond water utilization indicated that under all the production systems with protective irrigation registered higher cotton equivalent yield as compared to rainfed situation.  Among the different production systems, Ber with supplemental irrigation recorded higher cotton equivalent yield  (2829 kg/ha) and net income (Rs. 29176 /ha) as compared to other production systems.  Among the crop components, Ber recorded significantly higher cotton equivalent yield.  Next to Ber,Cotton + Blackgram intercropping system recorded higher seed cotton yield.  Ber crop with supplemental irrigation recorded 25% higher cotton equivalent yield as compared to the crop without supplemental irrigation.



Cropping System:

Soil moisture estimation at 0 - 15,  15 – 30 cm depth indicated that during the initial growth period (up to 30 days) of different crops in land use system, the annual crops viz., Cotton + Blackgram intercropping system and sunflower had utilized more soil moisture than Blackgram and cenchrus grass.  This was reflected in lower soil moisture percentage recorded in Cotton +Blackgram and Sunflower sole cropping system.  Among the different land use systems Agri–Horticulture system (Tamarind +Blackgram) recorded higher income than annual crops.


Nutrient Management:

In the permanent manurial experiment with jowar as test crop it was observed that the application of 20 kg N / ha as urea + 20 kg N/ ha as FYM + 10 kg P/ha as SSP recorded the highest plant height of 154 cm and earhead length of 29.1 cm.  This treatment recorded the highest grain (2320 K/ha) and straw yields (4690 kg/ha) followed by the treatment of application of 20 kg N/ha as Urea + 20 kg N/ ha as OFR + 10 kg P/ha as SSP (2290 & 4360 kg /ha of grain and straw yield respectively). The organic C content of the Soil was the highest in the treatment with the   application of FYM at 5 t/ha.   The soil available N, P and K, at harvest followed marginal build up due to their addition through external sources. 


In the long term manurial experiment with jowar as test crop revealed that the application of 50 per cent of the recommended N as Urea (20 kg N / ha) and the rest as FYM (20 kg N / ha) along with 20 kg P/ha recorded the highest plant height of 169 cm and earhead length of 25.5 cm followed by the application of same level and source of N without P.  The application of 50% of the recommended N as Urea (20 kg N/ha) and the rest as FYM (20 kg N/ha) along with 20 kg P/ha recorded the highest grain and straw yields (3050 and 5570 kg/ha respectively). The application of FYM at 40 kg N/ha recorded the highest maximum water holding capacity of 77.1 per cent and organic carbon content of 0.39 per cent.


In an experiment to study the effect of organics and inorganics on soil properties, nutrient availability and yield of cotton-cumbu in a rainfed Typic chromustert, Bajra (Variety ICMV.221) was raised as test crop.  The results showed that the application of 50 percent of the recommended N (20 kg N/ha) as composted coir pith and the rest as urea (20 kg N/ha) recorded the highest plant height (175 cm), earhead length (25.8 cm) and the number of tillers per plant (5.9).  The same treatment recorded the highest grain yield (2340 kg/ha) and straw yield (3350 kg/ha).   Although the application of composted coirpith showed a marked increase in the soil organic carbon content, the available N, P and K content of the soil at harvest was not significantly influenced by the different treatments tried.


To study the effect of secondary and micronutrient application on available nutrients, nutrients uptake and yield of cotton a field experiment was conducted with KC2 cotton.  The results on seed cotton yield indicated that spraying of 0.5% ZnSO4 + 1% MgSO4 + 1% DAP at 45 and 60 DAS recorded the highest value (610 kg ha-1) which was 37.2 per cent higher than NPK treated control. Soil application of MgSO4 at 25 kg ha-1 registered seed cotton yield of 600 kg ha-1.  Application of 0.5% ZnSO4 and 1% MgSO4 + 1% DAP as foliar sprays at 45 and 60 DAS recorded higher plant height of 47.2 cm, number of symbodial branches / plant of 12.8 and number of bolls/plant (12.5).  This treatment registered higher N uptake by cotton (4.78 kg/ha).  Magnesium uptake and Zinc uptake by cotton was more in the treatment which received 1% MgSO4  + 0.5% ZnSO4 FS at 45 and 60 DAS.


The results of an experiment on fertilizer management of microwatershed for sustainable productivity revealed that the application of GLM at 20 kg N ha-1 plus urea at 20kg N ha-1 recorded higher grain yield of blackgram than all other treatments tried.  The increase in yield was 40 per cent over urea alone application at 40kg N ha-1.  Seed cotton yield was higher (580 kg ha-1) in the same treatment. The organic carbon (0.49%) content was higher in the same treatment.  The maximum water holding capacity (68.7%) was higher in FYM at 40 kg N ha-1 treatment. GLM at 20 kg N ha –1 + urea at 20 kg N ha –1 recorded the highest uptake of N (6.12 kg /ha) and P (1.90 kg /ha). In case of intercrop blackgram, application of GLM at 20 kg N ha –1 + urea at 20 kg N ha-1 recorded the highest uptake of N (13.5 kg ha-1) and P (2.74 kg / ha).


From a study conducted on integrated nutrient management in sorghum + cowpea intercropping system, it was observed that the grain equivalent yield of sorghum was significantly higher in sorghum based cowpea intercropping system than sole crop of sorghum.  Application of 15 kg N through compost and 20kg N as inorganic fertilizer (T6) recorded higher grain yield in sole sorghum (1336 kg/ha) as well as intercropping of sorghum with cowpea (1840 kg/ha).  Next to this, application of 15 kg N through compost and 10 kg N through green leaf manure recorded higher grain yield.  The treatment T6, recorded 10.0 and 5.5 per cent increase in grain yield over recommended dose of fertilizer application in sole sorghum as well as intercropping system respectively.  Similar trends were observed in stover production also.


Application of 15kg N through compost and 20kg N as inorganic fertilizer (T6) recorded higher net return and benefit cost ratio in sole crop of sorghum (Rs. 4871/ha) and intercropping system (Rs.8833/ha) with a B:C ratio of 1.41 and 1.68 respectively.  Higher net return of Rs. 2259/- and Rs.3154/- per hectare was recorded by the sole crop  of sorghum and intercropping system respectively over the recommended dose of fertilizer application which accounts for 86.5 and 55.5 per cent increase in net return respectively. In rainfed  vertisols, to obtain higher production as well as net return it is recommended to grow sorghum in intercropping system with cowpea by fertilizing the crop with 15kg N through compost and 20 kg N as inorganic fertilizer.


Crop Improvement:

In the evolution study of high yielding blackgram varieties suitable for dry farming, in the MLT, the culture KBG 98005 recorded higher yield of 607 kg/ha followed by KBG 96026 (521 kg/ha), COBG 360 (521 kg/ha), VBG 66 (502 kg/ha) and COBG 593 (416 kg/ha) registering 74.9, 50.0, 44.7 and 19.9% increased yield over the check K1 (347 kg/ha).


The evolution study of suitable high yielding greengram variety under dryfarming situation was carried out.  The results revealed that in the MLT, among the 8 entries tested, the culture KGG 96034 recorded the highest grain yield of 770 kg/ha followed by KGG 96023 (753 kg/ha) and COGG 912 (750 kg/ha) registering 18.6,16.0 and 15.6% increased yield over K1.


The results of the study on evaluation of sunflower varieties for rainfed vertisols it was observed that in multilocation trial, the entry TNHAPZ has recorded the highest yield of 1574 kg/ha followed by TCSH (1435 kg/ha) and modern (1296 kg/ha) registering 126.8, 106.7 and 86.7% increased yield over the check K1 (694 kg/ha).



Teaching Staff position




1.         Vettiver planting for soil and moisture conservation

2.         1% MgSO4 Foliar spray at 45 and 60 DAS or basal application of 25 kg MgSO4/ha for magnesium deficiency

3.         0.5 % ZnSO4  FS at 45 and 60 DAS (or) soil application of ZnSO4 at 25 kg/ha in case of Zn deficiency 

4.         Agri-Horti system for sustaining income in dry lands

5.         Farm pond for rainwater storage in drylands

6.         50% of recommended  N as urea (20 kg N/ha) + 50% of recommended N as FYM (20kg N/ha) for sustaining yield under dryfarming

7.         High yielding, drought tolerant K1 green gram variety

8.         High yielding, drought tolerant K1 black gram variety

9.         High yielding, drought tolerant K1 sun flower variety

10.       High yielding, drought tolerant K11 dual purpose sorghum


Contact Address


Dr. K. Subbiah, Ph.D.,

Professor and Head

Agricultural Research Station,

Tamil Nadu Agricultural University,

Kovilpatti 628 501

Tuticorin dt.


Phone: (04632) 220533; 221133

E-mail: arskovilpatty@tnau.ac.in

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