KERALA AGRICULTURAL UNIVERSITY
Regional Agricultural Research Station, Kumarakom
The RARS, Kumarakom is situated at 9° 3' latitude and 76° 3' longitude in the Kumarakom village of Kottayam district on the southern side of the Kavanar (river). It lies at an altitude of 0.6 m. below MSL. The nearest municipal town is Kottayam, just 15 km. South of Kumarakom (Kavanattinkara). The total geographical area of the farm attached to the RARS is 44.76 hectares. The soil of the farm is riverine allumvium, silty clay in texture. It is acidic in reaction with the pH ranging between 5 and 5.4. Kumarakom enjoys a humid tropical climate. The normal annual rainfall is 2469 mm, the bulk of which (55.4%) is received during the span of 3 months from June to August. A dry spell prevails during December to April. The mean maximum and minimum temperatures are 30.8° C and 25.3° C, respectively. The mean relative humidity is 86.7 per cent. The bulk of the land area (19.5 ha) is planted with coconut. Rice, at present occupies an area of 3.0 ha only which can, however, be increased to 5 ha. Coconut is grown on bunds reclaimed from the Vembanad lake. The other important crops grown are, banana, vegetables, clove, nutmeg, cocoa, pepper and fodder grass. An area of about 150 ha is utilised for aquaculture of fisha and prawns.
Mandate of the Station
The objectives of the RARS, Kumarakom are the following:
To serve as a regional centre for solving the location sp0ecific problems in the special zone comprising Kuttanad, Onattukara, Kole and Pokkali tracts.
To take up research on integrated farming systems incorporating crops, livestock and fish.
To promote research efforts in respect of food grains, pulses and oilseeds particularly those that are grown under rainfed conditions.
To evolve agronomic practices and land use patterns in the influence area of the station viz., the special zone of problem areas.
To co-ordinate research efforts in the control and management of the dreadful disease, root (wilt) of coconut.
RARS, Kumarakom is the lead station for the zone. It has five satellite stations viz., Rice Research Station, Moncompu; Rice Research Station, Kayamkulam; Rice Research Station, Vyttila; Sugarcane Research Station, Thiruvalla and AICRP on Agricultural Drainage, Karumadi. The functions of these stations are:
|Stations||District||Agro-ecological situation||Lead function|
|Kumarakom||Kottayam||Kuttanad||Coconut and coconut based farming system Crop-livestock-fish integrated system.|
|Kayamkulam||Alleppey||Onattukara||Annual Oil seeds, Rice Pulses|
|Thiruvalla||Pattanamthitta||Sugarcane tract||Sugarcane, Vegetables|
|Karumadi||Alleppey||Kattanad Kari||Drainage in rice fields|
Thrust areas for research :
Projects in operation :
A total of 40 experiments are in progress under the different Project Coordination Groups.
N.W.D.P.R.A. Research Project for various agro-climatic regions (OEAP)
1. Identification and characterization of efficient strains of cowpea Bradyrhizobium suitable for special zone of problem areas.
The salient results which jhave emanated from the experiments conducted at the RARS are breifly mentioned below :
African payal - Salvinia molesta - which was a real menace to Kuttanad for a decade was suppressed using the tiny weevil Cyrtobagous salviniae. his is a classical example of biological control over a large area in India.
Exploitation of the genetic variability seen in the population of Garcinia cambodia for the identification of superior types and its popularisation is one of the area where much work has been in the centre. We could identify 17 elite types of garcinia and maintain them under the germplasm. Different vegetative propagation methods were tested and standardised to enable large scale production of grafts.
Seed dormancy in garcinia was yet another problem faced as it takes 5-6 months for germination. Delayed sprouting affects the task of large scale production of root stock for grafting purposes. Hence, our scientists succeeded in identifying an effective and a very simple seed treatment method. This gave 100% sprouting in 15.20 days time. Thus in a period of ten months time new root stocks will be ready for grafting work.
An economic fertilizer dose for coconut grown in the reclaimed alluvial soils on Kuttanad has bveen formulated - ie. 0.25 kg. N, 0.35 kg. P205 and 0.9 kg. K2) per palm per year.
Twod diggings in the interspaces of coconut palms results in higher yields. Clean surface removal of grasses is also equally effective.
Studies conducted on the management of root (wilt) affected palms indicated a general decrease in disease intensity due to incorporation of green manure crops (grown in situ) in the basins of palms. The green manure crops found ideal for sandy and laterite soils are, cowpea and sesbania, respectively
It is generally believed that micronutrient deficiency is one of the causes for root (wilt) disease incidence. The investigations conducted at Kumarakom rules out the possible role of Fe, Mn, Cu, Zn, B and Mo on the incidence of the disease.
The role of nematodes in root (wilt) disease expression has been studied in detail. These studies indicate that (I) no single species of plant parasitic nematode is constantly associated with coconut palm. (ii) there is no relationship between the total population of parasitic nematode and intensity of disease incidence and (iii) inoculation of parasitic nematodes does not result in root injury or lesions.
Root excavation studies in alluvial, laterite and sandy soils in the diseased tract indicated that root decay is more in root (wilt) infected coconut palms than in apparently healthy ones in fall the soils types. The total number of roots in diseased palms was only one fourt of that in apparently healthy palms.
A comparison of root development and decay between coconut palms in root (wilt) affected are and root (wilt) - free area has shown that there is tremendous difference in the total number of roots as well as decay of roots. A coconut palm in the healthy are possesses about ten times roots than of an apparently healthy palm in the diseased tract. As against no root decay in palms in healthy area, root decay was prominent in coconut palms in the diseased tract, including the apparently healthy palms. This presents clue for a hypothesis that root decay occurs prior to the symptoms of root (wilt) disease viz., flaccidity, yellowing and necrosis.
Administration of oxytetracycline and penicillin in root (wilt) affected palms has indicated a general decline in root (wilt) intensity iurrespective of treatments. This finding does not support the mycoplasmal etiology of root (wilt) disease.
Tissue isolation and inoculation indicate that a species of Cephalosporium possibly Cisaccharir is constantly associated with the leaf rot disease of coconut caused by Bipolaris halodes. In vitro and in vivo screening of fungicides against B. halodes the leaf rot pathogen, have shown that Bordeaux mixture (1 per cent) is the best. The organophosphorus fungicides viz., Hinosan and Kitazin are next in the order of merit.
Red palm weevil, Rhynccohorus ferruginous is a very serious pest especially of young coconut palms in Kuttanad. Being an internal feeder, red palm weevil is not easily amenable to conventional insecticidal application and an effective control measure is wanting. In an attempt to control the pest by insecticidal application, it has been found that the root application of monocrotophos (75 ml. Per palm in 75 ml. Water) results in complete control.
Studies on the nature and intensity of damage caused by meanly bugs Psuedococcus spp.) to coconut palms shows that quinalphos, phosalone and carbaryl are equally effective in controlling the pest.
Vegetable cowpea is traditionally grown as intercrop in coconut gardens. The absence of a high yielding vegetable cowpea with shade tolerance is a felt need of the farmers in Kuttanad. The screening trials conducted over a period of 3 years have resulted in the identification of a superior type - culture VS 4 - with an yield potential of 13.5t/ha. This cultivar is tolerant to shade also.
In another breeding experiment, Ptb-1 (Kanakamony) has been adjudged as the best grain type cowpea for cultivation in the partial shade of coconut
Screening for early duration (6 months) cassava varieties to be grown in the partial shade of coconut gardens led to the identification of culture 4/84 with potential yield of 24.5 tons per ha. It is superior to the released variety, Sree Prakash, in yield performance and quality attributes.
Two promising types of Dioscorea alata - DaK 10/86 and DaK 27/87 - have been identified for cultivation in the partial shade of coconut gardens on the basis of yield evaluation conducted since 1988. In performance, they are superior to the released varieties from CTCRI viz., Sri Keerthi and Sree Rupa. The potential yields of the pre-release types are 42 tonnes and 32.6 tonnes, respectively, per ha.
Initial evaluation trials with 24 types of Dioscorea esculenta have led to the identification of 2 high yielding types, DeK-4/86 (11.6 tonnes per ha) and DeK-17/87 (11.5 tonnes per ha). They are tolerant to shade and superior to Sri Latha released from the CTCRI.
Manurial recommendations for Sweet potato (50:25:50 kg/ha), Bhindi (70:05:15 kg/ha) and vegetable cowpea (10:20:10 kg/ha) have been formulated for the reclaimed soils of Kuttanad based on field trials.
Banana has been identified as an ideal intercrop in the coconut gardens. Among the cultivars of banana, Palayamkodan proved to be the most profitable. It could be raised in 2 successive ratoons with 3 suckers per hill.
Very high values of EC (3276 millimhos/cm), Sodium (500 ppm) and Chloride (46.4 me/lit) and very low pH (3.7) are observed in the `Kavanar' (river) water during the months of April and May. This indicates that the water in Kavanar is not suitable for rice and fish culture during April-May.
The cassava cultivar Ramanthala has been observed to respond to VA micorrhizal inoculatiomn. It registered an yield (tuber) increase of 43.6 per cent over the control when inoculated. The inoculation also resulted in an increase in colonization of VAM in the roots.
Trials conducted at Kumarakom have conclusively proved that fredsh water fishes like grass carp, rohu, mrigal, catla and common carp could be successfully raised in this tract. The average yield of fish is 4 tons per ha per year.
A cheap indigenous carp hatchery capable of increasing the hatching rate of carps to 85-90 per cent and at the same time reducing hatching time from 27 to 20 hrs. has been developed. This system is useful to small and marginal farmers engaged in fish seed production.
Studies on prawn culture in channels surrounding bunds on which coconut is grown have shown that an average production 0.80 tons per ha of fresh water prawns could be produced in 220 days, fetching a profit of Rs.21,050/- per ha. The fresh water prawns grow to a maximum size of 200 g. during this period with a recovery of 97 per cent.
Simultaneous farming of rice and fish has been proved to be a viable technology for the Kuttanad tract. A record yield of 0.60 tons per ha of fish has been obtained in 220 days when raised along with rice. The yield of fish recorded from this experiment is much higher than that reported elsewhere in India.
A mysterious fish disease broke out among wilt fishes in Kuttanad during the first week of August 1991 that gradually spread through the water bodies in Kerala and crippled the inland capture fisheries in the State. Scientists of the Regional Agricultural Research Station, Kumarakom were the first to report and diagnose the disease as the dreaded epizootic ulcerative disease that has appeared in several East Asian countries during the past. Symptoms of varying severity were observed among different fish species with murrels being the most seriously affected. The early stages of the disease appeared as haemorrhoidal abrasions on the skin, followed by necrosis of muscle tissue leading to haemorrhagic ulcers. The percentage of disease occurrence followed a pattern typical in epidemics, reaching a peak approximately 3 weeks after the first observation before gradually abating.
Identifying the magnitude of the problem, the Fisheries Department was alerted, detailed surveys were conducted and studies initiated to identify the etiology of the disease. Preliminary studies on pathogenicity of the fish disease at the station indicated the possible involvement of virus in the disease. In subsequent studies conducted at the centre, Povidone iodine was identified to be an effective chemotherapeutic agent to contain the disease in culture ponds.
Rotational cropping of rice and fish resulted in the production of 1.0 ton per ha of table sized fish in 184 days in addition to rice grain yield of 2.5 tons per ha. The study highlights that fish culture in rice fields after a crop of rice is more profitable than a second crop of rice. The study also showed that by a cyclic conversion of rice fields for fish culture, table sized marketable fishes could be produced even in a short interphase period of six months without additional expenditure on feed or fertilizers. This technology is catching up as a sustainable farming practice in Kuttanad.
The trials on fish-cum-duck farming indicated deshi ducks are suitable than exotic breeds for this integration. By raising ducks in a cage constructed over the fish pond, @ 400 birds/hectare, an yield of 5.4 tons per ha of fish could be harvested in 302 days with no extra cost on feed for fishes. The yield thus obtained was significantly higher than that of the control system where no duck was maintained. It has been demonstrated that duck droppings substantially enhanced the pond productivity. The yield of fish registered from this experiment is higher than that reported elsewhere in India.
Studies on pig-cum-fish farming under integrated situations revealed that cost on feeds that generally account for over 50 percent of the input costs in aquaculture can be fully saved by integrating 25 pigs per hectare of pond area. Fish yield upto four tons per hectare was realised.
A simple algebraic formula known as "P-GAN'S formula" have been derived to estimate precisely the influence of area and productivity on the production trend of a crop over a period of time. The formula can be used both for research and extension activities.
A study on "Changes in the eco-system of Kuttanad and their impact on the agrarian economy of the tract consequent on the commissioning of Thanneermukkom Regulator" has revealed that rice cultivators and toddy tappers were beneficiaries of the Regulator. Coconut cultivators were not benefitted by the Regulator. Fishermen community, coir workers and shell collectors were all adversely affected by the Regulator.
Extension programmes :
|Content credit :||Last modified:|