Future Strategies
FUTURE THRUST AREA
TAPIOCA
High yield, starch and drought tolerance
In Tamil Nadu Tapioca is grown in Salem, Namakkal, Dharmapuri, Villupuram and Cuddalore districts. Tapioca is mostly grown as rainfed crop. To combat the prevailing water scarcity and continuous drought conditions, developing cassava varieties with drought tolerance, high tuber yield with high starch content for industrial exploitations is the need of the hour.
Rapid multiplication technique
Rapid multiplication of disease free planting materials of newly released varieties has to be popularized among the farmers. Moreover, the setts produced from raised bed method doesn’t have good field establishment more specially under rainfed conditions. Hence, developing management technologies for cassava under drip fertigation system involving protray nursery with single bud setts and polythene mulching is essential.
Nutrient management
Though the green revolution that happened in India after the sixties improved agricultural production, the post green revolution era was characterized by several soil fertility problems particularly multi nutrient deficiencies including those of secondary and micronutrients. Cassava is generally grown in alfisols, ultisols and entisols which are poor in fertility, with low organic matter content, cation exchange capacity, nutrient retention and high P fixation capacity. Hence, development and evaluation of micronutrient mixture ensures alleviating micronutrient deficiencies thereby increasing the productivity and starch content in cassava.
Mealy bug management
Papaya mealy bug is the major threat in crops like papaya, hibiscus, tapioca and other agri-horticultural crops. Mealy bug infestation leads to severe distortion of leaves which ultimately resulted with poor tuber yield. Hence, as contingency plan, mass production and release of mealy bug parasitoid (Acerophagus papayae) to control papaya mealy bug infestation in cassava is needed.
CASTOR
Development of determinate plant type for synchronized maturity and mechanical harvest.
Development of drought tolerant castor varieties for aberrant weather conditions.
Development of perennial castor variety for current fallows.
Diversification of pistillate base with wilt resistance.
Optimizing closer spacing in castor hybrids for single harvesting
In fact, one of the major reasons for low productivity in hybrid castor in India is due to the maintenance of inadequate plant population and poor fertility management. Hence, standardization of plant density with suitable genotype for single harvesting is paramount important to obtain maximum seed yield for mechanical harvesting system. Furthermore, early and late maturing castor hybrids has sown during rainfed condition, the flowering stage will be highly coincided with peak rainy season, which leads to heavy incidence of Botrytis disease.
Standardizing nipping technology for newly released perennial castor variety YTP 1
To accelerate side branching in newly released castor variety YTP1, nipping at 8th, 10th and 12th nodes will be studied with different inter cropping system during kharif and rabi seasons for increasing cropping intensity and net returns.
Development of high yielding wilt resistant castor hybrid for Tamil Nadu.
To study the influence of nutrients in reducing Botryotinia in castor
Calcium is important for the structure of plant membranes and cell walls. Zinc and manganese increases the production of soluble phenols, which play a role in the resistance mechanisms of plants against fungal pathogens. Hence, application of Ca, Zn and Mn at bloom stage of castor may help reduce Botrytis infection.
To standardize the age old practice of rainfed groundnut and irrigated turmeric intercropped with castor to increase the farm income
In Salem and Namakkal districts, under rainfed condition farmers are cultivating preferably groundnut and under irrigated condition is turmeric. In this farming system, growing of castor as a intercrop is a traditional practice for getting additional farm income. Hence, the standardization of crop management practices for groundnut/turmeric based castor intercropping system is needed for getting additional farm income.
To standardize the crop management practices for exploring the maximum potential yield of perennial castor
Perennial castor has the potential to yield 5 kg / year /plant without adopting proper crop management practices. Hence, standardization of crop management practices viz., spacing, pruning and fertilizer management for exploring the maximum potential yield of perennial castor.
Behavioral approaches with special emphasis to pheromonal based management of capsule borer
Viable tool for integrated pest management practices, environment friendly and highly compatible to biocontrol agents.
Identification and cataloguing of parasitic fauna in castor ecosystem and utilization of parasitic build for biocontrol of lepidopteran and sucking pest
Parasitoids and predators play vital role in maintaining ecological equilibrium in castor ecosystem and help in the reduction of various pests by their cumulative action. Through this study identification of new parasitoids and predators is possible and catalogue calendar for host-parasitoid/prey-predator can be prepared along with new strategies for better biocontrol options can be developed by reducing input cost of chemicals.
Tritrophic interraction studies in castor against key pests of castor
This study will help in understanding the prey predator and parasitoid relationship and semiochemicals involved in the communication.
Screening of castor germplasm against key pests of castor and evaluation of newer insecticides against castor major pests.
Screening of castor germplasm helps in identification of resistant sources against major castor insect pests and evaluation of newer generation insecticides helps in understanding the bioefficacy, effect on natural enemies and economics of the newer insecticides.
Screening of castor entries against Botryotinia grey mold under field and artificial conditions
Host resistance has been on top priority to manage castor grey mold disease. Incidence of grey mold becomes severe during cyclonic weather and spreads very quickly through air borne conidia. Infected capsules rot and shed off. It causes 100% yield lose if prolonged wet weather prevails during flowering and capsule development. Cultivars of castor with spiny capsule borne in compact racemes were to be more susceptible than spineless capsule in open raceme type. Chemical control of disease is not effective due to inclement weather. No measures are fully effective at controlling the disease. Cultivars resistant to this disease is the only the most practical way to control the disease. Hence this study was under taken to find out the resistant source.
Prophylactic sprays of fungicides at 50% flowering and second sprays at disease appear for the management of grey mold
Grey mold caused by Botryotinia ricini is becoming a serious threat to castor cultivation. The crop is completely devastated during cyclonic and incessant rains, Occurrence of disease incidence was recorded ranged from 5% to 50% for past 5 year, In Tamil Nadu. Continuous wet and humid conditions during flowering and capsule development stages for 5-7 days leads to severe rotting of infected spikes. B. ricini survives through mycelia or dormant structures called sclerotia formed on the infected castor crop debris/seeds. Grey mold growth on the seed and also beneath the seed coat with mycelia fragments on and inside the seed surface and sclerotia formed on infected seeds produced apothecia even after 17 months. So, seed borne nature was conformed. The disease appears at flowering or capsule development stage. Seed treatment as well as prophylactic foliar spray of fungicides and bio control agents are the most important to reduce the inoculam on seeds and to reduce the disease incidence on flowers and spikes thereby increase the seed yield.
Biological control of castor wilt
Wilt disease is the most important soil and seed borne disease throughout the year in patches at all crop growth stages. Occurrence of wilt incidence was reported from 2% to 15% in castor growing areas of Tamil Nadu. It is now becoming a principle yield limiting factors in the production of castor. Control of wilt disease by bio-control agents is created a new milestone in non-chemical plant disease management system. Propagules of bio-control agents germinate on the seed surface and colonize roots of germinated seedlings and protect the pathogen attach. Trichoderma spp. is promising bio-control agent for control of soil borne pathogens. In the present study, integrated management of wilt disease by using bio-control agents and fungicides under field conditions will be tested for effective control of wilt in castor.