Crop Management


  • Fertigation with 75% RDF at 100% CPE recorded maximum tuber yield of 35.40 t ha-1 with a starch content of 28.50% in Co(Tp)4 tapioca variety.
  • Black Polythene mulching at the time of planting recorded 100% weed control efficiency with a tuber yield of 29.50 t ha-1 with the highest B:C of 5.7 in Co(Tp)4 tapioca variety.
  • Standardized low input technology for tapioca with Green manuring (daincha) @50kg/ha + RD of K + 50 % RD of NP + Azosprillium (5kg/ha) + Phosphobacteria (5kg/ha) which recorded maximum tuber yield (42.50 t ha-1) and starch content of 25.30%.

Cassava tonic (500 lit per hectare) for improving yield starch and reducing CMD incidence

  • 100 kg cowdung mixed in 200 lit of water and filter it. Add 2.5 kg of biocontrol agent and 2.5 kg neem cake, stir well, tie the container with gunny bag and keep mixture for fermentation. Filter the fermented solution and add nutrient mixture and mix well and make up to 500 lit with water and spray three times from one month after planting at 21 days interval.
  • TNAU can provide neem cake, biocontrol agents and nutrient mixture in solid form of single pack. The farmers can use their own farm cowdung for preparation of cassava tonic.


  • Inter cropping of castor with blackgram (1: 2) in rainfed situation increased seed yield (1600 kg ha-1) and farm income with B:C ratio of 3.2 compared to sole castor cropping (1450 kg ha-1 with less B:C ratio of 1.9).
  • Seed priming with 1% KCI for 3 hours and sowing a week before onset of monsoon resulted in maximum germination percentage (85%) and better seed yield (1650 kg ha-1) in castor compared to control with less germination percentage (70%) and lesser yield (1375 kg ha-1).
  • In castor basal application of 40 kg gypsum along with foliar application of 0.5% each FeSO4 and ZnSO4at 30 and 45 DAS produced more number of spikes per plant (14) and effective spike length (59.5 cm) and substantially higher seed yield of 2050 kg ha-1.
  • Best suited land configuration method for conserving the moisture (15% at 0-15cm depth and 13% at 16-30 cm depth) underrainfed castor cultivation in red soil is formation of tide ridges with the yield of 1902 kg ha-1. Lowest yield was recorded in flat bed (1380kg ha-1) with least moisture conservation of 10% at 0-15 cm depth and 5% at 16-30 cm depth.
  • Castor intercropping with onion is an ideal intercropping system produced highest castor yield of 3363 kg ha-1 with 3083 kg ha-1 of onion yield, highest net return and B:C ratio of 3.53 compared to sole castor cropping (castor yield: 2829 kg ha-1with less B:C ratio of 2:1).
  • Castor seed designed with red polykote, biofertilizers and biopesticides recorded maximum germination percentage (87%), early flowering (50 days), more number of spikes per plant (16), higher 100 seed weight (27.0 g) and increased the castor seed yield by 20 %(1760 kg ha-1) with less incidence of pest and diseases and BC ratio of 3.6.
  • Foliar application of plant growth regulator consortia (Castor Gold) @ 0.05% on 25 and 50 DAS for improving pistillate flower production efficiency and seed yield (1930 kg ha-1) with B:C of 4.1. Control recorded the lowest seed yield of 1545 kg ha-1. Castor gold is being produced at TCRS, Yethapur and readily available for sale @ Rs. 160/100ml pack for increasing the castor yield. So far 525 pack of castor gold produced and distributed to castor growers which covers 525 acres and revenue was generated for Rs. 84000/-.
  • Wider spacing of 120 x120 cm with allowing all the order of spikes recorded more number of spikes per plant (23) and higher seed yield (2675 kg ha-1) of castor under irrigated condition. In addition to that adoption of wider spacing requires reduced seed rate and also convenient for intercultural operations.
  • Drip fertigation with recommended total quantity of 60 kg of N (Urea) and 30 kg of K (MOP) per hectare once in 10 days applied in 9 equal splits upto 90th day along with application of 30 kg of P (Super Phosphate) per hectare as basal application recorded the highest yield of 3198 kg ha-1.
  • Under rainfed castor cultivation, pre-emergence application of pendimethalin at 1.0 kg a.i. ha-1 followed by a hand weeding on 40 DAS produced higher yield (2337 kg ha-1) and B:C ratio of 3.8.
  • Enhancing the castor productivity through selective mechanization

Selective mechanization in castor viz., sowing with tractor drawn seed drill, inter cultivation with power weeder, need based plant protection with boom sprayer, harvesting by secateurs and threshing and shelling by castor thresher recorded higher net return of Rs. 39,636/ha and B:C ratio of 2.94.

  • Comparative performance of PSB (TNAU) and bio-phos on castor productivity

Basal application of 60 kg P2O5   + Seed treatment with bio-phos @ 30 g inoculants /50 g seed recorded the highest kernel yield of 1652 kg/ha with net return of Rs.49380/ha.

  • Introduction of castor as intercrop in Samai based Cropping system in hilly areas of Tamil Nadu

Intercropping of Castor + Samai at 1:10 with 50% organic + 50% inorganic nutrient management (22 kg N through Urea & 22 kg N through FYM @ 8.0 t/ha) is the efficient resource management system for improving the productivity (Samai Equivalent Yield of 1790 kg/ha) with net returns of Rs. 38743/ha in Hilly areas of Tamilnadu over farmers practice (Rs.12220/ha).

    • Optimizing plant spacing and nutrients (NPK) requirements of newly released hybrid castor YRCH 2 under rainfed and irrigated conditions
      • Irrigated: Higher seed yield of 2260 kg/ha in castor (YRCH 2) was registered under the treatment comprising of 150% RDF (135:65:65 kg NPK/ha) + 180 cm x 150 cm plant spacing with returns of Rs.68560/ha and B:C ratio of 3.84 in irrigated situation.
      • Rainfed: Higher castor seed yield (2020 kg/ha) was recorded under application of 125% RDF (75:35:35 kg NPK/ha) +180 cm x 150 cm plant spacing (2020 kg/ha) with B:C ratio of 3.47 in rainfed situation.