Colocasia is an important tuber crop in Andhra Pradesh. It can be grown all over the State both in Coastal and Telangana districts. It is generally cultivated for its tubers which are used as a vegetable. The tubers have wide acceptance when compared to other tuber crops.
Climatic requirement for growing Colocasia/Arbi
It is a warm season crop requiring high moisture content. Temperature 21-27OC, 1000 mm rainfall with high humidity ideal for the crop.
In Telangana area, it is generally planted from February-April whereas in Coastal districts there are two seasons i.e. February-April and June-July under irrigated conditions with a duration of about 150-210 days.
Fertile and well-drained black loamy alluvial soils and deep sandy loams.
Varieties of Colocasia/Arbi
A Variety released from Horticultural Research station, Kovvur, a free budding type with round medium-sized tubers. It is suitable to grow in Andhra Pradesh. The duration is 6-7 months.The tubers are low in oxalate with excellent cooking quality and good market with a yield of 22 tons/ha.
2. Pancha Mukhi
A high yielding variety with tuber yield of 23 tons/ha. Leaves are also used as a vegetable.
3. Sripallavi (C-266)
It is also a high yielder with 23 tons of tubers/ha. Leaves used as a vegetable.
Yield 18 t/ha, round and oblong, less in oxalate content, good cooking quality.
It is a long Duration variety ( 8 months ) with good quality tubers and a yield potential of 35 t/ha.
Short duration variety with (5 months) good quality tubers and a yield potential of 24 t/ha.
Land Preparation for Colocasia/Arbi farming
One deep summer ploughing and 3 – 4 times with cultivator.
Propagated commercially by daughter or mother corms. Generally, daughter corms are preferred.
Seeds and Sowing
Sow the sprouting tubers (40-50g) in the bed at a distance of 30×45 cm spacing for short duration varieties and 45×45 cm for long duration varieties. Seed tubers should be treated in 0.3% copper oxychloride for 30 minutes before planting to prevent seed-borne diseases. For good establishment, irrigation should be given after planting.
Manures and Fertilizers for Colocasia/Arbi
Apply 25.0 t. of FYM/ha in last ploughing. The recommended dose of fertilizers is 120:60:80 Kg. of NPK/ha. Total phosphorus is to be given as basal and Nitrogen and Potash to be applied in 3 equal doses at 30, 60 and 90 days after planting.
The plot is to be kept free of weeds for the first three months till the plant cover the interspaces. Pre-emergence herbicides like Butachlor or Pendimethalin@ 5.0 lit/ha or fluchloralin2.5 lit/ha mixed in 500 litres of water may be sprayed immediately after sowing to control the weeds during the initial months.
First earthing up is to be given by 2nd month of planting. A subsequent earthing up can be done lightly to prevent exposure of the growing tubers which would otherwise turn green.
Irrigation of Colocasia
Irrigations at 7 – 15 days interval depending on soil type and season
Harvesting of Colocasia/Arbi
The crop is harvested when the leaves turn yellow-brown and dry up. Harvesting is carried out by ploughing carefully to avoid damage of the tubers or manual digging by pickage.
Post harvestt Technology
The freshly harvested tubers (daughter corms) are sorted out from the mother corms, cleaned and send to the market. It has a shelf life of 2-2 ½ months, but sprouts in February. The seed material can be stored under shade for the next planting season.
They suck the sap from the underside of the leaves and the leaves become chlorotic and in severe cases the leaves become dry and the yield will be reduced.
Spraying of Dimethoate or metasystox @ 2ml/lit of water can control the pest.
Diseases of Colocasia/Arbi and its Control
1.Leaf Blight (Phytophthora colocasiae)
This disease is more severe during the rainy season. Small dark round spots on upper surface enlarge, coalesce together, forming characteristic rings of yellow and brown zones. Infection in petioles leads to the collapse of plants. It destroys chlorophyll and reduces photosynthetic area, causing 25-50% yield losses.
Spraying of Mancozeb 0.25% or Ridomyl 0.2% in 20 days interval can control the disease.
- Y.S.R. Horticulture University, Andhra Pradesh.