Okra

Climate and Soil :Okra is a crop of tropical and subtropical climate. It requires a long warm and humid growing season. The crop growth is vigorous during rainy season compared to spring summer. Seeds of okra fail to germinate below 200C temperature and optimum temperature for seed germination is 290C.
Okra can be grown on all types of soils, but the soil should be friable. However, it grows best in light soils ranging from sandy loam to loam. Okra can tolerate slightly acidic soil reaction (pH 6.8 to 6.0)


Improved Varieties :
Punjab-8 (1995) : Plants are medium tall with splashes of purple pigmentation present on the stem. Leaves are deeply lobed and less serrated. Leaves, stem and petiole are less hairy. Fruits are thin, long, dark green and five ridged. It has resistance to yellow vein mosaic virus and tolerant to jassid and borer. It is suitable for processing. Average marketable yield is 55 q/acre. It is suitable for February-March as well as June-July sowings.
Punjab-7 (1986) : The plants are medium tall with splashes of purple pigmentation present on the stem. Leaves are deeply lobed up to the base of the petiole and the margins are less serrated. The basal portion of the petiole is deeply pigmented. Leaves, stem and petiole are sparsely hairy. Fruits are medium long, green tender and five ridged. Fruit tip is slightly furrowed and blunt. It carries resistance to yellow vein mosaic virus. Average marketable yield is 45 q/acre. It can be sown in February-March as well as in June-July.
Punjab Padmini (1982) : Plants are taller than those of Pusa Sawani and with purple tinge on the stem and petiole, leaves deeply lobed and hairy, fruits quick-growing, dark-green, thin, long, five ridged and remain tender for a longer period. It has field tolerance to yellow vein mosaic virus. Low intensity of virus symptoms appear only on the new shoot growth quite late in the season. It is ready for Ist picking in 60 days. It is high yielding with an average yield of 45 q/ acre. It is suitable for sowing in spring and rainy season.

Agronomic Practices :
Sowing time : In north Indian plains, spring/summer crop is sown in February-March whereas the rainy season crop is sown in the month of June-July throughout India. The seed crop is usually sown in rainy season. The optimum sowing time of seed crop is middle of June.
Seed Rate : Fifteen to eighteen kg of seed per acre is required for sowing up to 15th February, 8-10kg for March sowing and 4-6 kg for the June-July sowing. Soak the seed in water for 24 hours before sowing. Sowing should be done on ridges in February-March and on flat in June-July.
Spacing : The row to row spacing should be 45 cm and plant to plant 15 cm. Progressively wide spacing may be adopted for late sowing.
Manures and Fertilizers :
15-20 tonnes of well rotten farmyard manure should be incorporated into the soil before sowing. Apply 36 kg of N (80 kg of Urea) per acre on soils of average fertility. Apply half of the N at sowing and the rest as top-dressing after first picking of fruits.
Weed Control : To keep weeds under control, give three to four hoeings. The first hoeing may be given when the seedlings are two weeks old and subsequent hoeings at fortnightly intervals. Besides this, use of Stomp 30 EC (pendimethalin) 1.0 litre/acre or 750 ml/ acre followed by one hoeing can be practised.Stomp 30 EC
(pendimethalin) should be applied at pre-emergence stage i.e. one day after sowing.
Alternatively, spray Basalin 45 EC (fluchloralin) @ 800 ml to 1 litre/acre as pre-plant application i.e. four days before sowing and incorporate it in to the soil by harrowing. Alternatively use Lasso 50 EC (alachlor) @ 2 litres/acre as pre-emergence spray i.e. one day after sowing. The spray may be followed by one hoeing after 60 days if the intensity of weeds is high.
Irrigation : Seed should be sown in proper soil moisture conditions. First irrigation should be given after 4-5 days of sowing. Further irrigations should be given after 10-12 days whereas during the rainy season, less irrigations are required. Total 10-12 irrigations are required.

Harvesting :
The crop will be ready for harvest in about 45-50 days depending upon season and variety. Fruits should be picked tender (10 cm long). Frequent pickings would be required during peak season and 10-12 pickings are done.
Seed Production :
For seed production of okra, minimum isolation distance of 200 meter between two cultivars is required. It requires a seed rate of 5-6 kg/acre which should be sown on flat soil maintaining a distance of 60 cm and 25 cm between rows and plants, respectively. A minimum of three field inspections should be conducted to produce true to type seed. The first inspection before flowering, second at flowering and fruiting and third before harvesting of the crop. The off type and diseased plants should be rogued off. The seed crop matures in 90-100 days. The pods are picked 3-4 times due to uneven maturity. The harvested pods are dried in the sun threshed and the seeds are cleaned. The average seed yield is 5-6 quintals per acre.
Plant Protection
A. Insect Pests

 

Pests and Symptoms

Control  Measures

Precautions

 

1. Jassid (Amrasca biguttula) and Spotted bollworms (Earias sp.) cause damage during May-Septem- ber. Plants attacked by jassid show yel- lowing  and  curling along the  margins, turn pale to bronze colour finally prema- ture defoliation oc- curs. A large number of greenish adults and nymphs are seen un- der  the  leaves. Shoots infected with borer  droop  down- wards and dry up. In- fested fruits have a varying  number  of holes.

 

(For vegetable crop only)
Spraying once or twice at fortnightly  interval  with 560ml Malathion 50 EC in 100-125 litres of water per acre will control sucking pests. As soon as flower- ing starts give three sprays at fortnightly interval with 70  g  Proclaim  05SG
(Emamectin benzoate or 500g of Sevin/Hexavin 50 WP (carbaryl)  or 100ml of Sumicidin  20EC
(fenvalerate) or 80ml of Cymbush  25EC (cypermethrin) in 100-125 litres of water/acre to con- trol the jassid as well as spotted bollworms.

 

 

1. Pick  all fruits  before spraying or atleast 2-days after spraying.
2. Uproot hollyhock and the ratooned cotton, which are host plants for bollworms. 3. Remove regularly the at- tacked fruits and bury deep in the soil.

1. Jassid and Spotted bollworms:

(For seed crop only)
Apply  8kg  Thimet  10G
(phorate) at sowing in fur- rows or spray 250ml Rogor 30EC (dimethoate) or 20 g Pride 20 SP (acetamiprid) in 100-125 litres of water/ acre. Repeat the spray af- ter 15 days if necessary. Spray the crop when 20- 30% shoots show borer damage with any of the fol- lowing insecticides using 100-125 litres of water/acre. i. 100ml Sumicidin 20EC
(fenvalerate)
ii. 80ml Cymbush 25EC
(cypermethrin)
iii. 160ml Decis 2.8 EC
(deltamethrin)

1. Do not apply these in- secticides  to  the  crop meant  for  use  as  veg- etables.
2. Do not handle these granular insecticides with bare hands.

2. Red spider mites:
attack  the  leaves, suck the cell sap and ultimately cause web- bing, nacrosis and de- foliation.

Spray 250ml of Metasystox 25EC (oxydemeton me- thyl)/Rogor  30EC
(dimethoate) in 100-125 litres of water.

 

Note : To  determine  percentage  of  shoot  infestations,  reguarly  observe  20 plants from each of
the 5 rows selected at random in field at 5- 7  days  interval.

B.  Diseases

Diseases

Causal Organisms

Symptoms

Control Measures

1.Yellow
vein
mosaic

Virus

First  veins  turn yellow  and later on all the leaves show severe yellowing. Fruiting  is reduced.

1. Sow resistant vari- eties, control whitefly
(the virus vector) by spraying  560ml  of Malathion in 100-125 litres of water/acre.

2. Dam-
ping off

pythium sp. Rhizoctonia sp. Fusarium sp.

Both pre and post e m e r g e n c e mortality of plants occurs.

Treat the seed with 3g of Captan or Thiram/ kg before sowing.

3. Cerco-
spora
leaf
spot

Cerospora hibisci

Small,  brown  to sooty black, vein- limited  spot appear  on  both the  surfaces  of leaves. The older spots  may coalesce.  The infection  results into  premature defoliation.

The disease appears in  July-August  and can be controlled by spraying  Bavistin @200g in 200 litres of water/acre at 14 day intervals, starting from appearance of symp- toms. Three  sprays are enough.