Seed Production Site  

      Seed production should be  taken in well drained ,weed and diseases free soil and preferably  the fields where preceding crop was not maize to minimize roguing and maintain the genetic purity.

Time of Sowing

Appropriate time of showing is very important for better crop establishment .For most part of India ,first week of July during kharif and first week of November during rabi are the optimum time of showing to avoid flowering from heavy rains during kharif and low temperature should not coincide with flowering .Rains during flowering wash the pollen in kharif and low temperature during winter causes mortally and killing another .

Method of sowing and layout

It is desirable to plant the crop on ridges (Photo 6). Sowing should be done on the southern side of the east-west ridges, which helps in good germination. Planting should be done at proper spacing (Photo 7 & 8). Optimum row and plant spacing should be kept at 60 and 20 cm, respectively. This spacing will ease the movement in the field for roguing and removal of tassels. Proper spacing also helps in improving the test weight. Identification labels/tags (Photo 9) should be put on the male and female lines to distinguish between them.

                                          Photo 6. Ridge and furrow                                          Photo 7. Putting seed at proper spacing    

                                        Photo 8. Covering seed with soil                                    Photo 9. Identification mark in male rows     

 Seed Rate

The seed rate depends on (a) seed size/test weight of male and female seed, (b) plant type as in case of erect plant higher seed rate is required to accommodate large number of plants per unit area than in spreading plant types and (c) male: female ratio. In general the optimum seed rate is 15 kg/ha for female and 10 kg/ha for male with at least 80% germination.

 Seed Treatment

                               Photo 10. Adding chemical in seed                                 Photo 11. Mixing chemical with seed  

 Untreated seeds should be treated with fungicides and insecticides (Photo 10,11 & 12) before sowing to protect it from seed and soil borne diseases and some insect-pests.

                                                         Photo 12. Drying treated seed in shade

·        Bavistin + Captan in 1:1 ratio@2g/kg seed for TLB, BLSB, MLB etc.

·        Apran 35 SD@4g/kg seed for BSDM

·        Captan 2.5g/kg for Pythium Stalk Rot

·        Imidachlorpit@4g/kg or Fipronil @4ml/Kg seed for termite and shoot fly.

Note:                                           

TLB                     : Turcicum leaf blight

BLSB                  : Banded leaf and sheath blight

MLB                    : Maydis leaf blight

BSDM                 : Brown stripe downy mildew

Nutrient management

In general, inbreds are slow growing and weak in nature and have poor nutrient uptake efficiency. Therefore, inbreds require high fertility as compare to hybrids. It is desirable to apply FYM@15t/ha 15 days prior to seeding. The fertilizer nutrients required for inbreds are N 180-200 kg, P₂0₅ 80 kg, K₂0 80 kg and ZnS0₄ 25 kg/ha.

                                                      Photo 13. Basal application of fertilizer

Full dose of phosphorus, potash and zinc and 10% N should be applied as basal (Photo 13). The remaining dose of nitrogen should be applied in four splits as per details given below to avoid losses and meet the requirement throughout the crop cycle:

1.      20% N at41eafstage

2.      30% N at 8 leaf stage

3.      30% N at  flowering stage

4.      10% N at grain filling

Water Management

                                                                   Photo 14. Irrigation in furrows

First irrigation should be applied very carefully. Water should not overflow on the ridges (Photo 14). The irrigation should be applied in furrows upto 2/3rd height of the ridges. Irrigation should be given as and when required by the crop depending upon the rains and moisture holding capacity of the soil (Photo 15). Light and frequent irrigations are desirable for inbred parents. Young seedlings, knee high stage, flowering, grain filling and 10 days after grain filling are the most sensitive stages for water stress for inbreds and irrigation should be ensured at these stages.

                                                                Photo 15. Irrigating crop

Weed management

Weeds are the serious problem in maize, particularly in wet (monsoon) season that competes with maize for nutrient and causes yield loss up to 35%. Therefore, timely weed management is needed for achieving higher yield. Atrazine being a selective and broad­ spectrum herbicide in maize checks the emergence of both broad leaves and most of the grasses. Pre-emergence application of atrazine @ of 1.0-1.5 kg a.i/ha in 600 litre water is effective way for control of weeds (Photo 16). While spraying, the person who is doing spray should move backward so that the 'atrazine film on the soil surface may not be disturbed. Preferably, three nozzle booms may be used for proper ground coverage and saving time. One to two hoeings are recommended for aeration and uprooting of the remaining weeds (Photo 17). While doing hoeing, again the person should move backward to avoid compaction and to ensure better aeration.

                                     Photo 16. Spraying atrazin                                                     Photo 17. Manual weeding  

Insect pest management

Stem borer is a serious problem in maize. It can be controlled by 1-2 spray of Carboryl or Endosulfan after 10 days and 20 days of germination. Spraying should be done in the central whorl of plant (Photo 18).

      1st Spray : 500 gm Carboryl or 625ml Endosulfan (35EC) in 500 litre water.

      IInd Spray: 750 gm Carboryl or 900 ml Endosulfan (35EC) in 700-800 litre water, if required.

                                                                       Photo 18. Spraying Endosulfan

Disease Management

Several. diseases occur during different seasons in various parts of the country that leads to loss to yield if not managed properly in time. Estimated losses due to major diseases of maize in India is 13.2% of which foliar diseases (5%), stalk rots, root rots, ear rots (5%) cause major yield losses. The major diseases and their management practices are described as below:

 Turcicum leaf blight (Photo 19) : Spray of Zineb/Maneb @2.5-4.0 gm/litre of water (2-4 appl ications) at 8-1 0 days interval.

 Maydis leaf blight (Photo 20) : Spray of Dithane M-45/Zineb @2gm/liter of water (2-­4 applications) at 8-1 0 days interval starts from first appearance of disease.

                                        Photo 19. Turcicum leaf blight                                            Photo 20.  Maydis leaf blight 

Polysora Rust (Photo 21) : Three sprays of Dithane M-45 @2-2.5gm/litre of water beginning from first appearance of symptoms at 15 days interval.

                                                                               Photo 21.  Polysora  rust                                         

Banded leaf and sheath blight (BLSB) (Photo 22) : Striping of 2 lower leaves along with leaf sheath, Seed treatment of peat based formulation of Pseudomonas fluorescence @16g/kg seed or as soil application @7g/litre of water (soil drenching), or foilar spray of Sheethmar (Validamycin) @2.7ml/litre of water.  

                                                                       Photo 22.  Banded leaf and sheath blight  

Sorghum Downy mildews (Photo 23) : Seed treatment with systemic fungicides Apron 35 W.P. @2.5g/kg seed. Roguing and destroying infected plants as they appear is the field.

                                                                            Photo 23.  Sorghum downy mildew

Removal of off-type plants and thinning

i)       At early stage i.e. after 12-15 days of sowing, off-type plants and excess plants should be removed and proper plant to plant distance of 20-25 cm should be maintained to provide an equal opportunity to each plant to grow,

 ii) At knee high stage and

iii) At flowering i.e. before anthesis.

Dissimilar plants should be removed (Photo 24,25,26 & 27) from the male and female lines to maintain the genetic purity of seed. Dissimilar tassel bearing male plant should also be removed.

                       Photo 24.  Identifying dissimilar plant                                            Photo 25.  Pressing dissimilar plant

                            Photo 26.  Pulling out dissimilar plant                                                  Photo 27.  Removing dissimilar plant  

Earthing up

One day prior to earthing up, third split of nitrogen should be applied followed by hoeing. On the next day earthing up operation should be completed with movement of the person in the backward direction. This operation should be done before tasseling stage to save the crop from lodging.

                                                                                   Photo 28.  Earthing up

Detasseling

Detasseling in female should be done before anthesis. It should be practiced row-wise. One person should follow to monitor the each row to check that no part of the tassel is left inside. The process of detasseling should continue for 8-10 days. While detasseling, leaf should not be removed which will other wise reduce the photosynthesis. It has been observed that the removal of 1 to 3 leaves along with tassel reduces 5-15% yield. The removed tassel should not be thrown in the field but fed to the cattle as it is nutritive fodder.

                                                                                  Photo 29.  Ways of detasseling

 Harvesting

Male parent should be harvested first than the female and should be kept separately. Optimum moisture content in grain at harvesting should be around 20%. The harvested cobs should be spread evenly instead of making heap.

Stages of crop inspection

·        At the time of sowing purpose: to monitor the land, isolation distance, planting ratio of male: female, proper sowing time, seed treatment etc.

                                                                               Photo 31. Inspection at vegetative stages                                                                          

 ·        During pre flowering/vegetative stage purpose: to verify the roguing and removal of off type plants (Photo 30 & 31 )

                                                                                 Photo 31. Inspection at pre-flowering stages

        ·        During flowering stage purpose : to check disease and pest infestation  

           ·        During post-flowering and pre-harvest stage purpose: to remove the late and diseased plants 

           ·        Harvesting time purpose: to see the proper time of harvesting