Maize is the second most important crop after rice in terms of area and production in Nepal. It is the way of life for the hill farmers of Nepal and traditional crop grown for food, feed and fodder. For the production of Maize in large quantity, production of quality seed is essential in the first place. Quality seed is defined as varietally pure which has high germination percentage with a proper moisture content and weight. It ensures good germination, rapid emeregence and vigorous growth of the plant. Also the variety selected from Nepal has higher adaptability and resistance than that of the seed imported from the foreign country.
Maize is cultivated during June-July, September-October and January-February seasons. Sowing of Maize during the month of November-December is suitable for seed production, since maturity stage will not coincide with rainfall. Water stagnation should be avoided during the early stage of this crop.
The quality seed production by individual farmer is very difficult as it is necessary to maintain the isolation distance in the seed production field. The isolation distance of min. 300m is necessary for seed production as there are high chances of pollination of maize with other varieties. South face is suitable for the production of maize seed in mid-hill region. Crop rotation and proper sanitation must be followed by the farmers in the field for quality seed production.The recent variety that has more demand and is adapted to particular environment should be selected in co-ordination with seed production group/ co-operative. Farmers should test the germination of seed in order to identify the vigour and germination rate of seed. This helps to identify the health quality of seed, future growth of seedlings and amount of future yield.
Maize seeds should be treated by fungicides for controlling damping-off of plant in initial stage. For the treatment of seed , 1.5 gm of Captan or Thiram fungicide is needed for per kg seed. 1.5 kg of maize seeds need to cultivate the maize for 1 Ropani, and 2.25 gm. of Captan or Thiram fungicides is enough to treat that much of seed. Around 50-60 bamboo baskets (DOKO) of well-fermented FYM per Ropani of land should be applied during the land preparation or first ploughing (1-2 month earlier of cultivation). Avoid the use of unfermented FYM as it can increase pest such as white grubs, cut worms. The seeds are sown in rows and 40kg N, 60 kg P and 40kg K per ha is applied as a basal dose. As Zn and Mg deficinecy occurs, ZnSO4 @20kg/ha as basal fertilizer should be applied. Irrigation should be given upto 30 days in less amount and after that once in 10 days the field should be irrigated.
Two hand weeding on 25 and 45 days after sowing is essential to remove the weeds like Cyperus rotundus,Chenopodium album, Gnaphalium aphine,etc. Also the spraying of Atrazin 500g mixed in 1000lit water and light irrigation on third day controls the weeds in maize fields. Adequate and timely roughing is extremely important in quality seed production. Roughing refers to the removal of undesirable plants from the seed production plots. In maize, the crop should be rouged three times at the vegetative, flowering stage and before harvest because off-types and other varieties of the same species are most easily identified.
The major diseases of maize are Downy Mildew, Stem rot diseases, Black smut and Common ear rot. We can control the diseases by cultivating the disease resistant variety, using healthy seeds and treating seeds with Vitavex, Carbofuran. Major insects of maize are Shootfly and Stem Borer. Endosulphan and carbofuran granules can be used to control these insects.
Generally the maize cob should be harvested after full mature stage i.e. the husk should become dry, dark brownish, and seed should also be dried on the cob of standing plant in the field. After harvest,maize seed should be further sorted to have a good quality. While cleaning, weed seeds, dust, wrinkled seeds and seeds of other crops should be removed. Excessive moisture in the seed may loss its viability soon and fungus is likely to attack. So the seeds must be dried to the moisture content of about 10-12% for storage upto 8-9 months and <9% for more than one year storage. Seeds should be packed in Super-grain bags and stored on sunny day. Finally, maize seed is tagged and labeled with all the details like crop name, variety, class of seed, lot number, quantity, date of test, purity percentage, inert matter percentage, germination percentage and other necessary information.
When quality seed is produced in Nepal, farmers don’t have to depend on other countries like India for the import of seeds and they have to pay less amount of money for the seeds. Also the chances of scam by the suppliers with the poor quality of the seeds will be reduced. Seed production system should be strengthened by involving local farmers. Seed production should not be confined to research station and seed company farm only. Different programs for educating and training the farmers about quality seed production should be conducted and farmers should be encouraged to produce seed. It should be also done in farmers field with the participation of local farmers facilitated by extension officer and research scientist.
4th sem, IAAS Paklihawa