Maize zea mays
Origin: Central America
2n = 20
- Maize is a non-tiller plant.
- Maize is usually a cross-pollinated crop.
- In maize yellow color due to presence of: Cryptoxanthin
- Maize possesses the highest yield potential among the cereals that is why known as queen of cereals.
- Maize grain contains 10% protein, 4% oil and 70%
carbohydrates. Maize protein is called zein' and is deficient in tryptophan and
lysine - Maize required optimum temperature for germination is 21°C.
- Maize is particularly sensitive to water logging
- Seminal roots present in maize to nourished seedling plants
- Maize is monoecious plant having two different types of inflorescences.
- Maize is a warm weather plant and requires warm night temperature for higher yield
- Water requirement for maize is about: 500-800mm
- If maize is sowing in east-west direction it helps to augment the grain productivity due to greater availability of light
- In the persons who wholly depended on maize lead to a disease called 'pellagra' due to low content of vitamin B complex, niacin and tryptophan in maize.
- The terminal male flower clusters are called tassel, it is a branched panicle bearing of pollen or stamináte inflorescence
- The style is a very long silky filament, bears the female hairy cluster of which is known as "silk".
- The female pistillate inflorescence also called the ear or cob comes out from a node generally half way on the stem
- Idea of hybrid maize was first conceived by E.M. East and G.H. Shull in 1910 by single cross technique among the inbred lines
- An inbred line is a 'pure line' developed by self-pollination and selection until apparently homozygous plants are obtained. (ICS Exam-1993)
- D.F. Jones (1920) proposed the use of Double cross technique for hybrid seed production
- At present double cross techniques are mostly used in India.
Varieties:
- First time in India (1961), four double cross hybrids Ganga-1, Ganga-101, Deccan, and Ranjeet were released under all India co- ordinated research project on maize
- Mahi Kanchan and Mahi Dhavanare varieties of maize originating from Rajasthan.
- Top cross varieties: Ganga-2 and Hi-Starch.
- A top cross hybrid is obtained by combing an inbred line and an open-pollinated variety.
- In 1967, six composites were released: Vikram, Vijay, Amber, Kisan, Jawahar and Sona.
- Composites for early duration: Pratap, Agety-76, Kanchan, Laxmi, Tarun etc
- In 1971, Lysine rich Opaque-2 composites Protina (4% lysine), Shakti and Rattan were released (these are very rich in lysine and tryptophan amino acids).
- Synthetic variety: Means their advanced generations of a multiple hybrid increased by open-pollination e.g. Amber
- New varieties of quality protein maize (QPM) have released by using Opaque-2 gene e.g. Shaktiman-1, Shaktiman-2 and HQPM-1.
- Optimum plant population in Kharif is 65,000-70,000 plants/ha.
Seed rate:
- For composites: 15-20kg seeds/ha (in kharif crop).
- For hybrids: 25 kg/ha.
- For fodder purpose: 40-50 kg/ha
- RxP: 60 X 20cm.
Critical stages for water:
- For moisture and nutrients point of view period between tasseling and silking stage is critical. (IARI, Ph.D-1998)
Important question:
- Suitable temperature for growth of Zea mays is: 32°C.
- Commonly herbicide used in maize is: Simazine (0.5-1.0 kg)
- Hybrid varieties of maize: Sangum and Ganga safed.
- Double cross techniques of production of maize introduced by: D.F Jones (1920).
- On maize plant, first appearance is: Tassels (male flower).
- Water requirement for the maize crop is: 500-800mm.
- Protein content of maize: 10%
- Rabi maize is extensively grown in: Bihar
- White bud: In maizedue to deficiency of zinc the apical leaves become white.
- Phosphorus deficiency in maize is characterized by
stunte growth, leaf tips & margins are purplish and abnormally dark green
leaf colour
