Maize PDF

Lecture 7 Chapter No.2 MAIZE (Zea mays) Importance: Maize is one of the important foods, green forage and industrial crops of the world. It is called queen of the cereals. The crop plants which belong to the fami...

Lecture 7 Chapter No.2 MAIZE (Zea mays) Importance: Maize is one of the important foods, green forage and industrial crops of the world. It is called queen of the cereals. The crop plants which belong to the family poaceae. maize has highest yield/ha among the cereal crops. It is now grown in all countries except Antarctica and under a more varied range of climates than any other cereal crops. The National Commission on Agriculture observed that maize can substantially contribute to the additional total food grain production by increasing its present contribution from 6-7% to 10%. Though it is mainly used as a food crop in India by the rural population in the form of bread and gruel, it has vast industrial potentialities as well having many as 50 different uses. Ex: it can be put to the manufacture of starch, syrup, alcohol, acetic acid, lactic acid, glucose, paper, rayon, plastic, textiles, adhesives, dyes, synthetic rubber, resin, artificial leather, boot polish etc. Economic importance :-  Cobs harvested slightly ahead of maturation are grilled and consumed tasty soups and pancakes are cooked out of corn flour. Fermented corn is also common.  Pop corn, which swellsand pops up on rapid heating are much relished snacks consumed all over the world. Corn flour is mostly processed into tortillas in Mexico in Latin America.  Corn is used in industries in several ways. Grains ground into flour are employed to prepare corn flakes. Corn germ oil is a good cooking medium. Corn starch is raw material in many brews and jams. It is also good for pr oducing alcohol. Some of the non food uses of corn are in preparing starch based adhesive. Proteins are of use in pharmaceuticals textiles, in addition corn germ is used in the soap making industry. CLASSIFICATION OF MAIZE TYPES : 1. Dent corn (Zea mays var indentata sturt) This is the most common type grown in SA. Dent formation on the top of the kernel having yellow or white colour. The depression or dent in the corn of the seed is the result of rapid drying and shrinkage of the soft starch. 2. Flint corn (Zea mays var indurata sturt) It is widely grown and cultivated in India. Endosperm of kernel is soft and starchy in the centre and completely enclosed by a very hard outer layer. The kernel is rounded on the top. The colour may be white or yellow. Grown in Europe, Asia, central America and South America. 3. Popcorn (Zea mays var everta sturt) It possess exceptional qualities. Size of kernels is small but the endosperm is hard. When they are heated, the pressure build up within the kernel suddenly results in an explosion and the grain is turn out. Grains are used for human consumption and is the basis of popcorn confectionery. Its cultivation is mainly confined to new world. 4. Flour corn ((Zea mays var amylacea sturt) It possess a soft endosperm. Kernels are soft and though all coloured corns are grown but white & blue are the most common. They are like fruit kernels in shape. Grown in USA & S. Africa. 5. Sweet corn (Zea mays var saccharata sturt) The sugar and starch makes the major component of the endosperm that results in sweetish taste of the kernels before they attain the maturity and after maturity, the kernels become wrinkled. The cobs are picked up green for canning and table purpose. Mainly grown in North half of the USA. 6. Pod corn : (Zea mays var tunicata kulesh) Each kernel is enclosed in pod. It is a primitive type of corn and hence of no importance. 19 7. Waxy corn (Zea mays var ceratina Kulesh) The endosperm of the kernel when cut or broken gives a waxy appearance. It produces the starch similar to tapioca starch for making adhesive for articles. Origin and distribution Origin of maize plant is still not definitely known, probably because of its wild relatives having become extinct during the long period of cultivation. The wild relative of maize is Teosinte. Geographical origin of maize is said to be somewhere in tropical zone of South America or Mexico, probably in the South western part of the Amazon river basin. Area and production Among cereals maize crop occupies 3rd place in the world after wheat and rice. America ranks first in productivity followed by Europe. In these areas maize is used primarily as a source of animal feed. Nearly 54% of the total area is located in South America, Asia and Africa, but they contribute only 33% to the total production of the maize in the world. In these areas, average productivity is low. Maize is consumed primarily as a source of human food. India cultivates 5.4% of the total area and provides 1.7% of the total production of maize in the world. In India, UP ranks first in area production while the productivity is highest in Karnataka. Punjab ranks fourth position. Adaptataion and climatic requirements Maize is a tropical plant which prefers warm humid weather. It is grown under extremely divergent climatic conditions in different parts of the world ranging from tropical to temperate regions. Generally, it does not grow satisfactorily in semi arid regions. Since, it is a short day plant with C4 type of photosynthesis, the crop has very efficient utilization of solar radiation. It is very sensitive to excess or deficit soil moisture. It is widely cultivated from 3900m MSL though it varies with latitudes. Therefore, it has adapted mainly in areas having sandy loam soils and sub humid climate. To some extent, the crop is cultivated in areas having semi arid climate provided the soils are deep with heavy texture. The optimum pH range of soil for maize is 6.5- 7.5. It can be successfully grown where the night temperature does not go below 150 C. It cannot with stand frost at any stage of growth. Optimum temperatures for germination is 21 0C and for growth is 320C. Minimum 90C , optimum 320C and maximum 460C temperature required for growth and development of maize. 600 mm rainfall with even distribution is sufficient for good cultivation. Soils : Maize can be grown on a variety of soils, but it grows best on well darined soils which are rendered fertile by adequate supply of manures. Best soils are --- Deep dark silt loams In semi arid climates -- Deep soils [heavy texture] In sub humid climates --- Sandy loam soils. Optimum PH --- 6.5-7.5 Seasons : Kharif season --- with onset of monsoon i.e in June or July and harvested in late September or October. Crop grown from Oct to January as irrigated one. Sowing maize at about 5 days before onset of monsoon [i.e last week of May to the second week of June] and providing irrigation, results in good plant stand and highest grain yields. Seed bed preperation [land preparation: At least 2-3 shallow tillage operations during summer season are essential in all maize growing areas. Deep ploughing is also helpful to control weeds and for efficient moisture conservation similarly bed and furrow or ridge and furrow systems are suitable in semi arid and sub humid regions. In high rainfall regions ill drainage reduces the yields. Therefore in Dehradun valley the system of ZINGG terracing has been found 20 suitable. Seeds and sowing : Yield of maize remains the same over a wide range of pant populations. On an average 60000-80000 plants/ha is optimum for good yields. For pure crop --- 20-25 kg seed/ha [60x25 cm or 75 x20 cm] For intercropping with soybean --- 15 kg/ha [1:2 ratio] For intercropping with soybean --- 10 kg/ha [1:3 ratio] For fodder maize --- 40-50 kg/ha Test weight of variety decides seed rate. High flexibility in crop geometry has been found in case of maize crop. Crop geometry of 45x20 cm is found to be optimum for most of the areas. Method of sowing : It is desirable to dibble the maize seed by the side of the ridges at a distance of 1/3 from the top of the ridge. Dibble seed 2-3 cm deep and should not be more than 5 cm. Ridge sowing facilitated irrigation as well as drainage. Weed management: Timely weed control is important. Proper and timely inter cultivation helps in aeration by loosening the surface soil and assures good yields. Weeds --- grasses --- Cynodon dactylon, Echinoclhloa colonum Sedges --- Cyperus iria, Cyperus rotundus Firnbristilis miliacea Brood leaved --- Celosisa argentina Commelina bengalensis, Convolvulus arvensis, Tribulus terrestris Solanum nigrum, Phyllanthus sps Maize needs two intercultivations and two handweedings.First inter cultivation is done between rows to break ridges/furrows and earthing up of plant rows. See that intercultivation should not be done too near the pants nor deep to avoid injury to the growing roots. Growing maize by the side of the ridges and earthing up in the early stages reduces injury due to water logging. Lecture 8 Water management : Maize is sensitive to both drought and water logging. Proper water management is a must for increasing yields. The most critical period for moisture stress is flowering stage [i.e. tasselling and silking]. Upto 40 DAS, the crop is more sensitive to excess moisture and from preflowering to maturity, it is more sensitive to drought. Maize plant utilizes about half of its seasonal intake of water during the 5 weeks following attainment of its maximum leaf area which is about the tasselling stage. It has been observed that continuous saturation of the top soil even for 4 days has resulted in reduction of yield of 50 q/ha. So it is always advisable to grow the crop on the side of the ridges in areas with poor drainage or heavy rainfall or on black soils. Popcorn is very sensitive to drought. If soil moisture stress occurs during early vegetative stage, then flowering is delayed. Drought at flowering stage, reduces yield and at later stages affect size and popping quality in popcorn. Furrow method of irrigation is both efficient and convenient for maize crop. Precautions to be observed with regarding to irrigation and drainage during the life cycle of maize crop: 1. Apply water evenly and uniformly while irrigating the maize crop. 2. Drain out excess water promptly. 3. Open the filed drains at even if to avoid the chances of damage due to excess water or rain. 4. Do not allow the maize crop to wilt due to shortage of moisture. 5. The crop should be irrigated immediately if the leaves roll or wilt during the day and fail to unfoll in the followring morning. Sometimes leaf wilting may occur in the evenings and the leaves will not recover by the 21 next morning. This is a sign of extreme moisture stress. 6. Do not allow the crop to wilt at the flowering stage. The soil should be kept moist for proper grain selting and development. Manures and fertilisers : At maturity ½ of the dry matter production is accounted for starch in the grain. The percent of N and P in embryo of the seed is highest compared to any other tissue of maize plant. More than ½ of N, accumulates in the grain. There is a continuous uptake of P during the growing season. K accumulates in all the tissues of the plant and it reaches a maximum at about middle of August when sown towards the end of May. As in other crops, a balanced and integrated nutrient management plays a pivotal role in maize cultivation. The nutrient uptake depends on soil fertility status, variety, crop growth stage, plant density and time of cultural operations. NITROGEN : The maize crop should have continuous supply of N at all stages of growth till grain formation. N deficiency symptoms are indicated by the yellowing of the tips of lower leaves and the deficiency gradually spreads to mid ribs and finally affects the upper leaves. So N deficiency in maize plants even at an early stage of crop growth will reduce grain yield substantially. PHOSPHORUS : A higher % of P is needed in early stages than in the later stages. P comprises an important component of maize plant tissues and the developing grains. Thus, if P deficiency exists, it will show up before plants have reached before knee-high stage. The contribution of P through fertilizers decreases rapidly though plants take up this element up near maturity. POTASSIUM : Maize takes up K from knee high to post flowering stage. AP soils are medium to high in available k. So K deficiency in maize is not common. If K deficiency is found, it should be corrected immediately. ZINC : Majority of maize hybrids growing areas show zn deficiency. Table no. 2.1Recommended doses of fertilizers (Kg/ha) Nutrient Irrigated Rainfed N 120-150 80-100 P 60-75 40-50 K (Based on soil test) 35 35 ZnSo4 (once in 3 seasons) 25-50 25-50 Time and method of fertilizer application : In case of rainfed crop, apply all the fertilizers in single dose as basal dressing. Place the fertilizers 10 cm away from seed rows and 5 cm below the seed. In case of other situations, adopt the following method for N in Table no. 2.2 Apply 2nd & 3rd splits of N in the after noon when there is no dew. Fert. Should be mixed up in the soil with a hand hoe. Immediately after fert. Application, filed has to be irrigated in case of irrigated crop. In case of rainfed crop, it the N is to be applied as top dressing, there should be enough moisture in the soil or fertilizers are to be applied after receipt of rain, when the soil is in proper condition. In case of Zn deficiency, apply 25-50 kg zn so4/ha as a basal dose to the soil separately and worked in to the soil but not alongwith the basal dressing of phosphatic fertilizers. 22  In case of ZnSO4 not applied to soil fotiar spray of ZnSO4 @ 5 kg + 2.5 kg lime/ha. Repeat 2-3 times at weekly intervals till the deficiency symptoms disappear. Basal application of ZnSO4 is superior and more lasting effect than foliar application. Symptoms of Zinc deficiency in maize : Stunted growth with short nodes pale green colour, lower half of leaf having broad ends of bleached tissue while mid rib and leaf margins remain green. Table no. 2.2 Sl. Type of Quantity to be season Stage Method of appln. No. soil apply. Drill 10 cm away & 5 i) sowing ¼N cm below the seed rows ii) knee hight (i.e. 30-35 K Broad cast b/n rows and Light or DAS) (25-30 DAS for ½N 1 R mix up with soil sandy popcorn) S iii) Pre tasselling i.e. 50- 55 DAS (40-45 DAS for ¼N -do- popcorn) i) sowing Drilling ¾N Broadcast & mix with ii) knee hight ¼N K Soil Heavy or 2 S black soil i) sowing Drilling ¼N R Broadcast and mix with ii) knee hight ¾N Soil 23 HARVESTING : Hybrids of maize mature within 90-110 days. Test for maturity is that ? the husk cover turns pale brown and the grains are too hard to be pressed in with finger nail. The cobs may be harvested at about 20% grain moisture. The plants may remain green when the cobs are dry and ready for harvest. Therefore do not wait for stalks to dry up for harvesting. This is desirable as such plants can be used as fooder. SHELLING : Enough time should be given for drying and shelling. Generally, the plants are left in the field for one or 2 days after harvesting. The grains dry up during this period. Remove the husk and cobs are kept in sun for 2-3 days before shelling. The grains are separated easily from the ears if they are dried thoroughly and grain moisture is reduced to less than 15 %. Shelling can be done either by beating with sticks or by using maize shellers operated by hand or power. After shelling, the grains may be cleaned, dried thoroughly and stored at 10 to 12% grain moisture. Popcorn ears should be harvested at 30-35% moisture and dried slowly in shade. Quick sun drying results in cracking of grains and poor popping expansion. The ears may be shelled at 12% moisture. The optimum moisture for best popping is 12-14%. Therefore, grain is to be stored at 12% moisture in water proof bags. YIELD ATTRIBUTES : 1. No. of cobs/plant 2. No. of grains/cob 3. Grain weight/cob 4. Test weight (100 grain weight) YIELD : Hybrids : 35-40 Q/ha Locals : 15-20 Q/ha High lysine composites : 1. Shakti : 95-100 days ; 10.6% protein ; 3.45% lysine yield 45 q/ha 2. Rattan : 95-100 days ; 10% protein ; 3.46% lysine yield 40-45 q/ha. Grains similar to shakti. Tolerant to top borer and downy mildew. 3. Protina : Compos ite with high nutritional quality contains 11% protein; 4% lysine against 2% lysine in normal varieties duration 100-105 days; yield:40-45 q/ha. 24