Sorghum.pdf

Lecture 9 Chapter No. 3 SORGHUM (Sorghum bicolor) It is most important cereal crop in India. It stands second in area (next to rice), but third in production after rice and wheat. It is cultivated primarily a...

Lecture 9 Chapter No. 3 SORGHUM (Sorghum bicolor) It is most important cereal crop in India. It stands second in area (next to rice), but third in production after rice and wheat. It is cultivated primarily as a crop both during kharif and rabi and is one of the main reasons for low average yields (864kg/ha). It is mostly grow n in marginal lands which do not suit for wheat and maize. It is one of the major food crops of the world (wheat, rice, maize and jowar). Millions of people in Africa and Asia depend on sorghum as their staple food. ORIGIN: East and Central Africa (Ethiopia/ Sudan) is regarded as the place of origin of sorghum because of the greatest diversity of types grown in that region. USES OF SORGHUM 1. Jowar is used as human food and animal feed. 2. Jowar is used as fodder for animals. 3. Chopped green stems and foliage are used to prepare hay or silage and also as pasture crop. 4. Sweet sorghum & pop sorghum are perched and consumed by human beings. 5. Jowar flour is used for preparation of roti. 6. It is also used in breweries to prepare alcohol and malting purposes. 7. Jowar cake can also be prepared from fermented dough. 8. Sweet sorghums are used to prepare syrups, biscuit making in bakeries. 9. Left over stubbles are used as a source of fuel. 10. Tribals eat sorghum grains and sweet stems containing 10% sugar. 11. "Vani jowar" is a speciality of south Gujarat which is eaten under green perched conditions. 12. Jowar dhani i.e. pop sorghum is very popular among children. 13. Grain is sometimes fed to cattle, poultry and swines besides being used by human beings. CYANIDE( HCN) : Sorghum varieties and sudan grass produce toxic quantity of cyanide. The cyanide concentration is highest in seedling stage and declines as the plant grows. MERIT: The greatest merit with jowar is that it has the capacity to withstand drought due to waxy coating on stems and leaves. AREA AND DISTRIBUTION: World area is 43.7 million hectares with a production of 62.8 million tones and productivity of 1.3t/ha. While India leads (first) in the world in acreage, USA ranks first in production. The other important jowar grow ing countries are Pakistan, South America, USSR, Europe , Africa, China, Nigeria, Sudan etc., In India, jowar is grown in 10.9 million hectares with a production of 8.0 million tones and the average yield is 0.73t/ha. 1/3 sorghum area is in India. ADAPTATION It is a sturdy crop and can withstand varied climatic hazards more than any other crop. It is successfully grown in arid areas of UP, Rajastha n and also in humid regions of W.Bengal and B ihar. It is primarily a tropical warm weather crop. It can withstand wide range of temperatures varying from 15.5 DC to 40.5 DC with rainfall variations of 35-150cm per annum. Although it is a crop of plains, it grows within plateau region of South India up to an elevation of 1000m. Sor ghum is a short day plant. Flowering and grain formation starts when day length shortens during winter. Soils: Sorghum can be grown in heavy black soils to red soils, but comes up weII in heavy black soils. The best crops are grown the clay loams. Jowar does not grow well under gravely and marshy soils. The crop 25 grows well in neutral pH of 7.0. Main field preperation: Jawar is a poor man's crop which is mostly grown under low input conditions. However, soil management and land preparation are very important items of work for increasing production. The preparation of land for sowing of jowar is not as thorough as for most of the cereals. In black cotton soil areas, if the land is infested with weeds, ploughing followed by harrowing is practiced. Good tilth should be obtained by ploughing with iron plough/country plough for the grain production of jowar. Tractor discing or ploughing is also advisable. Normally, the land is well ploughed, then worked with a cultivator or blade harrow. Cattle manure may be applied 12 t/ha and mixed with 'soil by ploughing or harrowing. The land is w orked with blade harrow 2-3 times, Sometimes gorru without seeding attachment is worked 2-3 times. Incase of irrigated crop, after sowing and covering of the seed, beds are formed with the provision of irrigation channels to irrigate the beds. An irrigation channel is formed for every pair of beds to irrigate the beds situated on either side of the channel. Incase of transplanting, beds are formed first, water is let into the beds to soak the land and seedlings are transplanted. For an irrigated crop, the best system is to form ridges and furrows, adopting a spacing of 45cm apart with the provision of irrigation channels at 7.5-10m apart across ridges and furrows to adopt furrow irrigation. At the time of sowing, dibble the seed by the side of the ridge at a distance of 1/3 from the top of the ridge. Ploughing, harrowing and blinding in jowar is necessary for: 1. Good seed bed 2. Reducing weed population 3. Preventing soil eros ion 4. Conserving soil moisture 5. Conserving ent ire rainfall in dry ares for the USE of jowar crop 6. Providing drainage i'1 wet and humid areas 7. Mixing up organic manures in the seed bed. YEAR ROUND TILLAGE: To assist the farmers in combating weeds and to enable him to carry out sowing under improved seed bed conditions with this tillage and seeding equipment using bullock power "a year round tillage programme" was developed at CRIDA, Hyderabad. The year round tillage has several advantages: l.The primary tillage with country plough in the kharif is done during the non crop season when the farmers are relatively free and at a time whe n the land and bullocks are in good condition. This operation minimizes carryover of weed population from one crop season to another. 2.The subsequent harrowing operations have the advantage of a thorough weed control. Firm, seed bed and conservation of moisture in the seed zone which in turn enables early planting and good plant stands is so vital for increasing the productivity in dry lands. In an intercropping system, is necessary to till or harrow the field immediately after the harvest of one of the component crops as otherwise weeds take over and the yield of longer duration component is drastically reduced. GROWTH STAGES OF JOWAR Development of sorghum crop could be classified into number of ways. A fairly simple classification is based on 3 growth stages (GS1, GS2 and GS3 ) and are described as follows ( Vanderlip and Eastin ) GS1 ( Emergence to PI ) : Growth stage 1 is a strictly vegetative period. Relatively little information is available how this stage influences sorghum yields. It is necessary for producing sufficient leaf area and functional root system to support maximum grain deve lopment. GS2 ( PI to Anthesis) : This is very critical stage in the development of crop, since maximum potent ial seed number is set. Higher seed number has generally is the most important yield component associated with 26 increasing yield in sorghum. GS3 (Anthesis to Maturity): Ultimate yield is the function of both the length of the grain filling period and metabolic or synthetic efficiency. During that period either seed number or potential size (sink) are not limiting. SEEDS AND SOWING Sorghum is sown by various methods in different parts of the country. The methods are 1.Broadcasting 2. Drilling 3. Dibbling 4.Transplanting 5.Ratooning 1. BROADCASTING: This method is not much used by farmers because the seed rate required is more and the distribution of the seed is also uneven. Seeds are broadcasted and are covered by wor king with a country plough. The seed rate varies from 12-18kg/ha. Dry lands require less seed than irrigated lands. This method is usually done in irrigated lands where beds and channels are made and for sowing of fodder sorghum under irrigated farming. 2. DRILLING: It is carried out by locally prepared seed drills, gorru and covered by guntaka or brush harrowing. Seed rate is 8-12kgjha. Higher seed rate is recommended for light soils and low rainfall areas while lower seed rate is given for black soils. Spacing of 45x15-20cm and at 3-4 cm depth is common in dry soils. 3. DIBBLING: It is a time consuming method and requires more human labour. It is otherwise economical because the seed required is much less Le. 6kg/ha and gives the equal opportunity to all plants for their grow from the beginning. It is recommended where labour is not a constraint for both kharif and rabi jowar in order to obtain higher grain yield. Seeds are dropped in plough furrows directly or through bamboo tube attached to plough(akkadi) since the land will be leveled thoroughly and marked with a marker crosswise, keeping a distance of 45x15cm. The seed is covered by the succeeding furrow. This method is adopted usually in dry lands , where the moisture content of the soil is low. In case of irrigated crop, 2 or 3 seeds are dibbled by the side of the ridge adopting 12-15cm spacing in the row, where ridge and furrow method is adopted. Depth of sowing will be around 2.5 to 5cm by adopting population of 1.8 to 2 lakhs/ha. Thinning is to be done at 15 to 20 DAS leaving one seedling per hill. Fill up the gaps with the pulled seedlings. This method is usually practiced in sorghum research centres. 4. TRANSPLANTING: In areas with sufficient rainfall, transplanting of jowar seedlings is done. This practice is prevalent in the districts of Srikakulam, Vizag, E&W Godavari districts with regard to cultivation of KONDA JONNA during july-aug. When the soil gets sufficiently moist, seedlings of jowar obtained from a nursery after topping the leaves are dropped in the plough furrow. The root portion of the seedlings is covered when the next furrow is opened.As an irrigated crop, the beds of the field are irrigated and seedlings are planted. Even the hybrids can be transplanted. A light irrigation before or soon after planting helps for better establishment. The transplanting method is mostly used for hybrid sorghum. In Tamilnadu and in adjoining areas of Tirupathi, the seed growers follow the transplanting method of sowing. This method is developed by them for obtaining perfect synchronisation of male and female lines of sorghum hybrid CSH-5. The female Iines are dibbled by hand or drilled directly in the fields. The male lines are sown in the seed bed. The 2 week seedlings of male lines are then transplanted in the field in the ratio of 4 female lines to 2 male lines. Due to transplanting of male lines, the flowering in the male lines would be delayed by about a week. Due to this method, the farmers in South India are able to organize a good hybrid sorghum seed production programme than North Indian farmers. 5. RATOON CROP: The cultivation of an additional crop from the re growth of stubbles of previous main crop after its harvest, there by avoiding reseeding or replanting such as sugarcane, sorghum, rice, fodder grasses etc. Hybrids of sorghum can be ratooned with good success. They give extra11 quintals yields to the 27 main crop if they are properly managed. Out of all CSH-1 is the best for ratooning and the local varieties are not at all fit for ratooning. This is only possible under irrigated conditions. STEPS: 1. The main crop has to be harvested while the stem is green, leaving 4” to 6” stubble above ground level. 2. The 2nd day after harvesting, an irrigation has to be given to induce sprouting from the nodes. 3. Fertilizers @ 60kgN/ ha has to be applied at 2 splits. 1st split at the basal stage and the 2nd split of N at 30 days after from date of ratooning. 4. From each stubble, a number of sprouts come up. The weak sprouts have to be thinned out leaving 2 or 3 good healthy sprouts in each stubble 5. Maintain sufficient moisture from boot leaf to grain hardening stage. 6. The ear head size though small in ratoon crop gives equal yield to main crop as it put forths 2 or 3 sprouts. 7. Ratoon comes to harvest in 80-85 days. 8. Plant protection measures have to be taken up in time against pests and diseases as in planted crop. 9. For a ratoon crop of jowar, all the plants in the field have to be harvested at one time. 10. Ratooning reduces expenditure on land preparation, sowing, fertyilisers and gives more net income when it is managed well. Spacing for sorghum: 45x12-15cm Seed treatment: For control of grain smut disease - treat the seed with sulphur @ 5g/kg seed. OR With organo mercurial compounds or carbomates @ 2.5g/kg seed. For shoot fly-carbofuran 50 WP@ 100g/kg seed. Lecture 10 MANURES AND FERTILISERS : Both N & P are essential for stepping up grain yields of jowar. The effect of P in increasing grain yield is more pronounced when it is applied in combination with N. Application of N consistently increases uptake of P at all stages of growth. N uptake is also significantly increased at high levels of P application even at 60 days growth stage. Response to N is better in hybrids than in local improved varieties. Response of jowar to K is infrequent. K need not to be applied to jowar except in areas known to be deficient regarding potash. For rainfed varieties, in many cases 25kg N+ 25 kg P2O5/ha gave higher yields compared to 50kg N/ha under dry land conditions. Under irrigated conditions the doses of N & P are 40 kg/ha each. TIME AND METHOD OF APPLICATION OF FERTILISERS : When fertilizers are applied in direct contact with seeds, injury to germination frequently occurs. Drill the fertilizers into the soil before the sowing of seed at 5cm below the seed level. Basal application gives better response when drilled into the soil. HEAVY SOIL: All N & P2O5 could be applied basally or drilled into the soil at sowing 2" away and 2" below the seed. LIGHT SOILS: N should be given in 2 equal splits i.e. half as basal and other half at 30-35 DAS i.e at knee high stage. General dose for HYV's is 80-40-20 kg NPK/ha POINTS TO BE CONSIDERED FOR EFFICIENT FERTILISER MANAGEMENT 1. Jowar crop removes large quantity of nutrients from soil. 28 2. Growth and nutrient uptake will be more rapid after 40 days from sowing. Adequate supply of nutrients and water are necessary to provide maximum growth. 3. Jowar ear heads may not exert out completely from the flag leaf without adequate nutrients and water. 4. Final grain yield depends upon the rate of dry matter accumulation in the grain. NPK are necessary for dry matter accumulation. Nutrients at all stages of development of jowar crop are required for obtaining maximum yield. 5. Use of fertilizrs after getting the soil properly tested. WATER MANAGEMENT: Though jowar is drought resistant, it responds well to irrigation. It is primarily a rainfed crop. It has an extensive and deep fibrous root system. It is observed that on an average, about 6-9 irrigations, each of 5-6 cm depth are necessary depending on climate. Total water requirement is about 500- 600mm. CRITICAL STAGES FOR IRRIGATION: Irrigation is needed at 5 stages of the crop i.e. 1. Germination (at the time of sowing) 2. Knee high stage (30-35 DAS) 3. Flag leaf stage (50-55 DAS) 4. Flowering ( 70-75 DAS) 5. Grain formation stage (100-105 DAS) The peak water needs of jowar crop is at booting to seed setting stage. TIME OF IRRIGATION: The optimum time for irrigating jowar is when the soil moisture (ASM) is depleted to the extent of 50-60% in the effective root zone. It was observed that irrigating the crop when the ASM falls to 50% in the root zone of 60 cm has given the highest yield of grain. Irrigations to maintain a high moisture content during the seedling stage of the crop have been found to be detrimental to the growth of jowar due to lowering of soil temperature below the optimum and leaching of plant nutrients from the root zone. Irrigation at 45th day even for rainfed crops which coincides with boot leaf ensures good yields. Peak water requirements are at boot to flowering and early grain development stages i.e 25th , 45th and 55th DAS. These days correspond to PI, boot leaf and flowering respectively. For irrigated crop, irrigation once in 7-10 days for light soils and once in 15-20 days for heavy soils may be necessary. About 50% of jowar root is within 50 cm depth of soil though roots may go as deep as 150 cm. A pre-sowing irrigation to bring 120 cm depth of soil to field capacity is essential. An irrigation at 15 days after emergence in shallow soils is important. The irrigation may be given to bring 90 cm of the soil to field capacity. POINTS TO BE CONSIDERED FOR BETTER WATER MANAGEMENT IN JOWAR 1. Deep tillage and other moisture conservation practices to increase infiltration and soil moisture storage. 2. To provide drainage in black cotton soils during periods of excessive rainfall as jowar crop cannot tolerate water logging conditions. 3.Water harvesting during periods of excessive rainfall to make use of all available water for improving and stabilizing crop production. 4.Following improved irrigation techniques and timing to utilize a limited supply of tank or well water most effectively. 5.Adjusting of planting dates and cropping systems to optimize efficiency of water use. 6. Use of fertilizers and other improved production practices to increase WUE. 7. Severe moisture stress after flowering in kharif jowar can result in "blasting" and poor head filling. Providing only one irrigation at this stage can boost yield. 29 8. Final yields depends on the rate of dry matter accumulation in the grain and the length of time it accumulates. So, all the factors related to improve dry matter accumulation should be efficiently managed. Important weeds associated with sorghum: Grasses : Cenchrus sps, Digitalis sanguinalis, Echinochloa crussgalli, Eleusine indica Sedges : Cyperus rotundus Broad leaved weeds : Amaranthus viridis, Celosia argentina, Commelina bengalensis, Striga lutea Weed management: Mechanical – intercultivation Rainfed crop: Inter cultivation is done in between rows with small implements known as danthi i.e., small blade harrow - i )to remove weeds ii)to stir the top soil and iii)to give slight earthing up to jowar plants. A light country plough is also used for this purpose and the interspaces are ploughed. lnterculturing commences when the crop is about 15-20 DA5 and it is repeated at 10 days interval. Irrigated crop: A hand weeding is done within 20 DAS. A light plough is worked in between rows to break the ridge and earth up the rows of jowar plants when the crop is 30-38 cm in height. Chemical: (a) A pre emergence application of Atrazine or Propazine @ 0.25 - 0.50 kg a. i./ha in 900 lit water for effective control.This is followed by a late weeding which is the best and safest. (b) A post emergence application of 2 lit of MSMA /ha in 700 lit water can be used to control nut grass effectively. During the application, avoid as far as possible spraying on the crop (MSMA=Monosodium methyl arsenate) (c) 2,4-D @ 0.75-1.0 kg a.i./ha as post emergence 4-5 days after sowing for broad leaved weeds. One or two inter cultivations in sorghum may provided adequately effective control of weeds. Striga Witch weed (striga sps), a root parasite which falls in the group of higher parasitic plants, comprises of major threat to sorghum production. The common species of striga are l.Striga asiatica 2.Striga lutea 3.Striga densiflora 4.Striga euphrasiodes 5. Striga hermonthica. Striga lutea , an erect herb grows to a height of 10-30 cm. It is the most wide spread species of striga causing severe crop losses and occurs through out India. Striga robs the host sorghum plant of food and hormones through the roots attached to the sorghum roots. Growth of sorghum consequently remains stunted and the plant vigour is adversely affected. The total effect is drastic reduction in sorghum yield. This parasite which grows on the root of jowar plant, depleting it of its nourishment and there by arresting the growth and reducing the yield. Striga can be controlled by systematic removal before it flowers. Spraying with chemical weed killer, methaxone or 2,4-0 @ 0. 2% solution can control striga. Some other measures to control striga are 1.Deep ploughing 2.Double the recommended dose of N 3. Growing resistant varieties like SPV-462, N-13 etc., 4.Growing catch crops and trap crops like cotton, redgram, groundnut, linseed, sunflower, cowpea. 5. Use of methyl bromide @ 200 kg / ha as a fumigant, which is costly 6. Post emergence spray of 2,4-D @0.75-1. 0 kg a.i. / ha gives moderate control. Harvesting and threshiing When the grain is ripe and hard, the crop is to be harvested (i.e. , whe n the grains become hard and contain less than 25% moisture, they are considered fully ripe for harvesting). Generally, the irrigated crop matures later than dry crop. The plants are pulled out with the roots, cut at the base with sickles; when the crop is of short height are where mixed cropping is practiced, the ears a lone are harvested firs t, leaving the stalks to be cut at a future date. The harvested plants are allowed to dry in the field for 3-4 days and the ears are then removed. The straw is kept in stacks in the field for a week for complete drying. Then it is carted and 30 stacked in the yard. Sorghum grown for fodder purposes should be harvested either up to or at 50% flowering. Younger jowar plants posses, a high hydrocyanic acid (HCN) content which is poisonous to the animals. Further, there is a sharp decline in the protein content and digestibility of nutrients beyond the flowering stage In case of multi cut varieties – first cutting: 2 months after sowing -Subsequent cuts: 30-40 days after the first cut Threshing of the dried ears is done by beating with sticks or trampling under the feet of cattle. Stone rollers are also used for this purpose. The grain has to be winnowed, cleaned and dried to reduce the moisture to about 12-13 %. Threshing machines are also available. Sorghum effect: Sorghum is an exhaustive crop. It removes more amounts of nutrients. So, two exhaustive crops like sorghum and cotton should not follow each other. Instead pulse crop can follow sorghum. It was experienced that some of the succeeding crops to sorghum do not thrive well due to some toxic effect left over by the jowar crop. This can be counteracted by good manuring of the succeeding crop with FYM and by green manuring with indigo or wild indigo or crop rotation or sorghum mixed cropping. CROPPING SYSTEMS: North India -(i) Sequences Sorghum - Wheat Sorghum - Wheat- greengr a m Sorghum - Whea t – Cowpea Sorghum – Pea Sorghum - Safflower/ Sunf lower (ii) Mixed cropping Sorghum + Soya bean Sorghum + Pigeonpea Sorghum + Greengram/Blackgram South India - (i) Sequences Sorghum- Cotton Sorghum - Rabi sorghum Sorghum - Tobacco Sorghum - Finger mille t - Groundnut Groundnut - Rabi sorghum (iii)Mixed cropping(kharif) Sorghum+pigeonpea Sorghum+greengram Sorghum+blackgram Sorghurn+cowpea Mixed cropping(rabi) Sorghurn+safflower/ sunflower The average grain composition of sorghum grain contains Protein : 7.4 – 14.2%, Lipids : 2.4 – 6.5%, Carbohydrates : 70 – 90%, Fibre : 1.2 – 3.5% and different minerals like Ca, P and Fe. Compared to other cereals, sorghum protein is deficient in lysine and rich in leucine. Lysine is required for bone formation. Children are more susceptible to lysine deficiency than adults. (The sticky nature of cooked rice is determined by the relative proportion of amylo protein and amylase. The main protein in rice 31 is Oryzenin. Among a mino acids, the glutamic acid content is highest in rice which is also rich in lysine.) YIELD ATTRIBUTES: 1. Number of panicles/unit area 2. Length of the panicle (cm) 3. Number of filled grains/panicle 4. Test weight or 1000 grain weight Yield is the function of above yield attributing factors. YIELD: Rainfed: 20-25 q/ha, Irrigated:50-60q/ha 32