Sugarcane Agronomy 2m5s2q

Sugarcane Agronomy

The sugarcane agronomy deals with cultivation aspects of sugarcane including its ing sections of soil science, crop physiology, agro-climate, varietals planting and harvesting seasons, mechanical harvesting .The important aspects of crop production issues are covered in this chapter.

Seed bed preparation The field must be brought in such a tilth, which can ensure proper development and functioning of good root system. Formerly soil was ploughed and harrowed many times to bring about very fine tilth but under present concept the old method is obsolete and costly. Presently there is a belief that there is need to have minimum tillage because there is less time gap between two successive crops and a very fine tilth is not needed. Moreover, the land preparation is governed by the method of planting to be adopted. Keeping all in mind one deep ploughing by mould board plough followed by two-three shallow ploughing or harrowing and cross planking is sufficient to keep down the weeds, to provide better aeration, to preserve moisture, to incorporate and help in decomposing matter into the soil etc. The soils which have developed hard pan in the sub soil needs sub soiling for better penetration of roots. Without Subsoiling

Methods of planting

With Subsoiling

1. Planting in flat beds.

Low rainfall areas generally opt this planting method, which is simplest as well as cheapest of all. In this method the furrows of about 40-50 cm depth are opened with the help of double mould board plough or furrowers at 90 cm distance wherein the seed-pieces are placed followed by planking for a better seed soil . Two blind hoeings are given to replace the insect damaged setts. After germination, two to five inter row cultures may be given at proper intervals to control the weeds and to facilitate the tillering. Generally, earthing is not done but some times, if it is necessary the crop may be given one earthing during July-August to protect the crop from lodging and to provide drainage in the field. 2. Ridge and furrow method.

The method is generally adopted in areas with moderate rainfall but have drainage problems. The furrows are made in ‘v’ shape about 90 cm. Apart and about 20-25 cm deep. The setts are placed in horizontal position, usually in end-to-end system but if the seed stalk is not good and inter-nodes are longer eye-to-eye system of planting setts may be done. To minimize the border effects of gaps, doubling of setts is done at the ends of the furrows. As the canes start growing, the furrows are partly filled with soil and inter-row cultivation is carried out. This repeated inter-row cultivation results in leveling of the land by end of May or Mid of June which is called as first earthing. Further repetition of inter-row cultivation transforms the furrow into ridges by putting soil around the plants and inter-row space become furrow automatically, through which irrigation or drainage is provided. This transformation of furrows into ridges is called as second earthing.

3. Trench method or Java method.

This method is commonly practiced in Java.In this method the land is poughed and trenches are made about 1 meter apart with 20-30 cm depth and the soil taken out from trenches is put in the inter-row spaces. The trenches are given “U” shape and the soil at the bottom of the trenches is stirred up and mixed with manures making them ready for planting. The setts are placed now in horizontal position, as in the previous two methods by putting them either in end-to-end system or eye-to-eye system depending upon the type of seed stalk. The cane planter developed by Indian Institute of Sugarcane Research (IISR), Lucknow can be used which combines the operations of opening the furrows, placement of the fertilizers and then planting the setts in the rows. This planter can be used in all above-mentioned methods because it does the job quickly with minimum possible cost 4. Rayungan method.

Seed stalks are decapitated (topped off) about 4-6 weeks before the planting time. When, as a consequence, lateral shoots develop into tailed Rayungan they are cut off and planted out in the trenches made ready. Thus, by removing the upper rayungans, the lower buds are made to sprout and they are also similarly used. The trenches with 30 cm depth are made 90 cm apart and the soil is put in the inter-row spaces at the time of detopping the standing canes (seed stalks). The button of the trenches is stirred up to next 15 cm depth and the manures are mixed in this soil. The trenches are irrigated and the soil of the trench is mixed at 2-3 times before planting the setts (in vertical position 40-50 cm apart). The fertilizer is applied, the trenches are irrigated after putting back soil into them and the branched rayungans are cut off and pressed vertically into these trenches. At least 2-3 nodes must be underground to develop an effective rooting system.

5. Wider row/Paired row plantation:

To increase cane productivity and reduce the cost of production it is recommended that the sugarcane varieties having high tillering characters can be planted with a row spacing of 150cm in case of heavy soils and 120cm for lighter soils .The paired row plantation with 30-150-30cm is also suited for sugarcane. These methods of planting ensure to take up intercrops in sugarcane together with higher inputs use efficiencies.

6 Tjeblock method.

Tjeblock method is an improvement over the rayungan method because it takes care of proper availability of energy and nutrient to all the buds, whereas in rayungan method there is a considerable stress of nutrient supply on lower buds. In Tjeblock method the stalk is cut off at its half length and planted vertically with one node under the soil for rooting. The planted ones and the mother stalks are adequately irrigated and fertilized. Now the upper buds of both Tjeblocks and mother cane, which sprout in due course of time, are planted by cutting them into setts, as rayungans.

7. Bud transplanting.

Sugarcane buds with half of its stalk can be planted in small polythene sleeves (which are filled with leaf mould and soil) and after they have sprouted out they can be transplanted in the final field along with the polythene bag (opened at bottom). The seedling mortality has been found to about 5%. This is modified method of bud chip method where in bud chips of cane are taken out and placed in the required media for growing and then these seedling are used for planting cane .

Planting time Crop needs about 93-100oF temperature, 56% relative humidity and winds, which are neither desiccating nor very hot for the successful germination. The south Indian conditions are favourable for year round planting but in north India the conditions required for sugarcane germination can be met with only during spring and autumn season. The autumn planted crop is generally intercropped with potato, mustered, wheat, Lucerne, berseem etc and in case of south depending upon the season crops suitable for intercrops are selected. The following growing seasons are popularly used under Indian condition. 1. Adsali. This planting is done during July-August in south and the crop takes about 15 to 18 months time for harvesting. 2. Autumn. This planting is popular in north India, which is done during October-November.The sugarcane saplings after germination remain dormant during winter season and start growing with the rise in atmospheric temperature i.e. in February. The germination is recorded to be over 70% with very low mortality and the crop gets sufficient time for tillering and growth and is harvested after almost one year. 3. Eksali. This planting is common in south India and the crop is planted during January-February. The crop is given one-year time for harvesting. 4. Spring. The planting in this case is done during February-March in north India. It has been observed that the farmers usually plant sugarcane in April-May after taking rabi crops. Generally, when

the sowing is delayed, we observe a very hot and desiccating wind, which results in drying of sugarcane seedlings, and the plant population invariably goes very low. Moreover, the crop gets hardly six to eight months time to grow in the filed before it is harvested. Thus the yield becomes very poor.

Selection of the Seeding Material: The commercial sugarcane is a vegetatively propagated crop in which a potential healthy bud grows into a normal plant. Thus the planting material has a direct bearing on the germination of a bud in a seed piece. In order of getting higher germination one has to take care in selecting the seed with utmost care keeping the following points in mind: (1) So far as possible only top portion should be selected for seed purposes because of younger and well protected buds. The bud tissues are also rich in glucose, moisture, growth regulating substances etc. (2) Cane seed material is from plant cane and age of harvest of the crop cane seed should be 810 months. (3) The planting material must not have undergone drought, frost or flood as otherwise the buds would be abnormal with poor germinability. (4) The mother stalks must have been well nourished particularly with nitrogen and water because preparation of an ideal seed starts several months ahead of planting. (5) The buds on the sett must be green, projected and free from dry scaly leaves.

Fertilizer management of sugarcane

The fertilizer needs of the crop depend on the climatic conditions, rainfall, drainage, length of growing cycle and sink capacity of the variety. Sugarcane, being a very long duration crop, needs plenty of organic manure for a long term and continuous supply of plant nutrients. Therefore, well decomposed organic manures such as Farm Yard Manure. Compost and/or leaf mould at 50-60 t/ha along with 3-4 t/ha of powdered neem cake should be applied at least 15 days ahead of planting the cane setts. Nitrogen:

For a better crop of sugarcane it is advisable to apply 150-250 kg nitrogen in the form of ammonium sulphate in normal soils, urea in saline soils and calcium ammonium nitrate in acidic soils. Sugarcane plants, in their early growth period up to about 0-120 days, take nitrogen in the form of ammoniacal nitrogen, half of the total nitrogen should be applied at the planting time and the remaining half in two split doses i.e. 1/4th at the beginning of the tillering phase and rest 1/4th at the grand growth phase after which its application increases moisture content and glucose content in the canes and the sugar recovery from canes becomes very poor.

Phosphorus: Phosphorus has been considered essential for development of the roots, stem elongation and ultimately for quality improvement. Phosphorus helps in nitrogen uptake by plants and any imbalance in N/P causes a severe lodging of canes and thus impairs the quality. It has been observed that the applied phosphate gets fixed into the acidic soils or gets reverted into unavailable phosphate in the alkaline soil. It has been found to be fully utilized when placed under the setts. The recovery can still be increased if the phosphate is placed along with well rotten F.Y.M. leaf mould/compost. In case of alkaline soils the phosphate is recommended to be applied is recommended to be applied as foliar application. Phosphate application at the rate of 120-150 kg P 2 O 5 /ha is found to be very beneficial for the crop. Potassium: It helps in carbon assimilation, ,photosynthesis, and protein synthesis, translocation of sugar and proteins and starch formation. On an average a good crop of 125 t/ha removes about 550 kg K 2 O/ha, but Indian soils being rich require about 100-150 kg K 2 O/ha to produce a better crop of sugarcane. The potash may be given along with irrigation water but the best results have been obtained only when it is applied as basal at sowing time.

Micronutrients:

The cane growth and development has been found to be affected by B, Cu, Fe, S, Mg, Mn, Mo, Cl, Si and Zn. Most of these are required in trace amounts and it is seldom necessary to add any of these to the soil. It is reported that calcareous soils require Zn and S application for better growth and development of canes. An application of 15-20 kg ZnSO 4 and about 10 kg S/ha (as basal application) have been found to be best for highest yield of canes.

The table given on next page indicates the minimum value of the nutrients at which maximum response of fertilizer application can be obtained and the deficiency may occur if they are not applied. It also indicates the maximum levels beyond which it becomes a luxury consumption of nutrients, if applied.

Soil and Plant Tissue Test Values Nutrients

Soil analysis in ppm Minimum level (ppm) for Max. level (ppm) beyond which deficiency an application luxury consumption takes place give best yields

Plant tissue analysis in % Maximum contents below which deficiencies are indicated which heed correction*

N

10

40

2.25

P

5

30

0.08-0.09 as P 2 O 5

K

40

100

2.25 as K 2 O

Moisture

--

--

83-85

*Analysis of plant tissues were done at juvenile growth phase (between 4-8 months of planting) Weed management: Most common weeds of sugarcane in India are Sorghum halepense, Cyperus rotundus, Cnodon dactylon, Digitaria sanguinallis, Eleusine indica, Saccharum spontaneum, Trianthema monogyna, Euphorbia hirta, Eclipta alba, Commelina benghalensis, Digera arvensis, Phyllanthus nirui, etc. If these weeds are not controlled from very beginning the reduction in sugarcane yield may be as high as 10-70%. The most critical period for the week competition in sugarcane is up to 4 months after sowing beyond which the crop

smoothers the weed flora by itself.

Control measures: The mechanical methods of weed control include cultural practices, hot weather ploughings, hoeing and weeding, mulching, cropping system etc. that reduce the weed population and increase the sugarcane yield. But these methods are very cumbersive, time taking, expensive and at times it becomes difficult because of non-availability of labour and unfavourable climatic conditions for such operations. Chemical control of weeds offers a good substitute.

List of herbicides used for weed control in sugarcane

Name of the Herbicides

Rate of application (a.i.)

Time of application

Remarks if any

1.Simazine

1.5-2 kg/ha

Pre-

Pre-

Post-

Plant

emergence

emergence

2.0 kg/ha

--

3 DAP

--

2.0 kg/ha

--

-do-

--

2.0 kg/ha

--

-do-

--

1.5 kg

--

-do-

--

or Atrazine or

If 2, 4-D amine is applied @ 1 kg/ha at 45 DAP it gives better result (in addition to simazine)

Ametryne, Prometryne,

-do-

Desmetryne 2. Diuron, Alachlor or Tafazine, Karmex

DAP = Days after planting

-do-

RATOON MANAGEMENT Although sugarcane productivity has shown the increasing trend, a wide gap exists between potential (competition crops) and existing (Commercial plots) productivity levels. Ratooning constitutes around 50% of the total area under cane and ratoon productivity invariably falls below that of the plant cane, even though theoretically ratoon crops are expected to have higher productivity and early maturity than the plant crop. Several countries like Mauritius, Hawaii, U.S.A., South America, etc., rise multiple rations, thereby saving on the cost of the seed material, labor involved in planting and attaining much higher profitability per unit area compared to India, where we generally do not grow beyond one or two rations. Ratoon productivity has been proved to increase with proper management involving timely operations.

Hence for increasing the productivity of ratoon crop the following points should be taken into : 1.

Selection of sugarcane varieties which can give fair or better ratoon yield

2.

The crop should be timely (at optimum age) and plants should be harvested close to the ground.

3.

The left over of plants viz. dry leaves or cane trashes should be partially removed and make

stubble shaving at ground level. If the preceding crop is infected with severe pest, diseases and weeds then burn the field soon after harvesting. The burning of trashes helps in destroying eggs, larvae of pests and inoculum’s of diseases, weed seeds etc.,. Burning evolves heat, which converts sucrose of stubbles into glucose for a quick sprouting of ratoons (tillers) during winter. 4.

After stubble removal and burning of trashes the bunds should be destroyed and the field should

be given irrigation and then inter cultivation by running wooden plough for providing better aeration to roots, for making soil loose and for root pruning. This helps in a quick root production and sprouting of ratoons.This is termed as off-barring . 5.

While doing off barring sow the recommended chemical fertilizers along with organic manures at

the base of the ratoon stubble so as to have higher fertilizers use efficiency. 6.

The gaps in the ratoon crop should be attended by using any of the following method. a. With pre-germinated settling raised through polybag system b. Taking the clumps from thickly populated area and filling the gaps c. Removing the clumps from one side of the plots and the place vacated in the process may be

replanted fresh. 7.

When all the above-mentioned operations are over the field should be given irrigation according

to the crop needs. 8.

Trash mulching helps to check the weeds, reduce water requirement and as organic manure for

soil. 9.

The crop should be provided an efficient drainage for draining out excess water from the field.

10.

The weed control, earthing up, hoeing and plant protection measures should be followed as they

are done in the planted crop. Relative merits and demerits of ratooning Merits

De merits

1. Cost of seed, seed bed preparation and planting is saved.

1. Ratoon crop is invariably attacked severely by insects, pests and diseases. Thus the yield is very poor.

2. Ratoon crop utilizes the residual Fertility of the previous crop.

2. The soil becomes poor in fertility when ratooning is done for more than two years.

3. Ratoon crop matures earlier and helps in running sugar mills earlier. Thus the field is vacated earlier for the next crop. 4. The quality of the produce is superior to planted cane. 5. Total cost of cultivation is less as compared to the planted one. 6. The yield remains equal to the planted crop if due care is taken.