Agronomy of plant and ratoon sugarcane crops is summarised in the form of package of practices for sugarcane crop.
Plant Sugarcane Crop:
Sugarcane crop grown by planting the seed cane is called plant crop. Management practices for a plant crop are different from those for ratoon crop.
Tillage:
1. Two to three ploughings followed by harrowing, at optimum moisture content, for breaking the clods.
2. Formation of flat beds/ridges and furrows/pits for planting the cane setts.
3. Provision of adequate grade to drain excess water to prevent waterlogging.
Varieties Recommenced for AP:
1. Early maturing:
Co 6907, Co 7804, Co T 8201, Co 8013, C o 8014, CoC 671, 83R23, 87A298, 88A189, 90A272, 91V83, 93V297, 83R23, 90R5, 93A145 (Sarada), 2000V59 (Swathi), 2005V46 (Bharani), 97A85 (Visakha).
2. Mid-late maturing:
Co 62175, Co 7219, CoA 7802, 87A380, 87A397, 88A162, 93A21, 94A109, 96A136, 89V74.
Seeds and Seeding in AP:
1. Optimum sowing times are: January-March for coastal areas, January- February for Rayalaseema and in Telangana, for eksali December-January and adsali August- September.
2. Recommended seed rate is 30,000 to 40,000 three-budded setts per ha.
3. Place the three budded setts end-to-end in furrow spaced 60-90 cm apart (ridges and furrows 60-90 cm apart).
4. Setts must be treated (Carbendazim, Malathion, hot water) against insect pests and diseases before sowing.
Fertiliser Schedule for AP:
1. Srikakulam, Vijayanagaram, Viaskha and Medhak districts: 112 N + 100 P2O5 + 130 K2O kg ha-1.
2. Krishna, Godavari and Guntur Districts: 167 N + 100 P2O5 + 130 K2O kg ha-1.
3. Rayalaseema: 225 N + 100 P2O5 + 130 K2O kg ha-1.
4. Nizamabad (eksali): 250 N + 100 P2O5 + 130 K2O kg ha-1.
5. Nizamabad (adsali): 400 N + 100 P2O5 + 130 K2O kg ha-1.
6. Entire dose of P and K should be applied and incorporated into the soil during final land preparation.
7. Nitrogen should be applied in two equal splits at 45 and 90 DAS. For Nizamabad eksali, N in two equal splits at 60 andl50 DAS and for aksali, 120 and 169 DAS.
Earthing up and Propping:
1. Earthing up should be done before monsoon onset at the crop age of 3-4 months to check excessive tillering and weed growth besides facilitating irrigation.
2. A well-grown crop needs propping against lodging.
Water Management:
1. Tillering, grand growth period and early ripening period are more sensitive to soil moisture stress.
2. If water is available for one irrigation, it should be given at third order tillering, if for two, second and third order tillering and if for three, first, second and third order tillering.
3. In south India (tropical region), first four months (pre-monsoon) of the crop period, in general, needs irrigation once in 10-12 days (10-12 irrigations). About 8 irrigations would be adequate during monsoon period.
4. A drying off period of 4-6 weeks prior to harvest has to be allowed.
5. Waterlogging should be avoided
Weed Management:
1. Tillering phase is considered most sensitive for weed competition. In general, first 90-100 DAS is considered as critical period.
2. Three intercultivations (30, 60, 90 DAS) with blade harrows/local implements appear economical. Otherwise, three manual weedings are necessary for checking the weed growth.
3. Among the herbicides, PRE spray of Atrazin followed by 2,4-D 60 DAS is most common I method of weed management.
Ratoon Sugarcane Crop:
Generally, early maturing varieties are poor ratooners than mid-late or late varieties. Varieties with high yields as plat crop are also better ratooners with high yield. In tropical belt, December- March harvested crop gives best ratoon where as in subtropical belt, spring harvested crop (February- March) give good ratoon.
Varieties for AP:
1. Co 6907, Co 8-13, Co 8014, 84A125, 81 A99, 81V 48, 85A 261, CoA 7692, Co 8021, 86A 146, 87A 298, 83V15, 83V288, 86V96.
Stubble Shaving and off-barring:
1. Stubble shaving should be to the ground level using sharp blade or stubble shaver.
2. Off barring and ridge flattening is necessary to improve soil physical condition.
Caps and Plant Population:
1. For ratooning, all out efforts should be made to have a good stand of plant crop.
2. Ratoon with gaps beyond 15 per cent of total clump population (27, 000 to 33, 000) needs gap filling.
3. Gap filling may be with young sprouted material raised either in polybags or in nursery.
4. Material for gap filling should be at least 30-35 days old.
5. Application of cycocel or ethereal to foliage before 30 days of cane harvest can promote bud sprouting in ratoon crop under subtropical low temperature conditions.
6. Trash mulching between cane rows stimulates bud sprouting and aids in moisture conservation.
Fertiliser Schedule for AP:
1. Recommended fertiliser schedule is additional 112 kg N ha-1 over the NPK recommendation for plant crop for a particular area.
2. Additional N should be applied in two equal splits at ratooning along with P and K and 45 days later by placement (8-10 cm deep at each clump).
3. Zn, S and Fe, if necessary, may be given as foliar spray.
Earthing up and Propping:
1. Earthing up should be done after grand growth phase (July-August).
2. A well-grown ratoon crop needs propping against lodging.
Water Management:
1. Low temperature in subtropical region inhibits sprouting. As such, relatively frequent irrigations are to be given.
2. If irrigation water is not a limiting problem, tropical ratoon crop needs 6 to 8 irrigations during rainy season and 10 to 12 during post monsoon.
3. If water is adequate for two irrigations, it should be applied at start of the ratoon and as pre monsoon irrigation (late-May).
4. Waterlogging should be avoided.
Weed Management:
1. Tillering phase is considered most sensitive for weed competition. In general, first 90-100 DAS is considered as critical period.
2. Manual hoeing and weeding at 0, 45 and 90 days after ratoon initiation is more effective against weeds.
3. PRE application of Atrazin followed by one hoeing at 45 days after initiation of ratoon is effective and economical.