On what basis do you believe/hypothesise that the rate is limited?

Abstract

Sucrose is formed from glucose-1-phosphate and fructose in the presence of tissue homogenates or undialyzed crude extracts from leaves of sugarcane. Optimum pH for the reaction is 8, although sucrose is formed readily from pH 7 to 9. Optimum concentrations of both glucose-1-phosphate and fructose lie in the area of 6 µmoles per milliliter of digest. Small quantities of sucrose are formed when either of the hexoses is added in the absence of the other. The reaction is stimulated by UTP, indicating that the formation of UDPG, and consequently the enzyme UDPG-fructose transglycosylase, is involved in sucrose production. UMP likewise stimulates the production of sucrose when added with ATP. DPN in cystein solution promotes the reaction in the presence of UDPG and ATP. There is no conclusive evidence that Mg, ATP, and DPN are required for sucrose production when added individually. ATP appears to promote glycolysis and retard sucrose formation under certain conditions, and promote sucrose production at other times by phosphorylative reactions.

Common Micronutrient mixture : To provide all micronutrients to sugarcane, 50 kg /ha of micronutrient mixture containing 20 kg Ferrous sulphate,10 kg Manganese sulphate, 10 kg Zinc sulphate, 5 kg of Copper sulphate, 5 kg of Borax mixed with 100 kg of well decomposed FYM, can be recommended as soil application prior to planting.

Reinforced compost from sugarcane trash and press mud:

Spread the sugarcane trash to a thickness of 15 cm over an area of 7 m X 3 m.  Then apply pressmud over this trash to a thickness of 5 cm.  Sprinkle the fertilizer mixture containing mussoorie rock phosphate, gypsum and urea in the ration of 2:2:1 over these layers at the rate of 5 kg/100 kg of trash.  Moist the trash and pressmud layers adequately with water.  Repeat this process till the entire heap rises to a height of 1.5m. Use cowdung slurry instead of water to moist the layer wherever it is available.  Cover the heap with a layer of soil and pressmud at 1:1 ratio to a thickness of 15 cm.

Leave the heap as such for three months for decomposition.  Moist the heap once in 15 days.  During rainy season, avoid moistening the heap.  After three months, turn and mix the heap thoroughly and form a heap and leave it for one month.  Then turn and mix heap thoroughly at the end of the fourth month.  Moist the heap once in 15 days during 4th and 5th month also.  This method increases the manurial value of trash compost by increasing, N, P and Ca content.  It also brings down the C:N ratio by 10 times as compared to raw cane trash.

Bio fertilizer:

• Application of azospirillum gives atmospheric nitrogen to the sugarcane crop. By applying phosphobacteria crop can get undissolved phosphorous from soil without any loss.

• Apply azospirillum 5 kg/ha, phosphobacteria 5 kg/ha and FYM 500 kg /ha mix it and apply on 30 days after planting along the furrow and irrigated it. Same repeated on 60th day.

• Bio fertilizer can also apply through fertigation.

• Don’t mix the bio fertilizer and chemical fertilizer for application.

• Apply bio fertilizer as 10- 15 days before or after application of chemical fertilizer.

Neem cake:

• Neem cake is the residue left, after oil has been extracted from neem seed kernel.

• It performs the dual function of both fertilizer as well as

• It contains Nitrogen 2.0% to 5.0%, Phosphorus 0.5% to 1.0% and Potassium 1.0% to 2.0%.

• Apply 27.5 kg/ha of neem cake on 30th, 60th and 90th day

INTEGRATED NUTRIENT MANAGEMENT

• In many sugarcane growing areas, the productivity of the soils has declined due to intensive cropping and lack of proper soil fertility management practices. The soil productivity can be restored through rationalized integrated nutrient management (INM) involving organic manures, fertilisers and biofertilisers.

• Bulky organic manures like farmyard manure, compost and pressmud must be incorporated into the soil at the rate of 15 to 25 t/ha before planting

• Sunnhemp green manure can be grown as intercrop and incorporated into the soil around 30 to 45 days after planting.

• Soil-test based fertiliser schedules are advisable. When this is not possible, a blanket schedule of 275-65-115 kg of N, P and K can be adopted.

• Phosphatic fertilisers, preferably super phosphates can be applied basally or at the time of first hoeing and weeding during 30 to 45 days after planting.

• Nitrogenous and potassic fertilisers must be applied in four splits, first split during 30 – 45 days, second split during 60-75 days, third split during 90 – 105 days and fourth split during 120 – 135 days after planting.

• The efficiency of urea can be enhanced by blending it with neem cake powder in 4:1 ratio, a day before application. It is advisable to apply the mixture of urea and potash fertiliser in holes of 10 cm depth at intervals of 15 cm spacing on the sides of the plant rows.

• Fifty kg of micronutrient mixture/ha made up of 20 kg of ferrous sulphate, 10 kg of manganous sulphate, 10 kg of zinc sulphate, 5 kg of copper sulphate and 5 kg of borax may be applied basally in the planting furrows.

• When the chlorotic symptoms due to deficiency of iron or zinc are observed on the leaves of the crop, 5 kg of ferrous sulphate, 2.5 kg of zinc sulphate and 5 kg of urea per hectare may be dissolved in 500 litres of water and sprayed over the foliage. If necessary, one or two more sprayings can be given at intervals of 15 days.

• Azospirillum and phosphobacteria biofertilisers at 10 kg each/ha may be mixed with 10 kg of compost and applied basally in the planting furrows or at the time of first hoeing and weeding during 30 – 45 days after planting. The soil pH must be maintained in the neutral range of 6.5 to 7.5 for the crop.

Fertiliser Requirements

Sugarcane – plant crop (meant for sugar mills) 275: 62.5: 112.5 kg N, P2O5 and K2O per ha

Recommendation for Plant crop

Blanket Recommendation(Kg/ha)

Straight Fertilizer(Kg/ha)

N

P

K

Urea

Super phosphate

Muriate of potash

Basal

-

62.5

-

-

390

-

30-45 days

90

-

37.5

200

-

62.5

75-90 days

92.5

-

37.5

205

-

62.5

120-135 days after Planting

92.5

-

37.5

205

-

62.5

Total

275

62.5

112.5

610

390

187.5

Apply FYM at 12.5 t/ha or compost 25 t/ha or filter press mud at 37.5 t/ha before the last ploughing under gardenland conditions.

Sugarcane – Ratoon crop (meant for sugar mills)                 275 + 25% extra N: 62.5: 112.5 kg N, P2O5 and K2O per ha

Recommendation for Ratoon crop

Blanket Recommendation(Kg/ha)

Straight Fertilizer(Kg/ha)

N

P

K

Urea

Super phosphate

Muriate of potash

Basal

68.5

62.5

-

148

390

-

30-45 days

90

-

37.5

200

-

62.5

75-90 days

92.5

-

37.5

205

-

62.5

120-135 days after ratooning

92.5

-

37.5

205

-

62.5

Total

343.5

62.5

112.5

758

390

187.5

Sugarcane for jaggery manufacture (plant as well as ratoon crop)                  225: 62.5: 112.5 kg N, P2O5 and K2O per ha

Recommendation for jaggery manufacture

Blanket Recommendation(Kg/ha)

Straight Fertilizer(Kg/ha)

N

P

K

Urea

Super phosphate

Muriate of potash

Basal

-

62.5

-

-

390

-

30-45 days

75

-

37.5

162

-

62.5

75-90 days

75

-

37.5

162

-

62.5

120-135 DAP or DAR

75

-

37.5

162

-

62.5

Total

225

62.5

112.5

486

390

187.5

Ankit Bhasker

Thank you for your detailed answer.

Dear Paul Milham ,

I am not talking about the rate. But, I am thinking of how we can speed up the formation of Sucrose in sugarcane, by using some nutrients in fertilizer, and forward scheduling the harvest of sugarcane.

Thank you for the detailed information about inputs. However, I don't see that it addresses the hypothesis question. Is there good data about deviation from 'sufficient' foliar element concentrations? Or is the question really about restoration of degraded soils. For example are they sitting atop acid sulfate layers that are being oxygenated?

Paul Milham

Thank you for your response. Let me provide more clarification.

Based on my preliminary research, I found that:

Sucrose formation in sugarcane is a two-step process:

Here's a breakdown of some key points:

• Source vs. Sink: Sugarcane leaves act as the source, producing sucrose through photosynthesis. The storage area in the stalk (culm) is the sink, where sucrose is deposited.
• Enzyme Activity: Enzymes like sucrose phosphate synthase (SPS) and sucrose phosphate phosphatase (S6PP) play a crucial role in sucrose synthesis. Other enzymes like invertases regulate the breakdown of sucrose for the plant's needs.
• Storage and Breeding: Sugarcane has a unique ability to store high amounts of sucrose in its stalk. Breeders continuously work to develop varieties that accumulate more sucrose earlier in the growing season.

Sugarcane's efficient sucrose production makes it a major source of sugar for human consumption and biofuels.

My question is that is there a way (especially through adding some nutrients in fertilizer) to speed up the sucrose synthesis to form the sucrose and forward scheduling the harvesting time of the sugarcane by, for example, 15 days?