Sweet Sorghum Techno Guide (Part 1)
Sweet sorghum [Sorghum bicolor (L.) Moench] is similar to grain sorghum with sugar-rich stalks. Being a water-use efficient crop, sweet sorghum has the potential to be a good alternative feedstock for ethanol production.
It is a multi-purpose crop which can be cultivated for simultaneous production of grain from its earhead as food and feed ingredients, sugary juice from its stalk for making syrup, jaggery, or ethanol, and bagasse and green foilage as an excellent fodder for animals, as organic fertilizer, or for paper manufacturing.
Production
A study was conducted by the Mariano Marcos State University with the title “Commercial Production and Utilization of Sweet Sorghum (for Ethanol, Food, Feed and Forage)”.
Eight (8) promising sweet sorghum varieties came from ICRISAT and were used for multi-location tests. Study showed that of the eight sweet sorghum varieties, only five (5) showed adaptability to local conditions in MMSU.
Recommended Varieties
- NTJ 2
- SPV 422
- ICSV 700
- ICSV 93046
- ICSR 93034
Adaptability of the top 5 Varieties
| Variety | Stripped Stalk Yield (tha) |
Grain Yield (tha -1) |
Percentage Sugar by Brix’s |
|||
| Seed Crop |
1st Ratoon |
2nd & 3rd Ratoon |
Seed Crop |
1st Ratoon |
||
| NTJ 2 | 45-50 | 48-55 | 51-60 | 3.62 | 4.40 | 18.5 |
| SPV 422 | 55-60 | 57-65 | 62-73 | 3.28 | 3.92 | 19.0 |
| ICSV 700 | 43-48 | 45-50 | 47-54 | 3.46 | 4.11 | 18.0 |
| ICSV 93046 | 47-52 | 48-55 | 52-59 | 3.40 | 4.08 | 15.0 |
| ICSR 93034 | 46-52 | 47-53 | 50-55 | 3.46 | 4.25 | 18.0 |
Adaptability of the top 5 Varieties per Region
- Region IV-A
- RCBD with 4 replications was used
- Basal fertilization of 14-14-14 at 800 g/20sqm
- Thinning done 10 – 12 DAP
- Side dressing with Urea at 180 grams/plot
- Hilling – up 30 DAP
- Observed armyworm and cutworm which were controlled with Hostathion
- Typhoon “FRANK” caused lodging with ICSV most affected
- Region V
- Highest stalk production was observed in SPV 422 (73 tons/ha) and lowest on ICSV 700 (35 tons/ha)
- Grain yield was highest on SPV 422 (9.55 t/ha) and lowest on NTJ 2 (3.87 t/ha)
- Sugar content was recorded using Atago refractometer. SPV 422 (18.62 brix) and ICSR 93034 (18.3 brix) and lowest on NTJ 2 (9.25 brix)
Highlights
Highlights
| Varieties | Plant Height (cm) |
Stalk Yield (tons/ha) |
Grain Yield (tons/ha) |
Sugar Content (% raw sugar,brix) |
| NTJ-2 | 220.47 | 52 | 3.87 | 9.25 |
| ICSR-93034 | 220.92 | 52 | 9.06 | 18.3 |
| ICSV-93046 | 280.92 | 35 | 5.14 | 10.87 |
| SPV-422 | 223.15 | 73 | 9.55 | 18.62 |
| ICSV-700 | 335.0 | 35 | 8.23 | 12.25 |
3. Region VI
| Variety | Shoot Fly (21 DAP) |
Stem Borer (35 DAP) |
Leaf Disease |
| NTJ 2 | 1 | 1 | 2 |
| SPV 422 | 1 | 1 | 2 |
| ICSV 700 | 1 | 1 | 2 |
| ICSR 93034 | 1 | 1 | 2 |
| ICSV 93046 | 1 | 1 | 2 |
| NTJ 2 | SPV 422 | ICSV 700 | ICSR 93034 | ICSV 93046 | |
| Plant Stand (24 DAP) | 1 | 1 | 1 | 1 | 1 |
| No. of days to 50% Flowering | 75.5 | 76.5 | 83.25 | 77.0 | 83.25 |
| Plant Height, cm (21 days after sowing) |
52.58 | 54.01 | 45.31 | 53.97 | 44.79 |
| Plant Appearance Score | 1 | 1 | 1 | 1 | 1 |
| Lodging Score | 1.25 | 1.00 | 1.50 | 1.00 | 1.50 |
| Plant Height, m (at harvest) | 3.10 | 3.10 | 3.46 | 3.16 | 3.18 |
| Stalk Yield, kg | 8.42 | 8.37 | 7.33 | 9.04 | 7.00 |
| Stripped Stalk Yield, kg | 7.62 | 7.42 | 7.08 | 8.50 | 6.33 |
| Stalk Jucie Yield, g | 777.67 | 750.00 | 766.67 | 1,143.33 | 825.00 |
| Stalk Juice Volume, mL | 647 | 630 | 651 | 943 | 722 |
| Stillage Yield, kg | 6.08 | 5.96 | 5.71 | 6.71 | 5.81 |
| Total Soluble Solids, Brix | 12.40 | 10.27 | 13.57 | 10.90 | 13.57 |
Ecological Requirements
Good surface drainage is preferred although sweet sorghum can withstand long waterlogged condition; clay loam is preferred with soil acidity not lower than pH 6.
Land Preparation
Two rotavations at a depth of 25-30 cm is desirable to attain a fine and good soil tilth. This is necessary to have a uniform germination because sweet sorghum seed are small as compared to corn.
Setting of furrow
Two planting seasons are possible for sweet sorghum. During the wet season, furrows are set 100 cm apart while the dry season planting are set 75 cm apart.
to be continued..