Sorghum (Bicolor sorghum) is one of the world's oldest and most versatile cereals, known for its adaptability and ability to thrive in conditions where other crops fail. This article provides a comprehensive and detailed guide to the Sorghum care and characteristics of this plant, integrating and expanding all the relevant information you need to successfully grow sorghum, from variety selection to pest control and harvesting.
Main characteristics of sorghum
Sorghum is a fundamental cereal for both human and animal nutrition and is also used in the production of biofuels and industrial products. Its main characteristics are:
- Drought resistance: Sorghum stands out for its remarkable tolerance to water scarcity.
- Short vegetative period: The life cycle of sorghum can vary between 90 and 120 days depending on the variety and climatic conditions.
- Multiple use: In addition to being a staple food grain, sorghum is used in the production of fodder, flour, syrups, beverages, thickeners, and biofuels.
- Adaptability: This plant can grow in sandy, clayey or mixed soils, even tolerating certain salinity or alkalinity in the soil, although optimal development occurs in soils with a pH between 5,5 and 7,5.
- Ease of machining: Its agronomic characteristics allow it to be perfectly used with mechanized sowing and harvesting methods.
Importance and distribution of sorghum
Sorghum is the fifth most cultivated cereal worldwide. Major producers include African, Asian, and American countries. In Latin America, nations such as Argentina, Brazil, Mexico, Colombia, Ecuador, Peru, and Venezuela have increased the area planted with sorghum due to its agronomic and nutritional benefits.
Sorghum originated in Africa, from where it spread to Asia and later to the rest of the world. Archaeological records show that it was one of the first cereals domesticated by humans.
Among the reasons why sorghum is so important in agriculture are:
- Low production cost per hectare
- Its nutritional value (rich in carbohydrates, fiber and minerals, low in fat)
- Climate and soil adaptation capacity
- Usefulness in soil conservation and erosion prevention thanks to its extensive root system
Stages of sorghum development
The sorghum plant goes through nine main stages during its vegetative cycle:
- Leaf expansion: Three leaves with visible ligules.
- Appearance of new leaves: Up to five leaves with visible ligules.
- Maximum growth: Between 30 and 40 days, the plant absorbs the greatest amount of nutrients and reaches its maximum height.
- Stem elongation: The leaf area increases significantly.
- Boot condition: The potential number of grains is determined.
- Flowering (50%): Beginning of flowering, a critical period for grain production.
- End of flowering: The formation of pimples begins.
- Grain development: The grain reaches 75% of its development and begins to harden.
- Physiological maturity: The grain reaches its highest dry weight and is ready for harvest.
Climate requirements for sorghum cultivation
The adaptability Sorghum's ability to adapt to different climates is one of its competitive advantages. It can grow in semi-arid areas and withstand periods of drought that would severely affect other crops.
- Optimum temperature: Between 26 and 27°C, although germination is efficient from 15°C. Development is optimal at temperatures of 25 to 30°C.
- Sunlight: It requires 6 to 8 hours of direct sunlight per day. Light is vital throughout all stages, especially during the vegetative phase; however, during periods of extreme heat, it can tolerate some shade.
- Precipitation: It prefers annual rainfall between 400 and 600 mm, but its deep root system allows it to survive even in periods of low rainfall.
- Radiation sensitivity: During the flowering stage, sorghum can become sensitive to excess light and heat, which affects flower formation and grain filling when combined with water deficit.
Soil requirements and site preparation
Sorghum is flexible to soil type, but to obtain a excellent performance it is recommended:
- Well-drained clay soils and with the presence of clay in deep layers for water retention.
- Optimum pH between 5,5 and 7,5. Although it can tolerate some salinity and alkalinity, acidic pH negatively affects its development.
- Avoid puddles: It can tolerate brief flooding, but prolonged waterlogging reduces production and promotes root diseases.
- Improve the soil by adding organic fertilizers such as compost or aged manure before planting.
Soil preparation for sowing sorghum
Proper soil preparation is essential to ensure successful sowing and sorghum development:
- Initial cleaning: Remove plant debris, stones, waste and weeds.
- Deep tillage: Plow the soil 20 to 30 cm deep to break up compaction and improve aeration.
- Leveling and tracking: Rake the soil to obtain a uniform texture that facilitates sowing and seed-soil contact.
- Sewer system: In wet soils, create raised ridges or rows to prevent water accumulation.
- Background fertilizer: Incorporate organic fertilizers or base fertilizers according to the results of soil analysis.
Selection of sorghum seeds and varieties
The choice of variety of sorghum It depends mainly on the end use and agroclimatic conditions:
- Grain sorghum (milo): Cultivated to obtain seeds, used in human and animal food.
- Forage sorghum: Produced for its high biomass yield and nutritional value for livestock.
- Sweet sorghum: Rich in sugars, it is used to make syrups, fermented beverages and biofuels.
The quality seeds They should be large, fresh, free of impurities, and selected for disease resistance and regional adaptability. Remember to consult with local agricultural experts to learn about the best options in your area.
Optimal time and planting techniques for sorghum
La sowing sorghum It is usually done in late spring or early summer, making sure to do it after the last frost.
- Minimum soil temperature for sowing:
- Recommended planting depth: Between 2,5 and 5 cm. In sandy soils, you can dig deeper, but in heavy soils, do not dig deeper than 2,5 cm.
- Distance between rows: Between 18 and 75 cm, depending on the variety and the objective of the crop (greater biomass or greater grain production).
- Distance between floors: Adjust according to the required density, so that they do not compete excessively for resources.
Sowing can be done manually (seed scattering) or with a seeder (direct sowing), preferably uniforming the distance and depth to maximize germination.
In late sowing, it is recommended to increase the density by 15 to 20% to compensate for the lower tillering capacity (emission of productive tillers).
Sorghum Fertilization: Keys to Healthy Development
This cereal requires a balanced fertilization to ensure its performance. Prior soil analysis is essential to determine the appropriate dosage.
- Nitrogen (N): Essential for vegetative growth and grain formation (guideline dose: 80-120 kg/ha).
- Phosphorus (P) and potassium (K): Essential for root development and stress resistance (suggested dose: 40-60 kg/ha each).
- Secondary elements: Sulfur improves nitrogen use efficiency, magnesium and zinc contribute to overall plant vigor and hardiness.
Application is usually split: phosphorus and potassium are provided primarily as a top dressing at planting time, while nitrogen can be split between planting and early development stages.
Irrigation and water management of sorghum
Despite its drought tolerance, sorghum responds positively if irrigation is properly planned, especially at critical stages:
- During germination: Overwatering is generally not necessary; maintaining moisture is sufficient to promote initial rooting.
- At flowering and grain filling: If it does not rain, supplementary irrigation is essential to achieve good grain size and quality.
Avoid excess water and ensure good drainage; waterlogging is a risk factor for root diseases and yield reduction. For more information on sorghum pests, see pest control and insect benefits.
Sorghum care during the growing cycle
During its development, sorghum requires careful agronomic practices to maximize production:
- Weed management: Weeds are the main threat during the first few weeks. Chemical control (pre-emergence herbicides) and mechanical control (hoeing, weeding) are necessary to prevent competition for vital resources.
- Pest monitoring and control: Among the main enemies of sorghum are the sorghum midge, aphids, the ear bug, the stem borer, weevils, and the fall armyworm. Integrated control, with frequent monitoring, the use of resistant varieties, and crop rotation, is essential.
- Disease prevention: Sorghum is vulnerable to more than 50 diseases, including fusarium wilt, downy mildew, anthracnose, smut, and panicle blight. Early identification and application of specific pesticides or fungicides are recommended, in addition to choosing treated seeds or resistant varieties.
Main pests and diseases of sorghum
Diseases and pests They vary by region and environmental conditions, but these are the most common:
- Pests: Flea beetle, aphids, weevil, fall armyworm, ear fly and bug.
- Diseases: Fusarium wilt, corn leaf stripe virus, downy mildew, anthracnose, smut, root rot, and panicle blight.
Duration of the growth and maturation cycle
La sorghum cycle length It depends on the variety and temperature. In warm environments, some varieties reach maturity in 90–110 days, while others may require up to 140 days or even longer in less favorable conditions. When average temperatures drop below 20°C, the cycle lengthens and can exceed 250 days in very cold regions. For proper management, it is important to consult the specific characteristics of the cultivated variety and local climatic conditions.
Harvesting and storing sorghum
The optimal time to harvest sorghum is when the grains have reached physiological maturity. Some signs are:
- Presence of a black spot at the base of the grain.
- Moisture content between 20% and 25% (ideal for starting the harvest).
- Dry leaves and stems.
Harvesting can be done manually on small plots of land, but in extensive crops, calibrated harvesters are used to separate leaves and stems.
It is important to dry the grain to a moisture content below 13% before storage to prevent mold and spoilage. Proper storage helps maintain the quality and properties of sorghum over the long term.
Agronomic benefits and environmental advantages
- Rotation and conservation: Sorghum contributes to soil conservation and helps prevent erosion, thanks to its robust root system.
- Tolerance to adverse conditions: It is drought resistant, tolerates low fertility soils and some varieties can be grown in saline or alkaline conditions.
- Livestock value: Its high biomass production makes it ideal as fodder.
- Production of biofuels and industrial foods: Sweet sorghum is an effective raw material for the production of ethanol and syrups.
Extra tips and best practices for growing sorghum
- Plan the planting depending on the climatic conditions of your region and the final use of the grain.
- Perform frequent health monitoring to detect any pest or disease problems early.
- Perform periodic soil analysis to adjust fertilization and maintain fertility in the medium and long term.
- Implement crop rotation and uses plant remains as green manure to improve soil conditions.
- Educate yourself and consult reliable sources or precision agriculture platforms to improve agronomic practices and locate the best resources in inputs and varieties.
Sorghum is one of the most resilient and versatile crops currently grown in global agriculture. Due to its drought resistance, ease of management, low production costs, adaptability to diverse soils, and multiple industrial and food applications, this crop remains a strategic option for both small and large-scale farmers. With proper planting planning, phytosanitary management, and sound resource management, this crop can guarantee stable harvests and contribute to the sustainability of agricultural systems.
