top of page

Crop characteristics and management- comprehensive guide


The objective of this guide is to provide information on various crop characteristics to help readers identify different crops. Understanding crop characteristics is essential for effective crop management, as it enables professionals to make informed decisions based on the specific needs of each plant species. The section will cover:

Morphological features: Learn the physical characteristics of various plants, including leaf shape, stem structure, root systems, flower types, and fruit types. Recognizing these characteristics will aid in the identification of crops in the field.

Growth habits and life cycles: Learn the various growth patterns (erect, spreading, prostrate) and life cycles (annual, biennial, perennial) of crops. This information will aid in crop management and crop rotation planning throughout the life cycle of plants.

Phenological stages: Understand the different stages of crop development, from germination to maturity. Knowing these stages is crucial for making timely management decisions, such as irrigation, fertilization, and pest control.

Environmental requirements: Learn about the specific temperature, light, and moisture requirements for various crops. This knowledge will help in selecting suitable crops for specific regions and optimizing their growth conditions.

Morphology

Common crops in South Carolina include corn, soybeans, cotton, peanuts, and wheat. These crops are grown in rotation with other crops to maintain soil health, control pests, and maximize yield.

Corn: Corn seeds are yellow. The average hybrid corn plant develops about 20–21 leaves, silks around 65 days after emergence, and matures around 125 days after emergence. Corn is one of the most widely grown crops in the world and is used for a variety of purposes, such as food, animal feed, and biofuel production. It is also an important source of carbohydrates, fiber, and essential nutrients in many diets.

Soybean: Soybean seeds are light yellow and shiny, nearly spherical, and 5–10 mm in size. The mature plant has palmately (radiating from a central point) compound leaves with netted veins, white or purple flowers at the nodes, and hairy stems. It is an annual crop. The plant is commonly grown for its edible seeds, which are high in protein and used in a variety of dishes. It is also known for its ability to fix nitrogen in the soil, making it a valuable crop for improving soil fertility.

Wheat: Wheat seeds are reddish-brown, naked, and 5–9 mm in size. The mature plant has a spike-type inflorescence (a cluster of flowers on a branch or system of branches), many awned lemmas (bristly, hair-like structures that protrude from the spikelets of some wheat varieties), and twisted veins that are oriented clockwise. The leaves are thinner and narrower than barley.

Cotton: Cotton seeds are small, brown, and smooth, with a long, white, and fuzzy fiber attached. The mature plant has lobed leaves, yellow or cream-colored flowers, and a woody stem. Cotton is typically grown as an annual crop and harvested for its fiber, which is used to make textiles.

Peanuts: Peanut seeds are small, oval-shaped, and covered with a thin, papery skin. The mature plant has compound leaves with four leaflets, yellow flowers that develop into "pegging" stems that grow into the soil, and a fibrous root system. Peanuts are typically grown as an annual crop and harvested for their nutritious kernels, which are consumed raw or roasted.

Other common crops in South Carolina include:

Sorghum: Sorghum seeds are small, round, and typically beige or white. The mature plant has long, narrow leaves, red or yellow flowers, and a tall, thick stem. Sorghum is typically grown as an annual crop and harvested for its grain, which is used for animal feed or processed into flour.

Sweet potatoes: Sweet potato seeds are actually roots, or "slips," that are planted in the soil. The mature plant has large, lobed leaves and trailing vines and produces edible tubers that are orange or purple in color. Sweet potatoes are typically grown as a perennial crop and harvested for their nutritious and delicious tubers.

Tobacco: Tobacco seeds are small and brown, and are typically sown in a seedbed before being transplanted to the field. The mature plant has large, broad leave, and produces clusters of small white or pink flowers. Tobacco is typically grown as an annual crop and harvested for its cured leaves, which are used for smoking or chewing.

Growth habits and life cycles

Growth Patterns of Crops

Erect: Erect plants have a vertical growth habit, growing straight upwards with limited branching. This growth pattern allows for efficient use of space and light, making erect plants ideal for high-density plantings. Crops such as corn, wheat, and barley typically exhibit an erect growth pattern.

Spreading: Spreading plants grow horizontally, branching out and occupying more ground area. This growth habit helps the plant cover the soil, reducing soil erosion and suppressing weed growth. Crops like peanuts, groundnuts, and some cultivars of soybean exhibit a spreading growth pattern.

Prostrate: Prostrate plants grow close to the ground, with stems that often trail along the soil surface. This growth pattern helps the plant tolerate harsh environmental conditions, such as strong winds or grazing animals. Prostrate growth is common in forage grasses, like creeping bentgrass and some clover species.

Life Cycles of Crops

Annual: Annual crops complete their entire life cycle—germination, growth, reproduction, and death – within a single growing season. These crops must be replanted each year. Examples of annual crops include corn, wheat, soybeans, and many vegetable crops.

Biennial: Biennial crops require two growing seasons to complete their life cycle. In the first season, these plants grow vegetatively, producing leaves and storing energy in their roots. In the second season, they flower, produce seeds, and then die. Examples of biennial crops include some varieties of onions, carrots, and beets.

Perennial: Perennial crops live for more than two growing seasons, and often for several years. They may produce flowers and seeds annually, or only after a certain number of years. Perennial crops have the advantage of not needing to be replanted each year, reducing labor and input costs. Examples of perennial crops include alfalfa, asparagus, rhubarb, and fruit trees.

Crop management and rotation planning

Understanding the growth patterns and life cycles of crops is crucial for effective crop management and rotation planning. By considering these factors, farmers can:

Optimize planting density: Aligning planting density with the growth pattern of the crop ensures efficient use of space, light, and resources, leading to higher yields.

Minimize soil erosion and suppress weeds: Planting crops with spreading or prostrate growth patterns can help reduce soil erosion and suppress weed growth, reducing the need for herbicides and tillage.

Enhance soil fertility and structure: Crop rotation, which involves alternating between crops with different life cycles, growth patterns, and nutrient requirements, can help maintain soil fertility and structure. For example, rotating legume crops (which fix nitrogen) with non-legume crops can improve soil nitrogen levels, reducing the need for synthetic nitrogen fertilizers.

Reduce pest and disease pressure: Rotating crops with different life cycles and growth patterns can disrupt the life cycles of pests and pathogens, reducing their populations and minimizing the need for chemical controls.

Growth Stages

This section describes the growth stages of agronomic crops such as corn, soybeans, small grains, forage legumes, and forage grasses, as well as South Carolina crops like cotton and peanuts.

Staging systems: Corn and soybeans use vegetative (V) and reproductive (R) stages. Small grains use the Feekes Scale, which includes seedling, tillering, stem extension, heading, and ripening stages. For forage legumes, the main stages are vegetative, bud stage, bloom, and pod stage.

Forage legumes: These plants develop a fleshy taproot for carbohydrate storage and are sensitive to photoperiod. The onset of flowering releases apical dominance, resulting in additional crown buds and vegetative growth from lower shoot buds.

Forage grasses: The apical and axillary buds remain close to the soil surface during tillering. Stem extension carries the apical dome up into the column of leaf sheaths. Root and tiller growth rates are at their maximum during cool weather in early spring and fall and are critical for carbohydrate storage and winter survival.

Corn: Corn is a staple crop in many parts of the world and is grown for its edible grain, which is used for food, animal feed, and biofuels. The growth stages of corn can be divided into vegetative (V) and reproductive (R) stages.

Vegetative stages:

V1: emergence - the seedling emerges from the soil and begins to grow. V2-V3: early leaf development - the plant develops its first two to three leaves and begins to grow rapidly. V4-V5: mid-leaf development - the plant develops four to five leaves and begins to form lateral roots. V6-V7: late leaf development - the plant develops six to seven leaves and begins to form a tassel. V8-VN: final leaf development - the plant develops eight or more leaves and begins to produce tillers or side shoots.

Reproductive stages:

R1: silking - the tassel emerges from the top of the plant and produces pollen, which fertilizes the silks on the ears. Silks are the long, thread-like structures that emerge from the tip of the ear and collect pollen for fertilization. R2: blister stage - the kernels on the ear begin to enlarge and fill with a milky fluid. R3: milk stage - the kernels continue to fill with a milky fluid and become more distinct. R4: dough stage - the kernels begin to harden and change from a milky to a doughy consistency. R5: dent stage - the kernels continue to harden and form a dent or depression on the top. R6: maturity stage - the kernels have fully matured and the plant begins to dry down and senesce.

Cotton: Cotton plants have a long growing season, typically 150–200 days from planting to harvest. The growth stages include emergence, vegetative growth, square formation, flowering, boll development, and boll opening. Square formation (R1) is the beginning of reproductive growth and marks the onset of flowering. Boll development (R2-R7) includes the formation and maturation of the cotton bolls, which contain the fiber and seeds that are harvested.

100–130 Peanut plants have a relatively short growing season of 100-130 days. The growth stages include emergence, vegetative growth, flowering, pegging, and pod development. Pegging (R3) is a unique growth stage where the flowers elongate and grow down into the soil to form the peanut pods. Pod development (R4-R7) includes the maturation of the pods, which contain the peanut kernels that are harvested.

Sorghum: Sorghum plants have a growth cycle of 90-120 days, depending on the variety and growing conditions. The growth stages include emergence, vegetative growth, heading, flowering, and grain development. Heading (Feekes 5) marks the beginning of reproductive growth and the emergence of the inflorescence. Grain development (Feekes 10.5) includes the maturation of the sorghum grain, which is harvested for animal feed or processed into flour.

Sweet potatoes: Sweet potato plants are typically grown as a perennial crop, with a growing season of 100-150 days. The growth stages include transplanting, vine growth, flowering, and root development. Root development (harvest) occurs when the vines start to yellow and die back, typically 90-120 days after planting. Sweet potato roots are harvested for their edible tubers, which can be boiled, baked, or mashed.

Tobacco: Tobacco plants have a long growing season of 120-150 days. The growth stages include seeding, transplanting, vegetative growth, flowering, topping, and harvesting. Topping (R6) is the removal of the top of the tobacco plant to promote leaf development and maturation. Harvesting (R7) occurs when the lower leaves have matured and turned yellow, typically 60-90 days after topping. The cured tobacco leaves are harvested and used for smoking or chewing.

Crop responses to conditions

In this section, we will discuss how crops respond to soil and weather factors, also known as "abiotic stresses." Understanding these responses is crucial for effective crop management and optimizing yields.

Mitscherlich's Law of Diminishing Returns: This law states that the increase in crop production due to a unit increment of a deficient factor is proportional to the decrement of that factor from the maximum. In simpler terms, the greatest response to fertilizer application occurs when fertilizer levels are low, while at high fertility levels, a smaller response is achieved with the addition of fertilizer.

Nitrogen application and tillering: Excessive nitrogen rates applied to small grain crops can stimulate excessive tillering, which in turn increases disease severity and lodging. This highlights the importance of carefully managing nutrient applications to avoid negative impacts on crop health and yield.

Drought stress: Crops are sensitive to water availability, and prolonged periods of low rainfall can result in reduced growth and yield. Some crops are more drought-tolerant than others, allowing them to survive and produce even under water-limited conditions.

Temperature stress: Crops have optimal temperature ranges for growth and development. Exposure to temperatures outside this range can cause stress, resulting in reduced growth, damage to plant tissues, or even crop failure. Cold stress can lead to frost damage, while heat stress can cause wilting, leaf scorch, and reduced photosynthesis.

Salinity stress: High soil salinity can negatively affect crop growth by reducing water uptake and causing nutrient imbalances. Some crops are more salt-tolerant than others, but in general, managing soil salinity is important for maintaining crop health and productivity.

Soil pH and nutrient availability: Soil pH affects the availability of nutrients, with certain nutrients becoming more or less available depending on the pH. Managing soil pH is crucial to ensuring optimal nutrient availability and crop growth. Crops vary in their ability to tolerate acidic soils. The general goal for most crops is to maintain a soil pH between 6.0 and 7.0. For barley and alfalfa, the optimum pH range is 6.5 to 7.0, while for corn, soybeans, wheat, and oats, it is 6.0 to 7.0.

Soil Drainage: Poorly drained soils have poor structure, aeration, and require more energy to raise soil temperature. These soils also experience nitrogen losses from denitrification. Proper soil drainage is essential for healthy crop growth. Denitrification is a process where nitrogen is converted into gas and lost to the atmosphere. To minimize nitrogen losses from denitrification, farmers can implement practices such as reducing soil compaction and applying nitrogen fertilizer at the right time and rate.

Temperature: Crop growth rate is influenced by temperature. Above the optimum temperature, growth rate decreases and can eventually stop. Tolerance to high temperatures varies among crops, with soybeans, cotton, and sorghum being more heat-tolerant.

Water requirements: Plant growth is proportional to the amount of water present, with growth restricted at both very low and very high soil moisture levels. Water is essential for carbohydrate synthesis, maintaining protoplasm hydration, and nutrient translocation.

Adaptation to precipitation extremes: Agronomically important crops have various adaptations to cope with extreme precipitation. Drought-tolerant crops, such as sorghum, have deep root systems and efficient water use, while flood-tolerant crops, like rice, can survive in standing water.

Growing Degree Days (GDD): GDD is a measure of accumulated heat for crop growth, calculated as (Temp Max + Temp Min - 50) ÷ 2 for each day. GDDs are used to predict crop development stages, such as silking and physiological maturity in corn, helping farmers make informed management decisions.

Understanding and managing these factors, such as soil pH, drainage, temperature, and precipitation adaptation, is vital for successful crop production. This knowledge is essential for crop advisors, agronomists, and anyone involved in agriculture and crop management.

Planting Timelines

In South Carolina, the planting timeline, fertilization and pesticide application schedules, crop adaptation to climate, and harvesting schedules for common crops can vary depending on the specific crop and regional conditions. Here is an overview of some common crops in South Carolina:

Corn: Planting: Usually planted from late March to early May. Fertilization: Pre-plant application of phosphorus and potassium, and split application of nitrogen (pre-plant and at V6 stage). Pesticide Application: Pre-emergence herbicides applied at planting, post-emergence herbicides and insecticides applied as needed based on pest scouting. Climate Adaptation: Corn requires a long growing season and is sensitive to drought and high temperatures during pollination. Harvesting: Generally harvested between late August and October.

Cotton: Planting: Usually planted from late April to early June. Fertilization: Pre-plant application of phosphorus and potassium, and split application of nitrogen (pre-plant, first square, and first bloom). Pesticide Application: Pre-emergence herbicides applied at planting, post-emergence herbicides and insecticides applied as needed based on pest scouting. Climate Adaptation: Cotton is drought-tolerant and prefers warm temperatures; however, it can be sensitive to cool temperatures during early growth stages. Harvesting: Generally harvested from September to November.

Peanuts: Planting: Usually planted from late April to early June. Fertilization: Pre-plant application of phosphorus and potassium, and in-season applications of calcium and boron. Pesticide Application: Pre-emergence herbicides applied at planting, post-emergence herbicides and fungicides applied as needed based on pest scouting. Climate Adaptation: Peanuts prefer warm temperatures and well-drained soils; they are sensitive to waterlogged conditions. Harvesting: Generally harvested from September to October.

Soybeans: Planting: Usually planted from late April to early June for full-season soybeans, and after wheat harvest for double-cropped soybeans. Fertilization: Pre-plant application of phosphorus and potassium, and in-season application of nitrogen if needed. Pesticide Application: Pre-emergence herbicides applied at planting, post-emergence herbicides and insecticides applied as needed based on pest scouting. Climate Adaptation: Soybeans are relatively drought-tolerant but can be sensitive to waterlogged conditions. Harvesting: Generally harvested from late September to November.

Wheat: Planting: Usually planted from late October to early December. Fertilization: Pre-plant application of phosphorus and potassium, and split application of nitrogen (pre-plant and at green-up). Pesticide Application: Pre-emergence herbicides applied at planting, post-emergence herbicides and fungicides applied as needed based on pest scouting. Climate Adaptation: Wheat is a cool-season crop and is more tolerant of cooler temperatures than warm-season crops. Harvesting: Generally harvested from June to early July.

Please note that these timelines and schedules can vary depending on local climate conditions, specific crop varieties, and management practices. It is essential to consult with local agricultural extension services or crop advisors for the most accurate and up-to-date recommendations.

Drones and precision agriculture

In this discussion, we have explored various aspects of crop growth and development, focusing on the response of crops to soil and weather factors, optimal pH ranges for different crops, and the growth stages of corn, soybeans, and small grains. We also covered the staging systems for forage legumes, anatomical features of major crops, and the planting timeline, fertilization, pesticide application, climate adaptation, and harvesting schedules for common crops in South Carolina.

Precision agriculture has the potential to revolutionize crop management, making it more efficient, sustainable, and cost-effective. As a precision agriculture business specializing in custom application of pesticide and fertilizer with spraying drones, you can utilize the information we've discussed to optimize your services for different crops and their specific growth stages, soil, and climate requirements.

Drones can be used in various ways, such as:

Soil and field analysis: By capturing high-resolution imagery, drones can help assess soil conditions, optimize irrigation, and identify areas that need specific nutrient management.

Crop health monitoring: Drones equipped with multispectral sensors can help detect crop stress, diseases, or pest infestations, allowing for targeted pesticide and fertilizer application at the right time and place.

Fertilizer and pesticide application: drones can efficiently and accurately apply fertilizers and pesticides, reducing the amount of chemicals needed, protecting the environment, and saving time and labor costs.

Planting and harvesting assistance: Drones can monitor crop growth stages and provide valuable information to help plan planting and harvesting schedules, ensuring optimal yields.

By combining the knowledge of crop growth stages, soil conditions, and weather factors with drone technology, you can offer tailored, efficient, and eco-friendly crop management solutions to your clients, ultimately enhancing their crop productivity and sustainability.

10 views0 comments
bottom of page