}]]}]}]}] 30:T2f4e,

### Introduction Agronomy focuses on field crop production while sustaining soil resources and the environment. Crops are categorized based on their agronomic, industrial, and nutritional uses to facilitate description and naming. ### Key Concepts - Crops are classified by **agronomic use, nutritional use, life cycle, and climate adaptation**. - **Agronomic crops** include cereals, grains, pulses, forages, fiber crops, cover crops, companion crops, green manure crops, and recreational turf crops. - **Bioenergy** can be produced from grain crops, forage crops, and oil crops. - **Nutritional-use classification** includes sugar crops, oil crops, protein crops, starchy seed crops, and root and tuber crops. - Crops can be grown for **medicinal purposes**. - Many plants are **toxic or deadly** to people and livestock. - Plants are scientifically described using **two-part scientific names** (genus and species). - **Taxonomy** is a system for organizing plants into species, families, orders, classes, and divisions. ### Divisions of Plant Kingdom - A crop is an organism cultivated and harvested for yield. - Plant kingdom divided into two divisions: - **Phanerogams** (flowering plants) further divided into Angiosperms. - **Angiosperms** further divided into two classes: **Monocotyledon & Dicotyledons**. - Classes are divided into orders, orders into families, families into genera & species, sometimes species into varieties. ### Importance of Classifying Crop Plants - Familiarization with crops. - Understanding soil and water requirements for different crops. - Knowing crop adaptability and growing habits. - Understanding climatic requirements. - Knowing the economic produce and use of crop plants. - Knowing the growing season of the crop. ### Classification by Climate - **Tropical:** Crops grow well in warm & hot climates. - **Temperate:** Crops grow well in cool climates. - **In Sri Lanka:** Upcountry Crops, Low Country Crops. ### Classification by Life Cycle (Ontogeny/Duration) - **Annual crops:** Complete life cycle in one season/year (e.g., rice, cassava). - **Biennial crops:** Grow vegetatively in one season, flower/fructify/perish in the next (e.g., sugar beet, carrot). - **Perennial crops:** Live for several years, growing and reproducing (e.g., sugarcane, fruit trees). ### Classification by Growing Season - **Maha season crops:** Grown in monsoon months (Sept/Oct-Nov), requiring warm, wet weather and short day length for flowering (e.g., Rice, Cassava). - **Yala season crops:** Short season crops grown with limited water from April/May to July (e.g., Pulses, Sesame). - **Inter-season crops:** Grown between conventional seasons, requiring warm day weather for major growth and flowering (e.g., Groundnuts, Watermelon, Pumpkins, Gourds). ### Use/Agronomic Classification #### Grain Crops - Cultivated grasses (Poaceae) grown for edible starchy grains. - Larger grains are staple foods (cereals). - Examples: Wheat, rice, corn, barley, sorghum. - **Cereal crops:** Grasses that produce edible grain, storing energy as starch (e.g., wheat, rice, corn). - **Grain crops:** Harvested portion of various grass crops; also includes legumes (soybean, kidney beans) and other plants (flax, buckwheat)