Explore important agronomic practices and decision points in the successful cultivation of castor as a commercial crop. Improve your understanding of castor crop requirements, pest management, and harvesting techniques.
What is generally considered the best time to sow castor seeds in tropical regions to maximize crop establishment and yield?
Explanation: The early monsoon season provides adequate soil moisture for castor seed germination and good initial growth. Peak summer is usually too hot and dry, while late winter and end of the dry season both lack the consistent rainfall needed for optimal establishment.
Which is the recommended seed rate (quantity per hectare) for sowing castor under normal spacing conditions?
Explanation: A seed rate of 8–10 kg/ha is suitable for proper plant population and healthy crop stand in most conditions. Higher rates like 20–25 kg/ha or 15–18 kg/ha lead to overcrowding, while 3–4 kg/ha is generally insufficient for uniform field coverage.
What is the ideal row-to-row spacing for castor cultivation to allow healthy growth and easy field management?
Explanation: A spacing of 90 cm x 60 cm ensures sufficient airflow and sunlight while facilitating weed and pest control. Narrower spacings like 30 cm x 10 cm or 45 cm x 15 cm can cause competition, whereas 150 cm x 120 cm is too wide and wastes field space.
Which pest is most commonly considered serious for castor crops, often attacking young capsules and reducing yield?
Explanation: Castor semilooper larvae feed on leaves and young capsules, posing significant yield threats. Cotton bollworm and rice weevil are more associated with other crops, and red spider mite is a pest but less damaging than semilooper for castor.
Which sign indicates that castor capsules are ready to be harvested to obtain high-quality seeds?
Explanation: Brown and dry capsules signify full maturity and readiness for harvest, ensuring best oil content and quality. Green or swollen capsules are immature, new leaf growth is not a harvest indicator, and yellow sticky pods are not typical for castor.