In the fertile Thanjavur delta of Tamil Nadu, which crop is intensively cultivated and grown three times in a year under irrigation?

Introduction / Context:
The Thanjavur delta, also called the rice bowl of Tamil Nadu, is one of the most important irrigated agricultural regions in India. Understanding which crop is cultivated there multiple times a year helps connect irrigation, river systems and cropping patterns in Indian agriculture.

Given Data / Assumptions:
• The region mentioned is the Thanjavur delta in Tamil Nadu. • The question asks which crop is cultivated three times in a year in this irrigated delta. • The options include wheat, rice, sugarcane and groundnut.

Concept / Approach:
The Thanjavur delta is formed by the Kaveri River and its distributaries. With abundant irrigation water, warm temperatures and suitable soils, farmers here practice intensive paddy cultivation. Rice, which requires standing water during much of its growing period, is ideally suited to this environment and is the dominant crop with multiple seasonal harvests such as samba, kuruvai and thaladi. Wheat, sugarcane and groundnut are grown in other regions but do not match the classic three crop pattern of rice in this delta.

Step-by-Step Solution:
Step 1: Recall that Thanjavur is widely known as a rice bowl due to extensive paddy fields. Step 2: Understand that the presence of perennial irrigation from the Kaveri system allows farmers to plant rice in more than one season each year. Step 3: Observe that wheat is mainly a rabi crop suited to cooler northern plains, while sugarcane is a long duration cash crop that usually occupies a field for many months and is not planted three times in a year on the same land. Step 4: Conclude that rice is the crop which fits the description of being cultivated three times in a year in the Thanjavur delta.

Verification / Alternative check:
Agricultural profiles of Tamil Nadu and standard school texts consistently refer to three rice seasons and multiple paddy crops in the Thanjavur delta region. No such reference exists for wheat or groundnut as triple crops on the same land in this particular delta, and sugarcane usually remains in the field too long for three crops per year on one plot.

Why Other Options Are Wrong:
Option A (Wheat) is mostly grown in the cooler north as a winter crop and is not a main triple crop in the hot and humid Thanjavur delta. Option C (Sugarcane) is an important commercial crop in parts of Tamil Nadu but has a long growing period and therefore does not fit a three crops per year pattern on the same field. Option D (Groundnut) is grown in some parts of peninsular India but does not define the Thanjavur delta agriculture in the way rice does.

Common Pitfalls:
• Some learners may think of sugarcane whenever they see the word delta or irrigation, and choose it without considering crop duration. • Others may overlook that Thanjavur is famous specifically for paddy cultivation, which makes rice the obvious answer when multiple crops per year are mentioned.

Final Answer:
In the Thanjavur delta, the crop cultivated three times a year is rice.