TYPES OF CROP YIELDS

TYPES OF CROP YIELDS

Cereals such as wheat, rice, maize, millets, and sorghum provide us carbohydrates for energy requirements. Pulses like gram (chana), pea (matar), black gram (urad), green gram (moong), pigeon pea (arhar), lentil (masoor), provide us with protein. And oil seeds including soyabean, groundnut, sesame, castor, mustard, linseed, and sunflower provide us with necessary fats (Fig. 15.1). Vegetables, spices, and fruits provide a range of vitamins and minerals in addition to small amounts of proteins, carbohydrates, and fats. In addition to these food crops, fodder crops like berseem, oats, or sudan grass are raised as food for the livestock.

Figure 15.1: Different types of crops

Different crops require different climatic conditions, temperature,s, and photoperiods for their growth and completion of their life cycle. Photoperiods are related to the duration of sunlight. Growth of plants and flowering are dependent on sunlight. As we all know, plants manufacture their food in sunlight by the process of photosynthesis. There are some crops, which are grown in the rainy season, called the Kharif season from the month of June to October, and some of the crops are grown in the winter season, called the rabi season from November to April. Paddy, soyabean, pigeon pea, maize, cotton, green gram, and black gram are Kharif crops, whereas wheat, gram, peas, mustard, linseed are rabi crops.

In India, there has been a four times increase in the production of food grains from 1952 to 2010 with only 25% increase in the cultivable land area. How has this increase in production been achieved? If we think of the practices involved in farming, we can see that we can divide it into three stages. The first is the choice of seeds for planting. The second is the nurturing of the crop plants. The third is the protection of the growing and harvested crops from loss. Thus, the major groups of activities for improving crop yields can be classified as:

*   Crop variety improvement

*   Crop production improvement

*   Crop protection management.

Questions

1.  What do we get from cereals, pulses, fruits, and vegetables?

​​​​​​​

Source: This topic is taken from NCERT TEXTBOOK

CROP VARIETY IMPROVEMENT

CROP VARIETY IMPROVEMENT

This approach depends on finding a crop variety that can give a good yield. Varieties or strains of crops can be selected by breeding for various useful characteristics such as disease resistance, response to fertilisers, product quality, and high yields. One way of incorporating desirable characters into crop varieties is by hybridisation. Hybridisation refers to the crossing between genetically dissimilar plants. This crossing may be intervarietal (between different varieties), interspecific (between two different species of the same genus), or intergeneric (between different genera). Another way of improving the crop is by introducing a gene that would provide the desired characteristic. This results in genetically modified crops.

For new varieties of crops to be accepted, it is necessary that the variety produces high yields under different conditions that are found in different areas. Farmers would need to be provided with good quality seeds of a particular variety, that is, the seeds should all be of the same variety and germinate under the same conditions.

Cultivation practices and crop yield are related to weather, soil quality, and availability of water. Since weather conditions such as drought and flood situations are unpredictable, varieties that can be grown in diverse climatic conditions are useful. Similarly, varieties tolerant to high soil salinity have been developed.

Some of the factors for which a variety of improvement is done are:

*   Higher yield: 

To increase the productivity of the crop per acre.

*   Improved quality:

Quality considerations of crop products vary from crop to crop. Baking quality is important in wheat, protein quality in pulses, oil quality in oilseeds, and preserving quality in fruits and vegetables.

*   Biotic and abiotic resistance:

Crops production can go down due to biotic (diseases, insects, and nematodes) and abiotic (drought, salinity, waterlogging, heat, cold, and frost) stresses under different situations. Varieties resistant to these stresses can improve crop production.

*   Change in maturity duration:

The shorter the duration of the crop from sowing to harvesting, the more economical is the variety. Such short durations allow farmers to grow multiple rounds of crops in a year. Short duration also reduces the cost of crop production. Uniform maturity makes the harvesting process easy and reduces losses during harvesting.

*   Wider adaptability:

Developing varieties for wider adaptability will help in stabilising the crop production under different environmental conditions. One variety can then be grown under different climatic conditions in different areas.

*   Desirable agronomic characteristics:

Tallness and profuse branching are desirable characters for fodder crops. Dwarfness is desired in cereals so that less nutrients are consumed by these crops. Thus developing varieties of desired agronomic characters help give higher productivity.

Questions

1.  How do biotic and abiotic factors affect crop production?

2.  What are the desirable agronomic characteristics for crop improvements?

Source: This topic is taken from NCERT TEXTBOOK