Food security occurs when all people are able to access enough safe and nutritious food to meet their requirements for a healthy life, in ways the planet can sustain into the future. However, food security faces a number of challenges due to low productivity from agriculture. Agriculture productivity has been adversely affected due to increasing global warming, drought, pest and disease, uncertain weather which are the major constraint for global food security. There are various agricultural inputs developed to overcome the constraints and enhance productivity. However among all agriculture inputs , seed is the most vital and crucial input for crop production and planting vigorous seed is one of the most effective ways to increase productivity without adding appreciably to the extent of land.
Seeds are central to crop production, human nutrition and food security. Seed is a fertilized mature ovule that possesses an embryonic plant, stored food material (endosperm) and a protective coat (testa), which is viable and has capacity to germinate. Not all seeds can germinate in every situation, only the high quality vigorous seed can germinate. Seed vigour is the sum total of all the attributes, which determine the potential level of rapid and uniform production of healthy seedlings stand establishment under a wide range of field conditions. Seed vigour is much essential to be considered for better crop stand and production in a changing environment. There are various factors affecting the seed vigour. The genetic factor is the most that affects the seed vigour. Some seeds are genetically susceptible to stress conditions while some are resistant and vigorous seed must be resistant to stress conditions. The normal sized seed without any mechanical and microorganisms damage, develops under favourable temperature and moisture with proper uptake of nutrients from fertile soil makes the seed vigorous. Vigour test can predict the potential of seed and helps to differentiate into low, medium and high vigour seed. The vigour test is done through following test:
Cold germination test : Cold germination test assesses the seedling ability to withstand the low temperature stress(5C-7C) typically experienced in early spring planting. The results are reported in two categories: Emergence and vigour. The benchmark for a high vigour seed lot is 80% emergence and 60% vigour.
Accelerated Aging Test : High Humidity and high temperature stress is imposed on the seed, which is incubated for a period of time under these conditions, then transferred to a growth chamber to assess germination potential. Seed lots that withstand these conditions, while maintaining germination rate 90% or above are considered high vigour.
Electrical Conductivity Test: The test evaluates the integrity of cell membrane and their ability to repair themselves during the soak period. Seed is soaked in deionized water for a short period of time, allowing sugar, starches and amino acids to leach from the seed. The higher the conductivity value of soak water, the lower the vigour.
Controlled Deterioration Test : It is used to predict storage and field planting potential. In this test, seeds are brought to 20% moisture and held at this value constantly during the deterioration period. Again, the seeds are transferred to the growth chamber and the germination potential assessed.
A key component of the performance of crop seed is the complex trait of seed vigour. Crop yield and resource use efficiency depend on successful plant establishment in the field, and it is the vigour of seeds that defines their ability to germinate and establish seedlings rapidly, uniformly and robustly across diverse environmental conditions. The high vigorous seeds have capacity to emerge through crusted soil too. They are resistant to different diseases and can grow healthy seedlings even in extreme cold or high temperature and pathogen infected soil.
No, food security isn’t realistic without vigorous seed. Climate change has become the global issue whose direct effect is observed in agriculture too. Drought is the major constraint in agriculture meanwhile agriculture also faces the challenges of pest and disease especially at seedling establishment period. In this situation the seed vigour plays an important role to produce healthy seedling by overcoming all these problems. The vast majority of crops produced in world agriculture begin with the sowing of seed to establish a new plant in the field. The successful seedling establishment is the first critical step for crop production that determines the success or failure of future harvest and the high vigorous seed always leads to successful seedling establishment even in extreme stress situations which ultimately increases production. Therefore to assure food security, vigorous seed is the most important input in agriculture.
