Physiological age and plant growth
Seed age and plant growth
Physiological age is determined by growing conditions, chronological age and storage conditions and
seed age affects plant growth to a great extend.
Seed -1 is physiologically young and is still in its apical stage.
Seed - 5 is physiologically old and has lost its growth vigour.
Crops from seed -1 have most vigour, but the number of stems is limited.
The best crops are from seed -2 and 3. These plants are vigorous, the number of stems is normal and the crop will not mature too early.
For a table crops "seed -2" may be the best and for seed crops "seed -3" may be preferred.
Seed of stage - 4 gives weak plants, but all tubers will emerge. The number of stems per seed is high, the crop is not vigorous and will mature early. The yield is low and tuber size of the yield is small.
Seed of stage - 5 has a delayed emergence or no emergence at all and produces weak plants.
Seed vigour
Growth vigour is the potential of a tuber to produce sprouts and plants rapidly under conditions favourable to growth.
Varieties behave differently with regard to growth vigour.
Varieties differ with regard to dormancy, sprout growth and storage characteristics.
As examples: Baraka and Diamant.
The variety Diamant has a relatively short dormancy and has moderately good storage characteristics. Diamant has a shorter growing period than Baraka. The variety Diamant fits well in a system where farmers grow two crops per year.
The variety Baraka has a longer dormancy and has good storage characteristics. The variety is suitable for farmers who store seed in natural ventilated stores for a relatively long period of time (eg more than 4 months).
The variety needs a longer growing period than Diamant.
It is evident that seed of the variety Diamant is stronger with regard to growth vigour then the variety Baraka.
Estimated growth vigour of seed of the variety Diamant and the variety Baraka. Growth vigour Diamant and Baraka
One of the characteristics of varieties with a wide adaptation is that the seed of these varieties has good physiological characteristics and is still suitable for planting after long storage under not too favourable conditions.