SOME PHYSIOLOGICAL AND ENVIRONMENTAL CONDITIONS THAT PROMOTE SEED PRODUCTION

Good growth conditions in general also promote good flowering. An ample flowering is a precondition for abundant seed production. In addition to good growth conditions in terms of soil and climate, flowering/fruiting also requires excess light and effective pollination. The main ecological factors that promote flowering/fruiting are the following:

1. Optimal soil conditions * (pH, fertility, structure, drainage, etc.)
2. Optimal climate (water, light, temperature, etc.)
3. Optimal conditions for pollination (pollination agent, synchronized flowering, etc.)
4. Reduced root competition (for water and nutrients).
5. Reduced crown competition (for light).

*Note: An average soil fertility is preferred since too fertile soil often promotes vegetative growth on the expense of flowering and fruiting.

Internal factors within the plant also influence flowering and seed production. Many trees do not produce a heavy seed crop every year. An abundant seed crop usually occurs when a period of accumulating nutrient resources in the trees is followed by a (brief) physiological stress period, which may be environmental or man-imposed. Following physiological factors promote heavy fruiting:

1. High level of internal resources in the plant.
2. Effective pollination (compatibility, timing).
3. Necessary level of flower promoting hormones.
4. Brief stress condition during flower differentiation.*
5. Optimum nutrient and water supply during fruit development.

*Note: Various plants may react differently to stress factors.

Some of the above factors are site specific and must be taken into some consideration when allocating the site for the seed orchards (see below). Others can be manipulated through proper management practice.