Seed Replacement Rate (SRR) indicates the percentage of cropped area sown with certified/quality seeds relative to farm-saved seeds.
In the case of $F_1$ hybrids (e.g., in maize, pearl millet, sorghum, cotton, rice):
Farmers cannot save and reuse $F_2$ grain as seed because segregation and recombination in the $F_2$ generation causes heterosis breakdown, high morphological variability, and a drastic yield depression of 20-35%.

Maize (Zea mays) is a monoecious crop with unisexual flowers separated on the same plant: the terminal staminate inflorescence is the tassel, while the lateral pistillate inflorescence is the ear/cob.
In commercial hybrid maize seed production plots:
Male (pollen parent) and female (seed parent) inbred lines are planted in alternating row ratios (e.g., 2 male : 4 female or 2 male : 6 female).
Before anthers begin shedding pollen, the tassels of all plants in the female rows are manually removed (detasseling) or genetically sterilized (CMS).
This ensures that female plants receive pollen exclusively from the adjacent male rows.

Standard ecological terms describing seed and diaspore dispersal mechanisms include:
Autochory: Self-dispersal by the plant itself (e.g., explosive pod dehiscence in legumes or balsams).
Hydrochory: Dispersal by water currents (e.g., coconut, water lilies).
Zoochory: Dispersal mediated by animals (endozoochory via ingestion, epizoochory via burrs/hooks).
Anemochory: Dispersal by wind currents.
'Zerochory' is a fabricated term and does NOT exist in botanical literature.