The document discusses rejuvenation of old or senile orchards as a way to restore their productive capacity. It describes how orchards become uneconomic over time due to issues like wild shrub growth, overcrowding of trees, damage from weather/pests, and use of inferior varieties. Rejuvenation involves pruning trees to renew growth from latent buds and improve the root to shoot ratio. Examples provided include heading back mango and guava trees to develop a new canopy in 2 years and increase yields by 4-5 times.