Resource Book on Horticulture Nursery Management

Organic Mulch: Wood Chips/Shavings Inorganic Mulch: Polythene Sheet
Characteristics of Good Mulching Materials
It should be easily and cheaply available. Material should not act as an alternate host
for pest and disease. It should be easily degradable.
Application of Mulching
Mulching material in general should be placed over the beds immediately after
sowing and removed after the seedlings have germinated and have attained sufficient
height or when the danger of frost or high temperature is over.
5.2.3 Plant Growth Regulators (PGR) in Nursery
Plant growth regulators are the chemical compounds other than nutrients which are
required in small or minute quantities to regulate modify or inhibit the plant physiological
processes.
Plant Hormones
Plant growth hormones are the chemical compounds synthesized by the plant inside
its body and transported from site of production to site of action to regulate, modify or
inhibit the plant physiological processes
Types/Groups/Classes of Plant Growth Regulators (PGR)
1. Gibberellins: Play important role in cell elongation in plant cells e.g., Gibberellic
Acid GA1, GA3, GA7
2. Auxines: Play important role in cell division and cell multiplication. These
substances are used mainly for the root initiation, e.g., Indol Acetic Acid (IAA), Indol
Butaric Acid (IBA) and Naphathalic Acetic Acid (NAA).
3. Cytokinins: Play important role in cell elongation, e.g., Kinetin, Zeatin
4. Abscisic Acid: Growth retarding substance and plays an important role in fruit drop
and thinning, e.g., ABA
5. Ehtylene: Mainly called as ripening hormone which hastens ripening in fruit crops.
Ethrel also useful for sex expression in cucurbitaceous vegetable crops. Eg, Ethephon,
Ethrel.
<strong>Resource</strong> <strong>Book</strong> on Horticulture Nursery Management : 102