4
COLUMNIST
Biostimulants:
A Boon To Flower Growers
What exactly are plant biostimulants?
Dr. Samuel Nyalala, Department of Crops, Horticulture and Soils, Egerton University, Kenya
Kenya’s ascension to global leadership in cut
flower production is largely attributed to the
quality and quantity of its floral produce.
While effective nutrition, irrigation and
crop protection remain the main drivers for
increased yield and improved quality of cut
flowers, growers strive to improve the nutrient
status of their crops to cushion the plants
against pests and diseases and abiotic stresses
using plant biostimulants.
It is imperative to put into perspective what
plant biostimulants are by asking some
pertinent questions; what exactly are plant
biostimulants? What advantages do growers
derive from using these products? How do
they impact plants? What should a grower
consider before purchasing a plant
biostimulant?
This article attempts to
answer these questions
among others.
Plant
biostimulants
are defined as organic
materials other than
fertilizers
that,
when
applied in small quantities,
enhance plant growth and
development.
Commercially
6
available
biostimulants
comprise of formulations of compounds,
substances and other products including:
microorganisms, trace elements, enzymes,
plant growth regulators and extracts that
are foliar applied or drenched in the growing
media to manipulate and enhance the
physiological processes in crops. However,
plant biostimulant products are broadly
grouped as: products containing hormones,
humic substances, amino acids, manure and/
or sea plant extracts.
Growers use plant biostimulants for a number
of reasons. The biostimulants may enhance
nutrient availability and metabolism, improve
water-holding capacity of the growing media,
and increase production of chlorophyll and
antioxidants.
Specifically, they facilitate the
absorption
and
transport
of nutritional macro and
microelements
thereby
reducing
fertilizer
use,
increase root and shoot
growth, enhance resistance
to stress and improve water
uptake.
These results in reduced
transplant shock, increased
resistance to water and
temperature stresses, enhanced