Page 18 - Vol.36-No.9 issue

CROP PROTECTION

plants avoid or overcome damping off
disease,” says Peter. DP98 is used in oth-
er countries where it is recognised to re-
duce seedling mortality rates caused by
damping off disease by bolstering root
and plant resilience.
Omex Combi (Micromax)
– foliar feeding for fast
growth

Plants removed from the nursey bed Soil removed from around a
Blossom end rot of tomato and transplanted into their final posi- tomato plant to show ‘tell-tale’
caused by a shortfall in calcium tions should be ready to take off with a swellings of the roots caused
may be avoided by foliar feeding corresponding thirst for nutrients, but by root knot nematodes (Picture
using Omex Calmax with its high are frequently thwarted by insufficiently courtesy Omex)
concentration of soluble calcium developed root systems and/or the un-
(Picture Dr Terry Mabbett) availability of nutrients due to prevailing foliar spray overrides any limited plant
soil conditions. availability of soil nutrients. Omex Com-
gal-inspired ‘damping off’ disease which Transplanted seedlings now shorn bi (Micromax) is used on the broadest
festers on soft, young plant growth in of root hairs are in a state of so-called spectrum of greenhouse crops including
crowded seedbeds and thrives on high ‘transplant shock’ and as such are unable tomato, capsicum peppers, aubergines,
humidity and leaf surface wetness. to secure and maintain uptake of water cucurbits, lettuce, brassicas, peas and
These soil-borne fungal pathogens and nutrients until a new complement of beans and grapes,” says Peter Prentis.
target and infect plants at different times root hairs is grown. “At no other time will Omex Calmax and Omex
in the seed germination and seedling plants benefit more from foliar feeding
establishment process to cause distinct with Omex Combi (Micromax) to pro- DP98 in tandem and
pre-emergence and post-emergence vide plants with a complete range of es- unison
phases of damping off. sential micronutrients in chelated form,”
In the pre-emergence phase seedlings says Peter Prentis. Omex Calmax and Omex DP98 work
are infected and killed just before they Root hairs are renewed and plant in tandem and unison, applied togeth-
reach the soil surface. Pre-emergence growth proceeds apace but other prob- er and operating together on the foliar
damping off is due to the rapid death of lems related to specific soil nutrient surface and in the plant tissue and cells.
the radicle (first root) and the plumule shortfalls may arise. “Periods of excep- This combination of Omex products
(first shoot) causing the complete rotting tionally rapid growth are the very times comes into play during the later stages
of seedlings. Post-emergence phase is when shortfalls of particular nutrients of crop cycles to ensure there is suffi-
characterised by infection of the collar are most likely to occur and show up cient plant available calcium to secure
(junction between root and shoot) at soil as nutrient deficiency symptoms. It is strength and quality of harvested pro-
surface level. The infected tissue be- worth remembering that the speed and duce. Omex Calmax supplies calcium
comes soft and water soaked and affect- success of overall crop plant growth and
ed seedlings topple over or collapse and development is dictated by the nutrient
hence the term ‘damping off’. which is in shortest supply,” says Peter
Prentis.
Nutrient deficiencies frequently oc-
cur when soil-based nutrients are plant
unavailable having become ‘locked up’
through interactions with other elements
and frequently caused by prevailing soil
pH (acidity/alkalinity). Zinc is a classic
case in point. Uptake of moderately mo-
bile zinc ions is generally inhibited by Omex products are sold
alkaline soil conditions and specifically throughout Saudi Arabia by its
The high degree of uniformity by soil phosphate interacting with zinc distributor Al-Yaseen Agricultural
Company seen here with a
shown by this crop of capsicum to form insoluble zinc phosphate. Simi- grower (Picture courtesy Omex)
pepper was achieved by larly, iron may be present in soils in con-
cultivation under protection and siderable quantities but unavailable to and Omex DP98 furnishes phosphite
the provision of foliar feeding growing plants due to high soil pH which ions which help to mobilise calcium and
(Picture courtesy Omex) generally prevails in the calcareous soils ‘carry’ the inherently immobile divalent
of Middle Eastern and Mediterranean calcium ions into the plant.
Damping off disease is caused by mul- basin countries.
tiple pathogens, including fungus-like I asked Peter how repeated applica- Making sure that plants and crops are
Phytophthora and Pythium and true fungi tions of Omex Combi (Micromax) could able to access sufficient calcium is one
such as Rhizoctoni and Fusarium. “Omex help in such situations. “Omex Combi of the biggest constraints even on calcar-
Nami applied during this early stage (Micromax) has a full complement of eous soils which ironically, as the name
generates stronger seedlings with more chelated micronutrients. Routine appli- suggests, are potentially high in calcium.
robust shoots and stems to help young cation of Omex Combi (Micromax) as a ‘Potentially’ is the ‘key’ word here be-

16 Vol. 36 No. 9