It is very important for a grower to start with high quality, disease-free seed.

Seed production areas that have endemic populations of the disease organisms and stricter governmental regulations that limit the use of pesticides are making the path to this objective a true challenge.

The seed industry has responded by developing various seed technology methods such as mechanical cleaning, disinfection procedures and specialized coatings in an attempt to eradicate seedborne microbial organisms and/or pathogens. Disinfection methods that are in use include treatments with hot water, calcium hypochlorite, ozone or UV-C radiation.

Some of these techniques are well known and widely used by the seed industry. Unfortunately they are not always successful in eradicating the targeted pathogen and all too often they have a negative influence on seed quality and result in a loss of shelf-life.

INCOTEC has ongoing research projects, which are focused on developing methods for the eradication of specific seedborne pathogens. A result of this research is a product range offered to the seed industy under the name "eXccit". The main advantage of this product is that it is effective, while being gentle to the seed. The resulting seed is free of the pathogen (0 infection in 30,000 seeds, using the best test methods available). On the other hand the seed germination characteristics remain equal or are even slightly improved, i.e. faster germination.

eXccit is a product that combines specific priming and disinfection technologies. In extensive tests the combination has been fine-tuned to obtain a treatment that combines the benefits from both technologies. This combination provides the optimal conditions for eradicating the targeted pathogens, while using the priming process to alleviate the putative negative effects.

eXccit has also successfully been used on a number of other crops infected by Xanthomonas spp. (see table 1)
 

eXccit products Targeted pathogen Brassica   Xanthomonas campestris pv. campestris Xanthomonas campestris pv armoraceae Carrot Xanthomonas campestris pv. carotae Leek Pseudomonas syringae pv porii Pepper Xanthomonas campestris pv. vesicatoria Tomato Xanthomonas campestris pv. vesicatoria Clavibacter michiganensis

Seed produced under natural conditions are not free of micro-organisms and commonly have a microbial population that includes bacteria, fungi and even some viruses. Usually this microbial population is made up of non-pathogens, or relatively harmless microbes. However, even these relatively harmless organisms can cause problems if their numbers become too high. They may cause for instance a decrease in germination capacity or loss of healthy seedlings.

INCOTEC has long recognized the need for the control of the microbial population and has developed procedures to also effectively deal with this problem during the seed priming process. Although priming is a good tool to enhance the quality of the seed, during priming microbes can and will increase in numbers if nothing is done for their control. 

Table 2
Effect of clean priming of cucumber seed on germination rate (GE) and capacity (GC), tested under sub-optimal conditions at 16° C.  Level of bacteria and fungi expressed in colony forming units per gram seeds.

Table 3
Effect of clean priming of tomato seed on germination and micro-organism level. Erwinia is an example of a putative problem causing micro-organism. GE = germination rate, GC = germination capacity. Bacteria and fungi level is expressed in colony forming units (cfu) per gram seeds.