IES uses innovative methods to help herbs and vegetables outgrow weeds

Since March 2019 researchers from the Institute for Environmental Solutions (IES) together with farmers from SIA “Vidzemes mežsaimnieks” and SIA “Damuižnieki” have been developing innovative seed preparation technologies for pre-sowing and sowing of slow growing plants. In the interview leading researcher Dr. Ieva Mežaka highlights the importance of seed preparation, research activities and the future endeavours.

IES: Why the preparation of seeds of herbs and vegetables before sowing is needed?

IM. Not all seeds can sprout within few days. For this research we chose herbs and vegetables that usually takes 14 to 24 days to sprout – dill, coriander, thyme, marigolds, carrots and onions. As it takes so long, weeds manage to sprout it faster and overtake the plants.

“We are developing new technology, that prepares the seeds of slow-growing plants before sowing so they could outcompete weeds already in the sprouting phase”

IES: During the autumn and winter season you researched impact of different environments on seed preparation. How successful was it and did you manage to find the best solution for seed pre-sowing technologies?

IM: That is right! During the last research period we carried tests to find the most suitable technology that provides the best results. From all tested alternatives, the most successful turned out to be the seed sowing in the soil when the radicle is already emerged. In this stage, plantlet has a potential to grow faster and more evenly on the field. Another crucial aspect is to safely deliver the germinated seeds into the soil without harming the radicle. Therefore, we were exploring different options for seed coating.

IES: Which of the tested sprouted seed coating alternatives had the best results?

IM: Initially, it was planned that sprouted seeds will be coated in pharmaceutical capsules. We also tested other options for sprouted seed coating – pelleting with various thickeners, coating in alginate capsules and liquid capsules. After testing the alternatives, we came to conclusion that the most suitable solution for sprouted seed sowing without harming the radicle is the liquid capsules. Now we just have to find the liquid capsule that would fit for all the researched herbs and vegetables.

IES: How do you foresee that sprouted seeds coated in liquid capsules could be sown into the soil?

“The best way to get these plants to sprout before weeds is to sow them at a stage when the root has already germinated”

IM: Aiming not to harm the radicle coated in liquid capsule during the sowing period we are currently designing a seeding – machine specially designed for liquid capsule sowing.

IES: During previous summer and autumn seasons first field research tests were carried out. What kind of outcome – results and conclusions you have gained?

IM: During the field research we tried different sowing methods for germinated adjusted from previous research studies. This approach helped to find the most suitable sowing solution for conditions in Latvia for the selected herbs and vegetables. As a result, we came to conclusion that the most suitable method is sowing germinated seeds in liquid capsule, considering that in this environment root can easily continue to grow when sown in the field. We also tested the controlled burning method – before sowing we burnt all the weeds that were already sprouted in the field. This approach buys a few days for slow growing plants to outcompete the weeds. These experiments will continue in spring, summer and autumn seasons of 2020.

IES: Will this technology be applicable for other slow sprouting plants?

IM: It is difficult to predict this right now. While we are still in the development stage of the research, we are focusing on the solutions for the selected herbs and vegetables. New technology needs to be adjusted for each of the researched herbs and vegetables. It is very likely that this technology will be applicable for other slow growing plants, but for now we cannot give a clear answer to that.

IES: What is your plan for the next research period?

IM: We will continue the work on technology development:

– we will study the most effective time frame of seed germination for each plant species. The time of seed sprouting varies from species to species, therefore, we need to understand how long each of them should be sprouted before capsulation;

– considering that the seed cannot be germinated simply in the water, development of germination technology will continue. We need to find the solution to ensure that plants have sufficient oxygen levels during the sprouting process. One option is to use aerators;

– work on development of capsuling solution will continue. We now understand that sowing the liquid capsules is the most suitable technology, but we have to work on field trials and up-scaling;

– machine specially designed for liquid capsule sowing is also under construction;

– additional important part of the research is field trials. The promising technologies selected in laboratory will be tested in field trials and compared to conventional sowing.

Innovative seed preparation technologies for pre-sowing and sowing of slow growing plants are developed as part of EU European Agricultural Fund for Rural Development, Rural Development Programme 16. action “Cooperation” 16.2. sub measures “Support for new products, methods, processes and technologies” supported project “New seed preparation technologies for pre-sowing and sowing” (Nr. 18-00-A01620-000051).

More about the project here.