A delivery system in biocontrol agents refers to the method or mechanism used to transport beneficial microorganisms or natural substances to their target pests or pathogens in agriculture. These systems are designed to improve the effectiveness, stability, and efficiency of biocontrol agents, enhancing their ability to manage pests and diseases while minimizing negative impacts on the environment.
Here are a few common types of delivery systems used in biocontrol:
1. Formulations: Biocontrol agents are often formulated into products such as powders, granules, liquids, or gels. These formulations can protect the agents from environmental stresses like UV radiation or desiccation, improving their survival and efficacy. For example, spore-based biofungicides can be formulated into wettable powders for easy application.
2. Encapsulation: This involves enclosing the biocontrol agent within protective materials such as alginate beads, microcapsules, or nanoparticles. Encapsulation helps to protect the agent from harsh environmental conditions and provides controlled release over time. It also allows for targeted delivery to specific plant parts or soil zones.
3. Seed Treatments: Biocontrol agents can be applied as seed treatments, coating the seeds with beneficial microbes or natural substances. This method helps protect seeds from soil-borne pathogens, promotes seedling vigor, and establishes early plant-microbe interactions.
4. Soil Amendments: Adding biocontrol agents to soil amendments like compost, vermicompost, or biochar can improve their distribution in the soil and enhance their persistence. This method is particularly effective for managing soil-borne diseases and promoting plant growth.
5. Spray Applications: Biocontrol agents can be sprayed onto plant foliage or soil using conventional sprayers or irrigation systems. The challenge here is to ensure good coverage and adhesion to the plant surface for effective pest or disease suppression.
6. Biodegradable Films and Matrices: These are materials that slowly degrade over time, releasing the biocontrol agents gradually. They can be placed in the soil or wrapped around plant roots to provide sustained protection against soil-borne pathogens.
Each of these delivery systems has its advantages and is chosen based on factors such as the type of biocontrol agent, target pest or pathogen, crop type, and environmental conditions. Effective delivery systems play a crucial role in the success of biocontrol strategies, offering sustainable alternatives to chemical pesticides in agriculture.
1. DELIVERY SYSTEM IN BIOCONTROL AGENTS
COURSE TEACHER
Dr. K. SANJEEVKUMAR,
ASSOCIATE PROFESSOR,
DEPARTMENT OF PLANT PATHOLOGY.
SUBMITTED BY
SUNIL SURIYA M,
I - YEAR M.Sc., (Ag.),
DEPARTMENT OF PLANT PATHOLOGY.
PAT- 613 PRINCIPLES AND APPLIED PLANT PATHOLOGY (2+1)
D E PA RT M E N T O F P L A N T PAT H O LO GY
FAC U LT Y O F AG R I C U LT U R E
A N NA M A L A I U N I V E R S I T Y
2. DELIVERY SYSTEM IN BIOCONTROL AGENTS
INTRODUCTION
• Control of plant pathogens and disease caused by them through antagonistic microorganism is termed as
biological control agents
• So the efficacy of the biocontrol agent rely on the mode of application.
• The uniform and precise application of microbial particles close to the target organism and to the plant to
protected can increase the success of a biological control treatment.
Fungal biocontrol agents - Trichoderma viride, Darluca filum, Nectria inventa and Chaetomium globosum.
Bacterial biocontrol agents - Bacillus subtilis, Fluorescent pseudomonads, Rhizobium radiobacter strain K84.
3. IDEAL CHARACTERISTICS OF BIOCONTROL AGENTS
• ECOLOGICAL COMPATIBILITY (Environment factor)
• TEMPORAL SYNCHRONIZATION (Sync with target pathogens)
• DENSITY RESPOSIVENESS (Vigorous attacking of the pathogen)
• REPRODUCTIVE POTENTIAL (Fast multiplication)
• CULTURABILITY (Ease to mass multiplication)
• HOST SPECIFICITY AND COMPATIBILITY (Diverse host range)
5. SEED TREATMENT
• Mix seeds with the formulation at the rate of 10 g/kg of seeds and soak the seeds in
water for overnight. Decant the excess water and allow sprouting of the seeds for 24
hrs and then sow.
METHODS OF SEED TREATMENT
• Dry seed treatment
• Wet seed treatment
Eg. Fluorescent pseudomonads 10g/kg of seeds, Trichoderma 4g/kg of seeds.
Dry seed treatments
6. SEEDLING ROOT DIPLING
• Mix 250 ml of Fluorescent
pseudomanads with 5 liters of
water. In this mixture, keep the
seedling roots in immersed
condition for 30 minutes and
then transplant the seedlings.
For paddy
Eg. Fluorescent pseudomonads.
7. SOIL APPLICATION
• Apply the product @ 2.5 kg/ha after 30 days of transplanting. This product should
be mixed with 50 kg of well decomposed FYM/sand and then applied.
Eg. Trichoderma viride, Fluorescent pseudomonads.
8. FOLIAR APPLICATION
• Spray the product at 0.2% concentration (1 kg/ha) commencing from 45 days after
transplanting at 10 days interval for 3 times depending on disease intensity. If there
is no disease incidence, a single spray is sufficient.
• Crop: Groundnut, Gingelly, Sunflower, Redgram, Greengram, Blackgram - root rot and
wilt
(i.e) Bacillus subtilis.
9. VOLUME OF SPRAY
The amount of spray fluid required for covering uniformly an area or a given amount of
foliage is known as volume of spray.
• High volume spray (HV) requires 500 L or more / ha
• Medium volume spray (MV) requires 150 to 400 L or more / ha
• Low volume spray (LV) requires 75 to 150 L / ha
• Ultra low volume spray (ULV) requires 1 to 10 L / ha
10. SUCKER TREATMENT
• Suckers were trimmed and sprinkled with Fluorescent pseudomonads @ 20g/sucker
• PARING & PRALINAGE
The paired sets should be dipped in a Bordeaux mixture – DBCP paste (made by mixing
20 kg hydrated lime, 20 kg copper sulphate, 1288 ml 70% DBCP and 455 litres of water)
DBCP paste 1,2 Dibromo-3-chloropropane C3H5Br2Cl
It is a highly persistent lipophilic (affinity towards the lipid), brominated, organochlorine
which actively affects the membrane system of nematodes Rhadopolus similis
(Burrowing nematode)
11. CAPSULE APPLICATION
• Application of Gelatin capsule
containing 50 to 60 mg of
Fluorescent pseudomonads PF
1, survive for 60days control
Panama wilt
12. MICROBIGATION
• Dicovered by Angela boari et al. 2008
• The recent and emerging trend in the application of biocontrol agent is the
microbigation
• The term ‘microbigation’ is here proposed for this kind of microbial application
technique
• Conidial suspensions of marketed or marketable agents were used,
(i.e). Fusarium oxysporum, F. solani, Trichoderma harzianum and Paecilomyces lilacinus.
• The experiments carried out demonstrated that conidial suspensions
(106 conidia/ml) can pass through the drippers without causing clogging, regardless
of their size, and remained viable.
13. • Mostly used in Protected cultivation.
Setup of microbigation
