Integrated Disease Management in Mulberry Cultivation: Strategies and Benefits

Mulberry cultivation sits at the heart of sericulture – and the health of those leaves directly determines the quality of silk. But mulberry plants face a relentless barrage of fungal diseases, from powdery mildew on the foliage to root rot lurking in the soil. For decades, the default response was to reach for chemical fungicides. That approach works – up to a point. Over time, it raises costs, degrades soil health, and risks leaving chemical residues on leaves that silkworms then consume. Integrated Disease Management (IDM) offers a smarter path forward by combining chemical treatments with biological controls, creating a system that is both effective and sustainable.

What IDM means in practice 🔗

IDM is not a single product or technique – it is a management philosophy. Rather than relying on one type of intervention, it brings together chemical fungicides, biological control agents, and cultural practices into a coordinated strategy. The core idea is straightforward: use chemicals when needed for rapid disease suppression, and use biological agents to maintain long-term soil health and reduce the need for chemicals over time. Each component complements the other rather than replacing it entirely.

In mulberry cultivation specifically, IDM is critical because the crop demands continuous, high-quality leaf production for silkworm feeding. Any disease – foliar or soil-borne – directly reduces leaf yield and quality. A purely chemical approach might control acute outbreaks but can leave soil biology weakened and create conditions for recurring disease cycles. IDM breaks this cycle by building the plant’s environment into a more self-sustaining, resilient system.

The chemical component: Indofil M-45 🔗

The chemical anchor of IDM in mulberry is Indofil M-45, a broad-spectrum contact fungicide containing Mancozeb 75% WP. It works by inactivating sulphydryl (SH) groups in fungal enzymes, disrupting the pathogen’s metabolic processes and halting disease spread. Because it attacks multiple sites simultaneously, the risk of pathogens developing resistance remains low – a significant advantage for crops grown in the same fields year after year.

Indofil M-45 is applied in two main ways in mulberry disease management. For foliar diseases such as leaf spot, powdery mildew, and leaf blight, it is used as a foliar spray at the onset of symptoms. For soil-borne root diseases such as those caused by Fusarium species, it is applied directly around the root zone after removing soil from infected plants to a depth of about 15 cm. New saplings are also soaked in an Indofil M-45 solution before planting to reduce early infection risk. Four doses per year at three-month intervals are typically recommended for sustained control.

Beyond disease control, Mancozeb supplies trace amounts of manganese and zinc to the crop, contributing to plant nutrition as a secondary benefit. This dual function – disease protection plus micronutrient supply – makes it a practical choice for farmers managing both crop health and soil fertility.

The biological component: Raksha and Trichoderma harzianum 🔗

Raksha is a commercial bioformulation containing concentrated populations of Trichoderma harzianum, a naturally occurring soil fungus that acts as a powerful biological control agent. Unlike chemical fungicides, which work by chemical toxicity, T. harzianum works through several active biological mechanisms simultaneously.

How Trichoderma harzianum protects mulberry 🔗

Once introduced into the soil, T. harzianum colonizes plant roots rapidly, outcompeting pathogenic fungi for space and nutrients on the root surface. It grows faster than most soil-borne pathogens, effectively blocking their access to the root system before they can establish themselves. In addition, it produces secondary metabolites – enzymes, peptaibols, and other compounds – that directly disrupt pathogen cell walls and interfere with their metabolism. This mechanism is known as mycoparasitism.

The beneficial effects extend beyond disease suppression. Trichoderma stimulates plant root development, enhancing water and nutrient uptake. It also triggers systemic resistance responses within the plant itself, priming the mulberry’s own defenses to respond more effectively to future disease threats. Research has shown that soils treated regularly with Trichoderma-based bioformulations develop richer populations of beneficial microorganisms over time, creating a more stable and disease-resistant soil environment.

Preparing and applying Raksha with farmyard manure 🔗

The standard IDM protocol for mulberry involves mixing Raksha (1 kg of T. harzianum) with 50 kg of farmyard manure (FYM) for every 100 plants. This mixture is stored in a shaded area, covered with gunny cloth, and kept at a moisture content of 20-30% for 15 days before application. During this period, the mixture is turned every alternate day to ensure even distribution of moisture and air. This curing period allows T. harzianum to grow and multiply within the organic matter, producing a biologically enriched substrate that is far more effective than applying the fungus directly.

The choice of farmyard manure is deliberate. Organic matter acts as a food source and habitat for beneficial microorganisms, allowing T. harzianum to establish and multiply more effectively after soil application. Once the mixture is ready, it is applied at a rate of 500 g per plant in the root zone, followed by irrigation to help the organisms colonize the surrounding soil. Applications are continued at four-month intervals for at least one year to build a stable, self-sustaining population of beneficial microbes in the root zone.

Sequencing chemical and biological applications 🔗

One of the most important practical aspects of IDM is timing. Chemical fungicides, particularly broad-spectrum products, can harm beneficial microorganisms if applied carelessly alongside biological agents. The recommended IDM sequence for mulberry root diseases reflects this concern.

When disease symptoms first appear – wilting, yellowing, or visible root damage – Indofil M-45 is applied first to suppress the pathogen rapidly and bring the infection under control. Once the chemical phase has run its course and pathogen pressure is reduced, the Raksha-FYM mixture is introduced into the root zone. This sequence allows the chemical to do its immediate suppression work without interfering with the biological agent’s establishment. Allowing 15-20 days between chemical application and bioformulation application gives the soil environment time to stabilize before T. harzianum is introduced.

For long-term healthy plantations not in acute disease crisis, the bioformulation can be applied preventively at the start of each growing cycle, building up beneficial microbial populations before disease pressure develops. Because Trichoderma multiplies on its own once established in the root zone, a relatively small initial application can provide season-long protection – unlike chemical seed treatments, which degrade within a few weeks.

Why IDM improves soil health over time 🔗

One of the clearest advantages IDM has over a chemicals-only approach is its long-term effect on soil biology. Repeated sole use of chemical fungicides can reduce the diversity and abundance of beneficial soil microorganisms – the very organisms that naturally suppress pathogens, decompose organic matter, and improve nutrient availability. Over multiple seasons, this creates soils that are biologically impoverished and increasingly dependent on external chemical inputs to suppress disease.

IDM reverses this trajectory. By regularly introducing T. harzianum through Raksha and pairing it with farmyard manure, farmers actively rebuild the soil’s microbial community. Trichoderma-based biocontrol techniques promote rhizosphere competence, improve nutrient availability, and create conditions where pathogenic fungi find it increasingly difficult to establish. Over time, this means lower disease incidence, reduced reliance on chemical fungicides, and better overall plant vigor – a compounding benefit that rewards consistent IDM practice.

Reduced chemical dependency and silkworm safety 🔗

In mulberry cultivation, chemical residues carry an added risk that doesn’t exist in most other crops: silkworms eat the leaves. Even sub-lethal residues of certain fungicides on mulberry foliage can impair silkworm health, disrupt cocoon formation, and reduce silk yield and quality. This makes reducing chemical inputs not just an environmental goal but a direct productivity concern for sericulture farmers.

IDM directly addresses this. By using chemicals only during acute disease outbreaks and relying on biological agents for ongoing protection, farmers reduce the total volume of fungicide applied across the season. The CSRTI Mysore mulberry disease management protocol explicitly notes that the Trichoderma harzianum application has no toxic effect on either mulberry or silkworms – a critical consideration that purely chemical programs cannot match. This makes IDM the responsible default for any farmer whose ultimate product is silk rather than grain.

Practical considerations for adopting IDM 🔗

Adopting IDM does require planning and discipline. The 15-day preparation period for the Raksha-FYM mixture means farmers need to anticipate treatment rather than react to it at the last minute. Applications need to be tracked across the four-month interval cycle to ensure continuity, and chemical and biological applications must be scheduled to avoid direct overlap. These are manageable requirements, but they do demand a more organized approach than simply spraying a fungicide when disease appears.

The economic logic is sound, however. A reduction in chemical fungicide frequency, combined with improved plant vigor and reduced replanting costs from healthier root systems, typically offsets the cost of bioformulations over a full growing season. The long-term soil health benefits further strengthen the case – a farm with biologically active soil requires fewer inputs to maintain productivity than one whose soil biology has been progressively depleted.

What do you think? As mulberry farmers face pressure to both increase silk yields and reduce chemical residues that could affect silkworm health, do you think the 15-day preparation protocol for Trichoderma bioformulations is a practical barrier for small-scale farmers – and what adaptations might make it more accessible? With soil-borne diseases like root rot capable of wiping out established mulberry plantations, how much weight should sustainable soil biology carry in disease management decisions compared to the immediate reliability of chemical control?

References

1. https://www.indofil.com/agro/fungicides/indofil-m-45
2. https://www.spraykaro.com/product/m45-fungicide-indofil-m45-crop-protection
3. https://pmc.ncbi.nlm.nih.gov/articles/PMC10189891/
4. https://www.koppertus.com/crop-protection/plant-disease-management/trichoderma-harzianum/
5. https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1160551/full
6. https://ipm.cahnr.uconn.edu/trichoderma-for-control-of-soil-pathogens/
7. https://link.springer.com/article/10.1007/s00248-024-02472-2
8. http://mulinfo.csrtimys.res.in/index.php/en/root-fungaldiseases
9. https://www.intechopen.com/chapters/1166092