Weeds are one of the most persistent problems in mulberry cultivation. They silently compete with mulberry plants for water, nutrients, and sunlight – directly reducing both the quantity and quality of leaves harvested for silkworm rearing. In fact, research published in Agricultural Reviews estimates that weeds can reduce mulberry leaf yield by 30-40%, a loss that translates to thousands of kilograms of leaves and a significant drop in raw silk production per hectare every year. Effective weed management, therefore, is not optional – it is essential for any mulberry garden aiming for consistent, high-quality leaf output.
Table of Contents
- Why weeds are a serious threat in mulberry gardens
- Common weeds found in mulberry fields
- Cynodon dactylon (Hariyali or Bermuda grass)
- Cyperus rotundus (nut grass or purple nutsedge)
- Manual weed management methods
- Hand weeding
- Weeding with sickles and hoes
- Timing and frequency
- Cultural weed management practices
- Mulching
- Intercropping with cover crops
- Chemical weed management
- Glycel (glyphosate) – the most common weedicide in mulberry
- Pre-emergence herbicides
- Precautions during herbicide application
- Integrated weed management: the best approach
- Economic impact of effective weed management
- Quick reference: weed management schedule for mulberry
Why weeds are a serious threat in mulberry gardens
Mulberry plantations are especially prone to heavy weed growth. The reasons are structural: mulberry is a perennial crop grown in wider spacing, pruned multiple times a year, and regularly supplied with manures and fertilizers after each harvest cycle. These conditions – open canopy, moist soil, and rich nutrients – create an ideal environment for weeds to thrive alongside the crop.
The damage weeds cause goes beyond just stealing resources. Weeds also harbour insect pests and disease-causing pathogens that attack mulberry plants, further reducing healthy leaf growth. And since mulberry leaves are the sole food source for silkworms (Bombyx mori), any decline in leaf quality has a direct impact on cocoon production and silk output. According to FAO documentation on mulberry cultivation in India, the quality and quantity of leaf produced per unit area has a direct bearing on cocoon harvest – making weed control a critical economic concern for sericulture farmers.
Common weeds found in mulberry fields
Before you can manage weeds effectively, you need to know what you’re dealing with. Mulberry fields across India host a wide variety of weed species – studies report anywhere from 57 to 141 weed species belonging to 28-44 plant families, depending on the region, soil type, and climate. However, two perennial weeds stand out as the most troublesome.
Cynodon dactylon (Hariyali or Bermuda grass)
Cynodon dactylon is a perennial grass that spreads aggressively through underground rhizomes and above-ground stolons. It is highly drought-tolerant and can establish itself in a wide range of soil conditions. A systematic review published in Agronomy for Sustainable Development classifies it as one of the worst agricultural weeds globally, second only to nut grass. Its rapid vegetative reproduction makes it extremely difficult to eradicate once established in a mulberry garden.
Cyperus rotundus (nut grass or purple nutsedge)
Cyperus rotundus is widely considered the world’s worst weed. It reproduces through underground tubers that can persist in the soil for extended periods, even under unfavourable conditions. Nut grass thrives in both wet and dry environments and has allelopathic properties – it releases chemicals that can inhibit the growth of surrounding plants, including mulberry. Its tuber-based reproduction system makes it particularly resistant to conventional weeding methods.
Manual weed management methods
Manual weeding remains the most widely practised method in Indian mulberry gardens, especially among smallholder farmers. It involves physically removing weeds from the field using hands or simple tools. While effective, it is labour-intensive, time-consuming, and increasingly expensive.
Hand weeding
This is the most basic approach – pulling weeds out by hand. It works best when the soil is moist, as roots and rhizomes can be removed more completely. Hand weeding is most effective for annual weeds but falls short against perennial species like Cynodon and Cyperus, whose underground root systems can regenerate quickly even after above-ground parts are removed.
Weeding with sickles and hoes
Tools like weeding sickles and hand hoes are commonly used to cut weeds at or just below the soil surface, particularly between mulberry rows. These tools speed up the weeding process compared to hand-pulling. However, care must be taken to avoid damaging shallow mulberry roots during the process. Light surface cultivation that targets weeds just below ground level is generally preferred over deep digging.
Timing and frequency
According to FAO guidelines on mulberry cultivation, the first weeding should be carried out about two months after planting, with a second round two to three months later. After that, inter-cultivation and weeding should be done after every shoot or leaf harvest cycle. Research shows that performing two rounds of manual weeding – once immediately after pruning and another 25 days after pruning – can achieve around 60% weed control efficiency.
Cultural weed management practices
Cultural practices complement manual methods and help suppress weed growth through smarter agronomic decisions. These methods don’t eliminate weeds on their own but create conditions that are less favourable for weed establishment and growth.
Mulching
Covering the soil surface between mulberry rows with organic materials such as straw, dried leaves, or compost suppresses weed germination by blocking sunlight. Organic mulches also improve soil moisture retention and add nutrients as they decompose. Black polyethylene mulch has been found particularly effective – studies suggest it can be more economical than repeated manual weeding in mulberry plantations. However, plastic mulch does not provide the same soil health benefits as organic alternatives.
Intercropping with cover crops
Planting short-duration leguminous crops like black gram or cowpea between mulberry rows serves a dual purpose. These cover crops compete with weeds for space and light while also fixing nitrogen in the soil, improving fertility for the mulberry plants. The key is to choose cover crops that will not aggressively compete with mulberry for water and nutrients. This approach is particularly useful in rainfed mulberry gardens where maintaining soil health is critical.
Chemical weed management
When manual and cultural methods are not enough – especially against persistent perennial weeds – chemical weed control using herbicides (also called weedicides) becomes necessary. However, chemical control in mulberry cultivation carries a unique risk: herbicide residues on mulberry leaves can be toxic to silkworms. This makes timing and application method critically important.
Glycel (glyphosate) – the most common weedicide in mulberry
Glycel is a commercial formulation of glyphosate, a broad-spectrum, non-selective, systemic herbicide. It is absorbed through the foliage of weeds and translocated to the roots, killing the entire plant including underground storage organs. This makes it particularly effective against deep-rooted perennial weeds like Cynodon and Cyperus that are difficult to eradicate manually.
The FAO’s documentation on Indian mulberry cultivation recommends applying glyphosate (41% agro grade) at 8.1 litres per hectare, split across two doses during the second and fourth crop cycles. Research cited in a comprehensive review on weed management in mulberry found that applying 0.71% Glycel within four days of pruning, followed by one round of manual weeding, reduced weed dry weight by 58% while improving mulberry leaf yields by 5-15%. This combined approach also saved approximately 250 labour-days that would have been needed for manual weeding alone.
Pre-emergence herbicides
Pre-emergence herbicides are applied to the soil before weed seeds germinate. In mulberry, herbicides such as diuron and pendimethalin have shown significant results. Studies have demonstrated that diuron applied at 1.25 kg per hectare as a pre-emergence treatment dramatically improved mulberry leaf yields compared to untreated fields. Similarly, pendimethalin at 2.0 kg per hectare reduced weed dry weight by around 60% compared to unweeded plots.
Precautions during herbicide application
Because mulberry leaves are fed directly to silkworms, extra care is necessary when using any chemical weedicide:
Avoid spray drift: Use protective shields or directed spray nozzles to prevent herbicide from contacting mulberry foliage. Since glyphosate is non-selective, any contact with the crop can cause serious damage.
Timing matters: Herbicide application is safest immediately after pruning, when mulberry shoots have not yet developed new leaves. Spraying during active leaf growth risks both crop damage and residual toxicity on leaves that will be fed to silkworms.
Avoid late-stage spraying: Once the second flush of weed growth appears (typically 30+ days after pruning), spraying herbicides is not advisable because mulberry leaves are actively growing and would be at risk of contamination. Manual weeding or mulching is preferred at this stage.
Follow recommended dosages: Over-application not only harms the soil ecosystem but can also increase the risk of residues persisting in the field environment.
Integrated weed management: the best approach
No single weed control method is sufficient for season-long protection in mulberry gardens. Research consistently shows that an integrated weed management (IWM) approach – combining two or more methods – delivers the best results while minimising risks.
The most practical integration strategies include:
Pre-emergence herbicide + manual weeding: Apply a pre-emergence herbicide right after pruning to suppress early weed growth, then follow up with manual weeding when the second flush of weeds appears later in the crop cycle. This keeps the field clean during critical growth stages without exposing growing mulberry leaves to chemical residues.
Manual weeding + cover crop intercropping: Perform manual weeding immediately after pruning, then establish a short-duration cover crop between rows to suppress subsequent weed growth. This is a chemical-free option well suited for organic or low-input farming systems.
Manual weeding + mulching: After the initial hand weeding, apply organic mulch between rows to prevent new weed establishment. This combination reduces the need for repeated weeding rounds and improves soil moisture retention simultaneously.
According to the review published in Agricultural Reviews, integrated approaches consistently outperform any single method when evaluated across multiple parameters – weed control efficiency, leaf yield improvement, cost reduction, and silkworm safety.
Economic impact of effective weed management
The economics of weed control in mulberry cannot be ignored. Manual weeding is expensive – it represents a significant portion of the total cost of mulberry cultivation, especially in labour-scarce regions. At the same time, leaving weeds unmanaged leads to yield losses of 30-40%.
If even half of this weed-related yield loss can be prevented through effective management, mulberry leaf output could increase by 9-12 metric tonnes per hectare per year. For sericulture farmers, this additional leaf can support the rearing of 1,500-2,000 more disease-free layings (dfls) per hectare annually, potentially producing 55-73.5 kg of additional raw silk. At current market rates, this represents a substantial increase in farm income.
Adopting integrated weed management is therefore not just an agronomic recommendation – it is a sound financial decision that directly improves the profitability and sustainability of mulberry-based sericulture.
Quick reference: weed management schedule for mulberry
Immediately after pruning (Day 0-4): Apply pre-emergence or early post-emergence herbicide (e.g., Glycel/glyphosate) using directed spray. Alternatively, perform manual weeding.
25-30 days after pruning: Carry out a second round of manual weeding to tackle the second flush of weeds. Avoid herbicide spraying at this stage.
After second weeding: Apply organic mulch or establish an intercrop of legumes like cowpea or black gram to suppress further weed growth.
After each harvest cycle: Repeat inter-cultivation and weeding before the next crop cycle begins.
What do you think? Are manual methods still practical for weed control in your mulberry garden as labour costs continue to rise, or is it time to shift toward integrated approaches that combine cultural, mechanical, and targeted chemical methods?
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