INTRODUCTION

Agriculture is a critical sector in Uganda’s economy, providing jobs for 80% of the workforce (UBOS, 2020). This sector accounted for 24% of the gross domestic product (GDP) and 35% of export earnings in the 2022 –23 financial year (URA, 2024). In Uganda, chili, hot pepper, bitter gourd, and aubergine are important export crops to European markets as of 2022 (Cabi, 2024;UBOS, 2024). Additionally, these crops play a significant role in food security, with aubergine being ranked as the sixth most important crop for urban and peri-urban farmers (Mugisa et al., 2017).

The United Nations Food and Agriculture Organization (FAO) defines organic agriculture as “a method of agriculture where no synthetic fertilizers and pesticides are used, with an emphasis on using inputs that encourage biological processes of available nutrients and defense against pests” (FAO, 2024). In September 2020, Uganda launched the National Organic Agriculture Policy to ensure sustainable food production and increase the income of farmers particularly that of smallholder farmers who represent 85% of the agricultural sector (The National Organic Agriculture Policy, 2019). In Uganda, in addition to the certified farmers, an estimated 120,000 smallholder farmers are engaged in organic agriculture (Walaga et al., 2005). Despite this, the production of organic products remains limited, meeting only 2% of the country’s demand, with a contribution of less than 5% to the global organic markets (The National Organic Agriculture Policy, 2019).

Pest and disease management is one of the major challenges facing organic horticulture in Uganda (Ronner et al., 2023, The National Organic Agriculture Policy, 2019). Table 1 presents the major diseases affecting key horticulture crops in Uganda, such as pepper, bitter gourd, and aubergine, while Table 2 outlines the main pests affecting these crops. In 2014, the false coding moth resulted in a loss of 67% of Uganda’s export revenue, amounting to USD 1.17 million (Nsabiyera et al., 2012;PARM, 2017; UBOS, 2017). Therefore, implementing cost-effective pest and disease management strategies is essential to minimize crop losses and enhance Uganda’s agricultural foreign earnings.

Pest management in organic agriculture is guided by four principles: prevention, avoidance, suppression, and monitoring (Ehler, 2006). Cultural practices are important for managing pests and diseases. Some of those adopted in Uganda include the achievement of higher seeding rates; careful consideration of planting distances; the use of trap crops, organic fertilizers, and resistant cultivars; crop rotation, sanitation, water management (mulching, minimum tillage), and the timing of planting and harvesting (Nassary et al., 2019).

Other pest and disease management strategies used in organic horticulture include mechanical control; the collection and destruction of insect pests (if pests are visible and easily accessible, this strategy is the most effective); the destruction of stubbles and agricultural residues; and the use of lethal temperature (high/low), pheromones, and other attractants as well as companion plants or intercropping (Mubiru et al., 2015). Biological control agents are also employed, including ladybird beetles to control aphids and other soft-bodied insects in beans and vegetables (Ekesi et al., 1998), entomopathogenic fungi, notably Beauveria bassiana and Metarhizium anisopliae to control termites, aphids, and caterpillars (Kisaakye et al., 2021), predatory mites (e.g., phytoseiid mites) to control twospotted spider mites in tomatoes and beans (Bellotti et al., 2005), and entomopathogenic nematodes (Heterorhabditis spp. and Steinernema spp.) to control root-knot nematodes (Meloidogyne spp.) and cutworms (Agrotis spp.) (Ekesi et al., 2003).

The International Federation of Organic Agriculture Movements (IFOAM) lists several chemicals that are acceptable for use in organic farming, including bio-pesticides and mineral origin protectants such as lime sulphur, copper, pyrethrum, and paraffinic oils (Table 3). Among these, botanical pesticides, which are derived from various parts of plants such as stems, seeds, roots, leaves, and flowers, are particularly valued in Uganda. They are celebrated for their spectrum efficacy, ease of processing and application, short residual periods, minimal environmental accumulation, and affordability due to their widespread availability (Mugisha–Kamatenesi et al., 2008). Table 4 lists the commonly used plant-derived bio-pesticides in Uganda.

However, the reliability of bio-pesticides is hindered by several factors. Their active ingredients are only effective during specific stages of plant growth and under favorable climatic conditions, making standardization challenging. Additionally, they have a short shelf life, and the raw materials may not always be readily available. Furthermore, bio-pesticides can undergo rapid biodegradation and cause harm to the environment (Damalas and Koutroubas, 2020).

Given the significance of organic agriculture in Uganda, it is important to explore pest and disease management options that are safe for humans and the environment, easily accessible, easy to standardize, and cost-effective. To meet international safety standards regarding pesticide residue levels and to ensure IFOAM certification, we have selected lime sulfur, copper, paraffin and pyrethrum as key inputs. These substances offer several advantages over other organic pesticides, including their cost-effectiveness, broad-spectrum efficacy, and high utility in domestic organic farming practices, which makes them particularly suitable for successful implementation in Uganda. This review provides an overview of lime sulfur and copper as fungicides, and paraffin and pyrethrum as insecticides approved for use in organic farming, with the aim of raising awareness of their effectiveness among Ugandan organic farmers.

RESULTS

Lime sulfur as a fungicide in organic horticulture

Lime sulfur/calcium polysulfide is a synthetic substance consisting of complexes of divalent calcium cations (Ca²⁺) and anionic polysulfide. It is also defined as a solution of calcium polysulfide in water (McCallan, 2012). Lime sulfur is a yellow-orange liquid with pH 11.5, a density of 1.26 g ml⁻¹, and a toxicity level ranging from moderate to acute (the oral LD₅₀ for rats is 820 mg kg⁻¹), although no chronic dietary toxicity or carcinogenicity has been identified (Anonymous, 1997). The safety hazards associated with lime sulfur include exposure to H2S gas derived from it and skin or eye burns caused by contact with the concentrated solution. The workplace limits for H2S established by the United States Occupational Health and Safety Administration are 10 μl⁻¹ for 8 hr and 15 μl l⁻¹ for brief exposures of 15 minutes (Anonymous, 1997).

Lime sulfur can be an effective fungicide in organic horticulture before and after harvest. It works by producing hydrogen sulfide, which permeates fungal and plant cells (Tweedy, 1981), affecting the respiration complex of mitochondria by interfering with the electron flux in the respiratory chain and resulting in multi-site toxicity and broad-spectrum activity (Jolivet, 1993). The fungicidal effectiveness of lime sulfur in organic farming is well documented. It has been shown to control apple scab 24– 45 hr post-inoculation both in the orchard and in vitro as well as powdery mildew (Mitre et al., 2018; Cormwell et al., 2011; Jamar et al., 2008;Holb et al., 2003), black rot (Xanthomonas spp.) in kale (Nuñez et al., 2018), leaf spot and downy mildew (Ferreira et al., 2022), apple rust (DeLong et al., 2018), brown rot blossom blight in cherry (Holb and Schnabel, 2005), sooty blotch and flyspecks in apples (Weber et al., 2016), and brown rot in organic stone fruits at 6 and 12 hr post-inoculation (Holb and Schnabel, 2008). Fernando et al. (2023) recorded an 80% reduction in the incidence of septoriose in tomatoes.

Lime sulfur can be used as a protective and curative fungicide. Jamar et al. (2017) reported that it was effective when applied to pear plants at 300 degree-hours (DH) before inoculation with pear scab and remained effective between 300 and 650 DH after inoculation. Its effectiveness was shown to gradually decrease after 650 DH, but partial effects were still observed (Jamar et al., 2017). To reach 650 DH, the temperature should be maintained at 18°C for 36 hr (Jamar et al., 2017).

Lime sulfur has excellent rainfastness, retaining its active ingredients on the leaves for an extended period. This property allows for a longer application time compared with most other fungicides, which usually need to be applied immediately after rainfall (Jamae et al., 2017). Rain can affect the effectiveness of fungicides by diluting them, causing redistribution or washing them away from the specific points where they were applied (Töfoli et al., 2014). The amount of fungicide that sticks to or is absorbed by the plants directly affects its ability to control plant diseases.

The phytotoxicity of lime sulfur may be a cause of concern (Holb and Schnabel, 2005;Holb et al., 2003), but more recent research proves otherwise. For example, it has been shown that 1.5% lime sulfur did not cause any significant damage to many fruit crops, (Holb and Schnabel, 2008) and that 3% lime sulfur had no phytotoxic effects on mature citrus fruits (Smilanick and Sorenson, 2001) and peach fruits (Poulos, 1949). Similarly, Venzon et al., (2013), found that lime sulfur concentrations of 9.5 ml l⁻¹ and 10 ml l⁻¹ had no phytotoxic effects on chili pepper, and Chagas et al. (2001) did not report any injury in papaya plants. Fernando et al. (2023) reported no visible signs of phytotoxicity in tomatoes at doses up to 30,000 mg l⁻¹. It is also crucial to remember that applying lime sulfur at temperatures below 26°C further reduces potential phytotoxic effects (OISAT 2024).

According to the Fungicide Resistance Action Committee (FRAC), M2 fungicides are considered a low-risk group that shows no signs of developing resistance. Lime sulfur is classified as an M2 fungicide (FRAC, 2024). Similarly, FAO lists lime sulfur under scheduled 2 chemicals, which are not subjected to the maximum residue limit (MRL). The MRL is the highest level of pesticide residue that is legally tolerated in or on food or feed when pesticides are applied following Good Agriculture Practices (FAO, 2024). Jamar et al. (2010) found no excessive residues on apple fruits after treatment with lime sulfur at different concentrations.

Lime sulfur can make the soil too acidic for the ongoing optimal growth of certain crops and can also harm ruminants if they ingest it. Lime sulfur is prone to spontaneous oxidation, damaging the eyes, skin, and respiratory tract (Gammon et al., 2010). It has also been demonstrated to reduce and completely eliminate predaceous mites (Daniel et al., 2001). To mitigate the risk to bees, lime sulfur should be applied during night time when bees are inactive. (Bisrat et al., 2020;Efrom et al., 2012). On the contrary, when used for the integrated pest management of fruit flies (Cardoso et al., 2021), lime sulfur has not been shown to cause lethal or sub-lethal effects on the larval-pupal endo-parasitoid Diachasmimorpha longicaudata.

Copper as a fungicide in organic horticulture

Copper has long been employed in agriculture for fertilization and controlling plant diseases. In organic farming, copper-based antimicrobial compounds are effective against a wide range of fungal and bacterial diseases. Although the exact mechanisms of action of this element against microorganisms are not fully understood, several theories have been proposed. These include the leakage of cellular electrolytes, disruption of the osmotic balance, chelation at the active sites of specific proteins, and induction of oxidative stress (INRA, 2018). Copper serves purely as a protectant and has no curative or systemic effects. When applied, it forms a protective film on plant surfaces, slowly releasing copper ions in the presence of water and low pH, which creates a toxic environment for microbes (Lamichhane et al., 2018).

The Bordeaux mixture, which consists of copper sulfate pentahydrate and lime, was the first copper-based antimicrobial compound utilized in agriculture (Gayon and Sauvageau, 1903). This formulation, along with copper itself, has been used for over 160 years to manage plant diseases. Copper is typically applied to crops in various salt-based formulations, such as copper sulfate, copper hydroxide, copper oxide, copper oxychloride, and copper octanoate, often with additional adjuvants (Coelho et al., 2020). Copper hydroxides are the most frequently used copper compounds due to their effectiveness in disease control and safety for plants. These products are commonly applied to the plant’s above-ground parts but can also be used for seed treatment or local applications, for example on pruning cuts or soil surfaces (INRA, 2018).

One significant advantage of copper-based pesticides is their broad-spectrum efficacy against bacteria, oomycetes, ascomycetes, and basidiomycetes (Tamm et al., 2022). Copper-based pesticides are used to control various plant diseases, such as downy mildew of grapevine, (Dagostin et al., 2011), late blight of potato (Ghorbani et al., 2004), apple scab (Holb et al., 2003), and various coffee diseases (Hindorf et al., 2015). Moreover, they are effective against bacterial diseases such as tomato spot (Roberts et al., 2008), citrus canker (Behlau et al., 2017), fire blight of pome fruits (Elkins et al., 2015), and walnut blight (Ninot et al., 2002).

Copper pesticides also have an advantage over certain synthetic fungicides due to their lower likelihood of developing resistance, which makes them a reliable choice for ongoing disease control. The mechanism through which they act on multiple sites reduces the risk of developing resistance. FRAC classifies copper as belonging to the M1 fungicides, which are recognized as having a low risk of developing resistance (FRAC, 2024).

Copper-based products exhibit strong rainfastness, which helps them adhere to plant surfaces and resist being washed away (Cha and Cooksey, 1991). Research has shown that these copper formulations offer superior rainfastness and extended residual activity on “Fortune” mandarin fruit compared to other fungicides such as mancozeb, difenoconazole, iprodione, famoxadone, and pyraclostrobin (Vicent et al., 2007). Additionally, cuprous oxide and copper oxychloride have demonstrated effective disease control against Alternaria brown spot affecting citrus for up to 28 days and could endure 71 mm of rainfall under orchard conditions.

Despite these benefits, copper poses some challenges; notably, its potential to accumulate in soils and adversely affect soil biota and plant health (Dumestre et al., 1993;Kandeler et al., 1996). Excessive copper can be toxic to plants, causing symptoms such as chlorosis, darkening of leaf surfaces, necrotic spots, and burned leaf margins (Lamichhane et al., 2018). Crops such as legumes, grapes, hops, and cereals are particularly vulnerable to high copper concentrations. The release of excess copper ions can be exacerbated by using soluble forms like copper sulfate or by applying solutions with a pH below 5.5, which increases the risk of phytotoxicity (Behlau et al., 2017).

To mitigate these effects, less soluble copper formulations like copper hydroxide and copper oxychloride are recommended. The use of copper sulfate, which is known for its high solubility and potential toxicity to both humans applying the treatment and the environment, is increasingly discouraged in many regions (Mackie et al., 2012). Additionally, since copper tends to remain in its insoluble forms in soils with higher pH levels (Zhu and Alva, 1993), increasing soil pH and/or enhancing soil organic matter content may help reduce copper leaching and its possible toxic effects (Alva et al., 1995). Adding lime or iron to soils can temporarily manage excess copper levels.

Due to their toxicity, copper pesticides are tightly regulated to manage environmental risks. In Europe, the maximum allowable amount of copper is 28 kg per hectare (ha) over a 7-year period (European commission, 2018). Internationally, Demeter International restricts the average annual copper application to 3 kg/ha, with a maximum of 500 g/ha/spray (Biodynamic Federation Demeter, 2021). National organizations such as Bio Austria (AT), Bioland (DE), Naturland (DE), Bio Suisse (CH), and PRO-BIO (CZ) have established specific limits for different crops (Tamm et al., 2022). Some European countries, including the Netherlands and Denmark, have prohibited the use of copper pesticides in both organic and conventional farming. In East Africa, the allowable amount of copper applicable for organic farming each year is limited to 8 kg/ha (EAOPS, 2020). However, research has shown that that copper quantities below the established limits can still effectively control diseases. While the permitted application rates range from 1.2 to 4 kg/ha (most commonly between 3 and 4 kg/ha) , studies have found that farmers often use less than half the allowed amounts in more than 50% of the analyzed cases (Tamm et al., 2022).

Paraffinic oils as insecticides in organic horticulture

Paraffinic, petroleum-based, mineral, aliphatic solvents and horticultural oils contain linear and branched alkenes and naphthenic or aromatic hydrocarbons. They may also contain minor compounds such as sulfur, nitrogen, oxygen, and metals. Paraffinic oils are graded based on their boiling point, boiling point range, density, vapor pressure, molecular weight, viscosity, and unsulfonated residues (Baliota and Athanassiou, 2023). Their molecular weight is expressed as nCy, where “n” represents normal paraffin (alkane) molecules, and “y” represents the number of carbon atoms. The higher the number of carbon atoms, the heavier the paraffinic oil. Most agricultural spray oils are nC21, nC23, nC24, and nC25 (Baliota and Athanassiou, 2023). Paraffinic oils can also be graded according to their volatility, which typically ranges between 412 and 468°F. Volatility levels measure how quickly the oil will evaporate before it penetrates the pest’s body or adheres to the cuticle without any insecticidal effect (Baliota and Athanassiou, 2023). Table 5 lists different aliphatic solvents accepted for organic agriculture.

Research has demonstrated that the saturated hydrocarbons in oils block insect spiracles, causing suffocation, whereas the unsaturated hydrocarbons exert toxic effects by penetrating and corroding insect tissues (Baliota and Athanassiou, 2023). The insecticidal activity of paraffinic oils starts after penetration into cuticles, waxes, and pore canals, which leads to suffocation.

By inducing suffocation, paraffinic oils can trigger dif-ferent reactions in insects, such as knockout effect, changes in body color and permeability, dehydration of the cuticle, discouragement of feeding, egg deposition, as well as disruption of the nervous system and abdomen contractions (Baliota and Athanassiou, 2023).

The effectiveness of paraffinic oils has been evaluated across a wide range of host plants, pest species, and farming systems. They have been shown to control citrus leafminer (Damavandian and Moosavi, 2014), mealybugs, and soft scale insects infesting guava trees (Helmy et al., 2012). Experiments have shown that female oblique- banded leafrollers rejected surfaces sprayed with paraffinic oil, and a 2% oil concentration caused egg mortality in this pest (Wins–Purdy et al., 2009). Additionally, paraffinic oils have been reported to have a lethal effect on red and purple scale insects in citrus orchards (Liang et al., 2010) and on the first generation of San Jose scale nymphs in apples and almond orchards (Sazo et al., 2008). High mortality associated with paraffinic oils has been reported for mealybugs (Albuquerque et al., 2023) and common tomato pests such as thrips, greenhouse white flies, russet mites, brown leafhoppers, and fruit flies (Kallianpur et al., 2002;Liu et al., 2002).

The phytotoxicity of paraffinic oils was a major concern, driving the efforts to produce oils with low phytotoxicity and high insecticidal efficiency (Atanu, 2023;Baliota and Athanassiou, 2023). Research has now shown that paraffinic oils with carbon numbers between C21 and C27 have low phytotoxicity levels. This is because the higher the number of carbons, the higher the purity, resulting in a narrower boiling range and a more uniform oil composition. Oils with lower boiling points volatilize more quickly, which reduces their interaction with plant tissues. This evaporation can limit the oil’s ability to penetrate the pest’s body or adhere to the cuticle, potentially decreasing its effectiveness as an insecticide (Baliota and Athanassiou, 2023).

Damavandian (2007) recorded a low phytotoxic effect after the application of paraffinic oil at 0.85% v/v on sweet orange trees, while treating the leaves and fruits of sweet oranges and pummel trees with different paraffinic oils (C2 and C27) did not result in any phytotoxic effect (Rae et al., 2000). Similarly, paraffinic oil concentrations between 1.0 and 1.5% have been shown to exert no phytotoxic effects on the stems and petals of tulips grown in a greenhouse (Marcinek et al., 2018). Similar results were obtained for greenhouse-grown chrysanthemums sprayed with 1%, 2%, and 4% paraffinic oil (Larew and Locke,1990). However, some studies have reported that light intensity increased phytotoxicity, recommending that spraying be scheduled in the early morning or late evening to minimize this risk (Santos et al., 2017). Phytotoxicity may also be associated with plant stress, ambient temperature, humidity, and application rate (Bogran et al., 2006).

Baliota and Athanassiou, (2023) provide a detailed account of the toxicity assessments carried out for paraffinic oils by the United States Environmental Protection Agency (US EPA 2007) and the European Food Safety Administration (EFSA, 2008). Both agencies reported no sub-chronic or chronic toxicity to mammals, birds, marine and freshwater organisms, honeybees, earthworms, and other non-targeted plants. No carcinogenic effects were observed in rats, and no safety concerns related to genotoxicity were reported. If used correctly, paraffinic oils have no adverse effects on terrestrial and most aquatic organisms. As sprayed paraffinic oils are only temporarily active due to their rapid evaporation, they do not contaminate soils or underground water sources (Bogran et al., 2006). Oils are also considered one of the few classes of pesticides to which insects and mites have not developed resistance (Atanu, 2023;Bogran et al., 2006).

Pyrethrum as an insecticide in organic horticulture

Pyrethrum, which accounts for 80% of the botanical insecticides used worldwide (PaVela, 2009), is a natural product derived from the flower heads of plants belonging to genus Chrysanthemum, family Asteraceae. In particular, the commercially important species are C. cinerariaefolium, C. coccineum, and C. marshalli (Soni and Anjikar, 2014;Casida, 2012). Pyrethrum extract consists of esters formed by a combination of chrysanthemic acid, pyrethric acid, and three alcohols: pyrethrolone, cinerolone, and jasmololone (Table 6). These esters are further grouped into two compositions: pyrethrin I and pyrethrin II. Together, these two fractions account for the insecticidal and knockout effects of pyrethrum, with pyrethrin II being the most potent inhibitor of sodium channel deactivation (Chen et al., 2018;Casida, 2012).

Pyrethrum causes a toxic effect in insects by penetrating their cuticle and reaching the nervous system, where it binds to sodium channels along the nerve cells, disrupting their normal function. As a result, the insect experiences hyperexcitation and loses the nerve cell function, which causes the nervous system to shut down, leading to the insect’s death (Soni and Anjikar, 2014;Isman, 2006). However, PaVela (2009) has reported no ovicidal, antifeedant, or growth-inhibiting effects caused by pyrethrum on insects.

Extensive research has evaluated the effectiveness of pyrethrum as an insecticide, reporting its knockout effect on flying insects as well the induction of hyperactivity and convulsions in many insects (PaVela, 2009;Isman, 2006). Notably, lepidoptera make up 40% of the targeted insects, followed by sucking insects and coleopterans (Garcia, 2011). The uses of pyrethrum include the control of aphids in African nightshades (Korir et al., 2021), whiteflies, aphids, and russet mites in tomatoes (Prota et al., 2014;Greenhill et al., 2011), potato beetles (Liu et al., 2014), maize weevils in stored maize (Fenn, 1984), and carrot flies and carrot weevils (Pree et al., 1996) as well as the elimination of cotton leafworm, aphids, and red spider mite (PaVela, 2009).

No phytotoxic effects have been observed after applying different pyrethrum concentrations to tomato leaves (Prota et al., 2014). Even at a high concentration of 3%, no phytotoxicity was observed on tomato and cucumber plants (PaVela, 2009), and similar results were reported for tomato leaves and sweet peppers sprayed with pyrethrum products (Antonious, 2004).

Because pyrethrum has a short environmental lifetime, it does not pose risks of toxicity to the environment. Technical-grade pyrethrum is less toxic to mammals, with an LD₅₀ of approximately 1500 mg kg⁻¹. In water, pyrethrum compounds are broken down to non-toxic products, and their half-life in soil is between 1 and 2 hr. Although it is extremely toxic to fish and moderately toxic to birds, its fat solubility makes it unlikely to concentrate in the food chain. In the field, the half-life of pyrethrum is 2 hr or less, but it can persist for up to 2 months indoors (Soni and Anjikar, 2014: Isman, 2006;Antonious, 2004). Pyrethrum is very toxic to honeybees and beneficial wasps, so care should be taken during application. It has moderate effects on predators and parasitoids, since it affects only the larvae and adults present at the time of application. New predators and parasitoids emerge from eggs, triggering new invasions (Nikolova et al., 2015).

The MRL of pyrethrum was found to be low in sweet peppers and tomatoes 1 hr after spraying, indicating that these fruits can be safely consumed shortly after treatment (Antonious, 2004). Similar results have been reported for the whole turnip plant, including its leaves and tubers, in China (Feng et al., 2018) as well as for green and black teas (Lu et al., 2010) and green lettuce, both in the open field and under greenhouse conditions (Pan et al., 2017). A study of stored durum wheat revealed an MRL value below the established limit of 3 mg/kg (Caboni et al., 2007), and residues were less than 0.2 mg/kg in barley grains at 7 days after treatment (Gao et al., 2024).

Resistance to pyrethrum has been noted in mosquitos (Schleier and Peterson, 2011) and in Helicoverpa armigera (Gunning, et al., 2011). High levels of resistance have also been reported in houseflies, diamondback moths on cruciferous crops in Taiwan, and tobacco budworm (Shono, 1985). Resistance can be avoided by using natural pyrethrum synergists to increase the lethality of this substance (B-Bernard and Philogene, 1993). It is important to note that pyrethrum, being a biological insecticide, is unstable when exposed to light, sensitive to low temperatures and rainfall, and rapidly degraded by UV radiation, which makes it less effective under unfavorable climatic conditions (Nikolova et al., 2015).

Conclusion and recommendations

The use of inputs such as lime sulfur, copper, paraffin, and pyrethrum provides Ugandan farmers with an effective way to control pests and diseases while maintaining their organic certification. This approach not only create opportunities to meet the growing demand for organic products, which often sell at premium prices, but also reduces exposure to harmful chemicals, especially in rural areas where healthcare access is limited. Additionally, lime sulfur and pyrethrum can be produced locally, reducing reliance on expensive imported pesticides, promoting self-reliance, and supporting the local economy. Ultimately, this will contribute to food security and improved livelihoods.

To optimize pest and disease management using lime sulfur, copper, paraffinic oils, and pyrethrum in Uganda, it is crucial to conduct research specifically tailored to the Ugandan environment, taking into account factors such as rainfall, humidity, and local crop varieties. This targeted approach will ensure inputs are applied at the optimal time, reducing wastage, improving crop health, and enhancing cost-effectiveness by minimizing unnecessary treatments. Ultimately, these findings will support Ugandan horticultural farmers in achieving sustainable crop production, environmental stewardship, and resilience, contributing to the overall socio-economic development of rural communities.

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