After eight decades of Dalbulus maidis presence in Brazil, organic management emerges as a promising tool to mitigate corn leafhopper damage.
The sustainable alternative against damage caused by CMVs (Complex of mollicutes and viruses) was recently launched under the name Organic Bloom HydroProtect.
The technology is 100% organic and composed of phytic acid, amino acids, and mucilage extracted from plant sources. Brazilian company Ingal Agrotechnology developed Organic Bloom HydroProtect in partnership with the Federal University of Santa Maria and represents a new strategy to work on multiple fronts in reducing and reversing damage to corn crops.
Cristiane Reis
“There was a need to develop new molecules that are more assertive in reducing damage caused by these phytopathogens, more economical, and less aggressive to the environment. Innovative products that provide greater protection of corn seedlings against phytopathogens and protect the crop throughout its development cycle emerge as pioneering tools that culminate in increased productivity, as they act on various fronts to mitigate the problem,” explains Cristiane Reis, Research and Development (R&D) Director at Ingal Agrotechnology.
According to studies conducted in the 2023/2024 corn season, Organic Bloom HydroProtect provided an increase of 15.97 bags/ha. The result was possible with five sprays of 300 mL/ha each on the corn crop starting at the V2 phenological stage with 7-day intervals. The study was conducted by Agricultural Engineer Dr. Jurema Rattes from AgroRattes – the only Brazilian research company specializing in Agricultural Entomology located in Santo Antônio da Barra/GO.
Cristiane Reis and Jurema Rattes
“The productivity increase results from the product’s multiple action fronts. The 39% reduction in stunt disease levels, provided by sequential applications of Organic Bloom HydroProtect, promoted gains in the evaluated agronomic characteristics, such as greater stem thickness, higher number of grain rows per ear, greater ear weight, and higher yield. Additionally, the application of Organic Bloom HydroProtect did not cause phytotoxicity to corn plants,” pointed out Cristiane Reis.
The study conducted by Dr. Rattes was presented at a breakfast organized by Ingal Agrotechnology for producers, consultants, and partner resellers in November 2024 in Rio Verde/GO. “The presentation of results was an important milestone for directing and intensifying field and laboratory studies, aiming to expand positioning,” highlighted the R&D Director.
Ingal Agrotechnology manufactures Organic Bloom HydroProtect at its headquarters, located in the Industrial District in Santa Maria/RS, strategically close to its innovative technology development partner, the Federal University of Santa Maria. The company also maintains a physical space within the university, where it maintains a permanent showcase of obtained results and prospects and develops new products.
History and Problem Characterization
The corn leafhopper, Dalbulus maidis, is one of the leading corn pests in Latin America. Besides feeding on corn plants, this insect can transmit, in a persistent-propagative way (where the pathogen multiplies inside the insect), the Maize rayado fino virus (MRFV) and two crucial bacteria: Corn stunt spiroplasma (CSS) and Maize bushy stunt phytoplasma (MBSP). These bacteria cause diseases known as pale stunt and red stunt, which harm corn plant physiology and nutrition, potentially reducing grain production by more than 70%.
Since 2015, corn crops in Brazil have faced significant and systematic production losses due to the occurrence of these diseases in various regions. More recently, these diseases were reported in southern Brazilian states. The crop’s economic importance, the vast production window, and the spread of volunteer corn plants created a “green bridge,” which favors the perpetuation of these pests and pathogens, which can generate phytosanitary threats to the crop over time. Additionally, the corn leafhopper’s (Dalbulus maidis) ability to exploit corn plant resources from the initial development phase until senescence, its high mobility, and excellent dispersal capacity have caused this species to spread throughout all cultivated areas.
The corn leafhopper (Dalbulus maidis) survives during the off-season through diapause, use of alternative hosts, and migration. However, volunteer corn plants are currently the primary survival strategy for this pest outside the growing season in Brazil. The role of these plants goes beyond merely providing shelter and food for leafhoppers. When infected leafhoppers (with phytoplasma and/or spiroplasma) move between volunteer corn plants to oviposit and feed, they transmit pathogens to all plants. The new generation of nymphs that develop on these plants acquires the pathogens immediately, resulting in a new population of infectious adult insects.
Corn Stunt Disease Symptoms
Corn stunt foliar symptoms vary greatly. In the field, diseased plants usually show reddish or yellowish leaves, especially at the margins and apical part, with chlorosis between secondary veins. Leaf margins may dry out.
However, it’s not possible to visually differentiate between the two types of corn stunt disease solely by leaf symptoms. Other symptoms include reduced height and tillering at the plant base and leaf axils. Discoloration is caused by chloroplast damage, while redness results from anthocyanin production in response to stress.
Early plant drying at the grain-filling stage is likely a plant strategy to drain photosynthates and fill grains, compensating for rapid water loss in tissues. Regarding production, smaller ears with small, sparse, and wrinkled grains usually occur.
Management of Corn Stunt Disease Complex
The complex of mollicutes and viruses (CMVs) transmitted by the corn leafhopper (Dalbulus maidis) forms a complex pathosystem due to interactions between vector insects, pathogens, host plants, and the environment. Currently, based on scientific knowledge, management of corn stunt disease complex focuses on adopting agricultural practices aimed at reducing vector insect populations and pathogen inoculum.
The pathogens (phytoplasma and spiroplasma) require a long period to multiply and for their content within the plant to reach levels capable of causing economic losses. Therefore, the earlier plants are infected, the greater the production losses. The initial phase of corn cultivation is thus a critical period for protecting plants against infection by these phytopathogens.
Different strategies have been used to reduce vector insect populations and minimize early plant infection, including the use of treated seeds and insecticide spraying between emergence and V8-V10 phenological stages, plus the use of tolerant hybrids. In this context, attention is needed regarding the adoption of management strategies since the economic damage level and vector insect control level cannot be determined based on vector abundance but instead on population infectivity rate.
In this scenario, various technologies and chemical and biological inputs emerge, mainly in complementary systems, due to the need for chemical alternation because of insect resistance risk and the slower action and necessary application care required for biological insecticides. It was in this context that Organic Bloom HydroProtect emerged – one of the great promises for upcoming Brazilian corn seasons.
