The Guide to Corn Nematodes: Strategies and Best Practices

Another pest that causes major concern for corn farmers is corn nematodes since they are known to result in great yield losses by affecting the corn roots. This blog emphasizes the importance of knowledge on corn nematode management; their life cycle, symptoms of the infestation, and management practices that could help in improving corn production. Some of the topics being included are aspects to be considered and effective means of controlling nematode populations These aspects shall be explained in more detail in this guide.

Types of Corn Nematodes

Corn nematodes include several species, each with unique behaviors and damage potential:

1. Corn Root Knot Nematodes – These nematodes cause galls on the roots, although the galls in corn are often small and indistinct.
2. Corn Cyst Nematodes – These nematodes form cysts on the roots and can survive in the soil for years, making them particularly challenging to manage.
3. Corn Lesion Nematodes – These nematodes create dark lesions on roots, which can coalesce and cause significant root damage and yield loss​.

Corn Nematode Symptoms

Identifying nematode damage can be challenging due to the subtlety of symptoms, which often resemble other stress factors like nutrient deficiencies or drought. Key symptoms include:

• Stunted growth and patchy areas of poor growth in the field.
• Root symptoms such as galls, lesions, and a proliferation of fibrous roots.
• Above-ground symptoms like chlorosis (yellowing) and general poor plant health​.

Corn Nematode Life Cycle

Understanding the nematode life cycle is crucial for effective management. Nematodes overwinter as eggs and hatch in spring when soil temperatures rise. The juveniles then feed on corn roots, causing initial damage and facilitating secondary infections. They molt through several stages before reaching adulthood and laying hundreds of eggs, leading to rapid population growth under favorable conditions. This cycle results in significant root damage and yield loss by mid-season. Timely interventions, such as applying nematicides, rotating crops, and using resistant varieties, can effectively disrupt their lifecycle and corn nematode control populations​

Strategies for Nematode Management in Corn

Effective management of corn nematodes involves a combination of cultural, biological, and chemical practices:

• Crop Rotation for Nematode Control

Rotating corn with non-host crops like soybeans or small grains can reduce nematode populations. However, it’s important to note that some nematodes have a wide host range, so selecting the right rotation crops is crucial​.

1. Resistant Varieties 

Planting nematode-resistant corn varieties can help manage specific nematode species. However, rotating resistant varieties is necessary to prevent the development of nematode strains that can overcome the resistance​.

1. Cover Crops 

When planning to use cover crops, rye or oats can be planted since these plants support nematode-antagonistic microflora. However, some of the cover crops can promote the establishment of more nematodes hence should be selected judiciously. 

4.  Organic nematicides as a method for the proper control of corn nematodes 

Due to this reason, organic nematicides are critical in controlling nematode infestation without instances of polluting the environment. These products rely on the natural forces to combat nematodes with less impact on other useful organisms and the quality of the soil. Two such products are Purpureocillium lilacinum nematode and nematicide manufactured by Novobac. 

Purpureocillium lilacinum (Paecilomyces lilacinus) 

Purpureocillium lilacinum biocontrol previously called Paecilomyces lilacinus is an endophytic fungus isolated from soils and possesses biocontrol potential against nematodes. This feeds mostly on nematode eggs, larvae and the mobile adult stages thus controlling their numbers to the bare minimum. This fungus operates to parasitize and kill nematode eggs and subsequently lay a check on their reproduction cycle. It also has this capability to parasitize juveniles and adults of nematodes hence enhancing the reduction of nematode population. 

Literature review has revealed that Purpureocillium lilacinum is more effective against nematodes such as; root-knot, cyst and lesion nematodes. These can be by seed treatment, soil drench or direct soil application of herbicides. It forms the tendrils in the soil and retains its effectiveness in protecting plants from nematodes for a long time unlike in chemical application where one has to apply it severally. 

Novobac’s Nema Pro nematicide

Another organic product very effective in control of nemandodes is Nema Pro nematicide. This product is eco-friendly because it targets nematodes specifically without harming other beneficial soil organisms essential for plant growth. Novobac nematicide controls nematodes through management chains and natural formulations, affecting their ability to reproduce effectively. The active substances in Novobac’s nematicide influence nematode stress reactions, reducing feeding and reproduction rates significantly. This results in a drastic long-term reduction of nematode populations in the culture, benefiting overall plant health. Applied to the ground, it is absorbed by plant roots, providing protection against nematodes that damage root hair.

 Benefits of Organic Nematicides 

Environmental Safety: Some of the organic nematicides include; Purpureocillium lilacinum, Novobac’s nematicide among others; these can be sourced naturally thus minimizing the effect of polluting the environment and affecting any other living organisms. 

Soil Health: These products improve nutrient cycling because they stimulate the eco-system of microbes in the soil. Aerobic microbes develop, enhancing the typically positive impact to the regenerative force and the plant life surrounding them. 

Resistance Management: Biological control agents do not contribute to the build up of nematode resistance, which normally happens with the chemical nematicides. 

Sustainable Agriculture: Organic nematicides are environmentally friendly hence prevent the overuse of chemicals within the farming systems and promote cultural balance. 

Nematicide Application Methods and Integration 

Therefore, there is a need to incorporate the use of organic nematicides when developing a nematode management strategy. Identify the particular nematode species that are problematic in the area, their life cycle, and field characteristics. Use other tactics like crop rotation, resistant varieties, and cover cropping alongside these biological control agents. For example, plant non-host crops sequentially and apply the biocontrol agent Purpureocillium lilacinum to target nematode species.

Results show a decrease in nematode numbers year after year. Likewise, Novobac’s nematicide ensures long-term nematode control. Pest management practices that do not negatively impact soil health or crop yields are essential for sustainable agriculture.

Integrated Pest Management (IPM)

Integrated use of several control strategies in an IPM plan is the best effective approach to controlling nematodes. IPM is the method of pest control which includes the employment of cultural, biological and chemical means, chosen according to the peculiarity of the fields. For instance, a grower may intercrop, establish biocontrol agents like Purpureocillium lilacinum nematode and apply nematicides where and when nematode populations and weather conditions would require such measures. 

 Soil Health and Management in Treating Corn Nematodes

 Some forecasts propose that overall, preservation of general health of covered soil is entirely important upon the control of nematodes. Soils with high levels of organic matter provide niches for microbiological antagonists which can control the levels of nematode infestations. Measures like minimum tillage, use of cover crops and organic matter will make the soil unfavourable for the nematode parasites. 

 Thus, it is crucial to say that proper corn nematode control is possible only within the framework of integrated action. It means that nematode biology, frequent checking of fields, and the combination of the nonuse of pesticides and use of biological controls that do not harm the crops could help ensure increased, non-nematode-inimical corn yield.

References:

1. Parajuli, Gita, Robert Kemerait, and Patricia Timper. “Improving suppression of Meloidogyne spp. by Purpureocillium lilacinum strain 251.” Nematology 16.6 (2014): 711-717.
2. WANG, Zhen, et al. “Synergistic efficacy of Purpureocillium lilacinum and organic material against tomato root-knot nematode.” Chinese Journal of Biological Control 31.1 (2015): 130.