Villa Crop is hosting a series of Answer Plot sessions on several of their trial farms across South Africa. AgriOrbit attended one of these events in Morgenzon, Mpumalanga. The purpose of the Answer Plot series is to keep farmers informed of the latest information gained from trails done by Villa Crop.

The trial farm Kleinfontein, which belongs to the Morgenzon Agricultural Academy, was divided into five sections, each with demonstrations and talks on one of the following topics: water quality, chemical application technology, herbicide grouping, fungal infections and maize nutrition.

Water quality

Did you know that water quality influences the effectiveness of chemicals that are mixed with water? For example, the quality of water affects the performance of herbicides such as glyphosate. Using poor quality water might unnecessarily diminish chemical performance and can be avoided. Therefore, it is important for farmers to know the qualities that dominate their water sources. Water quality includes water pH, salinity, water hardness, mineral and iron content.

Chemical application

Did you know that droplet size plays an integral role in effective chemical application? The Villa Crop team demonstrated the role nozzle size, and consequently droplet size, plays in deposition, distribution and drift. Droplet size is measured as volume median diameter (VMD). The ideal all round droplet size for application of pesticides is between 250 and 650 microns. During the demonstrations blotter paper was used to indicate how droplets were distributed.


Did you know herbicides are grouped according to their mode of action? This means that not all groups of herbicides kill off weeds in the same way. Nine herbicides were administered in the trial plot of the herbicide station. The nine chemicals used are classified as the most important groups by the Herbicide Resistance Action Committee.

Rows in the plot were planted with maize (grass) and soya (broad leaf). The Villa Crop team demonstrated the various actions each group had on grass and broad leaf plants. The team reminded farmers that proper herbicide management is key to herbicide resistance. In some cases, weeds have become resistant to certain herbicides in as little as three years.

Maize nutrition

Do you know all the phases of the maize plant’s life cycle? The life cycle of the maize plant plays an important role in understanding nutritional needs for the plant. Stress early in the plant’s life cycle can have a great impact on yield later in its cycle. The Villa Crop team discussed the life cycle of maize plants from vegetative phases through to reproductive phases. Although climate plays an important role in the plant’s development, proper nutrition applied at the right time, in the right form and at the right rate can help optimise yields.


Fungal infections

How well do you know your fungi? The team of fungi experts gave a brief overview of the main fungal infections affecting maize, soya and sunflowers in South Africa. The life cycle of Sclerotinia sclerotiorum was discussed at length, as well as ways to manage this fungus. Sclerotinia is currently wreaking havoc in soya and sunflowers across the country. Significant fungal infections discussed for maize included grey leaf spot, northern leaf blight and common rust. – Ursula Human, AgriOrbit