When growing maize, you may need to use different pesticides during the life of the crop. Maize crops are grown in rows and grow very quickly to become tall and wide. These mature crops have long spreading leaves which makes the gaps between the rows very narrow. This can make it difficult for you to spray safely and well.
1. Nozzle type. Choose the type of nozzle that will produce the right drop size. Hollow cone nozzles produce large numbers of small droplets and so are often used for spraying the upright leaves of maize. Also consider standard flat fan nozzles, which produce spray drops with more momentum to take the drops further and faster. Angle these nozzles to get more spray on the crop.
2. Swath width. Find the swath width that you need the nozzle to produce. When maize plants are still young and growing in rows, the downward spraying swath width should be the same as the width of the row of maize. This is so that all the pesticide is sprayed onto the crop and little reaches the ground on either side. For the taller, more mature crops, you may need to use an extension lance to get the nozzle to spray from a height, laterally and downwards, over the tops of the crop.
3. Foliage. The surfaces of maize leaves, stems and cobs are steeply angled and very waxy making spraying more difficult. In addition, when applying¨pesticide, it is very likely that you will need to spray in a small space with small drops, upwards and you may have contact with the sprayed crops. Thus, it is very important to take extra care to wear the correct personal protective equipment (PPE) to fully protect yourself.
4. Nozzle size. Find the size of the nozzle that will spray your chosen spray mix/water volume at your spraying speed, at the calibrated pressure that your knapsack sprayer must maintain; to give the swath width that you need.
When spraying tall maize crops, stand upwind so that the spray will not cover you as it falls. Take extra care to wear the correct personal protective equipment (PPE) to fully protect yourself.