When growers are planting their crops, often they are filling their planting equipment with more than seeds. 

The development of seeds coated with treatments, such as insecticides and fungicides, have led to challenges that interfere with flowability during planting. To combat this issue, many growers add talc and/or graphite to the batches of seeds they plant.

Talc is added as a dry lubricant that also acts as a drying agent. Seeds coated with insecticides and fungicides tend to quickly absorb water from the air that moves through planters. When this happens their surfaces become sticky, which can cause clumping and bridging in seed hoppers, and clinging to seed disks in seed meters.

The more humid the environment, the greater the problem becomes. "The coatings on seeds get rougher and stickier when they absorb moisture," says Kelby Krueger, product specialist at John Deere. "Talc fills the pores, smoothes and dries the surfaces of the seeds, and improves flowability." 

Like talc, graphite also provides the benefits of a dry lubricant. But as a conductor, its strength is in its ability to reduce static electricity and friction that can lead to clumping and bridging, as well as excess wear on equipment. "Static electricity can be a big problem with some seeds," says Daryl Cress, service manager at Great Plains Manufacturing, a leader in seeding equipment. "It varies between different types of seeds, seed coatings, and conditions. Milo and canola seem to have the worst problems for some reason."

The key to using talc and graphite successfully is to mix them into plant hoppers carefully and in the right amounts. This is especially important for seeds inoculated with beneficial strains of bacteria such as rhizobia. If a talc or graphite application dries the seed too quickly, it can reduce the amount of on-seed rhizobia colony forming units (cfu) applied to freshly inoculated seeds.

Fortunately, Sensient® Industrial Colors offers an alternative to talc and graphite: a high-luster seed enhancer which, like talc and graphite, works to improve flowability, reduce bridging and provide a faster dry time. However, Pearl MAXX™ provides these benefits without risking harm to beneficial bacteria strains. In fact, independent laboratory testing on soybean seeds inoculated with rhizobia demonstrated no significant difference in rhizobia counts between seeds coated with Pearl MAXX™ White and non-coated seeds. 

To learn more about how Pearl MAXX™ can help enhance your planting process and protect your seed treatments, contact us to discuss your needs.


1.   https://www.agweb.com/opinion/talc-or-graphite