One of the hardest seeds to keep pure is Corn or Mielies. Traditionally a staple South African crop that originated from the America’s, heirloom and Open Pollinated corn has now become more and more scarce and hard to source.
South Africa’s rich history of “mielie boerdery” has all but been destroyed by the large Agro Science companies with their hybrid and GM varieties, our own government has totally ignored the plight of subsistence and smaller farmers with their ill-considered thrust to supply this GM infected seed to small farmers throughout the country, destroying any traditional varieties via pollen contamination.
It is estimated that upwards of 80% of our annual mielie harvest is GM and you can be assured that if you are not growing your own you are certainly ingesting GM tainted food. This is especially true if you eat any grain fed meats, as these are predominantly fed with GM derived grains like corn and soya.
So how does one keep your OP or heirloom corn varieties pure? It’s a simple process as long as you follow a few rules and are aware of what your neighbours are planting.
The first and most important rule is stand size. Your planting cannot be less than 40 plants. This is the absolute minimum and double would be better. There is no way that one can effectively save seed from an OP variety with less than 40 plants. If you do, you will find that you have destroyed the genetic variation essential in heirloom and OP corn varieties that can never be recovered. Also with a stand size of less than 40 plants you will also find that a high percentage of your harvest will be poorly pollinated and kernels will be missing on the cob.
The next rule is that you should always plant your corn in a block, rather 8 rows wide and 8 rows deep, than planting one long straight row. As corn is wind pollinated the pollen is easily blown away if planted in a single row, whereas if planted in a block one plant will be able to pollinate the next few rows ensuring even pollination and maximum genetic spread.
Finally you will want to save seed for next year. Your best seed for seed saving will come from the centre of your block planting. This is seed that has the most pollen variation and the least chance of being contaminated by another nearby planting. Harvest a centre block of 3 or 4 rows for seed and use the outer rows for green mielies, or for grinding down as an organic mielie meal or animal food etc.
These three rules above if followed will ensure that you get a good harvest and ensure that your seed is genetically robust from year to year.
The next question is how does one plant more than one variety and still keep them pure? The answer is simple and very effective. Plant your stands of corn 4-5 weeks apart. This will give you an extended harvest of up to 4 varieties in a season and will allow you to plant and save pure viable seed from each one of these varieties. Bear in mind that a late planting will need at least 3 months to mature properly on the stalk, especially if you are saving seed that needs to dry out. Please note that using this method you will need to supplement watering during the dry periods.
Your biggest source of contamination (other than your own plantings) are what your neighbours are planting, as you will need to work around their planting / pollination dates.