Labour Legislation Has Forced many farmers, who used to plant by hand, to mechanise their planting and harvesting. However, mechanical planting can damage vulnerable bean seeds. We need to take every precaution to ensure a good stand and produce our crop as economically as possible. This starts from the beginning with seed loading. Most varieties of green beans are whiteseeded. However, white-seeded varieties have an inherently weaker seed coat, which cracks more easily than dark or mottled pods would. As we have little choice in the matter, we need to keep this in mind when handling seed.
One of the reasons bean seed is sold in more manageably-sized bags is to minimise damage if the bags are dropped. Since labour is accustomed to handling other grains, the chances are that, unless they are forewarned, they will drop the bags when off-loading. This can have a substantial effect on the germination and quality of seedlings. The drier the seed, the more easily it can be damaged.
If the germination is not directly affected, seedlings may be “bald”. Baldness is bad news in green beans – the plant will emerge with two cotyledons which won’t produce any leaves. Even if they do produce leaves, one or both cotyledons may also be broken off or damaged, which will affect the uniformity of vigour between the plants. Care should be taken with the planter too, as planters used for other crops may be too harsh for green beans. Never start planting before turning the planter wheel and checking that the seeds are emerging without any cracks or damage.
An easy test for seed health
Unless you’ve used the seed before, it’s wise to do a home germination test before planting. Beans are fast growers so this won’t take long, and it will alert you to any problems before it’s too late. The test is easy. Cotton wool or tissue paper is moistened and placed in a plastic container, then the seeds are planted and the lid replaced. Most of us did this for school biology projects. At a company I worked for, we did this test with every new batch before planting.
If the germination rate was low, we were forewarned. Then we could set the planter accordingly and still get the stand we were aiming for. Vigour is also important. When seeds are old, even if they’re not physically damaged, their vigour starts to drop. This makes it more difficult for plants to emerge in difficult soil conditions. Seeds take longer to germinate, and do so unevenly. Therefore, this quick and simple test can help you make better decisions when planting. Contact Bill Kerr on (016) 366 0616 or e-mail [email protected]