Caring for corn plants during the pre-harvest stage.
Do not cut off the top part of the corn stalk before it is fully ripe.
Do not cut off the top part of the corn stalk before it is fully ripe.
For corn plants, the ripening process goes through three stages: milky stage, waxy stage, and full ripening. In the milky stage, the accumulated dry matter accounts for about 30-35% of the kernel weight. In the waxy stage, the accumulated dry matter accounts for about 60-65% of the kernel weight. In the full ripening stage, the accumulated dry matter gradually decreases, and the leaves turn yellow from the bottom up. Thus, during the ripening period, corn leaves play a very important role in photosynthesis to produce dry matter to nourish the kernels, especially the top leaves.
In some areas, farmers utilize the old, dry leaves to improve aeration, reduce pests, and use them as feed for cattle. However, in practice, many farmers overuse the practice of cutting off even the green leaves to feed cattle or fish; some even cut the upper part of the corn stalk above the cob while the kernels are still green and in the waxy stage, with the aim of speeding up ripening. In reality, this significantly reduces yield and kernel quality, resulting in wrinkled, discolored, and low-quality kernels.
Farmers in Quynh Luu inspect their corn crops using Bai Oxide.- Photo: Tran To
The best way to ensure high yields and good quality corn, while also utilizing the leaves as feed for cattle, is to harvest the leaves starting to yellow from the bottom up, ensuring at least 6 to 8 leaves remain on top until the cob is harvested. For late-sown corn fields, allowing it to ripen completely will affect the planting season of subsequent crops. If the land needs to be cleared while the corn is ripe, it's advisable to cut both the stalks and the cobs and leave them for a few days to allow the kernels to firm up before separating the cobs. In alluvial soil areas, if the subsequent crop is beans, peas, sesame, etc., intercropping is recommended. Based on the growth rate of the intercropped plants, the corn leaves should be thinned appropriately to ensure sufficient sunlight for both crops to grow and develop well.
Producing baby corn requires timely detanning measures.
During the tasseling period, if the corn plants are growing and developing normally and weather conditions are favorable (moderate temperature, not dry, not heavy rain, light wind), farmers can cut off 2/3 of the tassels (cut off 2 out of every 3 plants) before the tassels release pollen, and should not cut off any leaves. This can increase yield by 5-8% because nutrients are not needed to nourish the tassels, and it also reduces damage from aphids. Cutting the tassels late, after the corn has released pollen, is ineffective.
For baby corn (vegetable corn), removing the tassels before pollination can increase the number of young ears per plant (usually yielding two ears instead of one), and the product quality is also better compared to not removing the tassels. This is because the plant doesn't have to nourish the tassels, and the young ears will be larger and smoother due to the lack of pollination and fertilization.
Apply fertilizer and prune shoots at the right time.
When the corn plants are about 50 days old, their stems have stabilized in height and they begin to flower and form ears. This is the final stage of fertilization to provide sufficient nutrients for increased yield and quality. Apply 5-6 kg of bio-fertilizer per 1000 square meters (sào) as a top dressing. Depending on the plant's growth stage, additional foliar fertilizers can be used to further increase the nutrient content of the corn field.
To ensure the highest yield and quality, 100% of the corn stalks must be thoroughly pruned before the tassels appear. Only the largest, first ear of corn should be left on each plant. Subsequent ears (second, third, etc.) should be pruned away, and this pruning should be done every 3-4 days to allow the plant to concentrate nutrients on the main ear. The ears should be broken when the tassels are 2-3 cm long. Use your hands or a knife to gently cut the shoots; this avoids damaging the plant and allows the young ears to be used as baby corn for consumption or sale to increase income.
Hoai Phuong
