When is the latest planting time for mung beans?
Mung bean is an annual herbaceous plant of the genus Phaseolus in the Fabaceae family. Its growth cycle is about 60 to 65 days. It has wide adaptability and strong stress resistance, tolerating drought, poor soil and shade. Its growth period is short, and it has the ability to fix nitrogen symbiotically and enrich the soil. It is often used as an excellent crop for replanting, catch cropping and famine relief, and has very high planting prospects. Let us take a look below at when mung beans should be planted!
Mung bean planting time
Mung bean has a short growth period and a long suitable sowing window. In many places it can be sown in spring or summer. Generally, it can be sown once the soil temperature reaches 16 to 20 degrees C. In most plots with irrigation conditions, the sowing period for mung beans is from May 15 to 30. On sandy ridge plots without irrigation conditions, sowing is mostly done from June 12 to 15. Generally, spring sowing is from mid-to-late April to early-to-mid May, and summer sowing is from late May to early-to-mid June. In the north, the suitable sowing window is short. For a single annual crop, the spring sowing period is from early May to the end of May, and the summer sowing period is from late May to early June. In the Northeast region, spring sowing is in mid-May and summer sowing is in mid-to-late June. Note that mung bean is a warm-season crop. If spring sowing is too early, individual development will be poor, the growth period will be prolonged, and yield will decrease. For summer-sown mung beans, earlier sowing is better. The seedlings grow robustly, and the flowering and pod-setting stage falls in the hot, rainy period, which is favorable for flower and pod formation, resulting in more pods, more seeds, heavier seeds and higher yield.
Sowing methods for mung beans
1. Fine land preparation: Mung bean is a dicotyledonous plant with large cotyledons, and the seedlings have weak ability to push through the soil. Therefore, before sowing, the land must be finely prepared. Through plowing, harrowing and rolling, achieve a level surface and fine soil, with a loose top layer and a firm lower layer. Where irrigation is available, build up soil moisture; where irrigation is not available, prepare the land early and wait for rain to sow. Generally, land preparation is done in early-to-mid April.
2. Seed treatment: Before sowing, remove diseased, mixed and hard seeds to ensure seed purity and germination rate. Use wind selection, water selection or machine selection to remove shriveled seeds, small seeds, impurities and weed seeds, and keep clean, large seeds for sowing. On a sunny day, spread the seeds thinly on a mat and turn them to dry for 1 to 2 days to enhance seed vigor and improve germination potential. For “iron mung beans” that are dark in color, rough-coated, poor at absorbing water and difficult to germinate, rub them gently so the seed coat is slightly damaged, making them easier to germinate and emerge. Sprinkle a small amount of water on the seeds, scatter the inoculant onto the wet seeds and mix well, using it immediately after mixing. Rhizobium fertilizer must not be mixed with chemical fertilizers or fungicides. Commonly used nitrogen-fixing bacteria inoculant contains 300 million rhizobia per gram, with a dosage of 125 grams per mu. Alternatively, use coating agents, drought-resistant agents, or micro-fertilizers containing molybdenum, boron, etc. for seed dressing.
3. Sowing method: Mung beans can generally be sown once the soil temperature reaches 16 to 20 degrees C. Spring sowing is in May, and for summer-sown mung beans, the earlier the sowing, the higher the yield. Drilling is most common, while hole sowing and broadcasting are also acceptable. For drilling, prevent covering the soil too deep, sowing too densely and missing spots. Intercropping, relay intercropping and scattered planting are mostly done by hole sowing. The sowing depth is generally 3 to 5 cm. The seeding rate is 1 to 2 kg per mu, less on fertile land and more on poor land.
Field management of mung beans
1. Pressing and replanting: After sowing, for plots with poor soil moisture, press the soil in time, pressing as you sow, so that the seeds are in close contact with the soil, increasing surface moisture, promoting seed germination and development, and achieving early and complete emergence. After mung beans emerge, if gaps or missing plants are found, replanting should be completed within 7 days.
2. Thinning and final singling: To ensure good individual development of seedlings, thin and finalize the plants. When mung bean seedlings reach the two-leaf-one-heart stage, remove clustered seedlings. At the 4-leaf stage, finalize the plants, with a plant spacing of 13 to 16 cm, and a row spacing of about 40 cm for sole cropping. According to the established density, remove weak, diseased, small and mixed seedlings and weeds, and keep strong seedlings. Keep a single plant per position to promote robust plant growth.
3. Cultivation and weeding: This not only eliminates weeds, but also breaks up soil compaction, loosens the soil, reduces evaporation, raises soil temperature and promotes nodule activity. It is a measure for increasing mung bean yield. Generally, after the first compound leaf of the mung bean unfolds, combine thinning with the first shallow hoeing. After the second compound leaf unfolds, begin final singling and carry out the second cultivation. At the branching stage, carry out the third deep cultivation and earth up around the roots. Cultivation should continue until the rows close. The cultivation depth should follow the principle of shallow-deep-shallow.
4. Irrigation and waterlogging prevention: Mung bean is a crop that needs more water but is not tolerant of waterlogging and fears being submerged. Mung bean seedlings have relatively strong drought resistance and need less water, while the flowering and pod-setting stage is the peak water-demand period. At this time, if drought occurs, irrigate in time. However, mung bean is also afraid of waterlogging and flooding. If there is too much moisture at the seedling stage, root diseases will worsen, causing root rot and seedling death. If waterlogging occurs later, plants grow poorly, show premature aging, flowers and pods drop, and yield declines. Therefore, during the rainy season, mung beans should be drained to prevent waterlogging.