Plants can create their own sugars through photosynthesis, from light, water and air. Under normal growing conditions, plants simply don't need added glucose. If a legume such as a mung bean plant is wilted, it is not receiving the nutrients it needs, nor can it make them. According to Petrik Laboratories, sugar is not recommended as a soil amendment, but watering with a sugar-water solution can perk a plant back up even if it isn't a long-term answer to the problem.
Recovery From Wilt and Dehydration
Mung beans are commonly grown for their sprouts, which are crisp and good in salads. Growing sprouts need a steady supply of light and water, and, if they don't get it, they'll quickly wilt. In this event, a pinch or two of cane sugar dissolved in a cup of water will give them a jolt, supplying the sugars that wilted leaves cannot produce through normal photosynthesis. Look for quick signs of recovery: rehydrated stems and deeper green leaves.
Vibrant, Vigorous Growth
Mung beans allowed to grow out of the sprout stage like to grow in well-drained, sandy soil. They can reach a height of 24 to 30 inches, producing clusters of bean pods. Soil that is too sandy may not allow the mung bean's roots to absorb enough water, especially if you water infrequently. Provide adequate moisture, and water with a sugar solution no more than once a month to maintain lush growth. A little added sugar will not affect the taste of mung beans.
Rot and Plant Death
Too much of a good thing can cause problems for sprouts and mature mung bean plants alike. Watering too often with sugar water, or putting too much sugar in the solution can kill quickly. Plants with a sugar overdose turn brown, soft and have a nasty odour. Too much glucose in the soil will also attract bacteria, fungus and insects, causing a host of different problems for the other plants in your garden.