The latest wax gourd leaves turn yellow. what's going on?

Wax gourd growth is a relatively easy to manage vegetables, because the wax gourd vine is relatively strong, the root system is also very strong, the absorption capacity is very strong, the leaf is very large, the photosynthesis effect is obvious. But sometimes they are also harmed by diseases and insect pests. If there is a yellow leaf phenomenon, we should first distinguish the specific causes and then aim at the treatment. Now let's take a look at the specific reasons for returning yellow leaves.

1. Grey spot

After being infected with gray spot disease, wax gourd leaves begin to grow faded macula, and the disease spot is irregular. After that, the plaque will gradually connect, and the plaque will become grayish brown in the later stage, so there will be yellow leaves in the early stage. Prevention and treatment is mainly the use of chlorothalonil seed disinfection, when the disease spraying 50% mixed sulfur suspension 500 times solution, generally spraying once a week, depending on the effect, can continue to spray several times.

2. Other reasons

Stagnant water or malnutrition, soil consolidation, and the impact of drought, drought affects the root system to absorb water, will affect the growth of leaf plants. Sometimes the phenomenon of long yellow leaves can occur when burned by strong light. Therefore, it must be planted on high-lying land, which is a breathable and fertile sandy loam. Replenish nutrients regularly and don't wait for instructions from yellow leaves to start fertilizing. Loosen the soil after rain, and pay attention to watering in the evening every day in drought.

3. Excessive fertilization

Wax gourd has strong absorptive capacity, if the one-time fertilization is too much, the concentration of soil solution is too high, which affects root absorption, the use of chemical fertilizer is too close, it is easy to burn roots, and after root damage, the absorptive capacity is weakened, which will lead to nutrition deficiency and yellow leaf phenomenon. Therefore, it is best to apply more base fertilizer, topdressing and farm manure. Or compound fertilizer, which is not easy to burn, should be watered after fertilization.

4. Nematode damage

Underground root-knot nematodes harm a variety of vegetable crops, wax gourd will produce the phenomenon of small yellow leaves after being damaged by nematodes, when there is no powdery or mildew on the surface of the yellow leaves, it may be nematode damage, no infection bacteria. The leaves will gradually die after yellowing, but they will not fall. Therefore, it is best to dig up the root system and check that there are nodules in the soil. Use 1.8% avermectin 500 times root irrigation, with some such as giant algae 1 500 times solution fertilizer together with root irrigation, quick recovery.

If the wax gourd leaves turn yellow, there are actually many reasons, but the symptoms are not quite the same, careful identification, and then do improvement treatment, prevention and treatment can be effective.