Rational Disease of Orchid Peanut-- Lower deciduous leaves

The lower leaves are usually related to root disease, leaf disease and scale insect damage, too old age can also cause lower leaves to fall off, and other non-pathogenic factors related to lower leaves are improper cultivation practices and water stress. For orchids planted in the field, improper cultivation and water stress are the most common causes of defoliation. When the soil is not properly treated and the roots of newly planted seedlings are not well covered with soil or ground cover, they cannot absorb enough water to be stressed. The lower leaves turn yellow, dry and fall off.

A period of hot weather; rapid transpiration of leaves; high levels of evaporation from the soil; thus, if the plant does not absorb sufficient water, water stress occurs. Continued water stress causes lower leaves to drop and inhibits growth, especially in newly planted plants.

Prevention: should be carefully planted orchids in the field seedbed, the new downhill plants should be carefully planted according to the correct method. Lower defoliation can also be prevented by row hollows, mulch and regular watering to avoid water stress. If replanting takes place during the rainy season, water stress in the newly planted plants can also be avoided. (Liu Zhongjian)