Diseases of Pinus melilotifolia

Diseases of Pinus melilotifolia

Disease symptoms of Pinus melilotifolia

The occurrence period is from May to November, and the peak period of damage is from mid-June to mid-October. The adults lay their eggs on the curled new leaves of the plant. After hatching, the larvae first burrow into the curled new leaves to eat the mesophyll. As the leaves grow, they often gather in the bud scales on the upper part of the plant or scatter on the younger leaves, biting the tender leaves of the plant.

Diseases and hazards of Pinus melilotifolia

When the damage is serious, only the petioles of the young leaves remain, and sometimes the petioles are hollowed out. At the peak of the damage, the young leaves will suddenly wilt and dry up within 3 to 5 days, or the leaflets will all shrivel and curl up. The leaves will be incomplete when unfolded, and the top of the apex will rot when it rains. The tree will not produce new leaves all year round, and it will lose its ornamental value.

Prevention and treatment methods

Cultivation measures

Before the beautiful leaf Phoenix thorn is brought into the greenhouse, the debris in the pot is removed, and special attention is paid to removing the mature larvae and overwintering pupae at the roots and bud tips of the beautiful leaf Phoenix thorn, so as to eliminate the source of overwintering insects.

Take steps to end hibernation early. Apply sufficient base fertilizer before June 30, move into the greenhouse before October 1, maintain the greenhouse temperature at around 15°C to promote early germination of new buds, and strive to grow new leaves before June 10 to miss the peak period of damage.

Chemical control

Spray 1000~1500 times diluted 21% cypermethrin emulsifiable concentrate.

Spray 800~1000 times diluted 20% chrysanthemum killing emulsion.