Common Problems in Conservation and Management of Potted Cycas debao

Debao cycad (Cycas debaoensis Y.C.Zhong et C.J.Chen) is endemic to China. It is a national first-class protected species with high research and ornamental value. It was discovered by Zhong Yecong, a researcher of Guangxi Forestry Survey and Design Institute, in 1996. Cycads are the oldest existing seed plants. They were once found all over the world in the Mesozoic era and are precious "living fossils". They were discovered in 1997 and caused a sensation because of their peculiar leaves and high ornamental value in horticulture.

There are more than 20 varieties of cycads in China, and common ones are often seen on the street. the scientific name: Taiwan cycads, and the rare ones in Chinese cycads are Debao cycads and polyphasic cycads, two varieties with bifurcated leaves, which are very beautiful and are the ancestors of modern iron trees.

It can be said that iron tree is very easy to live in plants. No matter it for a month, it will not die because there is no time to water it. The habits of rare species and ordinary iron trees are exactly the same, and they are suitable for planting all over the country.

Soil: iron tree likes sandy soil, if not, ordinary soil can be mixed with half of fine sand, as long as it is breathable without stagnant water and not hardened.

The cycad bulb itself stores a lot of water, so we don't have to worry that the cycad will dry to death in the course of transportation, such as a 5cm thick bulb, even if it is cut off for half a month.

The habits of rare cycads are similar to those of ordinary cycads, except for one thing: cycads with strong roots, such as Debao cycads, have a larger wound area after root cutting, so it is best to dry the roots in a cool and ventilated place for 1 week in winter. This can improve the survival rate, if there is no dry root, you can also cut off the excess root, the iron tree is a bulb succulent root plant, not a woody fibrous root plant, the old root retained by transplanting does not have much effect, and the new root is reproduced.

Here I have sorted out some problems often encountered in cycad planting, which will be constantly updated:

Cycads usually send new leaves twice a year, once in spring and once in autumn, as more and more leaves grow, they can prune them according to their preferences.

Cycads are very hardy and can be planted all over the country. A flower friend in Northeast China did an experiment. When it was 20 degrees below zero in winter, cycads were put outdoors to keep the soil dry and safe through the winter.

The problem of watering: the planting environment temperature is above 0 degrees, the soil dries quickly and then the water is completely cut off below 0 degrees.

Cycads are evergreen plants that do not lose their leaves in winter. The new leaves will naturally turn yellow after 3-4 years.

Iron trees can be planted indoors and outdoors.

One or more trees can be co-planted with different varieties, or they can be co-planted without any effect on growth.

You can bask in the sun immediately after transplanting without shading, because cycads are bulbous succulent roots, not woody fibrous roots, and there is a lot of water stored in the bulbs.

In the first year of transplanting, try to bury 2 / 3 of the bulbs in the soil [seedlings should be buried] the principle is that the deeper the better, the faster the leaves, because the bulbs also need to assist in absorbing water, but many flower lovers like to plant shallow and deep heaps of bulbs, and then wash away the soil with water after the iron trees have fully grown.

The problem of the basin: in general, the diameter of the basin only needs to be 2 times larger than the diameter of the bulb to meet the growth, of course, the bigger the basin, the better the depth of the basin: as long as it is not lower than the height of the bulb.

The problem of fertilization: the newly transplanted cycad is suitable for slightly poorer soil, it cannot be fertilized, it is easy to burn roots, and it is also easy to attract worms. The nutrition in the soil is enough to grow. You can change a larger pot in four or five years. If you don't change the pot, you can change the soil. You can also apply some ferrous sulfate, which is sold in the flower market, which is very cheap, a few yuan.

How to judge whether the iron tree is dead: if the iron tree is dead, the bulb is rotten into a very soft, or empty shell. If the bulb is hard, it's alive.

The height of the leaves of the iron tree can be controlled by itself, for example, the leaves that normally grow 1 meter high, do not water when sending new leaves, keep the soil dry and bask in the sun more, they will only grow to 40 meters and 50 centimeters high. If they are watered more and bask less in the sun, they may be as high as 2 meters.

In the first year of transplanting, two pesticides were sprayed in spring and autumn, methyl thiophanate and carbendazim were sterilized, zinc and parathion were insecticidal, and the three could be mixed and sprayed. Irrigation is OK, the specific method can consult the local agropharmacy sales staff.

Don't put nails in the basin. Some flower friends have heard that putting nails in the soil can make iron trees grow better. This is wrong. First of all, iron trees only absorb 2-valent iron, that is, ferrous iron. You can go to the flower market to buy ferrous sulfate and specialize in iron tree fertilizer. The most important point is: when you change the soil later, it will be troublesome if you are accidentally stabbed by iron nails in the soil, and if it is serious, you will get tetanus.

Don't cover your roots with plain sand. Rare varieties are not suitable

Iron tree yellow leaves: iron tree yellow leaves have many reasons, such as water, rotten roots, old leaves, natural yellow, mold, sunburn, insect gnawing, poor ventilation, frostbite, iron deficiency, yellow spot, and so on. But in general, as long as the bulbs are hard and do not rot, you just need to cut off the old leaves, and if the new leaves are still yellowing, you have to be treated.

Cycad small gray butterfly

Cycas small gray butterfly, Chilades pandava, belongs to the genus Lepidoptera and is the main pest of cycads. With the gradual increase of cycad cultivation, the occurrence of cycad butterflies is also increasing year by year. In some flower beds in Beijing, all the new leaves were eaten up in that year, resulting in serious economic losses.

The distribution and damage of the insect are mostly distributed in Nanjing, Guangdong, Fujian and other places in China, and the larvae are hidden in buds and leaves shortly after hatching. With the purchase of South Flower and North China is gradually settled in the north

Morphological characteristics

The adult body is 12 to 13 mm long, the wingspan is 26 to 35 mm, the body is covered with grayish black or grayish brown scaly hairs, the tentacles are as long as the leading edge of the forewing, and are stick-shaped, the compound eyes are brownish black, the forehead and lips are white, the ventral surface is white, and there is a black band protruding at the hip corner of the hind wing. The female is slightly larger, the wing is grayish brown, but the posterior edge of the hind wing is gray; the front wing of the female is red from base 1 to base 1, the rest is gray-black-brown, the base and leading edge of the hind wing are black and brown, the rest are red, the back of the abdomen is red, and the rest are white to gray. The larvae have a body length of 0.1 to 1.1 cm, a bright purple-black head, a fat and slightly flat body, fine hairs on the back of the body, a longitudinal pattern deeper than the body color in the center, and a ring longitudinal pattern on each side that is darker than the body color. The body color of the smaller larvae is light yellow and jujube red, the body color of the smaller larvae is light or even white, the head is obviously thin, and the larger larvae are dark, thick and flat, and the head often shrinks. The upper section of the head and tail and the longitudinal axis of the body are tilted at an angle of about 45 °.

3 Life habits

The insect can occur from May to November, and it is often clustered in the bud scales between and near the top of the head of the iron tree, or scattered on the front or back of the tender leaves, and mainly engages on the petioles and leaflets of the young leaves that have grown or have not grown. The dorsal part of the leaf is mainly eaten on the larger new leaves and older leaves, and only the upper epidermis is left in the eaten leaves. The damaged plants often do not send new leaves, the tender leaves wilt and die, or some or all of the leaflets dry up and roll up, and in serious cases, only the main leaf veins or even parts are left. When the insect population is more, the phenomenon of tender leaflet drying up and curling can suddenly appear in the whole plant in three or five days. The insect is very stubborn and hidden before the damage, although a large number of larvae can be killed at one time, but because it can not kill the eggs, it often occurs again a week later.

4 methods of prevention and control

At the end of April, spray leaves and tops with 21% EC 1000 to 1500 times, 20% chrysanthemum EC 1000 to 1000 times, and 40% dima mixture EC 1000 to 1500 times, once every 20 days until mid-November.

When insect pests occur, you can use the above agents to dilute the lower multiple spray, once every 10 days for a total of three times, and then do a good job of prevention.

In addition, domestic cycads can also be irrigated with cigarette butt extract (30 to 50 cigarette butts) / kg water or Sophora flavescens decoction (30 g to 50 g plus 1.5 kg water).

Time: 2019-04-22 Click: