Cassia angustifolia Also known as Yina, senna and soaked bamboo leaves. It is a grass shrub in Leguminosae. Produced in India, Egypt, Sudan and other countries. Guangdong Province and Yunnan Province were introduced into tropical areas of China, and Yuanjiang County, Yunnan Province, with less rainfall, was in a better position. Dry leaves can be used as medicine, so can fruit pods. The main medicinal materials are sennoside A and B, aloe-emodin, chrysophanol, rhein and so on. Pharmacologically, it mainly has purgative effect, antibacterial, bacteriostatic and curare-like effects. The aqueous solution of Senna leaves (1∶4) has inhibitory effect on Microsporum and Nocardia stellata in vitro. Sweet, bitter and cold. Has the functions of purging accumulated heat and promoting defecation. Indications: dyspepsia, abdominal distension and constipation.

I. Morphological characteristics

The plant height is about1m. Leaves alternate, even pinnately compound, with stipules; Leaflets 4-8 pairs, ovate-lanceolate to linear-lanceolate, with acute apex, slightly asymmetrical leaf base, glabrous or almost glabrous, entire. Racemes axillary; Sepals 5, slightly irregular; Petals 5, yellow, the lower two petals are larger; Stamens 10, of which 2 are longer, 5 are shorter, 3 are degenerated, the anthers are slightly square, the base is arrow-shaped, 4-loculed; The pistil is single carpel, curved like a sickle, and the ovary is superior and sparse. The pod is flat, long and rectangular, with a sharp spike at the top of the back seam. It is brown when mature and contains 4-9 seeds. The seeds are flat and shield-shaped, and yellow-green to brownish-yellow at maturity (Figure 17— 12).

Fig.17 ——12 senna leaf morphology.

Second, biological characteristics.

Biological characteristics of (1) seeds

Seeds germinate in trees when they are ripe and rain, so they should be harvested in time. The emergence rate of mature yellow seeds is 74%, and that of immature green seeds is 62%. It is suitable to use yellow mature seeds as seeds. If seeds are scarce, you can also use green seeds. Fresh seeds are soft when not dried, with a germination rate of only 20%, and hardened after drying, with a germination rate of 74%, so they should be used as seeds after drying. The germination rate of seeds stored for 4 months is 86.7%; The germination rate in the bottle is 40% after half a year, and it loses its germination ability after 1 year. Therefore, the sowing time after harvest should not exceed half a year. Seeds should be dried and stored in a dry place with a dryer or bottle device to prevent insects and mice from eating or absorbing water.

Sowing under the condition of daily average temperature of 22-24℃, the initial stage of emergence is 5-6 days after sowing, and the peak stage of emergence is 8 days, with the emergence rate of 76-80%; Sowing under the condition of daily average temperature 17.9℃, the initial stage of emergence is 9 days after sowing, the peak stage of emergence is 1 1 day, and the emergence rate is 22%. Therefore, under the condition of high temperature, the emergence rate is fast and high. Although sowing in high wet rainy season has a high emergence rate, it is easy to get sick and die, so sowing in dry season is appropriate.

(2) Growth and development and requirements for environmental conditions

Senna leaves only need 3-5 months from sowing to flowering and fruiting. The average temperature should not be lower than 10℃, and the number of days suitable for growing areas should be 180-200 days, during which the accumulated temperature should not be lower than 4000-4500℃. When the temperature is 1-2℃, the leaves fall off, stop growing and die at 0℃. Originated in dry and hot areas. In Sudan producing areas, the annual average temperature is 24-26℃, the monthly average temperature in 1- 14℃, and the annual rainfall does not exceed 250-300mm. Introduced in Jinghong County, Yunnan Province, China, the annual average temperature is 2 1.8℃, and the annual rainfall is 1 197.6 mm. It grows well in the dry season from March to May, and the branches and leaves die or even the whole plant dies in the rainy season from June to July. The annual average temperature in Yuanjiang County, Yunnan Province is 23.8℃, and the annual rainfall is 784.7 mm, which is dry and hot. It should be introduced in areas where rainfall is scarce and the temperature can meet its growth and development requirements. The frost-free period in the north is short and the summer is dry and hot, so annual cultivation can be considered. Loose and well-drained sandy soil or alluvial soil is required, and the soil is slightly acidic or neutral. Soil with poor drainage or strong acidity is prone to diseases.

Third, cultivation techniques.

(1) land selection and preparation

Choose sunny land with high and dry terrain and convenient irrigation and drainage, loose sandy loam or alluvial soil for planting. If the acidity is too strong, add a proper amount of lime. Dig deep and level the soil, apply foot fertilizer, and make a high ridge with a width of1.5m..

(2) sowing

Breeding with seeds, generally using field direct seeding. The dry season from February to March is suitable for sowing, when the temperature rises, which is beneficial to seedling emergence. After a long dry season, plants grow healthily and improve the disease resistance in rainy season. Or sow in 10- 1 1 month, and the temperature can still meet the requirements of seedling emergence during the rainy season, with less rain and less disease. It is not suitable for sowing in rainy season and low temperature season. The row spacing is 70×50 cm, and holes are dug and watered the day before sowing. Sow 5-6 seeds per hole, cover with soil for 2cm, and cover with grass to keep moisture.

(3) Site management

After sowing, the soil should be kept moist to facilitate seed germination, but it should also be prevented from being too wet to avoid serious diseases. Do a good job of drainage in rainy season. Seedling height is about 10cm, and it should be transplanted in seedling-deficient holes with soil to ensure that there are 1 plant in each hole. Apply clear water fertilizer every half month at seedling stage. Apply slightly thick and decomposed human excrement and urine in bud stage, pick buds and remove cores, promote flourishing growth of branches and leaves, and increase yield. Leave the soil without picking buds, apply more phosphorus and potassium fertilizer to promote grain fullness. Weed and loosen the soil during the whole growth period, especially after rain, to prevent weeds from shading and competing for nutrients, and to prevent soil hardening.

(4) Pests and diseases and their control

1. Rhizoctonia solani

(Rhizoctonia. And Fusarium. )

It is caused by the compound infection of two kinds of bacteria. In order to harm the seedlings, the stem base near the soil surface showed brown waterlogging longitudinal stripes, then turned dark brown, the diseased part shrank, and the seedlings broke and fell to death. When the temperature is high and the humidity is high, the disease spreads rapidly and the harm is serious. Control methods: (1) Select suitable growth areas and sow in dry season; (2) Applying lime powder to improve soil pH value, preferably slightly acidic or neutral; (3) Strengthen the management of seedlings to make them robust and enhance their disease resistance; (4) Spraying1:1:kloc-0/50 bordeaux solution or 50% carbendazim 1000 times solution before or at the initial stage of onset.

2. Leaf spot disease

(Pholiota)

The diseased spots at the tip and edge of the damaged leaves are dry, dark brown and have small black spots (pathogenic conidia); After the branches are damaged, the tops turn yellow, the leaves fall off and gradually dry up from top to bottom. Control method: spray 1: 1: 100 bordeaux solution or 50% carbendazim 1000- 1500 times solution.

3. Pink Butterfly

(Escherichia coli. )

Larvae is harmful, and when it is serious, it will eat up the tender branches and leaves, which will affect the growth of plants. Control method: spray 800 times solution of 90% trichlorfon or 800- 1000 times solution of 80% dichlorvos; In Yuanjiang, Yunnan, natural enemies named "Lepidoptera insects" can be used for control.

In addition, there are underground pests, such as African crickets and scarabs.

Fourth, harvesting and processing.

At the peak of growth, pick leaves or immature fruit pods on sunny days, sow them in the sun in time and turn them over frequently. Don't pile it too thick in the sun, lest the leaves turn yellow and let them dry. Or dry at 40-50 DEG C.. Packed in wooden cases or cartons and stored in a dry place. It is better to have large leaves, complete leaves, green color, few stalks and no sediment and debris.