What are the characteristics of pepper?

(Wu Jinhua)

Piper nigrum L. is a climbing woody vine of the Piperaceae family. It is cultivated in Hainan, Guangxi, Yunnan, Fujian, Taiwan and other provinces and regions in my country. Hainan, Guangxi and Yunnan produce more, supplying the whole country and exporting a small amount. The fruit is used as medicine, containing alkaloids such as piperine, piperine, piperine A, B, C and volatile oils. Pharmacological tests show that piperine has anti-pentylenetetrazole convulsions, electroconvulsions, "audiogenic seizures" and sedative effects; water, ether or alcohol extracts have tapeworm-killing effects. The crude extract is made into anti-epileptic tablets, which have been tried on various types of epilepsy. It tastes pungent and is hot in nature. It has the functions of warming the body, dispersing cold, strengthening the stomach and relieving pain. It is used for colds, colds and pain in the epigastrium and abdomen, vomiting and diarrhea, and loss of appetite.

1. Morphological characteristics

The stem is tens of meters long, and the cultivation is controlled between 2.5-3m. The stem nodes are significantly enlarged and often have adventitious roots. The leaves are alternate, nearly leathery, with elongated leaf sheaths. The leaves are broadly ovate, ovate-oblong or elliptical, 6-16cm long, 4-9cm wide, with 5-7, and rarely 9, veins. Spikes are opposite to leaves; flowers are heterogeneous, often monoecious, without perianth; stamens 2, anthers kidney-shaped; ovary superior, subglobose, 1-celled. The berries are spherical, 3-4mm in diameter, red when ripe (Figure 15-43).

Figure 15-43 Pepper morphology diagram

1. Fruiting branch 2. Inflorescence branch 3. Enlargement of inflorescence part 4. Stamens 5. Stamens 2. Biological characteristics

(1) Growth and development characteristics

For production, pepper seedlings are cultivated from cuttings with 5-7 nodes, and the main vines are extracted 1-2 months after planting. When the growth point of the main vine is inhibited or there is sufficient water and fertilizer, the dormant axillary buds will produce primary, secondary, and tertiary branches in sequence, forming the backbone branches of the crown. The dormant lateral buds (mixed buds) on the branch nodes will produce primary, secondary, tertiary and other lateral branches in sequence, all of which can bear fruit and are collectively called fruiting branches. Each branch and the lateral branches sprouting from it constitute a cladogram of pepper. Generally, a normal fruit-bearing plant has 100-150 branches. The main vine and these branches form the pepper canopy.

When pepper vines are pulled out, sometimes the main vine and the branches are pulled out at the same time, so that no empty nodes will be formed; sometimes the main vines are pulled out but the branches are not, so empty nodes are formed, making the pepper vines branch in layers. The number of branches in a layer and the number of nodes between layers are determined by the growth of the plant and the nutritional status of the plant. Generally, there is a layer of 1-4 branches every 1-3 nodes (Figure 15-44). During pruning and shaping, the main vines are often cut from empty nodes to be used as propagation materials. At the same time, water and fertilizer management is strengthened to encourage new vines to branch out.

Figure 15-44 Schematic diagram of the layered branches of pepper

When the pepper vines sprout and grow, they bloom at the same time. When a large number of fruits are produced, the branches stop pulling out, so the 1-3-year-old ones need to be removed. The flowers are not allowed to bear fruit, so that the nutrients are concentrated and the tree crown is enlarged and taller, so as to form a high-yielding tree shape. The main vine generally grows 30-50cm per month. The growth is slow in the first year of planting, gradually speeds up in the second year by pruning the vines, and is fastest in the third year, with the monthly growth reaching 50-70cm. It grows quickly in seasons with high temperature and high humidity, but grows slowly in seasons with low temperature and drought, and may even stop growing if the top breaks off. In winter, pepper-growing areas with low temperatures often suffer from cold damage, and then sprout and grow again during the warming period. After three years of planting, the tree is capped to prevent upward growth and begin to form a tree shape. Flowering is retained during the appropriate season (called blooming, the same below) and allowed to bear fruit. The branches that bear a large number of fruits will break off on their own due to the consumption of nutrients. They will not sprout and grow until the fruits are harvested the following year. There is only one growth period in a year, which coincides with the flowering period. Branches that bear little or no fruit can germinate and grow at any time under conditions of suitable temperature and sufficient water.

There are root bands at the nodes of the main pepper vines, which can grow developed aerial roots (sucker roots), which serve to absorb and support the vines. When pulling out pepper vines, pillars and tied vines should be erected in time so that the root belt is close to the pillars and the aerial roots are developed and firmly absorbed. It is also conducive to the rooting of the pepper seedlings propagated by cutting the vines and developing the root mass. Plants propagated by cuttings do not have a real main root. The roots grown from aerial roots and incisions develop into backbone roots. From the backbone roots, lateral roots emerge, and the lateral roots give rise to absorptive roots. The roots are mostly distributed in the 0-60cm soil layer, with the largest number in the 10-40cm soil layer. If the soil layer is deep, the water table is low, or the soil is deeply plowed, the distribution will be deeper, up to 1m or more.

Under suitable conditions, the mixed buds on pepper branches form flower buds (can also form leaf buds) and develop into flower spikes. It takes about 11-17 days from the emergence of a flower spike to the beginning of the florets to bloom, and about 23-36 days to the completion of the florets. After the florets are pollinated, it takes about 5-10 days until the ovary begins to swell, and it takes about 10 months until the fruit matures. Fruit grows fastest within 30-120 days of formation.

The temperature required for flowering is 24-27℃ and the relative humidity is 70-80%. The small flowers generally bloom before 10 a.m., and can bloom all day long if the temperature and humidity are suitable. Low temperature and drought affect flowering and pollination, reducing the yield rate. When the ovary begins to expand, flower and fruit drop will occur if there is a lack of nutrients or low temperature and drought.

Conditions are suitable, and pepper heads and blooms almost all year round, but the main flowering period is March-May and September-November in Hainan pepper area, and May-July and October-November in Yunnan pepper area. Hainan often encounters spring droughts, but autumn rainfall is abundant, humidity is high, and it is warm and cool. There is no low temperature in winter that harms young fruits. Autumn flowers have long flower spikes and many fruits, so autumn flowers are generally retained and spring flowers are removed.

Although the temperature and humidity in Yunnan are suitable in autumn, low temperature and drought in winter and spring harm young fruits. However, June to August is rainy, humid, and the temperature is suitable, and the flowers and fruits have grown up by winter and spring, which can reduce the harm of low temperature and drought, so they should be preserved Summer flowers, remove autumn flowers.

(2) Requirements for environmental conditions

Pepper is a tropical warm-humid plant. The average annual temperature is 25-27°C in the main producing areas abroad and 19.5-26°C in the introduction and cultivation areas in my country. It can grow and develop normally. Growth begins when the temperature is 20°C, grows fastest at 24-28°C, and basically stops growing when the average temperature is 15°C. When the daily minimum temperature is <10°C, the young leaves will be damaged for 2-3 days; when the daily minimum temperature is <6°C, the young branches and vines will be damaged for 2-3 days, resulting in broken tops; and branch and fruit drop will occur around 2°C. However, pepper can survive short-term frosts, and even in areas with 4-5 frost days, some can obtain yields of hundreds of kilograms per mu. If the ground temperature is too high, accompanied by drought without shade, pepper heads and leaves close to the ground will be burned or even sunburned to death.

The rainfall in the main producing areas abroad is 1900-3000mm, while the planting area in my country is between 750-2400mm, with 1500-2400mm being more evenly distributed. In Hainan, the main production area in my country, when the monthly rainfall or the total rainfall in two consecutive months is >1000mm, plague epidemics or water damage will occur. Lujiang, Baoshan District, Yunnan Province, has an annual rainfall of 755.3mm. Artesian irrigation is used in the dry season, resulting in good growth results and few diseases. Drought significantly affects growth, flowering and fruiting, and may even die.

Most cultivated varieties only require shade during the seedling stage and initial stage of planting, and require sufficient sunlight during the mature stage to avoid excessive branches and leaves, which may affect flowering and fruiting. Pepper grows on pillars. The branches are fragile and are afraid of being damaged by strong winds. The leaves, flowers and fruits may be blown or blown off in a mild case, or broken branches, broken vines, or fallen pillars in severe cases. The wounds are susceptible to infection by pathogens. Falling leaves is conducive to the reproduction of pathogens, creating an environment for the spread of diseases. condition. Therefore, it is advisable to choose a quiet wind environment for cultivation. Hainan is often hit by typhoons, so windbreaks should be retained or built in a planned way.

It is particularly required that the soil be well-drained. Water damage and blast diseases may easily occur if it is too wet or stagnant. The lack of water in the soil will cause the young fruits to shrink, the inflorescences to become soft and wilted, and the leaves to become scalded, affecting growth and fruiting. The optimum soil pH value is 5.5-7. Large amounts of results require sufficient nutrients. A single plant that produces 2.5kg of white pepper annually consumes nutrients equivalent to 700g of ammonium sulfate, 150g of superphosphate, and 300g of potassium sulfate; the ratio of nitrogen, phosphorus, and potassium is roughly 6:1:5.

3. Cultivation technology

(1) Varieties

There are many varieties, which can be summarized into two types. The first is large-leaf species: large and thin leaves, thick and brittle branches, fast growth, large crown width, concentrated flowering period, long flower spikes, high fruiting rate, small and uniform fruit grains, early maturity, and yield per plant in the peak period. 3-6kg, ranging in age, with an economic life of 20-30 years, strong adaptability, and susceptible to pepper plague. Most of the varieties cultivated in my country belong to this variety. The second is small-leaf species: their economic life span is as long as 30-40 years, their seeds are pungent and disease-resistant, and other traits are opposite to those of large-leaf species.

(2) Site selection and preparation

Choose a warm, frost-free area. If you encounter light frost, you should protect yourself from cold. Choose a terrain with higher, open terrain where cold air can be easily discharged, and a south-facing slope with a slope of less than 20°. Do not choose low-lying, blocked places that are prone to cold air accumulation and wetlands close to water, as well as vegetable gardens and windy places to reduce cold damage, diseases and wind damage. It should also be considered that irrigation and transportation during the dry season will facilitate the transportation of fertilizers. It requires deep, fertile soil, strong aeration and water retention, and slightly acidic soil. If the soil quality is poor and thin, the soil should be plowed deeply.

Pepper gardens should be spread over a small area of ??3-5 acres to help control the spread of diseases. Set up windbreaks in areas with strong winds. The park has planned walkways, septic tanks and drainage and irrigation ditches. Make terraces on the slopes. Dig the soil 30-40cm deep and make it fully weathered. Clean the roots and rocks. Make the soil smooth. Dig a hole 60cm deep and 80cm wide. The soil in the hole should be fully exposed to the sun. Apply organic fertilizer (mixed with superphosphate) to each hole. Retting (fully decomposed) 15-30kg, mix evenly with soil, and fill the hole slightly above the ground.

(3) Propagation method

Propagation by cuttings combined with shaping and pruning of vines. Select excellent mother plants that have been planted for 1-3 years and are free from diseases, insect pests and cold damage. The vines are 4-6 months old, more than 0.6cm thick, have strong main vines with well-developed sucking roots and full axillary buds. Remove tops and prune branches 15 days before cutting to promote tissue enrichment. Cut cuttings 30-40cm long, with 5-7 nodes and branches on the upper two nodes. Soak in water for half an hour and place in a cool place to moisturize. Plant at an angle of 40-50° on the seedbed, with a row-to-plant spacing of 20-30×10-15cm, two nodes exposed on the soil surface, and 80-90% shade and moisture. Roots will begin to form in about 7-10 days. After survival, shade and watering will be gradually reduced. After 20-25 days of cultivation, it can be planted out of the nursery. According to the needs of breeding work, seeds are used to propagate. Harvest red ripe fruits, peel them and dry them in the shade. Avoid sun drying and sow them in time within one month of storage.

(4) Colonization

Plant the cuttings in a timely manner after 20-25 days of cultivation to avoid shoots growing too long and causing difficulties in colonization. Choose cool and humid weather for planting. The spacing between rows and plants is 2.5-3×2m, depending on the slope and fertility. The upper end of the seedlings should face west to avoid the western exposure of the pepper heads, and should be planted at an angle of 45°-60°. Cover the seedlings with fine soil, and apply 2-2.5kg of decomposed mixed fertilizer on both sides as auxiliary base fertilizer. Fill the soil 10cm above the ground into a pot-bottom-shaped mound to facilitate watering and cover with grass for shade.

(5) Field management

1. Shade, weeding, loosening, cultivating, and covering

After planting until the pepper heads are covered by pepper leaves, It is necessary to use translucent bamboo baskets or tents for shade to prevent the pepper heads from being exposed to the sun. Weed the garden regularly. After rain, lightly loosen the soil to a depth of 10cm around the crown; from March to April and November to December, loosen the soil to a depth of 200cm outside the crown and between the rows, and still loosen the soil lightly around the crown. Soil should be cultivated every 1-2 years. At the beginning of the dry season, use clean grass or green leaves to cover the roots or the entire garden to moisturize, regulate ground temperature, and improve fertility.

2. Fertilization

In the first three years after planting, apply 15-30kg of organic fertilizer to each plant every spring, mixed with 250g of superphosphate. From March to November in the growing season, apply a thin application of manure and water fertilizer frequently, once every half to two months to promote growth, and reduce the frequency as the age of the plant increases; apply once a few days before cutting the vines, and again when cutting the vines in the second and third ages. It is necessary to add 50-100g of ammonium sulfate to promote bleeding. Stop applying nitrogen fertilizer before winter, and apply 7.5-10kg of burned soil or 0.5-1kg of plant ash per plant to improve cold resistance. Results: Apply flower fertilizer to the plant in time after picking the fruit; apply auxiliary flower fertilizer during the flower bud germination period; apply fruit fertilizer during the early stage of fruit growth; and apply fruit fertilizer during the fruit development period. Use organic fertilizer, manure fertilizer, superphosphate, ammonium sulfate, potassium chloride, plant ash, cake fertilizer and fish fertilizer. Dosage is determined based on soil fertility, yield levels and nutrient consumption. Fertilizer must be fully decomposed, finely crushed, clean, and evenly mixed with the soil. The concentration, dosage, and fertilization location must be strictly controlled to avoid fertilizer damage. Fertility damage must be dealt with promptly.

3. Drainage and irrigation water

Irrigate regularly to prevent drought after planting and in dry seasons. Remove accumulated water in time during rainy season. If accumulated water causes water damage, deal with it in time.

4. Erecting posts and tying vines

When the pepper seedlings are cutting new vines, first insert temporary small pillars, and when cutting the vines for the second and third times, set up permanent large pillars. At present, cement pillars, stone pillars, etc. are generally used in production. Wooden pillars are easy to rot and damage, and replacement of pillars is troublesome. Living pillars compete with seedlings for nutrients and are rarely used now. When the new vines grow 3-4 nodes, use soft ropes to tie several main vines upright and evenly to the pillars under the vine nodes. Once every 10-15 days, the main vines used as seedlings need to be tied jointly. Tie, keep the messenger close to the pillar. As a result, the plants still need to be tied 1-2 times a year, especially before the typhoon season arrives, and the vines should be strengthened. You can also bury the main vines in the soil to suppress vines and promote long branches, for column-free cultivation or dwarf column cultivation.

5. Pick flowers and leaves

Pick off the flowers that bloom before the 1-3-year-old capping period and the flowers that bloom in other seasons except the flowering period of the fruit-bearing plants to accelerate the formation of tree shape and use nutrients. concentrated. When tying vines in the young stage or after picking fruits during the fruiting stage, remove the overly dense old leaves of the plant to allow ventilation.

6. Plastic pruning

When the plant height is 1.2m 6-8 months after cutting and planting, make the first cut at 20-30cm (3-7 nodes) from the ground. Vines, retain the first or second layer of branches. If the first layer of branches is higher than 40cm, bury the lower empty nodes in the soil (press the vines) so that the first layer of branches is 20-30cm above the ground. Keep 2-3 strong new vines sprouting in 2-3 nodes under the cut. When the new vines are more than 1m high after the previous cut, cut the vines for the second, third and fourth times from the 3-4 nodes above the previous cut. Each time, select 4-6 new vines under the cut. For the fifth time, cut the vines on the second layer of new vines, and also retain 4-6 main vines. When several main vines exceed the pillars by 20-30cm, move closer to the center of the column top, tie them at the intersections in order, and remove the tops 2-3 knots from the intersection, which is called capping. The upper part of the plant continues to grow, forming a cylindrical tree shape. If you do not want to plant seedlings, use the multiple detopping and shaping method, that is, after the first and second cutting of the vines, whenever the new vines grow 40-50cm in height, remove the tops from 3-4 nodes above the previous cut, and continue 5-6 times, until the limit is reached, the results can be achieved half a year in advance. Promptly remove excess buds and vines that sprout in the sapling stage, as well as leggy branches that sprout in the canopy of fruit-bearing plants and new vines that grow in the shade on the top of pillars. After the second cut of the vines, cut off the "grafting branches" brought by the seedlings; before the last cut of the vines, gradually cut off the old branches below 20-30cm of the plant to facilitate ventilation of the pepper heads.

(6) Pests and diseases and their control

1. Pepper blight

(Phytophthora palmivora var.piperis Muller.)

Also known as Pepper plague first infects the base of the main vine and then spreads to all parts of the plant. The xylem quickly rots and the plant suddenly withers and dies, while most of the root system is still intact. The source of infection is bacteria-carrying soil, diseased plant residues or wild hosts. Spread by wind and rain, it occurs in the late rainy season (September to November). Rainfall (especially continuous rainfall after typhoons) is the dominant factor in the epidemic of the disease. Focus on prevention. Ensure that the pepper garden does not accumulate water and the pepper heads are ventilated; maintain good field hygiene; do not enter the garden for operations on rainy days; disinfect imports and exports during epidemic periods to reduce human transmission; loosen the soil and expose it to the sun to eliminate surface soil germs; prevent wind and operate carefully to reduce wound invasion infection; choose disease-free seedlings and disease-resistant varieties, and pay attention to quarantine in new areas; the area of ??pepper orchards should not be too concentrated, 3-5 acres is better; apply nitrogen fertilizers impartially: apply more phosphorus and potassium fertilizers to enhance disease resistance; before the disease Use chemicals to disinfect the soil and spray plants for prevention; burn diseased plants in a timely manner, treat diseased areas with chemicals, spray to protect healthy plants, and carefully isolate diseased areas. The more effective agents include: Bordeaux mixture, 1% captafant, etc.

2. Bacterial leaf spot disease (Pseudomonas sp.)

It mainly damages the leaves, but also damages the whole plant, and is highly pathogenic. The lesions appear polygonal and water-soaked at first, then expand to brown in the middle and turn yellow at the edges. When exposed to dew, bacterial sap overflows, causing diseased leaves, flowers and fruits to fall off, diseased branches to become detached, diseased vines to dry up, and even the crown to shrink, leaving only a few bald strips. vines and loss of production capacity. It can occur throughout the year, and is mainly prevalent during the typhoon season. Typhoon rain is the leading factor in the prevalence of the disease. Cool weather and high humidity are conducive to the spread of diseases. Agricultural prevention and control measures are the same as pepper blight; detect early, eliminate the central diseased plant, remove the diseased part and its surrounding leaves as soon as possible, or spray the diseased leaves with 1% copper sulfate solution, spray 1:2:100 Bordeaux mixture to protect healthy leaves, and continuously Spray several times.

3. Mosaic disease

It is caused by a virus. There are two types of symptoms. One is that the leaves become smaller and curled, the main vines shrink, the internodes become shorter, and the plants are short and deformed. The flower spikes are numerous and shortened, with little fruiting. The other is that the plant grows basically normally, with only the leaves showing mosaics. It often occurs when the vines are cut due to poor management, plants damaged by fertilizer, water, or insects, or during periods of high temperature and drought. Prevention and control methods: No need for diseased seedlings; strengthen quarantine in new areas; strengthen management, rational fertilization, irrigation, and drainage to enhance plant growth and improve disease resistance; pay attention to pest control, and separate operating tools for diseased and healthy plants to avoid contact and infection; do not use them during high temperature and drought periods Cut the seedlings and apply enough water and fertilizer after cutting to promote the growth of the vines; if any diseased plants are found, pull them out and burn them and replant them; select disease-free plants to save seeds.

4. Other diseases include Colletotrichum necator Mass., which damages leaves, Corticium salmonicolor Berk, et Br., and Meloidogyne marioni, which damages branches and leaves.

5. Pests include scale insects, aphids, lygus bugs, stink bugs, thorn moths, chafers, ants, whiteflies, etc.

IV. Harvesting and processing

(1) Harvesting

Generally, flowers are capped and released 2-3 years after planting, and harvested in 3-4 years. Autumn flowers are harvested from May to July, and summer flowers are harvested from April to May. When the fruits in the ear turn yellow and 3-5 fruits turn red, they can be harvested. Generally, harvesting is done in batches 5-6 times throughout the harvest period, once every 7-10 days. The last harvest includes all immature fruits, so as not to affect the next flowering and fruiting.

(2) Processing

Mature or immature fruit ears are dried in the drying field for 3-4 days. When the peel shrinks, use a wooden stick to knock off the fruit grains, remove the fruit stems, and fully After drying, it becomes commercial black pepper. Use a bamboo basket or sack device to soak in running water for 7-8 days until the peel and flesh rot. Step on it in the bamboo basket or pool, rinse repeatedly with water, remove the peel, stems and other debris, wash them, and dry them on the drying field for 3-4 days. When it is completely dry, it is commercial white pepper. If soaked in flowing water, it will turn white after drying. If soaked in still water, it will be black, and the quality of the product will be reduced. It can also be dried by artificial heating. 100kg of fresh fruit can be processed into 25-30kg of white pepper, and 1kg of white pepper contains 19,000-24,000 peppers.