Table 30 Statistics of Economic Plants Investigation in Longhe Demonstration Area
(1) pitaya
Pitaya belongs to cactus family, its stems are fleshy, it grows on the ground in natural state, with poor support, shallow root distribution, strong drought resistance and low yield. The column cultivation or greenhouse cultivation can greatly improve the yield of pitaya (Chen Zhendong et al., 200 1). Pitaya has the characteristics of high survival rate, short recovery period, fast growth and early fruiting period, and needs more water and fertilizer. Pitaya is drought-resistant and waterlogged-resistant, and the survival rate of transplanting is almost 100%. After planting 15 days, new buds began to sprout, which germinated more than 5 times a year. Some plants blossomed and bore fruit in the first year of planting, and entered the high-yield period in the third year, with the highest yield reaching 1500 kg/mu.
The Longhe demonstration area adopts columnar cultivation. Before planting, fix a square cement column with a height of 2m (including buried soil of 40-50cm) and a width of 10cm at the planting site, then dig up the soil around it (with a depth of 30cm and a width of 60cm), add 10- 15kg cooked farm manure and mix well. The planting point spacing is 3m×4m, with 55 plants per mu.
Adequate water and fertilizer supply is an important prerequisite for the rapid growth, high yield and high quality of pitaya. Fertilization of pitaya can be divided into base fertilizer and topdressing. The base fertilizer is applied twice a year, that is, once before the growing season (March) and once after the fruit is harvested (September), with 20-25 kg/pit each time. "Early, thin and diligent" is the basic principle of topdressing pitaya. "Early" means that fertilization begins shortly after its survival and germination; "dilute" is mainly water and fertilizer such as bran water and biogas slurry water, with low concentration; "Diligence" means that the interval should be short and frequent, once every 10 ~ 15 days, and the interval between flowering and fruit picking should be appropriately shortened.
Binding and pruning are necessary measures to promote the growth and yield of pitaya. Only the best growing 1 bud is left to lean against the cement column, tied with cloth rope, and then the branches are extended to the bracket, and a bud is tied every 30 ~ 40 cm, so that the succulent stem can spread and grow along the cement column. After it grows to the support at the top of the cement column, it usually only prunes some weak branches that are not growing well, and keeps others as much as possible. After the end of the season, cut off the old branches or too dense branches that have already borne fruit and let them grow new branches again.
In Longhe Demonstration Zone, the first flowering period of pitaya is early July every year, and then it blooms and bears fruit in mid-September, which lasts for a long time and has a large amount of flowers. However, in the natural state, the fruit setting rate is low and the fruit is small. In order to improve the fruit setting rate and fruit weight, technical measures such as thinning flowers and fruits, artificial pollination and increasing the number of fertilization and irrigation were adopted, that is, picking weak flower buds or buds at the early flowering stage, leaving only 1 ~ 2 buds in each fruiting branch (node); Dip the pollen with a brush after flowering, and then touch the stigma for artificial pollination. During the flowering and fruiting period, in addition to ensuring water supply, water and fertilizer (biogas slurry+compound fertilizer) should be sprayed every half month.
(2) seedless wampee
Seedless wampee belongs to Rutaceae and is an excellent variety derived from wampee (Wu Jianhua et al., 2004). It has the advantages of large fruit, sweet taste, high yield and wide adaptability. Seedless wampee is moisture-proof and drought-tolerant, so it is not suitable for planting in places with high groundwater level or easy to be flooded (Xu Jiongzhi et al., 1998). Cultivated on flat land, with row spacing of 3m×3m and 74 plants per mu; In narrow terraced fields, planting points are arranged according to the direction of terraced fields, and the planting points in two adjacent rows are arranged in zigzag, and the spacing between plants can be appropriately reduced to 2.5m The planting pit is 80cm wide and 60cm deep. After digging, the pit is returned to 1/3 above the ground in the form of topsoil and subsoil, and 20kg of farmyard manure is added to mix with the soil. After planting, cut off the top 35 ~ 40 cm from the ground, and cover the tree tray with grass or film to reduce water evaporation and improve the survival rate of seedlings.
Seedless wampee grows fast and bears fruit early. Generally, it can be smoked 4-5 times a year, and it can blossom and bear fruit in the third year after planting. In order to cultivate a good tree shape with high yield, the early management of seedless wampee in Longhe demonstration area adopted technical measures such as "fixing stem, wiping bud, fertilizing and pruning". Fixed stem is to cut off the top of the plant 50 ~ 60 cm from the ground when planting; Early bud smearing means that only 3 ~ 4 new buds with good growth in different directions remain in the first batch of new buds after seedling survival, and all others are removed; Spraying urea, compound fertilizer or biogas slurry in shallow ditch 2-3 times a year before and after 1 new shoot aging and before each new shoot picking, with the dosage of 0.5- 1.5 kg/plant. In addition, base fertilizer is applied at the end of winter and the beginning of spring every year, and an annular ditch with a width of 20-30cm and a depth of about 30cm is dug along the crown drip line, and farmyard manure is applied to each plant. After each new shoot matures, combined with measures such as terminal bud picking and light pruning, the crown gradually forms a natural round head shape which is beneficial to high yield (Wu Gengmin, 1979).
Protecting flowers and fruits is very important to improve the yield and fruit quality of seedless wampee, and its basic measures include applying sufficient base fertilizer, frequently topdressing fertilizer and frequently coring. Seedless wampee has a large number of flowers and high fruit setting rate, but its physiological fruit drop is early, frequent and large, which can easily lead to low yield or no harvest if it is not managed properly. Therefore, it is necessary to re-apply base fertilizer, frequently topdressing and prevent pests. The basal fertilizer for young trees that began to bear fruit in 2004 was per plant 10kg+0.25kg compound fertilizer, which increased slightly in 2005, with topdressing 2-3 times a year and compound fertilizer 0.25 kg+50 g urea each time; Spraying 2% potassium dihydrogen phosphate +0.5% urea solution or "Baoguoling" solution before and after the physiological fruit drop ofNo. 1 and before the fruit ripens, erasing all the new buds irregularly, thinning out the small fruits with poor growth, and spraying dichlorvos (800 times) or dimethoate (1000 times) according to the insect situation.
(3) Niu Lixin and Li Guihua
Both of them are deciduous fruit trees of Prunus in Rosaceae, and they are excellent fruit tree varieties that have developed rapidly in recent years. They have the characteristics of good quality, early fruiting, high yield and strong adaptability, and are also fruit tree varieties worthy of key development in karst areas in the future. The planting density and techniques of Niuxin plum and Guihua plum are similar to those of seedless wampee, but the suitable height of pruning after planting is 70 ~ 80 cm (fruit tree pruning, 1983).
Niuxin plum and Guihua plum have high survival rate and short recovery period, and new shoots begin to sprout about 15 days after planting. Compared with seedless wampee, they have a shorter growth period in one year, and shoot two or three times a year. However, the new shoots grow more each time and the interval is shorter, so their annual growth is also larger and they need more water and fertilizer. Generally, basal fertilizer is applied to each plant twice a year, once in winter and once in summer, with 5 ~10 kg each time; Topdressing 2 ~ 3 times, 0.5 ~ 0.75 kg compound fertilizer each time, fruit trees can appropriately increase the number and quantity of fertilization.
Pruning of Niuxin plum and Guihua plum can be divided into summer pruning and winter pruning, with winter pruning as the main pruning. When pruning, heavy pruning or light pruning should be adopted according to the tree body condition, branch position and growth, light pruning of young trees and weak branches, and heavy pruning of big trees and strong branches.
Niuxin plum and Guihua plum blossom and bear fruit early. Generally, some plants will bloom in the second year after planting, but rarely bear fruit. After the third year, there will be a large number of flowers, and in the fifth year, it will enter a rich period. In Longhe Demonstration Zone, Niuxin Plum was planted in 2003, and a few plants blossomed in 2004. In 2005, the number of flowering plum plants accounted for more than 95% of the total number of plants, and the flowering amount was also very large. Moreover, 2% potassium dihydrogen phosphate or "Baoguoling" was sprayed once in bud stage and full bloom stage, but the fruit setting rate was very low because it happened in cold and rainy weather and lasted for a long time.
(4) macadamia nuts
Macadamia nut belongs to the family Alpinia, which is native to Australia. It is an evergreen fruit tree introduced in recent years and suitable for planting in South China (Du et al., 2004). Because of its high nutritional value, fast growth and wide adaptability, it has been paid more and more attention. Macadamia nut has shallow root system and more fibrous roots, but the main root is not obvious (Lu Zongchao et al., 1997). It is moisture-proof, with large tree body and crown width, and its plant spacing, pit planting specifications and base fertilizer consumption are slightly higher (greater) than those of seedless wampee and other fruit trees. The row spacing of macadamia nuts is 4m×4m, and 42 macadamia nuts are planted per mu. The width and depth of the planting pit are 80 cm, and 20 ~ 25 kg of farm manure is applied to each plant. Two-year-old grafted seedlings were selected as planting seedlings. Because of the high self-sterility of macadamia nuts, two excellent varieties, "695" and "900" cultivated by Guangxi Tropical Crops Research Institute were selected in Longhe Demonstration Zone, and the hybrid ratio was1:1.
Because macadamia nuts have a long physiological cycle and a late fruiting period, they generally bloom in small quantities within 5-6 years after planting. At the same time, it is a relatively thick tree species, with less demand for water and fertilizer, less pests and diseases, and simple management technology. In Longhe demonstration area, it is mainly to ensure the nutritional growth of macadamia nuts from planting to now. Apply organic fertilizer 1 time in February and July-August every year, with 5 kg/plant each time. At the same time, chemical fertilizer was applied once before (promoting shoot fertilizer) and once after (strengthening shoot fertilizer), and the dosage was compound fertilizer 25g, urea 50g and potassium fertilizer 15g/ plant. In 2005, the flowering rate of macadamia nuts was about 25%, and the fruiting plants accounted for about 10%, indicating that macadamia nuts had begun to enter the fruiting period.