1992 Vol. 5, No. 3
Display Method:
1992, 5(3): 251-262.
Abstract:
Forest site classification is a scientific foundation for silviculture and forest management. The paper deals with the forest site classification system in China. The principles and items of the forest site classification system are described. A scheme of the forest site classification system in China involved 3 forest site regions, 16 forest site zones, 65 forest site areas and 165 forest site subareas.
Forest site classification is a scientific foundation for silviculture and forest management. The paper deals with the forest site classification system in China. The principles and items of the forest site classification system are described. A scheme of the forest site classification system in China involved 3 forest site regions, 16 forest site zones, 65 forest site areas and 165 forest site subareas.
1992, 5(3): 263-270.
Abstract:
This paper took Picea schrenkiana and Cunninghamia lanccolata as study objects and aimed at improving the precision of the standard volume model. The study provided a. dynamic model and its fitting method which can use the sample information completely. The model not only can improve the precision significantly but also can explain the objective rules. The model has stable and reliable characteristics for application.
This paper took Picea schrenkiana and Cunninghamia lanccolata as study objects and aimed at improving the precision of the standard volume model. The study provided a. dynamic model and its fitting method which can use the sample information completely. The model not only can improve the precision significantly but also can explain the objective rules. The model has stable and reliable characteristics for application.
1992, 5(3): 271-277.
Abstract:
This paper deals with four treatments used for turning bamboo grove from off and on year into even year which include strong shoot -thinning, isolating rhizomes to bamboo individuals and changing felling time, retaining shoots during "off" year. The experiment lasting three "on" year and three "off year from 1985 to 1990 showed that there was the best effect in the treatment for the strong shoot-thinning during the on-year spring on inducement of bamboos in off-year and promoting the speed of transforming bamboo stand; there was an obvious inducement effect in the treatment of isolating rhizomes in last one off-year; and the effect of the combined treatment of strong shoot-thinning and isolating rhizomes into bamboo individuals was better than that of either of them; while there was no signifficant difference between the treatment of changing felling time and the check.
This paper deals with four treatments used for turning bamboo grove from off and on year into even year which include strong shoot -thinning, isolating rhizomes to bamboo individuals and changing felling time, retaining shoots during "off" year. The experiment lasting three "on" year and three "off year from 1985 to 1990 showed that there was the best effect in the treatment for the strong shoot-thinning during the on-year spring on inducement of bamboos in off-year and promoting the speed of transforming bamboo stand; there was an obvious inducement effect in the treatment of isolating rhizomes in last one off-year; and the effect of the combined treatment of strong shoot-thinning and isolating rhizomes into bamboo individuals was better than that of either of them; while there was no signifficant difference between the treatment of changing felling time and the check.
1992, 5(3): 278-283.
Abstract:
The biological characters of Psylla chinesis Yang et Li were studied systematically from 1987 to 1991. The results are as follows: (1) There are 6-7 generations a year on pear trees in the centre and south of Hebei Province. The peak of emergence occurrs from June to July. The period and stadium of every metamorphosises and generations was discovered. (2) The nymph of Psylla chinesis begin to release mucus in 3~7 days and it would be covered by mucus in 4~20 days. The mucus is a complex mixture of high molecular organic substances which contain =GH2, -OH, -NH2, C-H and C-O groups. (3) The spatial distribution patterns of the nymph in crowns and orchards are all determined as aggregate-type.(4) The lowest number of adult female suckers which cause the leaves fall are 4 on a leaf base and 12 on a leaf blade. (5) The place where the adults overwinter is in the fallen leaves and withered grasses. The results provided scientific basis for effective control.
The biological characters of Psylla chinesis Yang et Li were studied systematically from 1987 to 1991. The results are as follows: (1) There are 6-7 generations a year on pear trees in the centre and south of Hebei Province. The peak of emergence occurrs from June to July. The period and stadium of every metamorphosises and generations was discovered. (2) The nymph of Psylla chinesis begin to release mucus in 3~7 days and it would be covered by mucus in 4~20 days. The mucus is a complex mixture of high molecular organic substances which contain =GH2, -OH, -NH2, C-H and C-O groups. (3) The spatial distribution patterns of the nymph in crowns and orchards are all determined as aggregate-type.(4) The lowest number of adult female suckers which cause the leaves fall are 4 on a leaf base and 12 on a leaf blade. (5) The place where the adults overwinter is in the fallen leaves and withered grasses. The results provided scientific basis for effective control.
1992, 5(3): 284-289.
Abstract:
In 1984~1990, precipitation, runoff and soil moisture in the 22-year-old plantation of Cunninghamia lanceolata Lamb, and Pinus massoniana (Lamb.) Hook, were measured. Some results from 2 small experimental forest watersheds and 2 runoff plots are presented. The ranges of the average annual runoff were 15.648mm to 31.148mm, or 1.245% to 2.537% (annual runoff coefficient). Maximum runoff in a time period is about 2.16mm to 24.587mm or 3.07% to 31.35% (runoff coefficient). According to the analysis of multi-regression, runoff (y) approximates precipitation (x) in exponential cure regression, its equation is y=abx (a, b be parameter).
In 1984~1990, precipitation, runoff and soil moisture in the 22-year-old plantation of Cunninghamia lanceolata Lamb, and Pinus massoniana (Lamb.) Hook, were measured. Some results from 2 small experimental forest watersheds and 2 runoff plots are presented. The ranges of the average annual runoff were 15.648mm to 31.148mm, or 1.245% to 2.537% (annual runoff coefficient). Maximum runoff in a time period is about 2.16mm to 24.587mm or 3.07% to 31.35% (runoff coefficient). According to the analysis of multi-regression, runoff (y) approximates precipitation (x) in exponential cure regression, its equation is y=abx (a, b be parameter).
1992, 5(3): 290-297.
Abstract:
Two provenances of Teak (Tectona grandis L. f.), 3070 from Suugam, and 3072 from Masale of India, which have strong resistance to the Teak Rust (Oliva tectonae Thirum) have been selected after several years' observations and repeated tests. The disease condition indexes of 3070 and 3072 are 2.0% and 9.4% respectively,and the indexes of disease infection are 3.5% and 9.9% of that of the standard provenance respectively. Furthermore, their rust-resistance is quite stable. Summing up the evaluation for 7 characters namely disease-resistance,drought-resistance,volume growth, persistence of axis, degree of straight-bole, branching type and branch size, the aggregate index values of the two provenances increased respectively by 43%~97.5% and 31.4%~86.8% as compared to that of the standard provenance, and were 1.5 and 2.25 times as much as the mean aggregate index values of the provenances from Myanmar, Thailand, Laos and Vietnam. The two provenances are considered to be the superior ones in Hainan Island.
Two provenances of Teak (Tectona grandis L. f.), 3070 from Suugam, and 3072 from Masale of India, which have strong resistance to the Teak Rust (Oliva tectonae Thirum) have been selected after several years' observations and repeated tests. The disease condition indexes of 3070 and 3072 are 2.0% and 9.4% respectively,and the indexes of disease infection are 3.5% and 9.9% of that of the standard provenance respectively. Furthermore, their rust-resistance is quite stable. Summing up the evaluation for 7 characters namely disease-resistance,drought-resistance,volume growth, persistence of axis, degree of straight-bole, branching type and branch size, the aggregate index values of the two provenances increased respectively by 43%~97.5% and 31.4%~86.8% as compared to that of the standard provenance, and were 1.5 and 2.25 times as much as the mean aggregate index values of the provenances from Myanmar, Thailand, Laos and Vietnam. The two provenances are considered to be the superior ones in Hainan Island.
1992, 5(3): 298-303.
Abstract:
Chinese Fir is a fast growing wood species in China. A lot of excellent fast growing families were selected by selecting puls-trees, establishing seed orchards, progeny test etc. The regional test plantation was established with the selected excellent families. The analytical results of 5-year old plantation were showed as follows:(1) 41 excellent families were selected, and the average volume genetic gain was 23.9%, the selection rate was 39.4%. (2) The differences among sites, seed orchards and seed orchard x sites were all significant. The results showed that family selection would be efficient and the environment significantly affected the growth of Chinese Fir. (3) The benefit of establishing seed orchards was obvious. The average genetic gain of the 14 seed orchards tested was 18.6%. The gain from the central region was higher than that from the general region. The results was similar to that of provenance test.
Chinese Fir is a fast growing wood species in China. A lot of excellent fast growing families were selected by selecting puls-trees, establishing seed orchards, progeny test etc. The regional test plantation was established with the selected excellent families. The analytical results of 5-year old plantation were showed as follows:(1) 41 excellent families were selected, and the average volume genetic gain was 23.9%, the selection rate was 39.4%. (2) The differences among sites, seed orchards and seed orchard x sites were all significant. The results showed that family selection would be efficient and the environment significantly affected the growth of Chinese Fir. (3) The benefit of establishing seed orchards was obvious. The average genetic gain of the 14 seed orchards tested was 18.6%. The gain from the central region was higher than that from the general region. The results was similar to that of provenance test.
1992, 5(3): 304-310.
Abstract:
The research on the appraisal techniques for the early-stage characters of Loblolly Pine (Pinus taeda L.) was conducted, which included the correlation between seed weight and seedling height, the measurements of seed germination and the plant morphology in the seedling stage, the growth of dominant trees in free pollinated families in descendant seedling stage and the growth of graded seedling used for planting. The results have shown that seed weights have an effect on seedling height growth in the early 80 days or before seedlings reach 15 cm in height, which disappears gradually. The height growth at the fifth year can be predicted according to that in the descendant seedlings stage in the same family. There is not obvious correlation between seedling height and early or late seed germination. The height growth have a positive relationship with numbers of whorled branch when lifted from nursery. There is no significant relationship between terminal bud numbers and graded seedlings. The height and diameter breast height of graded seedling I (predominant seedling) have been maintaining a dominance after the planting of six years, and its stem volume is 14.5% more than that of the average of stand.
The research on the appraisal techniques for the early-stage characters of Loblolly Pine (Pinus taeda L.) was conducted, which included the correlation between seed weight and seedling height, the measurements of seed germination and the plant morphology in the seedling stage, the growth of dominant trees in free pollinated families in descendant seedling stage and the growth of graded seedling used for planting. The results have shown that seed weights have an effect on seedling height growth in the early 80 days or before seedlings reach 15 cm in height, which disappears gradually. The height growth at the fifth year can be predicted according to that in the descendant seedlings stage in the same family. There is not obvious correlation between seedling height and early or late seed germination. The height growth have a positive relationship with numbers of whorled branch when lifted from nursery. There is no significant relationship between terminal bud numbers and graded seedlings. The height and diameter breast height of graded seedling I (predominant seedling) have been maintaining a dominance after the planting of six years, and its stem volume is 14.5% more than that of the average of stand.
1992, 5(3): 311-316.
Abstract:
It has been evident from the treatment of PGR to Chinese Chestnut that BA(1000 ppm) promotes fruit bearing number,seed rate and individual tree yield while inhibiting the growth of new shoots the expansion of leaves area; both penicillin and RS(300 ppm,a mixture of chemicals with rare-earth elements) can increase seed rate, but, the former also promotes the formation of female flower and prevents from the stretch of new shoots, the later, on the other hand, has a lot to do in promoting the diameter growth of new shoots; MN(500 ppm, a special combinations of PGRs) has significant effects on promoting the formation of female flower, fruit bearing number, seed rate and individual tree yield; PP333 (500 ppm) can increase seed rate in some extent but retarding the expansion of leaves area; GA3 (200 ppm) though can increase seed rate, it promotes the growth of new shoots greatly as well, thus inhibiting the formation of female flower and reducing female/male flower ratio and fruit bearing number. The results of analysis on internal hormones suggest that higher GA, concentration is more favorable to the development of male flower.
It has been evident from the treatment of PGR to Chinese Chestnut that BA(1000 ppm) promotes fruit bearing number,seed rate and individual tree yield while inhibiting the growth of new shoots the expansion of leaves area; both penicillin and RS(300 ppm,a mixture of chemicals with rare-earth elements) can increase seed rate, but, the former also promotes the formation of female flower and prevents from the stretch of new shoots, the later, on the other hand, has a lot to do in promoting the diameter growth of new shoots; MN(500 ppm, a special combinations of PGRs) has significant effects on promoting the formation of female flower, fruit bearing number, seed rate and individual tree yield; PP333 (500 ppm) can increase seed rate in some extent but retarding the expansion of leaves area; GA3 (200 ppm) though can increase seed rate, it promotes the growth of new shoots greatly as well, thus inhibiting the formation of female flower and reducing female/male flower ratio and fruit bearing number. The results of analysis on internal hormones suggest that higher GA, concentration is more favorable to the development of male flower.
1992, 5(3): 317-320.
Abstract:
The change on contents of ZT, ABA and tannin in shoot of material trees and their cultures in Chinese Fir (Cunninghamia lanceolate) were analyzed. Results show: the contents of ABA and tanin were both positively correlated to tree age at all seasons. Yearly fluctuation of ABA content showed almost identical in shoots from 2,10 and over 20-year-old material trees, which was the highest in peak periods of shoot growing and the lowest in midsummer. According to ABA level, The peak period in spring was the best time for collecting materials for culture in vitro. ZT content had a marked rise while ABA level dropped dramatically in explants both from 2-and-lo-year-old material trees after 3-month original culture. Such changes were more striking in explant from 2-year-old material. After four successive subculture lasted for one year, the ZT content declined, but their difference was reduced between cultures from trees at different ages. At the same time ABA content increased again. The changes of their contents affected the capacity of shoot multiplication during culture in vitro.
The change on contents of ZT, ABA and tannin in shoot of material trees and their cultures in Chinese Fir (Cunninghamia lanceolate) were analyzed. Results show: the contents of ABA and tanin were both positively correlated to tree age at all seasons. Yearly fluctuation of ABA content showed almost identical in shoots from 2,10 and over 20-year-old material trees, which was the highest in peak periods of shoot growing and the lowest in midsummer. According to ABA level, The peak period in spring was the best time for collecting materials for culture in vitro. ZT content had a marked rise while ABA level dropped dramatically in explants both from 2-and-lo-year-old material trees after 3-month original culture. Such changes were more striking in explant from 2-year-old material. After four successive subculture lasted for one year, the ZT content declined, but their difference was reduced between cultures from trees at different ages. At the same time ABA content increased again. The changes of their contents affected the capacity of shoot multiplication during culture in vitro.
1992, 5(3): 321-327.
Abstract:
The sawfly Chinolyda flagellicorms (F. Smith) is a destructive forest pest, severely injuring to Cupressus funebris Endl. and Cryptomeria fortunei Hooibrenk ex Otto et Dietr.. It has one generation a year. Aestivation and hibernation takes place as prepupae in the soil. The adults emerge in early May in the following year and lay eggs soon afterwards. The peak of damaging period of the larvae is early and mid June. Using 3Y-35 type of insecticidal smoke producing machine and the mixed insecticide of 1 part 5% Decamethrin and 20 parts Diesel Oil to produce insecticidal smoke is very effective to kill 1-4 instar larvae.
The sawfly Chinolyda flagellicorms (F. Smith) is a destructive forest pest, severely injuring to Cupressus funebris Endl. and Cryptomeria fortunei Hooibrenk ex Otto et Dietr.. It has one generation a year. Aestivation and hibernation takes place as prepupae in the soil. The adults emerge in early May in the following year and lay eggs soon afterwards. The peak of damaging period of the larvae is early and mid June. Using 3Y-35 type of insecticidal smoke producing machine and the mixed insecticide of 1 part 5% Decamethrin and 20 parts Diesel Oil to produce insecticidal smoke is very effective to kill 1-4 instar larvae.
1992, 5(3): 328-334.
Abstract:
From 1985 to 1987, white wax broodscales were successfully introduced to Yanqian district with an elevation of 185 meters in Sanming City, Fujian Province, from Yongshang County with an elevation of 1350 meters and Zhaotong City of 1950 meters in Yunnan Province. These insects grow well in the new habitat with a generation a year. The average length, width and height of the broodscale are 9.58mm, 8.4mm, and 8.08mm respectively and the average, maximum and minimum of egg numbers produced by the broodscale is 5718, 12789 and 1647 eggs respectively; the average ratio of female and male is 1 to 3.04, the maximum 1 to 3.08, the minimum 1 to 2.34; the averaga thickness of wax encrustation is 5.61mm, the maximum 7.74, the minimum 3.74mm. The melting point of the wax is 82℃ to 83℃. From the above results, it appears that in the low elevation areas, white wax scales, whose biological and the other indexes can be comparable to those in the original place, not only can reproduce successfully, but also can produce superior white wax with an encrustation thickness no less than that in the original district, and the melting point reaching the national standard of China. The success of our experiment has solved the problem that white wax scales can not reproduce in the areas under elevations of 200 meters, and laid a scientific basis for the extension of white wax production in low elevation areas.
From 1985 to 1987, white wax broodscales were successfully introduced to Yanqian district with an elevation of 185 meters in Sanming City, Fujian Province, from Yongshang County with an elevation of 1350 meters and Zhaotong City of 1950 meters in Yunnan Province. These insects grow well in the new habitat with a generation a year. The average length, width and height of the broodscale are 9.58mm, 8.4mm, and 8.08mm respectively and the average, maximum and minimum of egg numbers produced by the broodscale is 5718, 12789 and 1647 eggs respectively; the average ratio of female and male is 1 to 3.04, the maximum 1 to 3.08, the minimum 1 to 2.34; the averaga thickness of wax encrustation is 5.61mm, the maximum 7.74, the minimum 3.74mm. The melting point of the wax is 82℃ to 83℃. From the above results, it appears that in the low elevation areas, white wax scales, whose biological and the other indexes can be comparable to those in the original place, not only can reproduce successfully, but also can produce superior white wax with an encrustation thickness no less than that in the original district, and the melting point reaching the national standard of China. The success of our experiment has solved the problem that white wax scales can not reproduce in the areas under elevations of 200 meters, and laid a scientific basis for the extension of white wax production in low elevation areas.
1992, 5(3): 335-341.
Abstract:
The contribution rate (CR) of scientific and technological innovation has been an important index to evaluate the level of science and technology and the economic development of industry. The Cobb-Douglas function which has widely been applied in the study of Economic Rates of Return(ERR), is limited to be applied in forest management industry. Because forest management industry is a long-term industry and is disturbed seriously by social and natural factors. In that case, we select the Analytical Hierarchy Process (AHP method), which combines qualitative and quantitative analysis to evaluate CR of forest management industry, and expect to look for the new way to evaluate CR. The results by AHP show that the CR is a 22% in forest management industry, which is in the range of 15%~25%.
The contribution rate (CR) of scientific and technological innovation has been an important index to evaluate the level of science and technology and the economic development of industry. The Cobb-Douglas function which has widely been applied in the study of Economic Rates of Return(ERR), is limited to be applied in forest management industry. Because forest management industry is a long-term industry and is disturbed seriously by social and natural factors. In that case, we select the Analytical Hierarchy Process (AHP method), which combines qualitative and quantitative analysis to evaluate CR of forest management industry, and expect to look for the new way to evaluate CR. The results by AHP show that the CR is a 22% in forest management industry, which is in the range of 15%~25%.
1992, 5(3): 342-346.
Abstract:
In the paper the relationship between graft effect and external morphology, growth phase, anatomical structure and nutrient composition of tender scions of Masson Pine have been studied systematically. The results showed that if tender twig was used as scion and the needle was covered with sheath or needle just appeared, the scion was delicate and produced rich callus easily. Moreover, water and nutrient composition content of tender scion was higher and organic carbon content was smaller, which was favourable to the healing between scion and stock and the increase of survival rate of grafting. Because tender scion was at primary growth phase, the ability of cell division and differentitation was stronger, and there was larger growth increment after grafting. The above result was good proof for establishing seed orchard of Masson Pine using tender twig as scion.
In the paper the relationship between graft effect and external morphology, growth phase, anatomical structure and nutrient composition of tender scions of Masson Pine have been studied systematically. The results showed that if tender twig was used as scion and the needle was covered with sheath or needle just appeared, the scion was delicate and produced rich callus easily. Moreover, water and nutrient composition content of tender scion was higher and organic carbon content was smaller, which was favourable to the healing between scion and stock and the increase of survival rate of grafting. Because tender scion was at primary growth phase, the ability of cell division and differentitation was stronger, and there was larger growth increment after grafting. The above result was good proof for establishing seed orchard of Masson Pine using tender twig as scion.
1992, 5(3): 347-350.
Abstract:
This paper deals with the effect of storage conditions on vigor of seed of Daemonorops margaritae (Hance) Becc. Seven levels of moisture content and two temperature treatments of each were conducted with coconut dust as storage material. The results showed that the seeds could be controlled in their safety moisture content (29%~31%) when they were stored in the material contained moisture content of 50%~65% at 15℃. In comparison with germination and moisture content of seeds, there were significant differences among the treatments; the seeds, stored in the material with moisture content of 55% and 65% at 15℃, could be able to keep their germination more than 65% for six months after storing, which were 4.0 and 4.5 times higher than that of seeds storing in the condition of room temperature (18°~25℃).
This paper deals with the effect of storage conditions on vigor of seed of Daemonorops margaritae (Hance) Becc. Seven levels of moisture content and two temperature treatments of each were conducted with coconut dust as storage material. The results showed that the seeds could be controlled in their safety moisture content (29%~31%) when they were stored in the material contained moisture content of 50%~65% at 15℃. In comparison with germination and moisture content of seeds, there were significant differences among the treatments; the seeds, stored in the material with moisture content of 55% and 65% at 15℃, could be able to keep their germination more than 65% for six months after storing, which were 4.0 and 4.5 times higher than that of seeds storing in the condition of room temperature (18°~25℃).
1992, 5(3): 351-355.
Abstract:
This paper deals with two categories of sampling of willow moth, Leucama Candida: (1) the parameter estimation samplings and (2) the decision-making samplings. There are four sampling methods, that is, simple random sampling, stratified sampling, systematic sampling and cluster sampling to be experimented in the parameter estimation. It is suggested that the cluster sampling is a better technique for the estimation of willow moth larvae among the 4 estimation samplings. The decision-making sampling may be carried out by sequential sampling. A mathematical model of sampling is given as T'(n) = 7.916 6nX1.4913±16.898 9X0.7457√n+0.5817X1.4913
This paper deals with two categories of sampling of willow moth, Leucama Candida: (1) the parameter estimation samplings and (2) the decision-making samplings. There are four sampling methods, that is, simple random sampling, stratified sampling, systematic sampling and cluster sampling to be experimented in the parameter estimation. It is suggested that the cluster sampling is a better technique for the estimation of willow moth larvae among the 4 estimation samplings. The decision-making sampling may be carried out by sequential sampling. A mathematical model of sampling is given as T'(n) = 7.916 6nX1.4913±16.898 9X0.7457√n+0.5817X1.4913
1992, 5(3): 356-360.
Abstract:
Abstract This research was conducted in three different types of occurrence regions (frequent outbreak region (Ⅰ), accidental outbreak region (Ⅰ), safety region (Ⅲ)) of Dendrolimus punctatus in the Anqin City of Anhui Province. Nearly 50 species of natural enemies were found during the period of over tworyear experiment. Anastatus sp., Rogas dendrolimi and Exorista sp. are the major parasites at the egg stage, larva stage, pupa stage respectively and the highest parasitism rates of each species is 13.6%, 5.5%, 23.4% respectively.There are about 31 species of natural enemies in (Ⅰ), 37 species in (Ⅱ) and 42 species in (Ⅲ). The result shows that the index of diversity and evenness of natural enemies community in (Ⅲ) is higher than that of the other two regions. Study on similarity of natural enemies community shows that similarity coefficient is the highest one between (Ⅲ) and (Ⅱ) and that between (Ⅰ) and (Ⅱ) is the second.
Abstract This research was conducted in three different types of occurrence regions (frequent outbreak region (Ⅰ), accidental outbreak region (Ⅰ), safety region (Ⅲ)) of Dendrolimus punctatus in the Anqin City of Anhui Province. Nearly 50 species of natural enemies were found during the period of over tworyear experiment. Anastatus sp., Rogas dendrolimi and Exorista sp. are the major parasites at the egg stage, larva stage, pupa stage respectively and the highest parasitism rates of each species is 13.6%, 5.5%, 23.4% respectively.There are about 31 species of natural enemies in (Ⅰ), 37 species in (Ⅱ) and 42 species in (Ⅲ). The result shows that the index of diversity and evenness of natural enemies community in (Ⅲ) is higher than that of the other two regions. Study on similarity of natural enemies community shows that similarity coefficient is the highest one between (Ⅲ) and (Ⅱ) and that between (Ⅰ) and (Ⅱ) is the second.
1992, 5(3): 361-364.
Abstract:
From 1986 to 1990, experiments on selection of favourable host plants of the white wax scale were carried out in Jingdong County, Yunnan Province. The results show that the two fast-growing and drought-resistant species with wide adaptability, Ligustrum calleryanum Decene and L. confusm Decene, are preferred host plants which can produce quality wax and brood-insects. So we recommend these two species be applied to large-scale wax production.
From 1986 to 1990, experiments on selection of favourable host plants of the white wax scale were carried out in Jingdong County, Yunnan Province. The results show that the two fast-growing and drought-resistant species with wide adaptability, Ligustrum calleryanum Decene and L. confusm Decene, are preferred host plants which can produce quality wax and brood-insects. So we recommend these two species be applied to large-scale wax production.
1992, 5(3): 365-366.
Abstract:
Large Chinese hawthorn (Crataegus pinnatifida var. major N. E. Br.) witches' broom was found in Beijing in China. Plant-diseased sprouted later, and there was not a distinct internodes on branches. Little leaves were bunchy and yellow. Branches infected withered slowly from the top downwards. Flowers were faded and degenerated, small and deformed. Flower buds can't produce normal fruit-twigs and fruits. White flowers turn pink or purplish red.Transmission electron microscope revealed numerous-spherical and elliptical MLO, in the sieve element of the top or the vein or the pedicel from MLO-infected plants. They were measured, the spherical is 433 nm and elliptical is 480nm×609nm. MLO, havn't been found in healthy plant samples.
Large Chinese hawthorn (Crataegus pinnatifida var. major N. E. Br.) witches' broom was found in Beijing in China. Plant-diseased sprouted later, and there was not a distinct internodes on branches. Little leaves were bunchy and yellow. Branches infected withered slowly from the top downwards. Flowers were faded and degenerated, small and deformed. Flower buds can't produce normal fruit-twigs and fruits. White flowers turn pink or purplish red.Transmission electron microscope revealed numerous-spherical and elliptical MLO, in the sieve element of the top or the vein or the pedicel from MLO-infected plants. They were measured, the spherical is 433 nm and elliptical is 480nm×609nm. MLO, havn't been found in healthy plant samples.
1992, 5(3): 367-370.
Abstract:
Located measurement of soil water were carried out on different forest lands in Jiulong Hill in Beijing. Results showed that: there are four peak values of soil water content during the tree growth stage, and the fluctuation is obvious. Relative soil water content (ratio of soil moisture to field moisture capacity) is often below 60%, and the amount of soil water isn't enough to supply the normal growth of trees in the region. It is not suitable to build commercial forest, but suitable for water and soil conservation forest. In order to ensure the trees grow normally, it is necessary to construct sparse structure forests.
Located measurement of soil water were carried out on different forest lands in Jiulong Hill in Beijing. Results showed that: there are four peak values of soil water content during the tree growth stage, and the fluctuation is obvious. Relative soil water content (ratio of soil moisture to field moisture capacity) is often below 60%, and the amount of soil water isn't enough to supply the normal growth of trees in the region. It is not suitable to build commercial forest, but suitable for water and soil conservation forest. In order to ensure the trees grow normally, it is necessary to construct sparse structure forests.