云南德宏、临沧五个橡胶树品种死皮病发病率调查

对云南德宏、临沧植胶区云研77-2、云研77-4、RRIM600、PB86和PR107等5个品种橡胶树死皮病调查结果显示:死皮病发病率均表现出随割龄增加而递增的趋势;云研77-4死皮病发病率明显低于云研77-2,PR107死皮病发病率明显低于RRIM600和PB86。     

橡胶树优良品种IAN873在云南的适应性

通过对国外橡胶树优良品种IAN873在西双版纳24年适应性观察研究,结果表明:该品种生长快,开割前年均增粗5.65cm,高于对照RRIM600(5.06cm)10.67%;林相整齐,开割时平均茎粗50.5cm,开割率80.2%,分别比对照高2.8cm和10.4%;产胶量中等,1-16割年平均干胶产量1 310kg/hm2,为对照RRIM600(1 969kg/hm2)的66.55%;年平均单株产量为4.0kg,略低于对照RRIM600(4.2kg/年.株)0.2kg;抗辐射寒害能力中等偏下,抗寒力小于GT1,但较RRIM600强;耐割性强,割胶16年后死皮发病率为15.79%,病指14.95,分别比对照(28.79%、27.58)轻13个百分点和12.63。     

不同割龄的RRIM600和GT1胶乳中硫醇和抗坏血酸的含量

本文研究了在同一地区不同割龄的RRIM600和GT1胶乳中硫醇和抗坏血酸的含量。结果表明,RRIM600胶乳中硫醇含量在第11割年以前较高,尔后开始下降,其中以第3割年最高,而抗坏血酸含量基本维持同一水平,在第16割年以后才开始下降。到第17割年,其硫醇和抗坏血酸含量都最低,分别为第1割年的42.55％和80.51％。GT1胶乳中硫醇和抗坏血酸含量与RRIM600有所不同,以开割第1年最低,以后逐渐上升,到第9割年达到最高值,分别为第1割年的215同.41％和172.5％,第10割年后缓慢下降,但其含量仍较高。     

橡胶树自育新品种高比区生长量、产量及抗寒性鉴定

对1992年种植的云研系列9个品种在高级试验系比的观察结果表明,生长量较对照RRIM600高的是云研73-477,20龄树150 cm处平均围茎74.2 cm,为对照RRIM600的106.9%,生势中等,其余品种均较对照生长慢;产量较高的是云研76-235、云研80-1983、云研78-768,11割年平均单株产胶量分别为4.5、4.4、4.3 kg,为对照RRIM600的137.4%、134.2%、130.7%;参试的9个品种死皮均较对照RRIM600重,为不耐刺激割胶品种;抗寒性方面,除云研73-477与对照GT1相当,属中等抗寒品种外,其余品种均比对照RRIM600弱,为不抗寒品种。     

橡胶树PR302品种在勐腊的适应性初报

1983年西双版纳勐腊农场从云南省热带作物科学研究所引进印尼橡胶所选育的橡胶品种PR302,进行大田试种。试区设于二分场(龙茵天然橡胶生产基地)十五队,海拔660m的西南坡,种植面积2.65hm2,共1 313 株,株行距2 m×10m。自1991年开割投产以来,PR302的产量、生长、抗病等综合性状反映良好,经2000～2002年3年调查比较,其综合性状均优于本农场种植的PR107、RRIM600、GT1等,现将观察结果报道于下。1　调查方法选1983年定植、1993年开割的PR302一个树位,以相邻的同年定植,同年开割,相同割制的PR107、RRIM600、GT1各一个树位为对照(表1),对…     

东风橡胶分公司橡胶芽接树新割制生产情况调查

通过对橡胶树割胶树位调查,低于20割龄胶树实施新割制,一般表现干胶产量增产和年度间产量变化平稳,累计死皮病率低,而高于20割龄胶树实行新割制、老龄割制和强割制,虽然提高刺激剂使用浓度,仍不能表现干胶增产,同时4～5级死皮率明显增高;品系GT1表现比RRIM更耐刺激,增产幅度大,死皮率更低。     

红松 云杉 落叶松出苗率及保苗率的研究

黑龙江省森工系统多年来一直采用公式ｘ＝１０ｐｎｃ／ＥＫ计算播种量，但在实际工作中，发现在对出苗率、保苗率以及保苗株数进行计算时，存在一定的误差，而现行的《黑龙江省林区育苗技术标准》中又没有具体明确的规定。因此，本文通过理论推算和实际调查，对此问题做了进一步的探讨。１　理论推算出苗率是指某新播树种，苗木出齐后的单位面积出苗株数与单位面积播种的有效种子粒数的百分比。保苗率是指某新播树种，单位面积保苗株数与单位面积出苗株数百分比。对于任何一个树种，在给定播种系数Ｃ和单位面积保苗株数Ｎ以后，那么播种的有效种子粒数即为ＮＣ（Ｎ在播种量的计算公式中代表设计密度，即苗木等级表中单位面积的保留株数）。依据播种系数、出苗率８０％、保苗率６０％进行理论计算（见表１），并从正方向和逆方向两方面加以分析。从正方向看，如果按规程规定播种系数２－５，设计密度按苗木等级表中保苗株数上限９００株／ｍ２（兴安落叶松），根据出苗率８０％和保苗率６０％计算所得保苗株数为１０８０株／ｍ２，超出苗木等级表规定上限１８０株／ｍ２，超２０－２％，这说明在计算过程中出苗率、保苗率过高。云杉亦如此，其计算保留株数超过苗木等级表规定上限１７００株／ｍ２，超６８...     

橡胶树优良新品种云研76-398选育初报

经过12年的初级系比和19年的高级系比试验观察,橡胶树新品种云研76-398早期生长快,高级系比植后第8年,离地150 cm处平均茎围52.8 cm,为对照RRIM600的117.65%;产量高,高产遗传性状稳定;初级系比年均产干胶3.43 kg/株,为对照RRIM600的173.23%,高级系比年均产干胶4.29 kg/株,为对照RRIM600的130.88%;抗寒力较低,但与对照RRIM600差异不明显;死皮病情重于对照,属速生、高产、不耐寒、不耐刺激品种。     

中龄RRIM600橡胶芽接树割制改革试验

西双版纳州东风农场有开割橡胶园约8700ｈｍ2,品系结构较为单一,ＲＲＩＭ600占开割胶园面积的53%(其中中龄树占628%)。由于ＲＲＩＭ600高产和易死皮等特点,几十年一直囿于ｓ/2ｄ/2的常规割制,人均割株400～450株,劳动生产率难以提高。近年来,橡胶生产的各项成本不断增加,...     

橡胶树新品种云研77-4、云研77-2的抗寒性生理鉴定

通过对橡胶树新品种云研77-4、云研77-2及云南植胶区主要栽培品种GT1、RRIM600的超氧化物歧化酶活性、可溶性糖含量、细胞电解质外渗率3个抗寒指标的测定,分析说明了4个橡胶品种的抗寒力大小为云研77-4>云研77-2>GT1>RRIM600。     

西双版纳橡胶树死皮病症状调查

调查西双版纳RRIM600和GT1两个品种橡胶树的不同割龄段死皮树的症状,根据排胶、割线颜色、树体状况三个方面的症状表现,死皮病典型症状可归纳为点状排胶或割线干涸,割线褐色、暴皮三种表现,其中RRIM600死皮树表现割线干涸和点状排胶的分别为41.7%和45.3%,割线表现内褐、褐皮平均分别为42.7%和35.2%,树体多数表现为块状暴皮,平均达44.8%;GT1死皮树症状以割线干涸为主,占61.9%,其次为点状排胶,占23.9%,割线表现为褐皮、内褐的分别占29.5%和44.9%,树体多数表现为短裂纹状暴皮,平均达34.1%。文章还对死皮病病程、诱因进行探讨。     

橡胶优良品种海垦2在云南的适应性

橡胶树优良品种海垦 2在云南省热带作物科学研究所、勐捧农场、孟定农场的适应性试验研究表明 ,1～ 11割年平均单株年产干胶 5.2 7kg ,是对照RRIM6 0 0的 12 2 .8% ;单位面积产量为 2 0 96kg/hm2 ,是对照RRIM6 0 0的138.5%。海垦 2干胶含量高 ,产胶潜力大 ,可以在云南省一类型植胶区大规模种植     

The potential for increasing rubber production by matching tapping intensity to leaf area index

Understanding resource capture can help design appropriate species combinations, planting designs and management. Leaf area index (LAI) and its longevity are the most important factors defining dry matter production and thus growth and productivity. The ecophysiological modifications and yield of rubber (Hevea spp.) in an agroforestry system (AFS) with beans (Phaseolus vulgaris L.) were studied. The experiment was established in Southeast-Brazil, with three rubber cultivars: IAN 3087, RRIM 600 and RRIM 527. The AFS comprised double rows of rubber trees along with beans sown in autumn and winter seasons in 1999. There was about 50% higher rubber yield per tree in the AFS than the rubber monoculture. Trees within the AFS responded to higher solar radiation availability with higher LAI and total foliage area, allowing its greater interception. All three cultivars had higher LAI in the AFS than monoculture, reaching maximum values in the AFS between April and May of 3.17 for RRIM 527; 2.83 for RRIM 600 and 2.28 for IAN 3087. The maximum LAI values for monocrop rubber trees were: 2.65, 2.62 and 1.99, respectively, for each cultivar. Rubber production and LAI were positively correlated in both the AFS and monoculture but leaf fall of rubber trees in the AFS was delayed and total phytomass was larger. It is suggested that trees in the AFS were under exploited and could yield more without compromising their life cycle if the tapping system was intensified. This shows how knowledge of LAI can be used to manage tapping intensity in the field, leading to higher rubber yield.     

橡胶树四种有机肥肥效试验

通过2006-2007年两年对橡胶树品种RRIM600、GT1的4种有机肥肥效试验结果:千州有机—无机复混肥处理的两个橡胶树品种的干胶含量显著高于生产常规施肥(对照)和其它肥料处理;RRIM600的平均刀次干胶产量显著高于生产常规施肥(对照)和其他肥料处理。     

橡胶芽接树RRIM600不同割制比较试验

１—６割龄ＲＲＩＭ６００不同割胶制度比较试验的结果表明，１—３割龄以采用ｓ／２ｄ／３割制，４割龄后转为ｓ／２ｄ／２割制为好。胶树茎围增长快，死皮轻，后期产量也高。     

Optimizing Tapping-Tree Density of Rubber (<Emphasis Type="Italic">Hevea brasiliensis</Emphasis>) Plantations in South China

Tapping-tree density in rubber plantations affects the production of dry rubber. Farmers can estimate rubber productivity when they know with certainty the number of tapping trees within a plantation and can therefore increase productivity through optimized planting schematics. Historical data on planting distance between trees and between rows, planting density (trees/ha) and tapping-tree density (number of trees under tapping for latex harvest per hectare) from 1952 to 2014 have been collected for plantations in the Hainan, Yunnan and Guangdong provinces of South China. A plantation survey was conducted to collect more detailed data on current tapping tree and planting densities in various plantations in the three provinces. Planting density and row spacing are found to have increased with rubber tree planting time and plant spacing to have declined from 1952 to 2014. Tapping-tree density of rubber plantations from 1955 to 1995 in South China ranges from 270 to 345 tree/ha, averaging 300 trees/ha. Strong typhoons and cold snaps are important drivers of fluctuations in tapping-tree density. The factors driving tapping-tree density are similar across the three provinces but the degree of change differs between provinces. Tapping panel dryness (due to tapping beyond the natural limit of the rubber tree productivity), severe wind damage and cold damage are the major factors resulting in loss of tapping trees in plantations in South China. These results suggest that a combination of environmental management for extreme weather and targeted breeding could improve tapping-tree density in rubber plantation and therefore dry rubber yield per unit area.     

Performance of different rubber tree clones against South American leaf blight (Microcyclus ulei)

This study was aimed to evaluate the behaviour of eighteen clones of Hevea brasiliensis (rubber) against South American leaf blight and to study progress of the disease. The experiment was conducted in Cachoeiro de Itapemirim‐ES, where 18 clones were evaluated. The experimental design was a randomized block with four replicates; each experimental unit consisted of three plants. Evaluations were performed at 15‐day intervals on 30 leaflets per tree. Disease incidence was quantified and infection classified according to the stages of development and type of damage. Leaf blight occurred during the entire experimental period; however, disease intensity varied with the resistance level of the clones and the time of year. Clones FX 3864, RRIM 725, RRIM 711, IAC 300 and IAN 873 exhibited the highest resistance to leaf blight.