柑桔病虫害综合防治研究

1985～1988年在国营广西浪湾华侨农场进行了柑桔病虫害综合防治试验。结果表明:(1)柑桔红蜘蛛、柑桔潜叶蛾、柑桔锈螨、蚧类和柑桔溃疡病是该场的主要病虫害,还有次要病虫10余种。(2)查知柑桔害虫天敌昆虫40余种。(3)总结提出一套可行的柑桔病虫害综合防治方案和综合防治年防治历,并在该场实施,取得显著效果。     

广西食螨瓢虫和黑囊食螨瓢虫的研究

通过系统调查和室内试验,明确了国营广西浪湾华侨农场和南宁市郊柑桔园中食螨瓢虫种类主要有广西食螨瓢虫、黑囊食螨瓢虫和越南食螨瓢虫等3种,其中以广西食螨瓢虫、黑囊食螨瓢虫为优势种。两优势种瓢虫在当地一年可发生9～10代,成虫的寿命最长达105天,每头雌虫一生平均产卵最多达117粒。成虫、幼虫均能捕食柑桔红蜘蛛,每头日捕食量与叶螨密度有关,密度越大捕食量越多。食螨瓢虫田间种群数量变动与食料和使用化学农药情况有关,红蜘蛛少或用药多的果园,常无这类瓢虫。     

柑桔黄龙病及其抗性育种研究（综述）

柑桔黄龙病是我国南方柑桔产区的毁灭性和检疫对象。其病原是一种树皮细菌分亚洲株系和非洲株系。通过加强对媒介昆虫柑桔木虱的检测和防治,以及建立柑桔无病苗木繁育体系可以控制黄龙病的为害。     

0.5%藜芦碱粉剂防治柑桔红蜘蛛初报

柑桔红蜘蛛繁殖较快,且抗药性强,为了寻找最适的用药方法,以达到安全而且防治效果又好的目的,利用不同浓度0.5%藜芦碱可湿性粉剂做处理,对柑桔红蜘蛛进行防治试验,结果发现0.5%藜芦碱可湿性粉剂600倍液防治效果理想。     

湖南省气象-柑桔产量预报模式研究

分析了影响湖南省柑桔产量的气象因子;在柑桔生长发育3个关键期,对柑桔产量歉年提出了5个气象灾害减产指标,对丰年也作了气象条件的定性分析.并在此基础上,建立了柑桔产量气象预测预报模式;其中柑桔产量营养积累均衡值的提出,为预报柑桔产量大、小年提供了一种新的方法;并以大气环流因子作为多个气象因子对柑桔产量作用的综合表征,更进一步提高了柑桔产量预报定量化的准确率和时效性.     

柑桔病毒症防治新技术：接种弱毒性病毒促进柑桔增产研究

接种弱毒性病毒是防治柑桔病毒症、促进柑桔增产的一项新技术。本文就该技术在柑桔生产上应用的意见、试验效果及使用注意事项做了重点介绍。     

基于GIS的陕南柑桔气候生态适宜性区划

陕南秦巴山区地处北亚热带气候区,是柑桔种植北缘地带。为了科学、合理地利用当地农业气候资源,进一步优化产业结构,达到趋利避害、防灾减灾的目的,本文根据陕南秦巴山区近30a的气候资料,采用极端最低气温多年平均值、1月平均气温、年平均气温及年降水量4个因子作为陕南柑桔气候适宜性区划指标;利用GIS空间分析及制图功能,在实现区划指标空间化基础上,采用模糊综合评判方法,对陕南秦巴山区柑桔气候适宜性进行区划,并对各适宜区柑桔生长气候条件优劣进行评述。结果表明,陕南柑桔气候适宜区主要分布于秦巴山区海拔700m以下的浅山丘陵区,在适宜区内,应根据地形特征,选择冷空气不易堆积的＂难进易出型＂丘陵坡地栽培,以减少冻害。     

气象条件对柑桔果实膨大速度的影响

根据2003-2004年柑桔果实膨大观测资料和相应的气象资料,对无灌溉条件下,降水、气温及日照等气象因子对柑桔果实膨大速度的影响进行了分析和研究。结果发现:降水与果径增长量呈显著的正相关;气温与果径增长量也有明显的线性关系,当日平均气温≤30℃时,果径增长量与气温呈显著的正相关;当日平均气温高于30℃时,果径增长量与气温则有负的相关关系;日照的影响分两种情况:当气温、降水都适宜时,果径增长量与日照有正的相关关系;当出现高温干旱等气象灾害时,果径增长量与日照呈显著的负相关。     

生态施肥技术对桔园土壤生态环境和柑桔产量及品质的影响

根据柑桔树体对土壤生态环境和营养元素的季节性需求变化特点,综合考虑各营养元素间的平衡、有机养分与无机养分之间的协调、土壤生物和土壤物理性状的改善,提出不同因子组合处理,进行了3年定位试验。结果表明:新型生态施肥技术,对桔园土壤生态环境和柑桔产量、品质有明显的效果,有效地提高了土壤有机质、全N、P、K和速效N、P、K含量,以速效P增幅最大,三年增26.92%~40.0%;除能提高所施用微量元素含量水平外,还提高土壤有效态Fe、Cu含量水平;土壤容重三年降低了0.04 g cm-3~0.10 g cm-3,总孔隙度增加10.4%~16.8%,通气孔隙增加19.9%~30.1%,全容水量增加7.0%~12.1%;有效地改善了柑桔的品质,增加了果实的单果重、可溶性固形物含量、可溶性糖含量以及Vc含量。     

柑桔根际土壤微生物种群动态及根际效应的研究

在柑桔根际土壤微生物的种群结构中，细菌占优势，最高达76871×10⁷个每克干土；真菌次之，达17549个每克干土；放线菌最少，达12462个每克干土。三种菌的根际效应非常显著，根际细菌最高约为对照的67.6倍，真菌约为12.4倍，放线菌约为26.9倍，柑桔中，温州密柑根际土壤细菌最多，年平均为6490×10⁷个每克干土；红桔的放线菌及真菌最多，年均分别为1326个每克干土及1728个每克干土。柑桔根际土壤微生物区系的种群结构和数量变动，受土壤理化性质的影响，并随树种、树龄、砧木及季节而变化。柑桔根部及根颈部对脚腐病、根腐病及线虫病的感病性和耐病性同柑桔同柑桔根际土壤微生物区系中，有益微生物与有害微生物的种类、数量及分布有密切的关系。柑桔根际土壤有益微生物有促进生长发育和保护的作用。     

~(14)C-葡萄糖在椪柑果实粒化枯水过程中的转移和转化

碰柑贮藏中期,囊辦注射~(14)C-葡萄糖后,在枯水果和正常果的果皮和非标记囊辦均出现放射性活度,并以标记囊辦及其对应果皮为中心,向周围递减,这可能是物理扩散的结果。初枯果果皮放射性活度显著低于正常果,而其不溶物的放射性活度和呼吸强度与对照相比均无显著差异;~(14)C-葡萄糖在初枯果果皮之间或囊辦之间的扩散显著比正常果容易。这说明枯水的起因并非果肉营养物向果皮转移,而可能与衰老有关。在枯水发展过程中,全枯果果肉有24.65%的~(14)C-葡萄糖转化为不溶性物质,显著高于正常果的6.41%;中枯果和全枯果的呼吸强度分别为17.18ml/h·kg 和23.64ml/h·kg,显著高于正常果的11.03ml/h·kR。因此,我们认为椪柑在枯水过程中,果肉可溶性营养物消失的主要原因是转化为不溶性物质向果皮转移和呼吸消耗。     

春季柑橘幼树生长对红壤水分条件的响应

以第四纪红黏土发育的红壤、2年生宫川温州蜜柑(Citrus unshiu Marc.cv.Miyaga Ma Mase)盆栽幼树为材料,采用土壤水分探头(FDR)实时监测红壤水分含量,控制红壤水分设5个处理:SMC30、SMC45、SMC60S、MC75和SMC90(分别代表红壤相对含水量的30%、45%、60%、75%和90%),研究了红壤水分条件对柑橘幼树根、叶、春梢和横径的影响。结果表明,当红壤水分为SMC75时最适合柑橘幼树生长,且柑橘幼树根、春梢和横径及叶面积、周长、宽生长参数均在此处理时达最大值。幼树根生长指标(根体积、总根长、根上下扫描面积和根表面积)均与红壤水分间呈极显著抛物线相关,叶形态指标(叶面积、叶周长、叶宽、叶长、叶长/宽比值、叶形状因子)以SMC75为界,随着红壤水分的增加或减少,其生长量均受到了一定程度的影响。SMC≤45%,幼树春梢长和横径受到显著抑制。     

IMPROVEMENT IN YIELD AND QUALITY OF KINNOW (CITRUS DELICIOSA X CITRUS NOBILIS) BY POTASSIUM FERTILIZATION

Citrus, especially Kinnow, fruit yield and quality in Pakistan is not competitive with other countries, which could be mainly attributed to a lack of good nutrient management for citrus orchards. Many of the soils under these orchards have been reported as deficient in potassium (K). Therefore, work was initiated for improving citrus fruit yield, size, and quality through K nutrition management. Experiments were conducted in four districts of Punjab including Faisalabad, Toba Tek Singh, Jhang, and Sargodha and four rates of potash, i.e., 0, 50, 75 and 100 kg dipotassium oxide (K₂O) ha^?1 were applied using sulfate of potash (SOP) along with recommended rates of phosphorus (P) and nitrogen (N). Soils of all the selected sites were clay loam or sandy clay loam and deficient in K. The leaf analysis also showed that all the selected orchards were deficient in K. Application of K increased the fruit yield and quality but K at100 kg K₂O ha^?1 was more effective in increasing the fruit weight and size, and peel thickness than other K rates in all the selected orchards. Juice volume and percentage significantly increased when K was applied at 75 kg K₂O ha^?1 at all sites. Nutrient uptake like K, P, and N enhanced with the increase in K application rate, however, the highest calcium (Ca)+ magnesium (Mg) was recorded at 50 kg K₂O ha^?1. The results indicated that all rates of K application improved the fruit yield and quality and reduced fruit dropping, however, 75 kg K₂O ha^?1 rate was more effective as juice volume and percentage, total soluble solid (TSS)/acid ratio and nutrient uptake showed significant improvement.     

柑桔大实蝇Dacus citri (Chen)辐射效应的研究

柑桔大实蝇的辐照适期为羽化前1—2天的末期蛹,即黑复眼黑翅期。9krad的辐照剂量对柑桔大实蝇的羽化率、寿命和交尾时间无影响,而卵的孵化率为零,是适宜的辐射不育剂量。     

EFFECTS OF DIFFERENT NITROGEN,PHOSPHORUS, POTASSIUM RATES ON THE QUALITY AND QUANTITY OF CITRUS PLANTS,VARIETY THOMSON NOVEL UNDER RAINFED AND IRRIGATED CONDITIONS

Plants require nutrients including nitrogen (N), phosphorus (P), and potassium (K) for their growth and production. Although there have been previously extensive research work regarding the effects of NPK on plant growth, data related to the effects of long term application of NPK on the quality and quantity of citrus under rainfed and irrigated conditions are little. Accordingly, such effects were evaluated in this research work using different chemical fertilization factorially combined and on the basis of a completely randomized block design. Using ammonium sulfate (100, 150 and 200 g tree ^{? 1}), triple super phosphate (0, 25, 50, and 75 g tree^?1) and potassium sulfate (0, 50, 100, 150 g tree ^{? 1}) the quantity and quality of citrus fruit, variety Thomson were determined in a 10-year experiment in two different research stations in Ramsar, Iran. NPK fertilization significantly affected the quality and quantity of citrus fruits, indicating the significance of NPK fertilization for citrus production.     

辐射不育技术防治柑桔大实蝇的效果

在贵州省惠水县中联桔园(500亩)中,1987年和1989年分别释放56272头和95320头辐射不育柑桔大实蝇,释放比分别为12.5:1和45:1,使柑桔大实蝇虫果率由常年的5—8％下降到0.005％,防治效果十分显著。测得柑桔大实蝇可飞翔扩散1500米远。     

STANDARDIZATION OF TIME OF SAMPLING FOR LEAF NUTRIENT DIAGNOSIS ON KINNOW MANDARIN IN NORTH-WEST INDIA

The first full and comprehensive attempt was made to standardize the time of sampling for the leaf nutrient diagnosis for Kinnow mandarin in North West semi arid zone of India by analyzing ten essential elements collected from spring cycle leaves. The samples were collected from February to January at monthly intervals for two years and the results revealed that the 6–7 month (August–September) old spring cycle leaves collected from terminal position of non- fruiting terminal is the best suitable time for foliar nutrient analysis in Kinnow mandarin grown in the North West India. In addition, the leaf nutrient concentrations of nitrogen and calcium of this period were best correlated and leaf phosphorus (P) and potassium (K) were least correlated with fruit yield by linear correlation analysis.     

QUANTITY AND QUALITY OF CITRUS ON A CITROMELO ROOTSTOCK AS AFFECTED BY DIFFERENT TYPES OF N FERTILIZATION (CHEMICAL AND ORGANIC)

With respect to the important effects of nitrogen (N) on plant growth and fruit production, a five-year experiment was performed to evaluate the effects of different sources of N fertilization including chemical and organic on the quantity and quality of citrus fruit. Using five-year old trees, different types of fertilization including ammonium sulfate, urea coated with sulfur, ammonium nitrate and manure were tested using seven treatments in five replicates from 2002 to 2007. Different plant quantitative and qualitative parameters were determined. The most effective strategy on fruit yield production was the use of urea coated with sulfur and manure with 92.46 kg ha^?1 fruit yield followed by ammonium sulfate and manure (87.06 kg ha^?1) and ammonium sulfate (86.43 kg ha^?1). The combination of mineral and organic fertilization may be the most suitable fertilization strategy for citrus production.