广西3个国营农场柑桔黄龙病发生和防控调查

为了解不同防控模式下的柑桔黄龙病防控效果及对果园产量和效益的影响,对广西农垦国有良丰农场、源头农场及立新农场及周边果园柑桔黄龙病发生、防控措施、更新种植模式及产量变化等进行调查。结果表明,椪柑平均发病率为9.49%,高于脐橙和温州蜜柑;农场果园采取严格的柑桔黄龙病综合防控措施后,柑桔黄龙病得到有效控制,发病率极显著低于防控措施不到位的果园,柑桔产量和效益可保持在较高水平。     

柑桔无病毒树的生长和结果表现初报

我国柑桔存在着碎叶病、裂皮病、黄龙病、衰退病和温州蜜柑萎缩病等病毒类病害 ,而广东则主要受黄龙病的为害 ,其次是裂皮病和碎叶病 ,近几十年来使柑桔生产屡遭重大损失。广东省柑桔生产近年大滑坡 ,黄龙病的长期肆虐是最主要的原因。栽培无病毒苗木是防治柑桔病毒病的有效途径。据调查 ,广东很多果园因未能种植无病毒苗使黄龙病的发病株率为 10 %～ 30 % ,严重的达 80 %以上 ,且幼龄树发病比重大[1] 。在生产上若柑桔感染黄龙病等病毒病 ,植株要经过一个潜伏期才表现症状 ,但在潜伏期间树体的生长、开花结果往往已受到抑制。柑桔栽培无病…     

柑桔苗营养袋假植技术

大苗定植建园可以有效提高土地利用率．大幅度提高桔园早期产量和效益。使用传统假植技术培育的大苗，在定植过程中．远距离运输和大面积建园都不容易做到带土移栽，苗木的根系会受到很大伤害．大苗叶片多而大，在运输过程中和移栽后水分蒸腾量大，苗木成活率低．缓苗期长。为解决这一矛盾，长阳县农业技术推广中心从2002年开始在长阳柑桔产区推广柑桔苗营养袋假植技术，取得了较好的经济效益和社会效益。     

柑桔营养袋假植育苗技术关键

柑桔营养袋假植育苗技术关键江西省自１９９１年实施果业工程以来，吉安地区果园总面积已达６．７万ｈｍ２。但各地新开发的果园存在成园率较低的问题。究其原因，主要是没有重视“大苗”的培养。１９９６年春，笔者通过营养袋假植培育脐橙苗９００株，沙田柚４００株，?..     

广西-湖南地区柑桔黄龙病综合防控技术模式集成及实践

"种植无病苗、大面积集中连片联防联控柑桔木虱和及时清除病树"是我国农牧渔业部1982年在广东召开的全国柑桔黄龙病检疫座谈会上确定的柑桔黄龙病防控三项基本措施,也是经实践证明行之有效的黄龙病防控技术措施。如何确保三项技术措施的严格落实并做到片区联防联控,是柑桔黄龙病防控中的难点。广西-湖南地区通过试验,研究集成了"以种植无病苗木为基础,以统一放控梢、大型植保机械喷施低毒高效药剂、果园悬挂黄板和梢期+冬季清园防治柑桔木虱为重点,以常态化普查清理病树为保障的柑桔黄龙病综合防控技术模式";在技术模式的应用上,因果园类型及黄龙病发病程度不同,采取分类防控策略;荔浦市为确保柑桔黄龙病防控三项基本措施严格落实,构建了以"政府责任制、宣传培训和村规民约"三大举措为核心的柑桔黄龙病片区联防联控"荔浦模式",并取得了显著成效。本文对上述技术模式进行了介绍,以期为其他柑桔片区防控柑桔黄龙病提供技术和经验借鉴。     

赣南地区柑桔黄龙病发生规律研究

根据2013年和2014年赣南各地柑桔黄龙病普查资料,对赣南柑桔黄龙病发病规律进行了分析。结果表明,赣南地区南北纵向不同区域间柑桔黄龙病的病情差异大,北纬25.330°以南为重发病区,北纬25.330°~25.880°之间为中等发病区,北纬25.880°以北为轻发病区;同一纬度,东西横向不同经度区域的病情差异不明显。柑桔黄龙病发生为害程度还与果园规模、树龄和柑桔种类有较密切关系,小规模果园病情重,10年以下低龄树和16年以上老龄树发病较重,温州蜜柑比脐橙敏感,脐橙比沙田柚敏感。     

防控柑桔黄龙病的实践与经验

柑桔黄龙病是严重威胁黄龙病区柑桔产业发展的毁灭性病害。广西是黄龙病重灾区,20世纪六七十年代,桂中、桂北大批柑桔园因黄龙病而淘汰,一些重病区至今未能恢复元气。柑桔木虱是黄龙病的传播昆虫。桂北于1981年发现木虱,1982年开始出现零星黄龙病病树,由于种种原因致使黄龙病大面积扩散蔓延。据桂林市水果生产办公室2007年3月的调查统计,截至2006年底,全市8.7万hm2桔园,受黄龙病危害的柑桔园面积达5.2万hm2,约占总面积的60%,果园平均发病株率达7.5%;2006年冬至2007年春共查出病树764.2万株,直接经济损失达9亿多元。广西柑桔研究所柑桔试验示…     

赣南柑桔黄龙病发生与防治现状调查

柑桔黄龙病由类细菌引起。 １９９９年 １０－ １１月，笔者就赣南地区会昌县柑桔黄龙病发生与防治现状作了调查，现报告如下。１调查方法在本县西江、小密、庄口、珠兰、湘江、高排、晓龙等镇（乡）的部分果园进行调查，小果园（０．６７ｈｍ２以下）采用详查法，大果园则随机抽查。柑桔黄龙病症状田间表现复杂，又与缺素等症状不易区分，本调查只根据柑桔黄龙病黄梢、叶片的斑驳型黄化典型症状作为判断标准，结合观察叶片硬化及畸形果发生情况。对发病较轻，不易区分者不统计。因此实际发病率要比本调查结果发病率高。２调查结果柑桔黄龙…     

柑桔根系接触与黄龙病传播关系的研究

黄龙病是柑桔最严重的传染性病害,其病原菌在病株地上各部位和根部均有分布,主要通过病芽嫁接和柑桔木虱Diaphorina citri Kuwayama进行传播。本文研究了黄龙病通过柑桔根部传病的可能性。结果表明,将感染黄龙病的红皮山桔实生苗与健康沙糖桔苗(红皮山桔砧)直接合种在一起,3年后健苗均没有发病;通过嫁接将病苗和健苗的一对侧根接合后合种,6个月后30株健苗中有1株感病,9个月后感染数达到9株,12个月后为11株,感染率达36.7%。说明,病树和健树根系直接交叉生长不能传播黄龙病,但通过根嫁接使病健苗的根接合在一起则可以传播黄龙病,且传播效率较高。     

浅谈营养袋假植育苗

以往我县柑桔类幼苗定植习惯在农历正月初八到元宵节前后这段时间,采用直接从苗圃起苗不带土定植的方法。这样可以避免春节前后可能发生的冻害,但成活率很低。特别是近几年,在常规定植的这段时间里气温往往高达30℃,且连续干旱10多天,蒸发量大,湿度小,果农尽管浇水抗旱,仍因“人不付出”而无济于事造成死苗。尤其是面积较大的果园及从外地购进的苗木,死苗更为严重,使果农蒙受损失。我们从1995年起,采用塑料营养袋假植,经过6～7个月的集中管理再进行定植的方法。几年来的实践证明,用营养袋假植育苗比常规直接从苗圃起苗不带土定…     

Plant growth,yield, and fruit quality of ‘Fallglo’ and ‘Sunburst’ mandarins on four rootstocks

Vegetative growth, yield, and fruit quality of ‘Fallglo’ and ‘Sunburst’ mandarins on ‘Rangpur’ lime, ‘Swingle’ citrumelo, ‘Orlando’ tangelo, and ‘Cleopatra’ mandarin were evaluated under subtropical climate of Northern São Paulo State, Brazil, from 2000 through 2006 harvest seasons. ‘Fallglo’ mandarin trees had the highest cumulative yield on ‘Rangpur’ lime, and the smallest on ‘Swingle’ citrumelo and ‘Orlando’ tangelo. Plants of this cultivar had the highest yield efficiency on ‘Rangpur’ lime, and the lowest on ‘Orlando’ tangelo. ‘Sunburst’ mandarin trees began to bear fruits later than ‘Fallglo’ mandarin trees, with no differences in yield induced by the rootstocks. ‘Cleopatra’ mandarin induced the most vigorous growth in ‘Fallglo’ mandarin as compared to plants on ‘Swingle’ citrumelo. On the other hand, the largest trees of ‘Sunburst’ mandarin were registered on ‘Orlando’ tangelo, and the smallest on ‘Rangpur’ lime. ‘Sunburst’ mandarin had higher alternate bearing than ‘Fallglo’ regardless the rootstock. Fruit weight and juice content were not affected by the rootstock. These two mandarin scion cultivars may be considered adequate alternatives to produce good fruit quality for the fresh fruit market. ‘Cleopatra’ mandarin and ‘Rangpur lime are suitable rootstocks for ‘Fallglo’ mandarin, whereas all rootstocks evaluated are adequate for ‘Sunburst’ mandarin.     

Tree performance and fruit yield and quality of ‘Okitsu’ Satsuma mandarin grafted on 12 rootstocks

The citriculture in Brazil, as well as in other important regions in the world, is based on very few mandarin cultivars. This fact leads to a short harvest period and higher prices for off-season fruit. The ‘Okitsu’ Satsuma (Citrus unshiu Marc.) is among the earliest ripening mandarin cultivars, and it is considered to be tolerant to citrus canker (Xanthomonas citri subsp. citri Schaad et al.) and to citrus variegated chlorosis (Xylella fastidiosa Wells et al.). Despite having regular fruit quality under hot climate conditions, the early fruit maturation and absence of seeds of ‘Okitsu’ fruits are well suited for the local market in the summer (December through March), when the availability of citrus fruits for fresh consumption is limited. Yet, only a few studies have been conducted in Brazil on rootstocks for ‘Okitsu’. Consequently, a field trial was carried out in Bebedouro, São Paulo State, to evaluate the horticultural performance of ‘Okitsu’ Satsuma mandarin budded onto 12 rootstocks: the citrandarin ‘Changsha’ mandarin (Citrus reticulata Blanco) × Poncirus trifoliata ‘English Small’; the hybrid Rangpur lime (Citrus limonia Osbeck) × ‘Swingle’ citrumelo (P. trifoliata (L.) Raf. × Citrus paradisi Macfad.); the trifoliates (P. trifoliata (L.) Raf.) ‘Rubidoux’, ‘FCAV’ and ‘Flying Dragon’ (P. trifoliata var. monstrosa); the mandarins ‘Sun Chu Sha Kat’ (C. reticulata Blanco) and ‘Sunki’ (Citrus sunki (Hayata) Hort. ex. Tanaka); the Rangpur limes (C. limonia Osbeck) ‘Cravo Limeira’ and ‘Cravo FCAV’; ‘Carrizo’ citrange (Citrus sinensis × P. trifoliata), ‘Swingle’ citrumelo (P. trifoliata × C. paradisi), and ‘Orlando’ tangelo (C. paradisi × Citrus tangerina cv. ‘Dancy’). The experimental grove was planted in 2001, using a 6 m × 3 m spacing, in a randomized block design. No supplementary irrigation was applied. Fruit yield, canopy volume, and fruit quality were assessed for each rootstock. A cluster multivariate analysis identified three different rootstock pairs with similar effects on plant growth, yield and fruit quality of ‘Okitsu’ mandarin. The ‘Flying Dragon’ trifoliate had a unique effect over the ‘Okitsu’ trees performance, inducing lower canopy volume and higher yield efficiency and fruit quality, and might be suitable for high-density plantings. The ‘Cravo Limeira’ and ‘Cravo FCAV’ Rangpur limes induced early-ripening of fruits, with low fruit quality. ‘Sun Chu Sha Kat’ and ‘Sunki’ mandarins and the ‘Orlando’ tangelo conferred lower yield efficiency and less content of soluble solids for the latter rootstock.     

Identification of S-alleles in pear (Pyrus communis L.) cv. ‘Rocha’ and other European cultivars

In this work we report the cloning and identification of S-RNase alleles responsible for gametophytic self-incompatibility (GSI) of ‘Rocha’ pear and of 13 other European pear cultivars that might be used as its pollinators. Partial sequences of S-RNase alleles were amplified by PCR with specific primers hybridising in conserved regions of previously identified S-RNase alleles of Pyrus communis, cloned and sequenced and the S-genotype of eight pear cultivars was fully determined. Three cultivars (‘General Léclerc’ (SqSl), ‘Tosca’ (SbSl) and ‘Alexandrine Douillard’ (SbSk)) shared no S-alleles with ‘Rocha’ (SaSe) and shall be totally compatible with this cultivar. None of the cultivars analysed showed an identical amplification pattern to the one observed in ‘Rocha’, so the other cultivars shall be at least semi-compatible. One new allele was identified in P. communis cv. ‘Beurré d’Avril’ (designated as St). The determination of both S-RNase alleles of cvs ‘Rocha’, ‘Beurré Precoce Morettini’ (SeSk) and ‘Tosca’ and the identification of one S-RNase allele in cvs ‘Carapinheira’ (Sb), ‘Amêndoa’ (Se), ‘Pérola’ (Sk) and ‘Beurré d’Avril’ (St) are important contributions for the effort recently developed worldwide to establish groups of sexual compatibility among European pears.     

Horticultural performance of ‘Folha Murcha’ sweet orange onto twelve rootstocks

Despite its outstanding position, the Brazilian citriculture is established on a very limited pool of varieties that limits its expansion and restricts the fruit availability throughout the year. This situation determines the urgent necessity of developing alternative scion and rootstock cultivars, with good performance under local conditions. ‘Folha Murcha’ sweet orange (Citrus sinensis (L.) Osbeck) is a late-harvest cultivar, suitable both for the juice processing industry and the fresh fruit market, being described as tolerant to citrus canker (Xanthomonas citri subsp. citri Schaad et al.), and less affected by citrus variegated chlorosis (Xylella fastidiosa Wells et al.). A study was conducted in Bebedouro, São Paulo State, Brazil, to evaluate the horticultural performance of ‘Folha Murcha’ sweet orange budded onto 12 rootstocks: the citrandarin ‘Changsha’ mandarin (Citrus reticulata Blanco) × Poncirus trifoliata ‘English Small’; the hybrid ‘Rangpur’ lime (Citrus limonia Osbeck) × ‘Swingle’ citrumelo (P. trifoliata (L.) Raf. × Citrus paradisi Macfad.); the trifoliates (P. trifoliata (L.) Raf.) ‘Rubidoux’, ‘FCAV’, and ‘Flying Dragon’ (P. trifoliata var. monstrosa); the ‘Sun Chu Sha Kat’ mandarin (C. reticulata Blanco); the ‘Sunki’ mandarin (Citrus sunki (Hayata) Hort. ex. Tanaka); the ‘Rangpur’ limes (C. limonia Osbeck) ‘Cravo Limeira’ and ‘Cravo FCAV’; ‘Carrizo’ citrange (C. sinensis × P. trifoliata), ‘Swingle’ citrumelo (P. trifoliata × C. paradisi), and ‘Orlando’ tangelo (C. paradisi × Citrus tangerina cv. ‘Dancy’). The experimental grove was planted in 2001, using a 7 m × 4 m spacing, in a randomized block design, with five replications and two plants per plot. No supplementary irrigation was applied. Fruit yield, canopy volume, tree tolerance to drought and to citrus variegated chlorosis, and fruit quality were assessed for each rootstock. Trees grafted onto the ‘Flying Dragon’ trifoliate were smaller in size, but had largest yield efficiency when compared to those grafted onto other rootstocks. Lower alternate bearing index was observed on trees budded onto ‘Cravo FCAV’ ‘Rangpur’ lime. Both ‘Rangpur’ lime rootstocks and the ‘Sunki’ mandarin induced higher tree tolerance to drought. The ‘Flying Dragon’ trifoliate induced better fruit quality and higher tolerance to citrus variegated chlorosis (CVC) to ‘Folha Murcha’ trees. A cluster multivariate analysis identified three groups of rootstocks with similar effects on ‘Folha Murcha’ tree performance. Among the 12 evaluated rootstocks, the ‘Flying Dragon’ trifoliate has a unique effect on plant growth, tolerance to drought and CVC, fruit yield and fruit quality of ‘Folha Murcha’ trees, and may be better suited for high-density plantings.     

Changes in fox squirrel anti-predator behaviors across the urban–rural gradient

Predator stimuli created by humans in the urban environment may alter animals’ anti-predator behaviors. I hypothesized that habituation would cause anti-predator behaviors to decrease in urban settings in response to humans. Additionally, I hypothesized that populations habituated to humans would show reduced responses to other predator stimuli. I observed three populations of squirrels (urban, suburban and rural) responses to human approaches, red-tailed hawk vocalizations (Buteo jamaicensis) and coyote (Canis latrans) vocalizations. Mahalanobis distances of anti-predator behaviors in response to human approaches were consistent with the urban–rural gradient. Flight initiation distances (X ² = 26.33, df = 2, P < 0.001) and amount of time dedicated to anti-predator behavior (X ² = 10.94, df = 2, P = 0.004) in response to human approaches were also consistent with the urban–rural gradient. Supporting the habituation hypothesis, naive juvenile squirrels increased flight initiation distances (X ² = 35.89, df = 1, P < 0.001) and time dedicated to anti-predator behaviors (X ² = 9.46, df = 1, P = 0.002) relative to adult squirrels in the same urban environment. Time dedicated to anti-predator behaviors differed among all three sites in response to both coyote (X ² = 9.83, df = 2, P = 0.007) and hawk (X ² = 6.50, df = 2, P = 0.035) vocalizations. Responses to both vocalizations on rural sites (coyote = 45%, hawk = 55%) greater than twice that found on the urban sites (coyote = 11%, hawk = 20%). This is possibly the first case of a transfer of habituation demonstrated under field conditions.     

Production of inter-section hybrids between Primula filchnerae and P. sinensis through ovule culture

Inter-section hybrids were obtained in the reciprocal crosses between Primula filchnerae (2n = 2x = 24) of Sect. Pinnatae and P. sinensis ‘Fanfare’ (2n = 2x = 24) of Sect. Auganthus by rescuing ovules on half-strength (1/2) Murashige and Skoog's (MS) medium supplemented with 50 g l⁻¹ sucrose, 2.5 g l⁻¹ gellan gum, 0.1 mg l⁻¹ α-naphthaleneacetic acid (NAA), 0.1 mg l⁻¹ 6-benzyladenine (BA) and 50 mg l⁻¹ gibberellic acid (GA₃). In ovule culture, germination occurred with radicle elongation but no plumule was observed. The radicle kept on the initial medium showed root proliferation with callus formation. When the calluses were transferred to (1/2)MS media containing 30 g l⁻¹ sucrose and 3 g l⁻¹ gellan gum, without plant growth regulators (PGRs) or with 1 mg l⁻¹ zeatin and 0.1 mg l⁻¹ NAA, plantlets were regenerated. The plants thus obtained were confirmed to be hybrids through flow cytometry (FCM) and random amplified polymorphic DNA (RAPD) analyses. The hybrid obtained when P. filchnerae was used as the maternal parent was diploid, whereas hexaploid hybrid was obtained when using P. sinensis as the maternal parent. The hexaploid hybrid might be produced through chromosome doubling of a triploid originated from the fertilization of P. sinensis with unreduced pollen of P. filchnerae.     

Effects of the commercial product based on Trichoderma harzianum on plant,bulb and yield characteristics of onion

Effects of the commercial product TrichoFlow WP™ (Agrimm Technologies Ltd., New Zealand), based on the fungus Trichoderma harzianum, on quality characteristics and yield of bulb onion was investigated. Bulb sets of the local cultivar Kantartopu was planted in soil with in and between row distances of 0.15 m and 0.40 m, respectively. The product, at considerably high dosages of 5 g m⁻², 10 g m⁻² and 15 g m⁻², was mixed with water and sprinkled once to the plots at planting. Analyses of data at harvest did not show statistical significance for Trichoderma effect on total bulb yield, bulb diameter, leaf length, number of shoot apex, %titratable acidity, number of internal (fleshy) leaves, number of external (papery) leaves, %soluble solids and %bulbs with diameters of 20–39 mm, 40–69 mm and ≥70 mm. The yields obtained from the plots treated with the dosages of 5 g m⁻², 10 g m⁻² and 15 g m⁻² and the control plots were 1063.7 kg da⁻¹, 1051.0 kg da⁻¹, 1066.5 kg da⁻¹ and 985.0 kg da⁻¹, respectively. Our results showed that high dosages of the Trichoderma product were not effective in enhancing onion bulb and yield characteristics under the given conditions.     

Cybrid/hybrid plants regenerated from somatic fusions between male sterile Satsuma mandarin and seedy tangelos

Somatic hybridization provides an alternative for transferring mitochondria-encoded cytoplasmic male sterility (CMS). Herein, symmetric protoplast electrofusion was conducted between embryogenic callus protoplasts of Citrus unshiu Marc. cv. Guoqing No. 1 (G1), a CMS cultivar, and mesophyll-derived protoplasts of seedy ‘Page’ tangelo [C. reticulata Blanco × (C. reticulata Blanco × C. paradisi Macf.)] or ‘Nova’ tangelo [C. reticulata Blanco × (C. reticulata Blanco × C. paradisi Macf.)], to transfer CMS trait. Flow cytometry analysis showed that 14 plants recovered from G1 + ‘Page’ tangelo that displayed typical morphological character of ‘Page’ were diploid, and 6 plants regenerated from G1 + ‘Nova’ tangelo were tetraploid. Genetic compositions of regenerated plants from the two fusions were determined by SSR, CAPS and chloroplast-SSR analysis. Cybrid nature of diploids from G1 + ‘Page’ tangelo with nuclear DNA from ‘Page’, mitochondrial DNA (mtDNA) from the G1 and chloroplast DNA (cpDNA) derived from either parent was confirmed. Tetraploid plants from G1 + ‘Nova’ tangelo were identified as somatic hybrids with random cpDNA inheritance. The regenerated cybrid and hybrid plants hold great potential for Citrus seedless breeding at diploid or triploid levels.     

Production protocol development for greenhouse cut Linaria, Lupinus, and Papaver flowers

Linaria maroccana Hook. f. Ann., ‘Lace Violet’, Lupinus hartwegii ssp. cruikshankii Lindl. ‘Sunrise’ and Papaver nudicaule L. ‘Meadow Pastels’ seeds were directly sown into 105 cell plug trays and received either ambient light or supplemental high intensity discharge (HID) lighting. For each species, a 2 × 3 × 3 factorial was used with two light intensities during propagation, three transplant stages, and three night temperatures. Seedlings were transplanted at the appearance of 2–3, 5–6, or 8–9 true leaves. Transplanted Linaria and Papaver seedlings were placed at 5/11, 10/16, or 15/21 ± 1 °C night/day temperatures and Lupinus seedlings were placed at 15/24, 18/25, or 20/26 ± 2 °C night/day temperatures. For this study, the optimum production temperature for Linaria was 10/16 °C as the cut stems produced at 15/21 °C were unmarketable and production time was excessively long at 5/11 °C. At 10/16 °C, Linaria seedlings should be transplanted at the 2–3 leaf stage to maximize stem number, stem length and profitability. For Lupinus the optimum temperature was 15/24 °C due to long stems and high profitability per plant. Lupinus seedlings should be transplanted at the 2–3 leaf stage when grown at 15/24 °C to obtain the longest and thickest stems; however, $/m² week was higher for plants transplanted at the 8–9 leaf stage due to less time in finishing production space. For Papaver, the 15/21 °C temperature was optimal as that temperature produced the longest stems in the shortest duration, resulting in the highest $/m² week. At 15/21 °C Papaver plants should be transplanted at the 2–3 leaf stage. Supplemental HID lighting had no effect on any of the species.