叶面喷肥对葡萄果穗着色的影响

试验证明，使用含Ｎ、Ｐ２Ｏ５，Ｋ２Ｏ，Ｍｎ，Ｂ，Ｆｅ，Ｃｕ，Ｚｎ，Ｍｏ的液体肥料在葡萄着色始期或着色中期喷布叶片或果穗均有显著的促进果穗着色的作用。     

新疆玛纳斯河流域葡萄霜冻发生规律研究

对新疆玛纳斯河流域多年霜冻发生规律及晚霜冻预防措施进行了研究。结果表明:新疆玛纳斯河流域终霜日80%保证率的日期是4月15日,2000~2009年平均终霜日是4月10日,表现出了终霜日提前、气候变化不稳定的特征。当地春季葡萄出土日期不宜早于4月10日,增加葡萄越冬埋土厚度、适当推迟葡萄出土时间、出土后及霜冻发生前时及时灌水、霜冻发生时烟熏等措施可在一定程度上减轻霜冻对葡萄造成的危害。     

枸杞炭疽病化学防治研究

室内毒力测定证明:58％甲霜灵锰锌,75％百菌清,50％退菌特,70％代森锰锌,64％杀毒矾以及70％代森锰锌和75％百菌清(1∶1)混配对枸杞炭疽病菌有较好的抑菌效果。上述药剂田间防治效果为78～91.4％,其中,58％甲霜灵锰锌1500ppm和70％代森锰锌75bpp+75％百菌清750ppm的防效最好,分别为89.6％和91.4％;其次是75％百菌清1500ppm和70％代森锰锌1500ppm,防效分别为85.6％和82.2％,可推广应用。     

双屋面温室双蔓坠枝葡萄套种草莓栽培模式

为了高效利用本地双屋面温室,提高农户经济效益,采用合理的葡萄架设和树形,科学搭配草莓和葡萄的种植时间,通过套种模式充分利用空间,达到了温室内作物综合产量的增加和经济效益的提高。当地双屋面温室双蔓坠枝葡萄套种草莓采摘模式,相比单纯以篱壁架种植葡萄采摘模式毛收入提高了311.7%,相比单纯种植草莓采摘模式毛收入提高27.1%,是一种即可增加农户收入也可促进观光旅游持续发展的栽培模式。     

葡萄幼树年周期碳素(~(14)CO_2)同化物分配输出规律的研究

本文用~(14)CO_2示踪法,研究葡萄幼树碳素同化物分配输出特性,结果表明,碳素同化物质分配有季节特点。生长前期主要集中供给地上部各新生器官;中期地上部与地下部分配比较均衡;后期则稳定回流。     

不同伐藤处理下次生林群落土壤种子库特征及演替趋势

本研究以五指山市受藤本植物危害严重的低海拔次生林群落为研究对象,采用野外植被调查和室内种子萌发试验相结合的方法,对不同伐藤处理下的次生林群落土壤种子库特征、物种多样性及其与林下植被的相似性进行了研究。结果表明:（1）人工除藤可提高研究区土壤种子库种子萌发数量及速度,也可延长其种子萌发天数;（2）不同伐藤处理下的土壤种子库中共出现74种植物,隶属35科67属,其中菊科、茜草科和禾本科植物种出现比例较高,而飞机草在不同伐藤处理下的土壤种子库中均为优势种;不同伐藤处理下的土壤种子库物种生活型组成,均以草本植物占明显优势,人工除藤可使土壤种子库中乔木、灌木等生活型的物种数明显增多;（3）不同伐藤处理下土壤种子库种子密度和物种数均随土层深度的加深呈递减趋势,人工除藤可使研究区2~5、5~10 cm土层土壤中的种子密度明显增加;（4）不同伐藤处理下土壤种子库物种多样性指数均无显著差异,且其土壤种子库与林下植被的相似性系数（0.173~0.302）普遍较低,但随着伐藤年限的延长,土壤种子库与林下植被物种组成的相似性增大,伐藤3年处理的群落显著大于未做处理的对照群落。综上可知,人工除藤可提高研究区土壤种子库的植被恢复潜力及天然更新能力,有助于推动该区域次生林群落的正向恢复演替。     

Past Studies on and Present Status of Lethal Yellowing Disease of Coconuts

Abstract

The symptoms and extent of lethal yellowing disease of coconuts are described. In research into the cause of the disease nutrient deficiencies, fungi, bacteria, nematodes and, more recently, viruses have been investigated without implicating any causal agent. Mechanical and insect transmissions were attempted by a number of methods. The incubation period was shown to be 3–9 months for young palms and 7–15 months for bearing palms. Experiments to control the disease have been unsuccessful.

Local and introduced coconut varieties and hybrids are being tested for resistance by field exposure. The Malayan Dwarf variety has been shown to have high resistance and is being used to replant the industry. No other variety or hybrid is deemed as yet to be sufficiently resistant for farm planting.

Mycoplasms were recently found associated with the disease. Future research must include confirmation of mycoplasm-lethal yellowing association, continuation of the search for the vector, experimental chemotherapy, and attempts to culture mycoplasms to develop an inoculation technique. Palms showing resistance will be used in the breeding programme. Promising hybrids will be produced in greater numbers for more extensive testing and further introductions will be made.     

半干旱土添加有机改良剂后有机质的化学结构变化

A 9-month incubation experiment using composted and non-composted amendments derived from vine pruning waste and sewage sludge was carried out to study the effects of the nature and stability of organic amendments on the structural composition of organic matter (OM) in a semi-arid soil.The changes of soil OM,both in the whole soil and in the extractable carbon with pyrophosphate,were evaluated by pyrolysis-gas chromatography and chemical analyses.By the end of the experiment,the soils amended with pruning waste exhibited less organic carbon loss than those receiving sewage sludge.The non-composted residues increased the aliphatic-pyrolytic products of the OM,both in the whole soil and also in the pyrophosphate extract,with the products derived from peptides and proteins being significantly higher.After 9 months,in the soils amended with pruning waste the relative abundance of phenolic-pyrolytic products derived from phenolic compounds,lignin and proteins in the whole soil tended to increase more than those in the soils amended with sewage sludge.However,the extractable OM with pyrophosphate in the soils amended with composted residues tended to have higher contents of these phenolic-pyrolytic products than that in non-composted ones.Thus,despite the stability of pruning waste,the composting of this material promoted the incorporation of phenolic compounds to the soil OM.The pyrolytic indices (furfural/pyrrole and aliphatic/aromatic ratios) showed the diminution of aliphatic compounds and the increase of aromatic compounds,indicating the stabilization of the OM in the amended soils after 9 months.In conclusion,the changes of soil OM depend on the nature and stability of the organic amendments,with composted vine pruning waste favouring humification.     

Susceptibility of the obscure mealybug,Pseudococcus viburni (Signoret) (Pseudococcidae), to South African isolates of entomopathogenic nematodes

Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae), the obscure mealybug, is a serious pest of apples and pears in South Africa. The potential use of entomopathogenic nematodes (EPNs) against P. viburni was assessed in laboratory bioassays. The results showed Heterorhabditis zealandica (J34) to be most effective, causing 80% mortality of P. viburni 48-h post inoculation at 25 ºC. After 48 h, the LD₅₀ and LD₉₀ values were 54 and 336 nematodes, respectively. H. zealandica (J34) and Steinernema yirgalemense successfully reproduced in P. viburni, with H. zealandica (J34) attaining greater penetration ability than did the S. yirgalemense. Mealybug size affected infectivity, with the crawlers being less susceptible (22%) than were the adults and intermediates, with mortalities of 78% and 76%, respectively. H. zealandica (J34) were able to enter the apple core of infested apples, where they infected the P. viburni. This work represents the first report on using EPNs to control P. viburni.