An innovative tapping system, the double cut alternative, to improve the yield of Hevea brasiliensis in Thai rubber plantations

In Thailand, the continuous decrease in the size of rubber plantations has led to the general adoption of intensive tapping systems which may lead to over harvesting, high rates of tapping panel dryness (TPD), short life-cycles of the plantations, and low labour productivity. In Thailand, farmers use a half-spiral downward tapping system (S/2) or a one third-spiral (S/3) with a tapping frequency of once two days (d2) or more. To increase productivity, it is difficult to reduce tapping frequencies, even with ethylene stimulation, as this would result in days without work for tappers. The purpose of this study was to characterize the behaviour of the Hevea latex yield under the double cut alternative tapping system (DCA). The aim was ensure the long-term sustainability of latex yield by increasing the time required for latex regeneration between two tappings through splitting this high tapping intensity (100% or above) into two different tapping cuts tapped alternately (S/2 d47d7(t,t). Over a period of 10 years, compared to a single cut tapping system (S/2 d2) of equivalent intensity, DCA increased cumulative rubber production by 9%. Ability of the trees to produce more latex under DCA was related to the sucrose and inorganic phosphorus contents of the latex cells in each tapping panel. DCA produced metabolic activity more favourable to yield during the first 10 years of tapping. But DCA also resulted in higher TPD rates, a sign of a metabolic dysfunction of the productive bark. DCA is a new tapping system. Further research is required to optimize the use of the DCA strategy. Such research will lead to new advances in our knowledge of the physiology of the rubber tree, mainly at the trunk scale.     

双季晚稻肥料利用率研究

[目的]研究安徽省东至县双季晚稻肥料利用率。[方法]2015年在东至县东流、尧渡、官港、昭潭4个乡镇开展双季晚稻肥料利用率试验。[结果]在产量上,配方施肥较常规施肥增产523.35 kg/hm~2,增产率达6.8%;在肥料利用率上,配方施肥氮、磷、钾的利用率分别为35.4%、17.7%和40.1%,常规施肥氮、磷、钾的利用率分别为34.5%、7.4%和24.7%,配方施肥氮、磷、钾的利用率分别比常规施肥氮、磷、钾的利用率提高0.9、10.3和15.4百分点。[结论]配方施肥的肥料用量适宜及配比合理,能达到增产增收的目的,且明显提高肥料利用率。     

农林院校“双平台双能力”专业实践教学体系的探索

从内外2个方面提出构建＂双平台双能力＂的必要性,明确了＂双平台双能力＂专业实践教学体系的内容及其构建思路、方法、保障。＂双平台双能力＂专业实践教学体系的实施有效提升了学生的创新能力和工程能力。     

丘陵旱地一年两熟制条件下小麦、玉米阶段耗水量研究

以野外定位观测的方法,对河南省辉县市张村的冬小麦耗水量进行了测定。结果表明,小麦在4500～6000kg/hm2产量水平下,耗水量216.3～345.2mm,播种-返青、返青-抽穗、抽穗-成熟不同生育阶段耗水量分别占全生育期总耗水量的25.9%～36.9%、22.0%～31.1%、31.9%～52.2%,但年际间变幅悬殊较大;夏玉米在6750～7500kg/hm2产量水平下,耗水量为299.6～462mm,分别占同期自然降水量的81.3%～97.4%,播种-拔节、拔节-大喇叭口、大喇叭口-成熟不同生育阶段耗水量分别占全生育期总耗水量的17.1%～17.3%、34.5%～39.1%、43.6%～48.4%。小麦、玉米拔节以后耗水强度明显增加,拔节期、灌浆期是小麦2个重要的水分需求期,大喇叭口期是玉米的重要水分需求期,在目前河南省中北部丘陵旱地,自然降水对玉米水分保证率较高,而对小麦保证率较低,节水补灌重点应放在夏粮作物上。     

Double TdR blocking induces synchronization of cell cycle in human gastric cancer SGC-7901 cells

AIM: To investigate the effects of double thymidine deoxyribonucleoside (TdR) blocking on the cell cycle of human gastric cancer SGC-7901 cells.METHODS: SGC-7901 cells in the logarithm period were selected in the study and treated with TdR at concentration of 2 mmol/L, 4 mmol/L or 8 mmol/L for 15 h as the first blocking. After incubation in TdR-free medium for 10 h, the cells were treated with TdR at same concentrations again for another 15 h as the second blocking. The blocked cells were released by washing in fresh medium twice and incubation in TdR-free medium containing 10% fetal bovine serum for 12 h. The cells were collected and the cell cycle was detected by flow cytometry.RESULTS: By double TdR (2 mmol/L, 4 mmol/L and 8 mmol/L) blocking to synchronize the cell cycle, the cells in G₀/G₁ phase accounted for 77.3%, 77.5% and 77.0%, respectively. After further incubation for 12 h in TdR-free medium, the proportion of the cells in each phase of the cell cycles returned to normal range. CONCLUSION: The method of double TdR blocking is an ideal access in short term to acquire a large number of cells in G₀/G₁ phase.     

我国农村公共品的双层治理研究

在分析农村公共品管理存在的问题的基础上,提出了农村公共品的双层治理模型。研究表明,该模型的良好运转可确保各主体职责划分的合理性及合作的可能性,通过体制内和体制外两种职责分工与合作的方式,利用各治理主体公平博弈形成的均衡,能形成对农村公共品的有效治理。     

全膜双垄沟播马铃薯套种大豆栽培技术及效益评价

在推广全膜双垄沟播栽培技术的基础上,从增加效益入手,进行全膜双垄沟播马铃薯大垄面套种大豆的研究。结果表明,相对马铃薯单种,马铃薯套种大豆的活动积温利用率提高32．94％,水分生产率提高18．4％,土地利用率提高36％,主粮平均产量达6373．5kg／hm^2,较单种马铃薯增产9．6％,经济纯收入提高25．0％,效益十分明显。     

玉米全膜双垄覆盖“一膜两季”模式效应研究

在固原市原州区开城镇深沟村旱作示范基地进行了玉米全膜双垄覆盖“一膜两季”免耕栽培模式试验研究。试验结果表明：该项技术与常规半膜覆盖相比前期0～20cm土壤含水量增加4．2％,平均单产达到9457．2kg／hm^2,增产29．3％,节本17．8％,纯收益增加71．2％;比玉米全膜双垄覆盖沟播栽培前期0—20cm的土壤含水量增加1.1％,增产0．9％,节本26．7％,纯效益增加12．7％,经济效益显著。     

旱地食用向日葵双垄全膜覆盖“一膜两年用”免耕栽培模式效益研究

为了达到节本增效,增产又增收,最大限度地降低生产成本的目的,开展了双垄全膜覆盖“一膜两年用”免耕栽培模式下的节本增效研究。结果表明,双垄全膜覆盖“一膜两年用”免耕栽培模式比双垄全膜覆盖沟播栽培（农肥＋化肥）模式投产比提高了40．66％,比双垄全膜覆盖沟播栽培（化肥）模式投产比提高了33．33％,比常规半膜覆盖栽培模式投产比提高了36．17％,为大面积推广应用提供科学依据。