西部新农村建设中农业信息化的实地研究

采用实地调研法,对西部新农村建设试点村韦寨村的农业信息化建设情况进行长期跟踪观察、实地调研,对该村农业信息化情况有了比较全面的了解。从信息使用者的视角,分析了贫困山区农村信息化建设中的困难和问题,提出了相应的改进措施,可为农村信息化和新农村建设提供借鉴。     

基于颜色阈值的田间籽棉图像分割技术

为正确分割田间籽棉图像,将棉花与背景视为二个类别,在典型的未成熟籽棉图像和不同质量等级的成熟/过熟籽棉图像中,用肉眼选取20 000个白棉、黄染棉和污染棉等棉花像素以及20 000个棉株、土壤等背景像素,在RGB、HSI、La*b*和Hunter颜色空间下获取二类像素之间的颜色阈值,基于阈值进行图像分割,选取噪声较少的HSI和La*b*颜色空间,进一步基于形态学滤波器去噪,实验结果表明,907幅籽棉图像分割的准确率为87.21%和86.33%。HSI颜色空间更适合分割成熟籽棉图像,La*b*颜色空间则适合未成熟籽棉;颜色阈值覆盖范围广,基于速度的阈值分割法能够适应田间籽棉环境。     

不同杀虫(螨)剂对蔬菜叶螨的田间防效评价

蔬菜田小区试验比较了11种杀虫(螨)剂对蔬菜叶螨的防治效果。结果表明,3种专一性杀螨剂哒螨灵、克螨特、噻螨酮及6种广谱性杀虫杀螨剂阿维菌素、虫螨腈、高效氟氯氰菊酯、甲维盐、氧苦.内脂和螺螨酯对叶螨均有良好的防治效果,彼此之间差异不显著。其中低毒药剂克螨特、噻螨酮、阿维菌素和甲维盐的防治效果最佳,药后3、7、10d的防效分别达到79.96%、88.50%和99.01%(克螨特),82.64%、88.79%和97.77%(噻螨酮),73.24%、91.16%和97.73%(阿维菌素),74.12%、87.46%和98.62%(甲维盐),适合用于蔬菜叶螨的防治。高效氟氯氰菊酯属中等毒性,而螺螨酯防治效果稍低,使用时间和剂量应有所限制。而氯虫苯甲酰胺和多杀菌素对叶螨没有防治效果。     

Prediction of yield and the contribution of legumes in legume-grass mixtures using field spectrometry

Productivity and botanical composition of legume-grass swards in rotation systems are important factors for successful arable farming in both organic and conventional farming systems. As these attributes vary considerably within a field, a non-destructive method of detection while doing other tasks would facilitate more targeted management of crops and nutrients in the soil–plant–animal system. Two pot experiments were conducted to examine the potential of field spectroscopy to assess total biomass and the proportions of legume, using binary mixtures and pure swards of grass and legumes. The spectral reflectance of swards was measured under artificial light conditions at a sward age ranging from 21 to 70 days. Total biomass was determined by modified partial least squares (MPLS) regression, stepwise multiple linear regression (SMLR) and the vegetation indices (VIs) simple ratio (SR), normalized difference vegetation index (NDVI), enhanced vegetation index (EVI) and red edge position (REP). Modified partial least squares and SMLR gave the largest R ² values ranging from 0.85 to 0.99. Total biomass prediction by VIs resulted in R ² values of 0.87–0.90 for swards with large leaf to stem ratios; the greatest accuracy was for EVI. For more mature and open swards VI-based detection of biomass was not possible. The contribution of legumes to the sward could be determined at a constant biomass level by the VIs, but this was not possible when the level of biomass varied.     

叶面喷施磷酸二氢钾对雪菊生长、产量的影响

为了研究叶面喷施KH2PO4对大田雪菊生长及产量的影响问题,以新疆农业大学三坪农场教学实践基地的大田雪菊为试验材料,采用测量大田雪菊植株性状与产量的方法对大田雪菊的生长及产量进行了研究。结果表明：7月份喷施0.5%的KH2PO4对大田雪菊的生长与产量的影响最为显著,在8月份喷施浓度为0.3%的磷酸二氢钾对大田雪菊的植株性状和产量的影响最为显著,故雪菊叶面喷施浓度为0.5%和0.3%的磷酸二氢钾对不同时间段的雪菊生长及其产量影响最为明显,并存在时间的差异性。     

不同药剂处理对白魔芋田间发病率和产量的影响

[目的]筛选白魔芋白绢病和软腐病的防治药剂。[方法]通过小区试验研究5个不同药剂组合对白魔芋田间发病率和产量的影响,并检测白魔芋葡甘露聚糖含量。[结果]溴硝醇600倍稀释液+300 mL/hm~2露娜森+安泰生800倍稀释液处理的白魔芋产量较高,防治效果较好,且葡甘露聚糖含量也较高。[结论]溴硝醇600倍稀释液+300 mL/hm~2露娜森+安泰生800倍稀释液处理方法可应用于生产中防治白魔芋白绢病和软腐病。     

不同杀虫剂对刺槐突瓣细蛾的田间药效

[目的]筛选防治刺槐突瓣细蛾的有效药剂。[方法]采用小区试验研究不同杀虫剂对刺槐突瓣细蛾成虫、幼虫的田间药效。[结果]对于成虫,施药后72 h,高效氯氰菊酯防治效果达93.3%~98.1%;灭幼脲悬浮剂的防治效果达85.7%~94.3%;阿维菌素乳油防治效果为81.0%~84.0%。对于幼虫,施药后72 h,灭幼脲悬浮剂的防治效果达93.7%~95.1%;乐斯本乳油防治效果达83.8%~86.3%;10%吡虫啉可湿性粉剂防治效果为77.2%~79.2%。[结论]灭幼脲对刺槐突瓣细蛾成虫和幼虫均有较好的防治效果。     

田间条件下小白菜对外源Cd的动态吸收特征

[目的]探究田间条件下小白菜对外源Cd的动态吸收特征,为Cd污染土壤上蔬菜安全生产提供理论依据。[方法]采用田间微区试验,共设4个Cd浓度处理,即0(CK)、1、2、5 mg/kg,每处理3次重复,研究外源Cd对小白菜生长的影响及小白菜对外源Cd的动态吸收特征。[结果]随着外源Cd浓度的升高及生长时期的延长,Cd对小白菜生长的抑制加重。5 mg/kg处理55 d时,小白菜的根长、株高、生物量较CK下降幅度均达到最大。任一Cd浓度下小白菜的Cd含量在前45 d快速增加,45 d后增速放缓,地下部Cd含量在55 d达到最大值,地下部平均Cd含量是地上部的1.62倍。[结论]Cd对小白菜的生长作用受Cd污染浓度、生长时期双重影响,且不同外源Cd浓度下小白菜各部位对Cd的吸收在不同生长时期呈现动态差异。     

Field evaluation of Lymantria obfuscata multiple nucleopolyhedrovirus for the management of Indian gypsy moth in Jammu & Kashmir,India

The Indian gypsy moth (Lymantria obfuscata) is a pest of national significance, which attacks a wide range of forest and fruit crops in India. The outbreaks of this pest over the past few years spurred interest towards sustainable biointensive approaches for quality fruit production of apple and walnut for agricultural export in Jammu & Kashmir (J & K). The exploratory survey's were conducted for the isolation of native strains of L. obfuscata multiple nucleopolyhedrovirus (LyobMNPV) and field evaluation was conducted to determine the most promising strain as a potential biological control agent of this pest. The virus was recovered from different locations of J&K with its natural incidence varying from 0.77 to 7.43 percent. This is the first report from the Indian sub-continent and worldwide of the occurrence of NPVs in natural larval populations of L. obfuscata. The in vivo mass production was optimised by inoculating per os late 3rd instar L. obfuscata larvae with an inoculum dose of 1.44 × 10⁵ OBs/larva and followed by a 10 day incubation period. To prevent the disintegration of larval cuticle and microbial contamination, moribund larvae were harvested with an average yield of 1.42 × 10⁸ OBs/larva. The field application of LyobMNPV against the host populations on apple and willow with the pre-standardised dosage of 2.5 × 10¹² OBs/ha reduced the larval population density by 25–63%. In the year following application, the larval population density in the treated blocks was 19–28% lower as compared to controls on both apple and willow. This suggests that the virus has considerable potential as a biocontrol agent and the timely application with LyobMNPV on non-fruit trees such as willow which are the preferred hosts for egg laying may help to initiate viral epizootics to keep population outbreaks under check.     

Nursery fertilization enhances survival and physiological status in Canary Island pine (<Emphasis Type="Italic">Pinus canariensis</Emphasis>) seedlings planted in a semiarid environment

We tested the hypothesis that fertilized containerized Pinus canariensis seedlings increases survival when planted in semiarid sites through the improvement of their physiological status during the establishment phase by an increment in root growth. Seedlings were cultured under two different regimes: traditional (in non-fertilized natural soil) and alternative (in fertilized peat). Morphological attributes and nitrogen content were measured before planting. Measurements of survival and growth in the plantation were made periodically for 2 years and physiological plant responses (leaf water potential, gas exchange and chlorophyll fluorescence) during the third summer after planting were tested and finally a set of plants were excavated to measure the same parameters as before planting. Seedlings cultivated using fertilized peat achieved the highest values for all of evaluated parameters. During the third dry season, big seedlings exhibited better physiological status. Therefore, enhanced root growth can result in better water uptake during the dry period thereby increasing survival and growth in the next few years after planting. A feed-back physiological model is proposed to explain P. canariensis establishment in a semiarid environment.