辽宁‘寒富’苹果贮藏后货架期品质变化

该文探讨了辽宁省‘寒富’苹果出库后果实品质的变化。结果表明,贮藏6个月后,常温下,不同产地‘寒富’苹果最佳货架期至少6～9 d,果实平均硬度6.00 kg/cm^2以上,果肉较脆、果汁较多、酸甜适口,时间再长果实便发绵,出库后务必及早销售。可溶性固形物含量在出库后12 d内变化不大,以康平、清河、苏家屯的含量最高,超过12%;庄河、东港最低,为10.4%、10.6%;其他居中。可滴定酸的变化也不大,似有降低的趋势;康平、苏家屯、清河、辽中、义县在0.3%以上、0.4%以下,表现适宜;其他为0.4%以上(含0.4%),有的接近0.5%。     

Proportions of bird damage in tree fruits are higher in low-fruit-abundance contexts

Frugivorous birds impose significant costs on tree fruit growers through direct consumption of fruit and grower efforts to manage birds. We documented factors that influenced tree fruit bird damage from 2012 through 2014 with a coordinated field study in Michigan, New York, and Washington. For sweet cherries, percent bird damage was higher in 2012 compared to 2013 and 2014, in Michigan and New York compared to Washington, and in blocks with more edges adjacent to non-sweet cherry land-cover types. These patterns appeared to be associated with fruit abundance patterns; 2012 was a particularly low-yield year for tree fruits in Michigan and New York and percent bird damage was high. In addition, percent bird damage to sweet and tart cherries in Michigan was higher in landscapes with low to moderate forest cover compared to higher forest cover landscapes. 'Honeycrisp' apple blocks under utility wires were marginally more likely to have greater bird damage compared to blocks without wires. We recommend growers prepare bird management plans that consider the spatial distribution of fruit and non-fruit areas of the farm. Growers should generally expect to invest more in bird management in low-yield years, in blocks isolated from other blocks of the same crop, and in blocks where trees can provide entry to the crop for frugivorous birds.     

苹果糖度近红外光谱小波去噪和iPLS建模

为了提高苹果近红外光谱糖度预测模型的精度,利用多尺度小波去噪法对苹果近红外光谱进行了预处理,并用改进后的间隔偏最小二乘法(iPLS)建立预测模型。应用结果表明,多尺度小波去噪法滤除了原始光谱中的部分噪声,但又保留了原光谱中的主要信息。运用间隔偏最小二乘法对预处理后的光谱建模,其校正时的相关系数rc和校正均方根误差RMSEC分别为0.9635和0.3026,预测时的相关系数rp和预测均方根误差RMSEP分别为0.9214和0.4113,主因子数为5个。结果表明,用多尺度小波去噪和间隔偏最小二乘法所建立的苹果糖度模型不但精度有所提高,而且更加简洁、数据运算量也更少。     

苹果生长期中钙元素含量的测定

[目的]测定苹果生长期中钙元素的含量,研究苹果生长期中含钙量的变化规律。[方法]采用干-湿法分解样品,用火焰原子吸收法测定苹果生长期中钙元素的含量。[结果]结果表明,该方法测定钙元素的回收率为101.0%,相对标准偏差(变异系数)为2.6%。[结论]该法具有快速、简便、灵敏的特点,且操作简便,易于掌握,分析周期短,速度快,干扰容易消除等优点,便于推广应用。     

授粉品种对红富士苹果坐果率及果实品质的影响

分别用国红、高岭、新世界、新红星、秦冠、王林、藤牧一、芳明、桑萨和金冠给红富士苹果授粉,调查各授粉品种对红富士苹果坐果率及果实品质的影响.结果表明:金冠、桑萨、芳明和新红星等适宜做红富士苹果的授粉品种.     

Integrated spectral and image analysis of hyperspectral scattering data for prediction of apple fruit firmness and soluble solids content

Spectral scattering is useful for assessing the firmness and soluble solids content (SSC) of apples. In previous research, mean reflectance extracted from the hyperspectral scattering profiles was used for this purpose since the method is simple and fast, and also gives relatively good predictions. The objective of this study was to improve firmness and SSC prediction for ‘Golden Delicious’ (GD), ‘Jonagold’ (JG), and ‘Delicious’ (RD) apples by integration of critical spectral and image features extracted from the hyperspectral scattering images over the wavelength region of 500-1000 nm, using spectral scattering profile and image analysis techniques. Scattering profile analysis was based on mean reflectance method and discrete and continuous wavelet transform decomposition, while image analysis included textural features based on first order statistics, Fourier analysis, co-occurrence matrix and variogram analysis, as well as multi-resolution image features obtained from discrete and continuous wavelet analysis. A total of 294 parameters were extracted by these methods from each apple, which were then selected and combined for predicting fruit firmness and SSC using partial least squares (PLS) method. Prediction models integrating spectral scattering and image characteristics significantly improved firmness and SSC prediction results compared with the mean reflectance method when used alone. The standard errors of prediction (SEP) for GD, JG, and RD apples were reduced by 6.6, 16.1, 13.7% for firmness (R_pred-values of 0.87, 0.95, and 0.84 and the SEPs of 5.9, 7.1, and 8.7 N), and by 11.2, 2.8, and 3.0% for SSC (R_pred-values of 0.88, 0.78, and 0.66 and the SEPs of 0.7, 0.7, and 0.9%), respectively. Hence, integration of spectral and image analysis methods provides an effective means for improving hyperspectral scattering prediction of fruit internal quality.     

介电特性在番茄和苹果品种识别中的应用

为了探索应用介电特性识别果品品种的方法,对FA189、402、国粹番茄以及红富士、红星苹果的介电特性进行了研究。以10kHz与100kHz下番茄相对介电常数的比值kε以及10kHz下的相对介电常数εr′10作为番茄品种识别的指标,并提出了识别方法,该方法对样品的平均识别率为81%。基于红富士和红星苹果相对介电常数εr′和电阻率ρ的差异,提出将εr′/ρ作为识别苹果品种的指标,该方法对红富士和红星苹果的平均识别率为91%。     

Simulation of nitrogen dynamics in an alluvial sandy soil with drip fertigation of apple trees

Abstract. In order to optimize the management of the N-fertilizer inputs with drip fertigation on sandy-silt soil under apple tree orchard cultivation, we observed in situ: (i) the N and water soil transfers, (ii) the N levels in all leaves, fruits and annual shoots, and (iii) the root distribution. Then we used a mechanistic one-dimensional model (WAVE, Vanclooster et al. , 1994) to quantify the annual parameters of the water and nitrogen balance on a daily basis. The horizontal heterogeneity along the row of the tree-soil-dripper system has been treated with two adjacent compartments: one under the dripper and receiving fertigation and the other outside this zone. N transfers in the tree make it impossible to estimate directly N uptake by roots over time.
The simulated N losses were due to equal amounts of N leaching below 0.9 m deep (9 g N tree⁻¹year⁻¹ and denitrification (7 g N tree⁻¹year⁻¹. The simulated losses of gaseous N were localized predominantly in the compartment under the dripper and showed a higher rate of leaching during the period of N input when the wet conditions and the high NO₃⁻ concentrations were favourable to denitrification. The N-leaching at 0.9 m depth was greatest outside the growing season and was caused by the extension of the N-inputs after the harvest date. This practice, based on the objective to store nitrogen before the period of dormancy does not seem to be justified.     

我国梨腐烂病病原菌的初步鉴定及序列分析

【目的】为了对我国梨腐烂病病原菌进行初步鉴定和序列分析,【方法】从我国15个省(市)梨产区采集腐烂病样品并观察其田间危害症状,通过组织分离法分离获得168份梨腐烂病菌分离株,从中选取72份进行单孢纯化,共获得79份梨腐烂病菌纯化分离株;观察在PDA、25℃黑暗条件下病原菌菌落形态以及产孢体形态,并对其在梨枝条上产生的分生孢子器徒手切片置显微镜下观察其结构特征和分生孢子形态;采用菌丝块接种法测定梨腐烂病菌在‘翠冠’梨离体枝条上的致病力。对部分菌株rDNA-ITS进行PCR扩增、测序,利用BLAST软件与GenBank数据库进行序列相似性分析,并用MEGA 4.1和邻接法构建系统发育树。【结果】根据梨腐烂病菌各分离株在PDA上的菌落形态特征可分为Ⅰ型和Ⅱ型两种菌落类型,不同梨腐烂病菌分离株在PDA上产生多种类型的产孢体,不同梨腐烂病菌菌株在离体梨树枝条上的致病力存在差异,我国梨腐烂病菌的rDNA-ITS核苷酸序列一致率为99.98%~100%,与苹果腐烂病菌分别聚在同一亚组的两个分支。【结论】我国梨腐烂病病原菌存在不同的菌落类型,其rDNA-ITS核苷酸序列分析显示均为V.mali var.pyri。