Relationship between sensory and NIR spectroscopy in consumer preference of table grape (cv Italia)

A combination of near infrared spectroscopy (NIR) instrumental measurements and sensory analysis was investigated to predict solids soluble content (SSC, assessed as Brix) and to classify preference in table grape cv Italia. SSC was monitored in each berry of whole bunches in order to evaluate intra-bunch distribution and variability. NIR spectra were recorded in the spectral region 12,000–4000 cm⁻¹ (833–2500 nm) using a set of 682 berries. The Partial Least Square (PLS) model based on cross-validation provided acceptable value for the main statistical parameters (coefficient of determination of cross-validation, r²: 0.85; standard error of cross-validation, SECV: 1.08; residual predictive deviation, RPD: 2.6) and was confirmed by external validation performed with 115 independent berries (coefficient of determination of prediction, r_p²: 0.82; standard error of prediction, SEP: 0.83). For consumer testing, the selected PLS model was used to predict the Brix value in 400 berries and Discriminant Analysis (DA) was then carried out to classify berries in terms of preference by relating NIR data to consumer judgment. The three defined preference clusters of berries were fully classified obtaining 100% membership. In cross-validation the value decreased especially for class 1 (78.5%) and 3 (75%) whereas class 2 obtained comparable values (98.7%). According to our results, NIR technology appears to be a promising technique for predicting SSC and obtaining information with regard to consumer preference in ‘Italia’ table grape for application of efficient and low cost on-line instruments in the fruit industry.     

不同水分胁迫对黄枝槐生理特性的影响研究

为得到黄枝槐最经济、合理的灌溉方式,研究了土壤中不同水分胁迫对黄枝槐生理的影响。采用Licor6400便携式光合仪测定黄枝槐的荧光和光合参数,应用蒽酮比色法测定糖含量,用丙二醛(MDA)与硫代巴比妥酸(TBA)反应测定叶片中MDA含量。结果表明水淹处理15天后,水淹对黄枝槐的生长造成明显影响,表现为qP、ETR、Fv’/Fm’和叶绿素含量均降低,而MDA、可溶性糖含量、qN上升;处理23天后严重影响植物生长及景观效果。处理19后,干旱胁迫组的qP、ETR、Fv’/Fm’、叶绿素含量、单位叶片含水量下降明显,而MDA、可溶性糖含量、qN值上升。中度干旱和轻度干旱处理19天后,使qP、ETR、叶绿素含量,可溶性糖含量有所上升;但中度干旱的Fv’/Fm’略微下降。土壤含水量日变化在18%~30%以内受轻度水分胁迫是园林中刺槐的最佳灌溉方式,不影响生长和景观效果。土壤含水量日变化在8%~18%以内受中度水分胁迫,接近不明显影响景观效果的底线。土壤含水量低于8%严重影响黄枝槐生长和观赏性。黄枝槐在园林应用中应避免超过15天的水淹期。     

Investigating the effects of simulated transport vibration on tomato tissue damage based on vis/NIR spectroscopy

Visible and near infrared (vis/NIR) spectroscopy combined with chemometrics were investigated to evaluate the effects of simulated transport vibration levels on damage of tomato fruit. A total of 280 tomato samples were randomly divided into 5 groups; each group was subjected to vibration at different acceleration levels. A total of 230 samples (46 from each group) were selected as a calibration set; whereas 50 samples (10 from each group) were selected as a prediction set. Raw spectra, differentiation (the first derivative) spectra, extended multiplicative scatter correction (EMSC) processed spectra and standard normal variant combined with detrending (SNV–DT) processed spectra were used for calibration models. SNV–DT processed spectra had the best performance using for partial least squares (PLS) analysis. The PLS analysis was implemented to calibrate models with different wavelength bands including visible, short-wave near infrared (SWNIR) and long-wave near infrared (LWNIR) regions. The best PLS model was obtained in the vis/NIR (600–1600 nm) region. Using a grid search technique and radial basis function (RBF) kernel, four least squares support vector machine (LS–SVM) models with different latent variables (7, 8, 9, and 10 LVs) were compared. The optimal model was obtained with 9 LVs and the correlation coefficient (r), root mean square error of prediction (RMSEP) and bias for the best prediction by LS–SVM were 0.984, 0.137 and 0.003, respectively. The results showed that vis/NIR spectroscopy could be applied as a reliable and rapid method for predicting the effect of vibration levels on tissue damage of tomato fruit.     

加拿大紫荆‘森林火焰’组培快繁技术研究

以紫叶加拿大紫荆（Cercis canadensis ‘Forest Pansy’）当年生嫩枝为试验材料,探讨不同培养基和植物生长调节剂如6-BA、IBA、NAA、TDZ对试管苗增殖以及生根的影响。结果表明：最适增殖培养基为DKW+TDZ 0.03 mg/L+PVP 0.5 mg/L;生根培养基为1/2 MS + IBA 25 mg/L+AC 0.6 mg/L。此体系中增殖系数可达4.27,生根率73.3%。     

Combining the simulation crop model AquaCrop with an economic model for the optimization of irrigation management at farm level

Water resources used in irrigated agriculture are increasingly scarce, particularly in many countries where irrigation has undergone recent expansion. To optimize the limited resources available, optimization models provide useful tools for technical and economic analyses. One of the key inputs of these models is the yield response to water which is often simulated with empirical water production functions. At present, dynamic crop simulation models, such as AquaCrop (Steduto et al., 2009) offer alternative predictions of crop responses to different irrigation strategies as inputs to economic optimization. A model at farm scale was developed and applied to an area in South-western Spain to assist farmers in pre-season decision making on cropping patterns and on irrigation strategies. Yield predictions were obtained from the AquaCrop model which was validated for four different crops. The model simulated the impact on farm income of: (a) irrigation water constraints; (b) variations in agricultural policies; (c) changes in product and water prices; and, (d) variations in the communication to farmers of the specific level of irrigation water allocation. The applications of the models to the study area showed that currently, the changes in cropping patterns induced by the agricultural policy will encourage water savings more than an increase in water prices. Under water restrictions, the best strategy combines planting of low water use crops in part of the area to release water to grow more profitable crops with greater water needs. The model predicted a strong negative impact on farm income of delaying a decision on the level of seasonal water allocation by the water authority, reaching up to 300 € ha⁻¹ in the case of the study area.