Hunting vulnerability, ecological characteristics and harvest rates of bushmeat species in afrotropical forests

We reviewed and analysed patterns and between-site variation in hunter-kill profiles of mammals in tropical moist forests in west and central Africa. Published data from 36 sites in seven countries were used. A total of 71 mammals from 8 orders and 22 families were hunted. Significant variation was found in number of species exploited, but ungulates constituted 73.2% of all hunted animals. Rodents and primates contributed 12.2% and 12.0%, respectively. Large-bodied species (15.0-99.9 kg) represented over half (54.4%) of the total hunted biomass. Most species were snared, and were generally medium-sized, fast, terrestrial, frugivore-herbivores. By species, we showed using meta-analysis, that abundance was the main predictor of harvest level. But, the relationship between hunter presence (calculated as average hunter numbers operating per 100 days) and hunter ease (an index of catchability of the hunted fauna) and site harvest levels was shown to be significant only for hunter ease. Site harvest rates were higher in areas with more hunter presence. Overall, an average of 2000 carcasses (16,000 kg in weight) per site was extracted in a year. Per hunter, this amounted to 200 carcasses (1000 kg) extracted. Such amounts fall within reported unsustainable harvest levels of the mammalian fauna in African forests.     

不同采收方式对烤烟上部叶片生长及烟碱含量的影响

2005年在长沙以K326为材料研究了一次性采收和分次采收方式对烤烟上部叶生长和烟碱含量的影响，结果表明：不同采收处理对烤烟上部烟叶的生物学特性有一定的影响，同时对烟碱在不同叶位上的积累也有着一定的调控作用。上部烟叶采收次数的增加和留叶数的减少不利于对上部烟叶烟碱的控制，而烤烟上部6叶整体一次性采收，能有效地控制上部烟叶尤其是顶叶烟碱含量过高的问题。     

Comparison of Growth,Pod Distribution and Canopy Structure of Old and New Cultivars of Oilseed Rape ( Brassica napus L.)

Growth, canopy structure and yield components of four selected spring-type cultivars of oilseed rape (Derby, Cyclone, Gulle and Christa) were studied in a field experiment conducted in 1993. Growth analysis was carried out by taking six samples at two-weekly intervals. Area indices of leaves, stems and pods as well as dry matter of plant components were measured. The cultivars showed two different patterns of development and were classified into two groups: old and new cultivars. The first group (Derby and Cyclone) was characterized by short plants, bearing more branches that started branching earlier and on a low position on the stem, while the second group (Gulle and Christa) were characterized by tall plants with thick stems and few branches, starting higher on the stem. Yield could not be directly related to differences in the canopy structure between old and new types. The highest yielding cultivar (Cyclone) belonged to the new category, but the second highest yielding cultivar (Gulle) was of the old type. The study of canopy structure revealed that the pods were distributed evenly on the uppermost branches of the cultivar Cyclone, while for the other cultivars most of the pods were on the main stem, especially in cultivars Gulle and Christa (old group). The cultivars differed significantly in most yield components. In addition to stem and pod development, number of branches and leaf area after anthesis were important characteristics for yield improvement. There were significant differences between cultivars in oil and protein content.     

Peach ripening: Segregation at harvest and postharvest flesh softening

The peach melting flesh cultivars ‘Ryan Sun’ and ‘Sweet September’ and the non-melting, ‘Kakamas’ were harvested according to their visually assessed ground color and divided into four, ripeness classes (M1, M2, M3, and M4). The following aspects were determined: fruit mass, soluble, solids content (SSC), ground skin hue angle (h°) and chroma (C*), the absorbance difference at 670 nm and, 720 nm index (I_AD), and the texture (fruit firmness measured with a needle, flesh firmness measured, with a 7.9 mm plunger, and uniaxial compression strength). Considering that in peaches, the h° of the, ground color and the I_AD are maturity indicators closely associated with ripeness and particularly with, flesh firmness, the texture parameters and their relationship to h° and I_AD were examined. The visual, assessment of the ground color was validated as the criterion for sorting the ripeness levels in peaches, as confirmed by h° and I_AD. Fruit firmness assessed with the needle and that with the 7.9 mm plunger, were highly correlated with each other and with the h° and I_AD, whereas the compression strength, exhibited less correlation with the optical properties of the skin. The non-melting ‘Kakamas’ showed, the poorest correlation between texture and h° and I_AD. Comparing both optical properties, the I_AD, showed a higher correlation with texture features than the h°. In a second experiment, fruit from the M3 ripeness class was maintained in a ripening chamber (20 °C, and 80% RH) until the flesh was softened for consumption. During postharvest, the first two principal, components of a principal component analysis explained 85% of the total variance of the texture, components and the optical properties of the skin. PC1 (67.2%) was defined positively by the texture, parameters and I_AD. The h° of the ground color was negatively related to all texture parameters, and, I_AD. PC2 (17.8%) was associated positively with the juice content, and this parameter proved to be, independent of all others.     

基因型对小麦生物产量和籽粒产量的影响

为了解基因型对小麦生物产量和籽粒产量的影响,选取7个不同基因型的小麦品种(系)作为供试材料,对其生物产量、籽粒产量与收获指数的差异进行了比较研究,并对生物产量与籽粒产量及其构成要素的关系作了分析。结果表明:不同基因型小麦的生物产量、籽粒产量和收获指数均存在差异,镇麦168的生物产量居首位,达到1656.3 g/m2,但其收获指数仅为0.45,导致其籽粒产量不高;宁麦13的生物产量较高,收获指数和籽粒产量均为最高。不同基因型小麦的籽粒产量与生物产量呈正相关关系,每穗实粒数、千粒重与生物产量相关不密切。     

收获期对南方春大豆产量、品质及抗劣变性的影响

通过田间试验,研究了收获期对湖南省主栽的4个春大豆品种产量、品质及抗劣变性的影响。结果表明:在完熟期收获的大豆百粒重和单株粒重均最高;过早收获时种子蛋白质含量、蛋脂总含量低,过迟收获时则脂肪含量低;在成熟期至完熟期收获能获得具有较高发芽势和发芽率的种子;收获期适当提前有利于增强大豆种子的抗劣变性。     

Influence Of Temperature Shift After Flowering on Dry Matter Partitioning In Two Cultivars of Snap Bean (Phaseolus Vulgaris)That Differ In Heat Tolerance

Abstract

The Partitioning of Dry Matter (Ratio of Dry Weight of Individual Parts To That of Total Dry Matter) Was Analyzed In Snap Bean Cultivars, Haibushi, A Heat-Tolerant Cultivar, and Kentucky Wonder, A Heat-Sensitive Cultivar, At Four Temperatures After Flowering on The Subtropical Island of Ishigaki, Japan. The Temperature Regimes Included 27/23ºC (Day/Night) As Normal, 24/20ºC As Low, 30/26 As High, and 33/29ºC As Extremely High. Most Growth Traits Increased After Flowering Time (35 Das), Displaying A Plateau At 68-75 Das. The Total Dry Matter Was Similar Under All Temperature Conditions, But Differed With The Cultivar. Haibushi Had A Higher Value of Total Dry Matter Than Kentucky Wonder, Which Was Mainly Due To Higher Pod Dry Weight Although Stem and Root Dry Weights Were Lower In Haibushi. A Sharp Decline of Dry Matter Partitioning To Pods Was Observed At 33/29 ºC. In The Temperature Range of 24/20 To 30/26ºC, Haibushi Showed Higher Partitioning To Pods Than Kentucky Wonder, Independent of Temperature. on The Other Contrary, Kentucky Wonder Showed Higher Partitioning To Pods At 27/23ºC Than At 24/20ºC. These Results Showed That The Partitioning of Dry Matter, Which Varied With The Cultivar and Temperature, Played An Important Role In Achieving Higher Harvest Index In The Heat-Tolerant Than In The Heat-Sensitive Cultivars.     

甘蔗生产全程机械化技术

随着甘蔗作物种植面积日益扩大,以传统人工、畜力种植、手工收获为主的生产方式已经不能满足农业发展的需要。该文介绍了甘蔗生产全程机械化所涉及的整地种植机械、田间管理机械和收获机械等,从4个方面提出了发展甘蔗生产全程机械化的保障措施。      

艾叶最佳采收时间及水法提取总黄酮工艺研究

[目的]确定艾叶的最佳采收时间,探讨水法提取总黄酮的最佳工艺条件。[方法]以采自河南省洛宁县的艾叶为材料,用水为提取剂对艾叶中的黄酮进行提取,采用三氯化铝比色法测定样品水提液的总黄酮含量,研究料液比、样品粒度、浸提温度及浸提时间对总黄酮浸出率的影响,通过正交试验确定艾叶中总黄酮的最佳提取工艺,并采用该工艺对不同时间采收的艾叶进行总黄酮提取量的测定。[结果]提取艾叶中总黄酮的最佳工艺是：料液比为1：25,浸提温度为90℃,浸提时间为30min;样品粒度为80目。经对不同时间采收的艾叶中总黄酮提取量的测定,确定艾叶的最佳采收时间为每年的8月份。[结论]用水提取艾叶总黄酮,操作简单,方便快速,是一种比较理想的提取方法。     

草莓采收期维生素C含量的测定

[目的]测定草莓中维生素C含量并确定其最佳采收期。[方法]采用直接碘量法测定不同采收时期的20份草莓中维生素c的含量。[结果]草莓中维生素C的含量随其成熟度的增加而增长,其维生素C含量从草莓绿熟期到釜红期由33．79％升高到46．91％,表明草莓的最佳采收期为全红期,该时期的维生素C含量最高,营养价值最丰富。该试验方法的回收率为95．67％-100．08％,表明碘量法是可以测定水果中维生素C含量的,且该方法具有所需试剂少及操作简单等特点。试验的相对标准偏差为0．59％,精密度偏低。[结论]该研究为增加人们对草莓的保鲜常识以及正确食用草莓补充营养素提供了参考。