共查询到19条相似文献，搜索用时 296 毫秒
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闽东无公害茶园建设技术措施 总被引：2，自引：0，他引：2
茶叶农药残留问题长期以来未予重视，直到1996年12月才着手抓这个问题。1997年全省在宁德、南平、泉州、三明、漳州、福州六地市建立无公害茶园示范点10个，闽东占4个。经过几年来的科学治理、示范、推广，茶园病虫害逐年减少，茶叶质量、产量逐步提高，全市现有无公害茶园13万亩，绿色食品基地2万亩。2000年全市茶叶抽查合格率在87%以上，各县（市）送检合格率达85%以上，具体有：①省技术监督局2000年6月份在宁德市蕉城区和寿宁县分别抽样36批次和20批次，“农残”合格率均为100%；②宁德市技术监督局2000年4月、9月在全市各茶区共抽检茶… 相似文献
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长江流域气候差异对棉花产量和纤维品质的影响 总被引：10，自引：0，他引：10
对长江流域５个主要产棉省中９个市（县）历年气象资料分析，１９９３年（４～１０月）农业气象特点为低温寡照偏涝年型，１９９４年则为高温干旱年型；而对历年产量资料分析结果表明，１９９３年为歉收年，１９９４年为丰收年。就对气候条件敏感性大小而言，霜前皮棉＞皮棉；产量组分中单株结铃＞铃重＞衣分；纤维品质主要物理性能指标间有比强度＞麦克隆值＞２．５％跨长；同时，品种间存在着明显差异，低温阴雨对早熟品种有利，高温干旱对晚熟品种有利，而有的品种如苏棉４号、中棉所１２对气候变化相对不敏感。 相似文献
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海南岛秋季暴雨天气的环流特征和形成机制初探 总被引：1，自引：0，他引：1
对海南岛2000年和2008年两次秋季暴雨的特性和影响系统的分析发现：暴雨的发生、维持和消失主要与大陆冷高、南海低值系统、热带云团活动密切相关，暴雨一般与华南沿海的低空偏东风急流相伴。对流层中层正差动涡度平流和副高南侧的暖平流破坏了海南岛及邻近区域的准地转平衡，动力强迫和热力强迫共同作用激发了次级环流，导致暴雨区上空的垂直运动的发展，促使暴雨增强。对流层中层干冷空气的侵入，正的差动假相当位温平流加剧了大气层结的不稳定，强的风垂直切变更促使对流上升运动的发展，这对暴雨局地的再增强起到了重要作用。可以综合提出 相似文献
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旱涝急转对不同花生品种生理生化指标的影响 总被引：2，自引：0，他引：2
为探讨旱涝急转对花生生理生化的影响,以不同旱涝耐性的3个花生品种中花8号（抗旱）、豫花15（耐涝）和湘花2008（旱涝兼耐）为材料,进行不同梯度的先旱、后涝连续处理,比较不同花生品种的叶片相对含水量,过氧化物酶（POD）、过氧化氢酶（CAT）、超氧化物歧化酶（SOD）、谷胱甘肽还原酶（GR）活性,以及丙二醛（MDA）含量的变化情况。结果表明,在旱、涝急转的胁迫过程中,干旱对叶片相对含水量的影响甚于湿涝。一定强度的旱或涝胁迫总体上均可使花生叶片的4种抗氧化酶POD、SOD、CAT、GR活性提高,随着胁迫的加深活性降低,复水后活性回落至对照水平,且旱甚于涝。MDA含量总体变化趋势是干旱胁迫下各品种花生叶片中MDA含量有所升高,并于复水解除干旱胁迫后恢复至对照水平;而湿涝处理阶段,MDA含量呈直线上升趋势,在胁迫解除后有所降低。中花8号、豫花15、湘花2008等3个花生品种具有显著不同的水分适应性,中花8号抗旱性更强而耐涝性较弱,豫花15抗旱性较弱而耐涝性强,湘花2008抗旱性中等而耐涝性更强,为水分广适性品种。 相似文献
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湖南省安乡县地处洞庭湖区西北部，是一个典型的湖区县，共有5条河流纵贯县境，外洲面积大，外洲上常年植荻（Miscan thus sacchariflorus）4400hm^2。近年来，荻管理机构为了夺取荻高产，往往在6月份采用喷雾器喷施2．4-D丁酯防除以藤本为主的阔叶杂草。由于2．4-D丁酯的挥发性强，极易随空气飘移到附近的棉花等阔叶作物上，从而造成药害。2004年安乡县畜牧场内5．73hm^2棉花因此受害， 相似文献
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暴雨是最重要的灾害性天气之一,对农业生产造成严重影响。对1960—2005年南靖县汛期暴雨气候分析表明,前汛期暴雨主要集中在5月下旬-6月中旬,后汛期暴雨主要出现在8月上旬、8月下旬和9月上旬。汛期暴雨日数的年际变化呈现出3年周期,前汛期与后汛期暴雨日数存在反位相关系,大暴雨日数月际分布呈现双峰型,从20世纪90年代起出现大暴雨的几率明显增大。产生暴雨的天气系统,前汛期主要是低层切变线,后汛期主要是热带气旋。针对南靖县暴雨特征提出了减轻汛期暴雨对农业生产造成危害的具体措施。 相似文献
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在吉林省气候条件下,研究了延迟播种、延期插秧对水稻产量与质量的影响。结果表明,吉林省适宜的播种期为4月12日,适宜的插秧期为5月25日,4月17～27日播种,5月30日至6月10日插秧,产量虽然下降9.57%～15.43%,但是产量能达到8 000 kg/hm2以上,与常规栽培的产量相近。5月2～17日播种,6月15～30日插秧,产量下降34.57%～88.83%,而且单穴穗数、每穗粒数、饱满千粒重、混合千粒重、饱满粒率、经济系数、生物产量、糙米率、精米率、整精米率、胶稠度等随播种期与插秧期的延后而明显下降;垩白率、垩白度明显上升。延迟播种不宜超过4月27日,延期插秧不宜超过6月10日。 相似文献
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《Plant Production Science》2013,16(4):503-513
AbstractIn Abashiri in eastern Hokkaido, Japan, grain yields of winter wheat (Triticum aestivum L. cv. Hokushin) in the western area, with umbric andosol or dystric cambisol soil types, are lower and unstable compared to those in the eastern area, with mostly haplic andosol soil type. The aim of this study was to evaluate yield differences between the eastern and western areas. The vertical root distribution of wheat plants was examined over two seasons in farmers’ fields in both areas by a wall profile method. Plants grown in the western area had shallower root systems than those grown in the eastern area. Poor soil porosity and high soil penetration resistance suppressed the vertical distribution of root systems in umbric andosol and dystric cambisol. Grain yields were not always correlated with the amount and distribution of the root system. Grain yield in the 2004/2005 season was not correlated with root depth index, whereas it was positively correlated in the 2005/2006 season. During the period from heading to maturity (mid June to late July) over the two seasons, grain yield was associated with precipitation more than with temperature and total solar radiation. In the 2005/2006 season, during the late growing stage of wheat, precipitation was extremely low and soils were very dry. The difference in grain yield between the eastern and western areas was significant and negatively related to precipitation during the period from heading to maturity. Significant correlations of yield with sunshine duration and solar radiation from the heading stage to maturity were observed only on haplic andosol. The results suggest that the major factor controlling yearly changes in the difference in grain yield of winter wheat between the eastern and western areas is the difference in photosynthetic ability, which is based on rooting depth and water supply in response to solar radiation during the late growing stage. 相似文献
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本研究分析吉林省西部半干旱地区1971~2015年气候要素变化特征,用Hybrid-Maize模型估算该区域品种熟期(GDD)不同玉米品种的产量潜力。结果表明,该区域近45年温度、降水和日照时数年均变化与玉米生长季变化趋势类似,但生长季变幅与年均值变幅差异较大,且生长季时间序列上突变点明显不同,温度和降水具有滞后性,日照时数具有超前性,其中,生长季温度增幅高于全年温度增幅,但突变时间滞后10年;长期年均降水波动性大,而生长季降水较全年呈现明显上升趋势,且2010年以来生长季均为较湿润阶段。生长季日照时数减少比年均减少趋势慢,为其下降速率的40%。以4月30日为适播期,种植密度60 000株/hm~2时,乾安、洮南、前郭推荐熟期相对较长品种(GDD=1656-1672),扶余、镇赉推荐熟期相对较短品种(GDD为1606和1500)。洮南、扶余、前郭玉米R/V值接近1.0,乾安和镇赉R/V超过1.15,利于获得较高产量。 相似文献
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Crop management plays an important role in the transition from a deepwater rice to a flooded rice production system but information about optimum management strategies are currently lacking. The goal of this study was to determine the effect of planting date and variety on flooded rice production in the deepwater area of Thailand. Two experiments were conducted at the Bang Taen His Majesty Private Development Project in 2009 and 2010 to represent conditions prior to flooding (early rainy season) and after flooding (dry season). The early rainy season crop covered the period from May to October 2009, while the dry season crop covered the period from November 2009 to April 2010. The experimental design was a split plot with four main plots and three sub plots replicated four times. The treatments for the main plot were various planting dates, while the treatments for the sub plots were rice varieties. The dates of the critical developmental phases of rice were recorded and biomass was sampled during the growing period. The collected data were statistically analyzed using ANOVA and treatment means were compared to identify the appropriate plating date and the best variety for the area. The highest average yield was obtained for variety PSL2 across transplanting dates from June 19 to July 23, with an average yield of 3898 kg ha−1. The dry season crop showed that both biomass and yield were affected by the interaction between planting date and variety. The highest yield was obtained for variety PTT1 transplanted on November 9. The research showed that the variety PSL2 is the most suitable variety for early rainy season production with a transplanting date ranging from June 19 to July 23, while the variety PTT1 planted on November 9 was the best management practice for the dry season crop. However, a high yielding flooded rice variety that has a short growth duration is still needed for this area. 相似文献
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气候变化对福建省牧草气候生产潜力的影响 总被引：2，自引：0，他引：2
以福建省为研究区域,研究牧草生产力与气候条件的关系及其对气候变化的响应.结果表明,近50a来,福建省气温呈现升高趋势,平均每10 a升高0.2℃;年降水量变化总体上呈不显著的增加态势;牧草气候生产潜力随年代的变化呈先减后增的趋势;空间上以厦门地区最高,三明地区最低.降水量对福建省牧草气候生产潜力的影响明显高于气温.若未来温度每降低1℃,降水减少1 mm时,牧草气候生产潜力分别降低318.3 kg·hm~(-2)·a~(-1)和22.7 kg·hm~(-2)a~(-1). 相似文献
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《Plant Production Science》2013,16(4):377-390
AbstractThe farmers’ management practices and grain yield were examined in the consecutive 4 cropping seasons from wet season rice (WSR) in 2008 to dry season rice (DSR) in 2010 across upstream, midstream and downstream fields, along two secondary drainage canals (located either upstream or downstream side along the main canal) in the Kamping Puoy Irrigation Rehabilitation area (KPIR). In WSR, standing water depth was much deeper in downstream fields where medium and late maturing varieties were planted from May than in upstream fields where early and early medium maturing varieties were planted later (mostly in July and August). In DSR there was less difference in water conditions between upstream and downstream fields and variation in planting and harvesting time was small. As the area percentage of fields where DSR was introduced increased from 2008 (54%) to 2010 (100%), planting time in WSR was later (e.g., from May to July) with declining proportion of dry seeding method and mid-season tillage. Grain yield was low in DSR, particularly in 2010 (287 and 247 g m-2 in 2009 and 2010 on average, respectively), due to insufficient weed control and small amount of fertilizer, and the yield was lowest in fields which practiced DSR for the first time. Grain yield in WSR (286 and 291 g m-2 in 2008 and 2009 respectively) increased by transplanting, use of high yielding Raing Chey variety, and application of a larger amount of N chemical fertilizer. These findings indicated that the agriculture extension support to farmers, particularly in DSR, is a key important factor for rice yield improvement in KPIR. 相似文献
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阴雨对早稻开花及受精结实的影响 总被引：9，自引：0，他引：9
利用人工模拟阴雨条件在抽穗扬花期对491个早稻品种进行了试验，并在自然阴雨条件下观察了39个品种的表现。在阴雨条件下，水稻开花率、受精率和结实率均明显降低。降雨主要造成开花率和受精率的大幅度下降，遮荫则使退化颖花和批粒增加。相同处理的不同品种之间差异很大，其中以闭花受精品种类型对阴雨适应性最强。并将水稻品种对阴雨的适应性分为5种类型。 相似文献
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Cabbage aphid control on June/July-planted cabbages was studied on four commercial vegetable farms in the Thames Valley and compared with an untreated crop at Silwood Park. At the four commercial sites, where growers followed their normal control practices, counts were made of aphids, their predators and parasites, throughout the cropping season and following the application of foliar insecticide sprays. Although natural enemies appear to be important in producing a mid-season trough in aphid numbers, they are unable to cope with the increase in aphid numbers later in the crop season. This problem of late aphid control is made worse because the effectiveness of foliar treatment also declines. At present, as the use of action thresholds does not seem feasible, it is suggested that improvements should be sought in more effective techniques of granular or foliar application. 相似文献