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江苏仪征低丘岗地营林开发模式优化选择研究 总被引:4,自引:3,他引:4
总结江苏省仪征低丘岗地开发的经济林、用材林等7种营林模式和5种纯板栗与农作物间作模式,评估其生产和经济效益,优化选择出了板栗与茶复合林模式、纯梨园、纯茶园、纯桃园等4种开发营林模式;板栗与山芋 雪菜、板栗与芝麻 胡罗卜、板栗与花生 苕子等3种板栗与农作物间模式。其中板栗与茶,并期板栗与山芋 雪菜等间作模式,可形成高效复合经营开发模式。文内还提出了该市低丘岗地综合治理与开发试点试区的建设原则,发展模式及应实施的集约组装技术。 相似文献
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Synchrony between development of five corn hybrid varieties of various seasonal growing rates (FAO numbers), seasonal flight
pattern of male cotton bollworm, Helicoverpa armigera Hb. (Lepidoptera: Noctuidae), as monitored by pheromone traps, and the subsequent appearance of newly hatched larvae on developing
cobs were studied at Mezőhegyes, South-Hungary, in 2003 and 2004. The phenological stages of corn hybrids were evaluated using
the Iowa State University Scale (R1–R5), the flight of male moths was monitored by large capacity, funnel type of pheromone traps and the appearance of freshly
hatched larvae on developing cobs were counted by visual inspection. The synchrony between the flight peak of male moths and
the peak apperance of L1 larvae on cobs was investigated by cross-correlation. In 2003 (average daily temperatures 20.7°C, average daily relative
humidity 59.9% for the period of 4–18 July) “DK 391”, “DK 443” and “Maraton” hybrid varieties already reached silking stage
(R1) by the time when pheromone traps indicated a peak, at 7 July (peak capture at 3-day intervals 755.5 males/traps). The number
of L1 larvae peaked on developing cobs of these varieties also at 7 July (7.0, 4.0 and 3.8 larvae/50 cobs, respectively). The synchrony
between the flight peak of male moths and the peak appearance of L1 larvae on cobs was proven (LAG = 0). A rather similar trend was observed in “Vilma” hybrid variety: it reached R1 stage at 7 July, and L1 larvae appeared only a few days later (11 July, 3.8 larvae/50 cobs) (LAG = −1). However, “Maxima” hybrid variety reached
R1 stage 1 week later (14 July) than the time of peak captures. Here L1 larvae peaked as late as at 18 July (0.8 larvae/50 cobs), i.e., only after the cob had reached R1 stage (LAG = −3). A reverse order of dates of R1 stage and peak capture was observed in “Maxima” in 2004 (average daily temperatures; 22.5°C, average daily relative humidities
72.6% for the period of 15 July–6 August): it reached R1 stage at 19 July, while peak trap captures were recorded at 6 August (peak capture at 3-day intervals 20.5 males/traps).
L1 larvae were found in the highest numbers on 2 August (1.5 larvae/50 cobs), practically in synchrony with peak caputres (LAG = 0).
“Káma” reached R1 stage in 16 July, and L1 larvae peaked at 2 August (1.3 larvae/50 cobs) (LAG = 0). On the rest of the corn varieties larvae were found only in too
numbers for performing statistical analysis. We conclude that in order to predict the appearance of L1 larvae, the phenological stage of the corn variety and the seasonal flight pattern of moths, as measured by large capacity
pheromone traps, should be considered in combination. If the corn variety already reached R1 stage, L1 larvae appear on cobs as early as the time of peak flight of moths. However, no young larvae appear on cobs despite of high
trap captures, until the corn reaches the R1 stage. These findings are discussed in the view of specifying optimal timing of a pesticide application. 相似文献
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本文描述了利用山杨材制和复合胶合板的研究,研究结果表明,以其优质材料旋切的单板为表层材料,以劣质木材制作的刨花板为芯层材料制作和复合胶合板的主要物理力学性能指标与传统的胶合板板基本相同。 相似文献
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固相萃取-气相色谱-质谱法测定韭菜中16种农药残留 总被引:4,自引:0,他引:4
建立了韭菜中16种农药的多残留分析方法。韭菜样本经微波炉加热处理,乙腈提取,新型固相萃取柱Cleanert TPT净化,以气相色谱-质谱-选择离子监测模式测定。结果表明:微波处理、固相萃取净化可以有效去除基质干扰,16种农药在0.02~2 mg/L范围内线性关系良好;在0.01和0.5 mg/kg两个添加水平下的平均回收率分别在84.6%~124.2%和92.4%~98.5%之间,相对标准偏差 (RSD) 均小于20%;16种农药的检出限(LOD)在1~6 μ g/kg范围内。 相似文献
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鱼藤酮-壳聚糖接枝物农药纳米粒子水分散制剂研究 总被引:1,自引:0,他引:1
通过全天然产物蓖麻油酸酐(RAN)与羧甲基壳聚糖(CMC)的酰化反应,合成了羧甲基壳聚糖接技蓖麻油酸(CMC-g-RA)共聚物。探讨了原料的相对分子质量、 RAN与CMC分子上氨基的物质的量之比、反应温度和溶剂等因素对产物取代度的影响。以CMC-g-RA为载体,通过在中性水中自组装大分子胶束的增溶作用,与植物源农药鱼藤酮(Rot)一起制备了一种新型的农药纳米粒子水分散剂。对其粒径、粒径分布、表面电荷、形态结构和Rot的负载率等物理性能进行了表征,探讨了CMC-g-RA和Rot溶液的浓度对纳米粒子各相关性能的影响。结果表明:所形成的纳米粒子干燥后外观形态呈密实光滑的球状,粒径在200~500 nm之间,具有较窄的粒径分布,表面带负电荷;该纳米粒子的Zeta电位值随CMC-g-RA和Rot质量浓度的升高而增大,在-40~-70 mV之间;Rot的负载率在20%~68%范围内。研究表明,改变Rot和CMC-g-RA溶液的质量浓度配比,可调节纳米粒子的物理性能;控制农药的负载率,有助于调控该新型制剂速效与缓释之间的关系。 相似文献