排序方式： 共有23条查询结果，搜索用时 15 毫秒
1.
采用高效液相色谱（HPLC）分析方法,研究了多菌灵在草莓与土壤中的消解动态和最终残留。分析结果表明,多菌灵最低检出浓度为0.05 mg.kg-1,添加浓度在0.05～2.0 mg.kg-1范围内,回收率为81.6%～102.6%,变异系数为1.44%～5.35%。田间试验结果表明,多菌灵推荐浓度和加倍浓度在草莓中的消解动态方程分别为C=3.212 2e-0.1354t、C=8.810 3e-0.1379t,土壤中的消解动态方程分别为C=2.941 1e-0.1011t、C=6.173 3e-0.1144t。多菌灵消解较快,草莓中的消解半衰期为4.2～6.7 d,土壤中的消解半衰期为5.4～7.3 d。加倍浓度和推荐浓度各施药2次,30 d后残留量均降至0.1 mg.kg-1以下,低于多菌灵在果蔬中最大允许残留量（MRL）0.5 mg.kg-1。 相似文献
2.
草莓属高档水果,但采后货架期短,严重影响草莓的品质和价值。为此开展了不同浓度一氧化氮（NO）,不同处理时间对延长草莓货架期的影响研究。结果显示,一氧化氮对延长草莓货架期具有显著作用,具体为：一氧化氮（下同）浓度5～10μL/L,处理2h对延长货架期效果最显著。同时对结果在商业上的应用也进行了探讨。 相似文献
3.
不同配方基质的理化性质及其对草莓生长的影响 总被引：5，自引：0，他引：5
为探究8种不同配比基质的理化性质及其对草莓生长和结果的影响,以草莓为试材,采用草炭、棉花秸秆、菇渣、蛭石和细沙为基质原料,筛选适合草莓栽培的基质配方。结果表明,处理1(V_(草炭)∶V_(棉花秸秆)∶V_(蛭石)=1∶1∶1)为最佳配比,其理化性质理想,栽培的草莓果实硬度、糖酸比、果形指数、株高、茎粗与对照(V_(草炭)∶V_(蛭石)=2∶1)无显著差异,株产量、单果质量、可溶性固形物含量显著高于对照。因此,腐熟后的棉花秸秆可代替部分草炭,草炭、棉花秸秆和蛭石体积比为1∶1∶1的基质可作为一种优质基质在草莓生产上进行推广应用。 相似文献
4.
Hydroponic and field experiments were conducted to assess the optimum nitrogen (N) levels in strawberry leaves for the appropriate management of its N nutrition under field or protected cultivation. Unlike the common view that leaf petiole is the right plant organ to sample for strawberries, the study showed that the leaf blade, of the most recently fully expanded leaf, is more responsive and therefore a better indicator of the N supply changes in the strawberry plant. This was attributed to the distinctive characteristic of strawberry plants to accumulate high concentrations of nitrates in leaf blades when there is luxury consumption of N. 相似文献
5.
以鼠尾藻为原料提取多酚,研究海藻多酚处理对采后草莓腐烂的控制与贮藏品质的影响。结果表明,鼠尾藻海藻多酚单体组成主要为儿茶素、表儿茶素、儿茶酚、阿魏酸和芦丁,其质量浓度分别为1.95,9.60,43.98,0.63,0.23 mg/mL。总酚质量浓度为16 mg/mL的鼠尾藻提取物可100%抑制草莓灰霉菌(Botrytis cinerea)的生长。新鲜草莓经质量浓度10 mg/mL的海藻多酚处理并于(2±1)℃,90%~95%RH贮藏12 d后,其腐烂率和腐烂指数分别比对照低61.6%和52.5%,草莓硬度、可溶性固形物及VC含量均明显高于对照(p<0.05)。在常温刺伤接种和冷藏不接种Botrytis cinerea 2种条件下,海藻多酚处理的草莓苯丙氨酸解氨酶(PAL)和过氧化物酶(POD)活性均明显高于对照(p<0.05)。结果表明,海藻多酚不但具有直接抗菌活性,可控制草莓的采后腐烂,而且能诱导草莓的采后抗病性,提高抗病相关酶活性,从而降低草莓果实的腐烂,保持草莓品质。 相似文献
6.
为开发凝固型混合果汁酸牛奶新品种，进行了果汁杀菌方式及果汁种类，配比与用量的对比试验，结果表明，果汁于８０℃杀菌３０ｍｉｎ，牛奶以ＵＨＴ法杀菌，冷却后混合菠萝民草莓酱的加入量分别占总配料量的２％，能获得色，香，味，形均优于普通酸牛奶和单一果汁酸牛奶的混合果汁酸牛奶。 相似文献
7.
Saara Tuohimetsä Tarja Hietaranta Marjatta Uosukainen Sanna Kukkonen Saila Karhu 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(5):408-415
Tunnel cultivation of berries is increasing on a global basis, and suitable management techniques are being studied for growing berry crops in a protected environment. Soil mulching and irrigation are among the techniques that significantly affect plant growth and yield. Tunnel cultivation is often limited to growing single cultivars, and little attention has been paid to the effects of growing several cultivars in the same tunnel. There are indications that crop yield and quality might benefit from cross-pollination. In this study, the effects of artificial self- and cross-pollination were studied in 15 strawberry and 6 red raspberry cultivars grown in a protected environment in a greenhouse. Four strawberry cultivars benefited from cross-pollination and one required it. In the case of raspberries, self- and cross-pollination had no effect on yield and fruit quality. In conclusion, particular berry cultivars are better suited to tunnel cultivation. 相似文献
8.
Allowable levels for pesticide residues in foods,known as tolerances in the US and as maximum residue limits(MRLs) in much of the world,are widely yet inappropriately perceived as levels of safety concern. A novel approach to develop scientifically defensible levels of safety concern is presented and an example to determine acute and chronic pesticide food safety standard(PFSS) levels for the fungicide captan on strawberries is provided. Using this approach,the chronic PFSS level for captan on strawberries was determined to be 2 000 mg kg–1 and the acute PFSS level was determined to be 250 mg kg–1. Both levels are far above the existing tolerance and MRLs that commonly range from 3 to 20 mg kg–1,and provide evidence that captan residues detected at levels greater than the tolerance or MRLs are not of acute or chronic health concern even though they represent violative residues. The benefits of developing the PFSS approach to serve as a companion to existing tolerances/MRLs include a greater understanding concerning the health significance,if any,from exposure to violative pesticide residues. In addition,the PFSS approach can be universally applied to all potential pesticide residues on all food commodities,can be modified by specific jurisdictions to take into account differences in food consumption practices,and can help prioritize food residue monitoring by identifying the pesticide/commodity combinations of the greatest potential food safety concern and guiding development of field level analytical methods to detect pesticide residues on prioritized pesticide/commodity combinations. 相似文献
9.
Since 1998, the greenhouse whitefly, Trialeurodes vaporariorum Westwood (Homoptera: Aleyrodidae), has emerged as a major insect pest of many horticultural crops in coastal California. Control of this pest has been heavily dependent upon chemical insecticides. Objectives of this study were to determine the status of the greenhouse whitefly susceptibility to neonicotinoid and conventional insecticides on strawberries in Oxnard/Ventura, a year-round intensive horticultural production area of southern California. For bioassay tests, adult whiteflies were collected from commercial strawberry crops, and immatures were directly developed from eggs laid by these adults. LD(50) values of soil-applied imidacloprid, thiamethoxam and dinotefuran were respectively 8.7, 3.2 and 4.9 times higher for the adults, 1.8, 1.2 and 1.5 times higher for the first-instar nymphs and 89.4, 390 and 10.4 times higher for the third-instar nymphs than their top label rates. LC(50) values of foliar-applied imidacloprid, thiamethoxam and acetamiprid were respectively 6.1, 6.0 and 1.7 times higher for the adults and 3.8, 8.7 and 4.4 times higher for the second-instar nymphs than their top label rates. For the adults, LC(90) values of endosulfan, malathion, methomyl, bifenthrin and fenpropathrin were 2.2, 1.2, 1.9, 2.3 and 4.9 times lower than their respective top label rates. Chlorpyrifos was not very effective against the adults, as indicated by its LC(90) being 120% higher than its top label rate. The present results strongly emphasize the need to develop resistance management strategies in the region. 相似文献
10.
Breeding barriers between the cultivated strawberry, Fragaria × ananassa, and related wild germplasm 总被引：1，自引：0，他引：1
Arias E. Marta Elsa L. Camadro Juan C. Díaz-Ricci Atilio P. Castagnaro 《Euphytica》2004,136(2):139-150
Five-hundred interspecific and intergeneric crosses were performed among accessions of the wild strawberries Fragaria vesca(2x), Duchesnea indica (8x), Potentilla tucumanensis (2x) and 9 genotypes of the cultivated strawberry, Fragaria×ananassa (8x), following an incomplete diallele mating design. Crosses between D. indica and F.×ananassa produced many putative hybrids when D. indica was used as female but a few achenes and plants when used as male; therefore, pollen-pistil compatibility relations were
analyzed by fluorescence microscopy in this direction of the cross. Of the genotypic combinations, 78.6% were incompatible
at the stigma level and 17.2% at the first third of the style. Only 3.6% were pollen-pistil compatible and produced fruits
with achenes (seven did not germinate or originated short-lived plants and nine produced normal plants). F.vesca×F.×ananassa crosses produced 35 hybrid achenes but only 14% germinated, yielding short-lived plants; histological analyses revealed that
inviable seeds had less developed (or collapsed) endosperms and smaller embryos than control plump F. vesca seeds. P.tucumanensis was only used as male, with negative results. These species and genera are partially isolated by a complex system of pre-
and post-zygotic barriers. Knowledge of their nature would allow the breeder to devise strategies to put the genetic variability
available in the group into a useful form.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献