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- Welsh onions (Allium fistulosum L.) are often affected by stressful environments, such as high light and drought, during summer cultivation, which hinders their growth.
- We used CO2 assimilation, OJIP transient and MR curves to analyse the photosynthetic characteristics of Welsh onion.
- The results showed that single high light stress caused a decrease in the net photosynthesis rate through stomatal limitation, while the single drought treatment and the combined stress induced nonstomatal limitation. FO and FJ increased, Fm decreased, and a distinct K‐phase was induced. High light and drought stress blocked MR transients, leading to a gradual decrease in VPSI and VPSII‐PSI.
- In general, photosynthesis of Welsh onion was inhibited by high light and drought, which destroyed the receptor and donor side of PSII and reduced electron transport capacity of PSII and PSI.
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Soil conservation practices for insect pest management in highly disturbed agroecosystems – a review
Decline in soil health is a serious worldwide problem that decreases complexity and stability of agricultural ecosystems, commonly making them more prone to outbreaks of herbivorous insect pests. Potato (Solanum tuberosum L., Solanaceae) and onion (Allium cepa L., Amaryllidaceae) production is currently characterized by high soil disturbance and heavy reliance on synthetic inputs, including insecticides. Evidence suggests that adopting soil conservation techniques often (but not always) increases mortality and decreases reproductive output for the major insect pests of these important vegetable crops. Known mechanisms responsible for such an effect include increases in density and activity of natural enemy populations, enhanced plant defenses, and modified physical characteristics of respective agricultural habitats. However, most research efforts focused on mulches and organic soil amendments, with additional research needed on elucidating effects and their mechanisms for conservation tillage, cover crops, and arbuscular mycorrhizae. 相似文献
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Jiqiang Zhang Ziru Niu Tianhua Li Yanqiang Wu Rui Xi Yuhua Li Guanghua Li Jialin Hou 《Phyton》2020,89(1):147-166
Considering the current low level of mechanization for domestic green
onion planting and the high labor intensity of artificial planting, a 2ZYX-2 green
onion ditching and transplanting machine, which can complete ditching, ridging,
transplanting, repression, soil covering and other operations, is designed in this
study. The Central Composite test design method was carried out with the speed
of the transplanting machine, the depth of the opener and the horizontal position
of the opener as the experimental factors and with the qualification ratio of
perpendicularity, the variation coefficient of the plant spacing and the
qualification ratio of the planting depth as the test index. Through the analysis of
the model interaction and response surface, the change laws that the influence
the machine’s forward speed, the depth of the opener and the horizontal position
of the opener were studied. The regression model was optimized by
Design-Expert 8.0.6 software, and the accuracy of the predicted results was
verified by experiments. The optimal working parameters showed that the
forward speed of the machine was 0.06 m/s, the depth of the opener was 102 mm,
and the horizontal position of the opener was 29 mm. Under conditions of
optimal working parameters, the qualification rate of the verticality was 86.83%,
the coefficient of variation for the plant spacing was 2.77, and the pass rate of
planting depth was 88.26%. The research related to the thesis can provide a
reference for the mechanized planting of green onion, which is of great
significance to the cost-effectiveness of the green onion industry. 相似文献
7.
Denis S. Willett Camila C. Filgueiras Jan P. Nyrop Brian A. Nault 《Journal of Applied Entomology》2020,144(5):382-387
Onion maggot (Delia antiqua) is an economically important pest of Allium crops in temperate regions throughout the world. Management of this pest is necessary to achieve economic returns and depends on insecticide regimes and cultural management. Current cultural management especially altering planting date, field location and crop rotation depend on monitoring. We evaluated the effect of shape, size, colour and chemical attractants on trap catch of field populations of adult D. antiqua flies in upstate New York. White, large diameter, spherical traps in conjunction with Delia Lure attractant performed the best in attracting and catching D. antiqua adults. These results suggest an improved means of attracting and capturing D. antiqua populations which could be useful in monitoring efforts and development of attract and kill strategies for pest control. 相似文献
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B. G. Howlett M. K. Walker L. E. Newstrom‐Lloyd B. J. Donovan D. A. J. Teulon 《Journal of Applied Entomology》2009,133(7):553-564
Understanding the role of unmanaged arthropod flower visitors as crop pollinators is critical if robust and reliable long‐term alternatives are to be found for honey bee pollination. However, data on pollinator assemblages can be scant. Field observation of crop flower visitors is a common data collection technique but it can be inadequate for species identification and is labour‐intensive if used across many sites. Trapping may reduce this problem, but trap performance and sampling consistency over long distances (sites separated by >100 km) are rarely examined. Window traps were designed to collect flower‐visiting arthropods from peak‐flowering onion (Allium cepa) and pak choi (Brassica rapa var. chinensis) fields across several regions throughout New Zealand. Trap efficacy was evaluated by comparing trapped samples with observations of flower visiting arthropods during the same trapping period, from dawn (6:00 to 7:00 hours) through to dusk (20:00–21:00 hours) at the same locations. Similar types of larger arthropods (length ≥3 mm) were observed and trapped within both crops, with the hymenopteran genera Apidae, Colletidae and Halictidae and the dipteran families Syrphidae, Calliphoridae, Anthomyiidae, Stratiomyidae, Sarcophagidae, Bibionidae, Tachinidae and Muscidae the most commonly recorded. The total counts of these taxa across fields were strongly correlated between the two methods; however, the ratio of trapped to observed individuals could vary greatly between taxa. Trapping allowed more arthropods to be identified to the species level and also helped record more small arthropods (body length <3 mm) when compared with observation. Window traps can be effective for assessing the relative diversity of flower visitor assemblages and the abundance of specific taxa in specific cropping systems at the regional scale, but variation in trap efficiency between arthropod taxa must be assessed for a true measure of assemblage composition. 相似文献
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采用CO2和He-Ne两种激光的三种剂量,分别辐照两个洋葱品种的湿种子,从激光辐照洋葱的变异后代中,经8年多的选育,培育出两个红皮洋葱新品种,2004年经四川省品种委员会审定通过,定名为西葱1号(川审蔬2004020)和西葱2号(川审蔬2004021)。新品种表现出早熟、耐贮存、株形紧凑、早期抽薹率低、产量高、抗病性好等优良性状,符合生产和市场要求,可作为目前生产上种植推广品种。 相似文献
10.
The induction of haploid plants by in vitro gynogenesis is a promising practice in onion breeding. In order to increase the frequency of embryo regeneration and haploid
plant production in Valcatorce INTA, Cobriza INTA and Navidena INTA cultivars, putrescine and CCC were used, either as a component
of the culture media or by spraying or injecting them to the umbels. Additionally, two concentration of gellam gum were tested.
A higher number of gynogenic embryos was achieved by using 7 g dm−3 gellam gum, and this number was not affected by the addition of putrescine to the media. CCC sprayed at the umbels significantly
increased the gynogenic embryo rate, which was more than three times higher than the control. Cobriza INTA showed the highest
induced embryo rate (4.76 %). 相似文献