scholarly journals Impact of Soil Water Stress at Seed Development Stage on Phenology, Fecundity and Seed Dormancy of Avena sterilis ssp. ludoviciana

Proceedings ◽  
2019 ◽  
Vol 36 (1) ◽  
pp. 1
Author(s):  
Mohammad Ali ◽  
Michael Widderick ◽  
Alwyn Williams ◽  
Steve Adkins
Keyword(s):  
Water Stress ◽  
Seed Development ◽  
Seed Dormancy ◽  
Development Stage ◽  
Wheat Crop ◽  
Wild Oat ◽  
Dry Period ◽  
Avena Sterilis ◽  
Soil Water Stress ◽  
No Till

Wild oat (Avena sterilis ssp. ludoviciana (Durieu) Nyman) is considered the most difficult-to-control winter weed in the northern grain region (NGR) of Australia particularly following the adoption of no-till conservation agriculture and the enhanced reliance on herbicides for weed control. A diversity of survival mechanisms is responsible for its persistence in no-till conservation cropping. Among them long-term, variable seed dormancy is the most important. A number of environmental stresses (for example drought) are known to affect the seed dormancy status. We hypothesized that the increasing frequency of hot and dry period in late winter/early spring season in the NGR might help to mature and shed less dormant wild oat seeds before the wheat crop is harvested. This early shedding of highly germinable seed better aids persistence in no-till conservation cropping systems. Our research showed that soil water stress applied at seed development stage resulted in lower number (16–22% less) of early maturing (5–20 days earlier) less dormant (28% less) seeds compared with control plants. This observation was made for a number of biotypes either coming from within one location or between locations within the NGR. Thus, the frequent hot and dry period at the time of seed development in the NGR is responsible for production of less dormant Avena sterilis ssp. ludoviciana seeds where no-till conservation cropping is helping to retain these seeds on the top soil. Under favourable germination conditions in the following season these less dormant seeds will immediately be available to re-infest the autumn/winter-sown wheat crop.

Dormancy studies in seed of Avena fatua. 13. Influence of drought stress during seed development on duration of seed dormancy

1982 ◽  
Vol 60 (6) ◽  
pp. 1016-1020 ◽  
Author(s):  
Ramma Sawhney ◽  
J. M. Naylor
Keyword(s):  
High Temperature ◽  
Water Stress ◽  
Drought Stress ◽  
Seed Development ◽  
Seed Dormancy ◽  
Pure Line ◽  
Avena Fatua ◽  
Primary Dormancy ◽  
Pure Lines

Plants of genetically dormant (D) and nondormant (ND) pure lines of Avena fatua were exposed to water stress during seed development. In comparison with normally well-watered controls, seeds produced by water-stressed plants exhibited shorter duration of primary dormancy. The magnitude of the effect varied among D families, but was consistently greater than in ND families.It is concluded that the dormancy phenotype of D lines is highly plastic and that the responses to high temperature and water stress are similar in a given pure line.

Herbicidal potential of Aerva javanica to control wild oat in wheat crop

2020 ◽  
Vol 51 (2) ◽  
pp. 177-194
Author(s):  
Al-Ghamdi A.M. ◽  
El-Zohri M
Keyword(s):  
Dry Weight ◽  
Soluble Carbohydrates ◽  
Wheat Crop ◽  
Aqueous Extracts ◽  
Wild Oat ◽  
Culture Experiment ◽  
Allelopathic Potential ◽  
Root Extracts ◽  
Wheat Germination ◽  
Radical Length

We investigated the phytotoxicity of desert cotton (Aerva javanica) extracts on wild oat and wheat. Aqueous extracts from A. javanica roots, leaves and inflorescences collected from Jeddah and Al-Baha regions, Saudi Arabia were used. Generally, the allelopathic potential of water extracts of A. javanica collected from Jeddah were more in inhibitory to wild oat germination and seedlings growth than those from Al-Baha. In both regions, root extracts were inhibitory to wild oat followed by leaves and inflorescences extracts. All test aqueous extracts of both regions did not inhibit the wheat germination or seedlings growth.Whreas, the wild oat germination was reduced by root extracts 58.62 %, 28.62 % leaves extracts : 32.72 %, 17.72 % and inflorescences extract 28.11 %, 12.13 % by in plants samples collected from Jeddah and Al-Baha, respectively. Wild oat radical length was inhibited by root extracts 53.27 %, 32.84 % leaves 42.35 %, 9.63 % and inflorescences extracts 22.64 %, 16.75 % in case of Jeddah and Al-Baha plants, respectively. In pot culture experiment, all treatments markedly reduced the plant dry weight and soluble carbohydrates, proteins and free amino acids contents in wild oat. The differences in the allelopathic potentials of studied A. javanica extracts were related to the qualitative variations in their phytochemicals constituents. Our results showed that A. javanica extracts could be safely used to control wild oat growth in wheat fields after more detsaled research..

scholarly journals Potassium Application Positively Modulates Physiological Responses of Cocoa Seedlings to Drought Stress

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 563
Author(s):  
Esther Anokye ◽  
Samuel T. Lowor ◽  
Jerome A. Dogbatse ◽  
Francis K. Padi
Keyword(s):  
Water Stress ◽  
Soil Water ◽  
Chlorophyll Content ◽  
Electrolyte Leakage ◽  
Seedling Survival ◽  
Biomass Accumulation ◽  
Biomass Partitioning ◽  
Chlorophyll Content And Fluorescence ◽  
Physiological Functions ◽  
Soil Water Stress

With increasing frequency and intensity of dry spells in the cocoa production zones of West Africa, strategies for mitigating impact of water stress on cocoa seedling survival are urgently required. We investigated the effects of applied potassium on biomass accumulation, physiological processes and survival of cocoa varieties subjected to water stress in pot experiments in a gauzehouse facility. Four levels of potassium (0, 1, 2, or 3 g/plant as muriate of potash) were used. Soil water stress reduced plant biomass accumulation (shoot and roots), relative water content (RWC), chlorophyll content and fluorescence. Leaf phenol and proline contents were increased under water stress. Additionally, compared to the well-watered conditions, soils under water stress treatments had higher contents of exchangeable potassium and available phosphorus at the end of the experimental period. Potassium applied under well-watered conditions reduced leaf chlorophyll content and fluorescence and increased leaf electrolyte leakage, but improved the growth and integrity of physiological functions under soil water stress. Potassium addition increased biomass partitioning to roots, improved RWC and leaf membrane stability, and significantly improved cocoa seedling survival under water stress. Under water stress, the variety with the highest seedling mortality accumulated the highest contents of phenol and proline. A significant effect of variety on plant physiological functions was observed. Generally, varieties with PA 7 parentage had higher biomass partitioning to roots and better seedling survival under soil moisture stress. Proportion of biomass partitioned to roots, RWC, chlorophyll fluorescence and leaf electrolyte leakage appear to be the most reliable indicators of cocoa seedling tolerance to drought.

scholarly journals Which Is More Sensitive to Water Stress for Irrigation Scheduling during the Maturation Stage: Grapevine Photosynthesis or Berry Size?

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 845
Author(s):  
Qingtao Zhang ◽  
Yixuan Chen ◽  
Yujiu Xiong ◽  
Shigeoki Moritani ◽  
Xinyu Wu ◽  
...  
Keyword(s):  
Water Stress ◽  
High Efficiency ◽  
Soil Water Potential ◽  
Net Photosynthesis ◽  
Development Stage ◽  
Irrigation Scheduling ◽  
Maturation Stage ◽  
Vitis Vinifera L ◽  
A Value ◽  
Berry Size

To better understand the sensitivity of berry size and grapevine photosynthesis to water stress, and determine the soil water potential (ψ) threshold for scheduling irrigation during the maturation stage, we simultaneously measured berry size with photographs, leaf net photosynthesis with a portable meter, and ψ with tensiometers during the drying cycles for grapevines (Vitis vinifera L.). Our results showed that in berry development stage III (maturation), photosynthesis was more sensitive to water stress than berry size. When ψ decreased beyond −13.2 ± 0.82 kPa, photosynthesis, stomatal conductance, transpiration, and extrinsic (AN/E) and intrinsic (AN/gs) water use efficiency (WUE) decreased rapidly and did not recover thereafter. In contrast, the berry size remained close to unaffected by the decreasing ψ until it reached a value of −16.2 ± 0.77 kPa and, thereafter, the berry shrank significantly. In conclusion, we suggest that during the maturation stage of grapevines, for the potted mixture used in our experiments, irrigation should be triggered when the ψ reaches a value of −13.2 ± 0.82 kPa. Further, ψ should be kept lower than −6.9 ± 0.15 kPa after irrigation, because the highest values of intrinsic WUE (AN/gs) occurred when ψ decreased from −6.9 ± 0.15 to −14.6 ± 0.7 kPa. In arid areas, the threshold ψ should be considered as −16.2 ± 0.77 kPa during maturation to achieve high-efficiency use of water resources and sustainable production of grapevines.

Impact of tillage and landscape position on nitrogen availability and yield of spring wheat in the Brown soil zone in southwestern Saskatchewan

1998 ◽  
Vol 78 (3) ◽  
pp. 563-572 ◽  
Author(s):  
V. Jowkin ◽  
J. J. Schoenau
Keyword(s):  
Spring Wheat ◽  
Nitrogen Availability ◽  
N Uptake ◽  
Wheat Crop ◽  
N Availability ◽  
Inorganic N ◽  
Brown Soil ◽  
Soil Zone ◽  
No Till ◽  
Crop N Uptake

Nitrogen availability to a spring wheat crop was examined in the cropping season in a side-by-side comparison of no-till (first year) and tillage fallow in an undulating farm field in the Brown soil zone in southwestern Saskatchewan. Thirty different sampling points along a grid in each tillage landscape were randomly selected, representing 10 each of shoulder, footslope and level landscape positions. Nitrogen availability was studied i) by profile inorganic N content ii) by crop N uptake and yield of spring wheat (Triticum aestivum L.) and iii) by 15N tracer technique and in situ burial of anion exchange resin membranes (AEM).Pre-seeding available moisture content of the surface soil samples was significantly higher under no-till compared with tillage fallow. However, no significant differences in pre-seeding profile total inorganic N, crop N uptake and yield were observed between the treatments. At the landform scale, shoulder positions of the respective tillage systems had lower profile inorganic N, crop N uptake and yield compared with other slope positions. Soil N supply power, as determined by 15N tracer and AEM techniques, was not significantly different between the tillage treatments, indicating that N availability is not likely to be greatly affected in initial years by switching to no-till fallow in these soils under normal moisture conditions. Key words: Summerfallow, landscape, nitrogen, wheat

scholarly journals Nitrogen fertilization in top dressing for wheat crop in succession to soybean under a no-till system

Bragantia ◽  
2017 ◽  
Vol 76 (2) ◽  
pp. 282-291 ◽  
Author(s):  
Shivelly Los Galetto ◽  
Angelo Rafael Bini ◽  
Adriano Haliski ◽  
Danilo Augusto Scharr ◽  
Paulo Rogério Borszowskei ◽  
...  
Keyword(s):  
Nitrogen Fertilization ◽  
Wheat Crop ◽  
No Till
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