scholarly journals Ratooned fennel relies on osmoregulation and antioxidants to damp seed yield decline with water limitation

Author(s):  
Morteza Akbari-Kharaji ◽  
Parviz Ehsanzadeh ◽  
Ali Gholami Zali ◽  
Ehsan Askari ◽  
Ahmad Rajabi-Dehnavi
Helia ◽  
2001 ◽  
Vol 24 (34) ◽  
pp. 145-154
Author(s):  
M.A. Khan Shafiullah ◽  
M.A. Poswal ◽  
M.A. Rana ◽  
M.A. Baitullah

SUMMARY Sunflower (Helianthus annuus L.) hybrid NK-212 was planted at National Agricultural Research Center, Islamabad, during 1992 and 1993 to assess the impact of various levels of simulated leaf damage, commonly caused by insects, hail or foliar diseases, on source and sink relationship. Insect attack, hail and foliar diseases often partially defoliate sunflowers and may become important factors limiting the production. Reduction in leaf area may also occur in the field as a consequence of pathogens or atmospheric conditions. Artificial defoliation was chosen as an experimental means to assess its effect on seed yield and plant behavior. It had also made possible to evaluate the effect of such a reduction at different phenological stages and to identify the leaves that contribute greatly to the seed yield. The leaves were clipped in various proportions from different parts of the plant, i.e., lower, middle and upper. The removal of upper 2/3 and 1/2 leaves caused a yield reduction of 29 and 55.8%, in 1992 and 37 and 44.8%, in 1993, respectively. In 1992, about 1% yield decline was recorded when the lower 1/3 leaves were removed and 6% yield decline with the removal of the lower 1/2 leaves. In 1993, the yield reduction was 26.7 and 39.2% due to removal of lower 1/3 and 1/2 leaves, respectively. This indicated that the upper leaves (source) contribute more towards seed yield (sink) than the lower ones. Correspondingly, the results indicated that insects and pests feeding on the upper portion of the sunflower plant can cause larger reduction in seed yield than those feeding on the lower leaves.


2016 ◽  
Vol 107 (2) ◽  
pp. 311
Author(s):  
Kazem Ghassemi-Golezani ◽  
Shabnam Heydari ◽  
Bahareh Ghassemi-Golezani

A field experiment was carried out as split-split plot in 2014 to assess the effects of four irrigation treatments (irrigations after 60, 80, 100 and 120 mm evaporation, respectively) on<strong> </strong>oil and protein changes of maize cultivars (SC704, NS640 and DC303: Late, mid and early maturing cultivars, respectively) at different seed positions on the ear (upper, middle and lower positions on the ear). Overall, the highest seed yield was obtained from SC704, followed by NS640 and DC303 cultivars. Seed yield of all cultivars was higher at lower seed position on ear than at middle and upper parts of the ear under different irrigation treatments. The highest oil and protein yields were also recorded for seeds at lower position on the ear. Seed yield of all maize cultivars at various seed positions decreased with increasing irrigation intervals. Oil percentage decreased, but protein percentage increased with decreasing water availability. Water limitation decreased oil and protein yields of maize cultivars. Changes in protein and oil yields of maize cultivars at different seed positions and irrigation treatments were attributed to changes in seed yield.


2017 ◽  
Vol 44 (1) ◽  
pp. 94 ◽  
Author(s):  
Lucia M. Acosta-Gamboa ◽  
Suxing Liu ◽  
Erin Langley ◽  
Zachary Campbell ◽  
Norma Castro-Guerrero ◽  
...  

Food security is currently one of the major challenges that we are facing as a species. Understanding plant responses and adaptations to limited water availability is key to maintain or improve crop yield, and this is even more critical considering the different projections of climate change. In this work, we combined two high-throughput -‘omic’ platforms (‘phenomics’ and ‘ionomics’) to begin dissecting time-dependent effects of water limitation in Arabidopsis leaves and ultimately seed yield. As proof of concept, we acquired high-resolution images with visible, fluorescence, and near infrared cameras and used commercial and open source algorithms to extract the information contained in those images. At a defined point, samples were also taken for elemental profiling. Our results show that growth, biomass and photosynthetic efficiency were affected mostly under severe water limitation regimes and these differences were exacerbated at later developmental stages. The elemental composition and seed yield, however, changed across the different water regimes tested and these changes included under- and over- accumulation of elements compared with well-watered plants. Our results demonstrate that the combination of phenotyping techniques can be successfully used to identify specific bottlenecks during plant development that could compromise biomass, yield, and the nutritional quality of plants.


2007 ◽  
Vol 58 (8) ◽  
pp. 788 ◽  
Author(s):  
R. A. C. Jones ◽  
B. A. Coutts ◽  
J. Hawkes

Losses in seed yield and quality caused by infection with Beet western yellows virus (BWYV) alone or in combination with direct feeding damage by Myzus persicae (green peach aphid) were quantified in field experiments with Brassica napus (canola, oilseed rape) in the ‘grainbelt’ region of south-western Australia. Plants infected with BWYV and infested with M. persicae were introduced into plots early to provide infection sources and spread BWYV to B. napus plants. Insecticides were applied as seed dressings and/or foliar applications to generate a wide range of BWYV incidences in plots. Colonisation by vector aphids and spread of BWYV infection were recorded in the plots of the different treatments. At sites A (Medina) and B (Badgingarra) in 2001, foliar insecticide applications were applied differentially at first, but, later, ‘blanket’ insecticide sprays were applied to all plots to exclude any direct feeding damage by aphids. When BWYV infection at sites A and B reached 96% and 100% of plants, it decreased seed yield by up to 46% and 37%, respectively. Also, variation in BWYV incidence explained 95% (site A) and 96% (site B) of the variation in yield gaps, where for each 1% increase in virus incidence there was a yield decrease of 12 (site A) and 6 (site B) kg/ha. At both sites, this yield decline was entirely because fewer seeds formed on infected plants. At site B, BWYV infection significantly diminished oil content of seeds (up to 3%), but significantly increased individual seed weight (up to 11%) and erucic acid content (up to 44%); significant increases in seed protein content (up to 6–11%) were recorded at both sites. In field experiments at sites B and C (Avondale) in 2002, insecticides were applied as seed dressings or foliar sprays. At site B, when BWYV incidence reached 98%, the overall yield loss caused by BWYV and direct M. persicae feeding damage combined was 50%. At site C, when BWYV incidence reached 97%, the overall combined yield decline caused by BWYV and direct feeding damage was 46%. This research under Australian conditions shows that, when aphids spread it to B. napus plantings such that many plants become infected at an early growth stage, BWYV has substantial yield-limiting potential in B. napus crops. Although the results represent a worst case scenario, the losses were greater than those reported previously in Europe and are cause for concern for the Australian B. napus industry. When applied at 525 g a.i./100 kg of seed, imidacloprid seed dressing controlled insecticide-resistant M. persicae and effectively suppressed spread of BWYV for 2.5 months and increased seed yield by 84% at site B and 88% at site C. Therefore, provided that mixing the insecticide with seed is sufficiently thorough, dressing seed with imidacloprid before sowing provides good prospects for control of BWYV and M. persicae in B. napus crops.


Agronomy ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 184 ◽  
Author(s):  
Wacal ◽  
Ogata ◽  
Basalirwa ◽  
Sasagawa ◽  
Ishigaki ◽  
...  

Sesame (Sesamum indicum L.) is an important oilseed crop, but is negatively affected by continuous cropping. There is still a lack of information on the effect of continuous cropping on soil chemical properties and mineral nutrition related to sesame growth and yield decline. Therefore, we investigated sesame growth and yield, nutrient concentration and soil chemical properties on five fields with continuous cropping history: non-continuous cropping (Year 0) and durations of two, four, five and six years on an upland field converted paddy in Tottori, Japan. Results show that plant height significantly decreased by 18.76%, 15.22%, and 13.64% in the Year 4, Year 5 and Year 6 fields, respectively, compared to Year 0. The effect of continuous cropping was more pronounced on the 1000-seed weight decline than seed yield. Compared to Year 0, seed yield decreased by 52.86% in Year 2 with no significant differences among the Year 2, Year 4, Year 5 and Year 6 fields, whereas the 1000-seed weight decreased by 6.68% and 12.20% in the Year 2 and Year 5 fields, respectively, compared to Year 0. Plant leaf tissue N concentration significantly decreased in the Year 2, Year 4 and Year 6 fields compared to Year 0, whereas leaf tissue K concentration decreased in the Year 6 field. The increase in duration of continuous cropping years gradually altered soil chemical properties. Soil pH, exchangeable Ca and Mg and cation exchange capacity (CEC) gradually increased in the long duration of continuous cropping, whereas total N and C, exchangeable NH4+-N, urease, dehydrogenase and catalase activities decreased. Our study suggested that the decrease in soil available N and enzyme activities, and decrease in K nutrition due to competitive ion effect as a result of increase in soil Ca and Mg could possibly contribute to the growth and yield decline of continuous sesame on upland field converted paddy.


2018 ◽  
Vol 24 (2) ◽  
Author(s):  
VIMLESH KUMAR TIWARI

Performance of developed genotype RMT 08-2 was evaluated in central, eastern and north-eastern states of India under rain-fed condition for quantitative and qualitative traits. It gave highest seed yield over checks in zone III and V. Morphologically plants were erect, medium spreading in nature and primary branches with dichotomous habit. Plants height ranged from 107124 (cm) which matured in 82-112 days. Mature seeds were round in shape and blackish brown in colour. No significant difference between RVT-2 and checks were observed for test weight trait. An average oil yield 485 (kg/h) was recorded over 7 places which was 10% higher than both checks i.e. 14.12% and 11.24% under AICRP trials. Maximum seed yield was obtained on farmers field during 2013-14 and 2014-15 which was 1500 (kg/h) and 1215 (kg/h) that is 33.42% and 26.30% respectively over farmers own seeds. At Morena center, highest seed yield (1753 kg/h) over Bhawani (1512 kg/h) was 15.94% higher than check whereas RVT-2 gave 2245 (kg/h) against Bhawani (1975 kg/h) which was 13.67% higher. DNA finger printing indicated that primers PUT-19, PUT-96, PUT-149, PUT-169, PUT-181 and PUT-271 are useful in generating unique profile of RVT-2 containing 27 bands for its discrimination from other varieties.


2017 ◽  
Vol 23 (1) ◽  
Author(s):  
A. B. SAGADE

The study of the effect of three well known mutagens, ethyl methane sulphonate (EMS), methyl methane sulphonate (MMS) and gamma rays (GR) on the yield contributing traits of the urdbean variety TPU-4 were carried out in the M3 generation. Effect of selected mutagenic treatments/doses of EMS (0.02, 0.03 and 0.04 M), MMS (0.0025, 0.05 and 0.01 M) and (GR) (30, 40 and 50 KR) on different yield contributing traits like plant height, plant spread, number of pods per plant, pod length, number of seeds per pod, seed yield per plant and 100 seed weight were analyzed in the M3 populations of the variety TPU-4. Seeds of M2 plants and control were harvested separately and sown to raise M3 population.. Genetic variabilty in the mutagen administered M3 progeny of the urdbean variety TPU-4 was analyzed by employing statistical methods. Data on mean values and shift in the mean of seven quantitative traits was evaluated on individual plant basis. The experimental findings revealed that concentrations / dose of the all these mutagens showed inhibitory effect on plant height, number of pods per plant, pod length and number of seeds per pod. Lower concentrations of mutagens exerted a promotory effect on plant spread, 100 seed weight and seed yield per plant while higher concentrations of these mutagens inhibited them to different extent.


Author(s):  
A.J. Cresswell

This paper, as well as being a testimonial to the benefit the writer has received from the Grassland Association, shows how the knowledge of scientists has been used to increase lucerne seed yields by methods of growing resistant cultivars especially for seed production as opposed to growing for hay, silage or grazing. It shows how new cultivars can be multiplied quickly by growing two crops in one year, one in each hemisphere, by using low seeding rates, wide plant spacing and very good weed control. Increased flowering of the crop has been achieved by the use of boron and the choice of time of closing; better pollination has been achieved by the use of more efficient bees - two varieties of which have been imported from North America. Weed and insect pest control and the use of a desiccant at harvest are contributing to a four-fold increase in seed yield, which should double again soon,


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