scholarly journals Effects of plant density and nitrogen fertilization in winter wheat (Triticum aestivum L.). 2. Incidence of Gerlachia nivalis and Fusarium spp. related to yield losses.

1987 ◽  
Vol 35 (2) ◽  
pp. 155-162
Author(s):  
J. Ellen ◽  
C.J. Langerak
Keyword(s):  
Plant Density ◽  
Triticum Aestivum L ◽  
Yield Losses ◽  
Fusarium Spp ◽  
Severe Attack ◽  
Plant Parts ◽  
Vegetative Plant ◽  
High Plant Density ◽  
Gerlachia Nivalis ◽  
Time Of Harvest

At the low plant density there was more infection by G. [Monographella] nivalis and F. spp. than at the high plant density. In the post-floral period this effect was reflected in a more severe attack of the vegetative plant parts and a greater number of grains being infected at the time of harvest. Delaying the first N dressing and/or the supplementary nitrogen fertilizations at a later stage in the growing season enhanced attack by M. nivalis and F. spp. M. nivalis was the most important; 75% of the attacked grains were infected by it. It is concluded that seed producers should apply nitrogen only in the early stages of plant development, which may reduce considerably the transmission of these pathogens to the new seeds. (Abstract retrieved from CAB Abstracts by CABI’s permission)

The Effects of Plant Density, Spatial Arrangement and Time of Harvest on Yield and Root Size in Carrots

1979 ◽  
Vol 93 (2) ◽  
pp. 431-440 ◽  
Author(s):  
P. J. Salter ◽  
I. E. Currah ◽  
Jane R. Fellows
Keyword(s):  
Plant Density ◽  
Potential Evapotranspiration ◽  
Seedling Emergence ◽  
Spatial Arrangement ◽  
Root Weight ◽  
Root Yield ◽  
High Plant Density ◽  
Plant Arrangement ◽  
Root Size ◽  
Time Of Harvest

SUMMARYFour experiments were carried out over a 2-year period to investigate the effect of plant density and spatial arrangement and the time of lifting on yield and root size of carrots. Plant arrangement was varied by growing the plants in 1-, 2-, 3-, 4-, 5- and 10-row systems in beds with rows 12–5 and 37–5 cm apart. With each row arrangement crops were grown at target densities of 108, 323 and 537 plants/ma. There were three times of harvest. Total root yield was not significantly affected by plant arrangement or, in three out of the four experiments, by plant density but yields progressively increased with later harvests at all density levels. Yields of canning-size roots (20–30 mm diameter) were influenced by plant density and time of harvest and there were highly significant interactions between these variables on canning root yields. Highest absolute yields were obtained from the latest harvests from the medium and high plant density treatments; with the lowest density treatments the highest yields of canners were obtained from the earliest harvests. Mean root weight was significantly affected by plant density and harvest time. Row system effects on mean root weight were shown to be largely accounted for by differences in percentage seedling emergence and hence the plant density obtained under the different row system treatments and a possible reason for this effect is discussed. The relationship between mean root weight and plant density was not affected by the pattern of plant arrangement in these experiments. Total root yields were shown to be related to cumulative potential evapotranspiration from sowing rather than to chronological time. It is concluded that with the range of row systems used in these experiments, row spacing had little effect on root yield but confirmed previous work that plant density and time of harvest were the most important variables controlling mean root size and hence the yield of roots of any particular size grade.

Stem Xylem as a Possible Pathway for Mineral Retranslocation From Senescing Leaves to the Ear in Wheat

1982 ◽  
Vol 9 (2) ◽  
pp. 197 ◽  
Author(s):  
P Martin
Keyword(s):  
Time Course ◽  
Flag Leaf ◽  
Triticum Aestivum L ◽  
Mineral Nutrients ◽  
Potassium Transport ◽  
Short Term ◽  
Plant Parts ◽  
Vegetative Plant ◽  
Nitrogen Retranslocation ◽  
Nitrogen Phosphorus

Retranslocation of mineral nutrients in wheat (Triticum aestivum L. cv. Kolibri) during the development phase from 19-22 days post-anthesis to maturity was investigated in isolated culms (with three leaves attached). From the amounts present in leaves and stem at the time when the culms were detached, 75% nitrogen, 86% phosphorus, 22% potassium, and 37% magnesium were retranslocated from vegetative plant parts to the ear. No calcium was retranslocated from the leaves, but up to 27% calcium in the stem was relocated. Steam girdling of the stem between the flag leaf and the ear did not change the amounts of nitrogen, phosphorus and magnesium retranslocated and transported to the ear but reduced calcium movement slightly. Potassium transport to the ear was, however, almost completely inhibited by the phloem discontinuity induced by steam girdling. The results for nitrogen and potassium were confirmed in short-term experiments (24-48 h) using 15N and 86Rb. In a comparison between girdled culms, it was found that removal or shading of the ear decreased nitrogen retranslocation from the leaves and delayed the time course of leaf senescence. The results show that a continuous connection by sieve elements between leaves as source and grains as sink in wheat is not a prerequisite for retranslocation of nitrogen, phosphorus or magnesium.

Defoliation studies in hybrid maize: II. Dry-matter accumulation, LAI, silking and yield components

1975 ◽  
Vol 85 (2) ◽  
pp. 247-254 ◽  
Author(s):  
R. P. Singh ◽  
K. P. P. Nair
Keyword(s):  
Yield Components ◽  
Dry Matter ◽  
Plant Density ◽  
Grain Weight ◽  
Dry Matter Accumulation ◽  
Area Index ◽  
Leaf Stage ◽  
Plant Parts ◽  
High Plant Density ◽  
1000 Grain Weight

SUMMARYData are presented from an experiment made in two crop seasons, to examine the effects of plant density and degree of defoliation at different stages of growth in maize at Pantnagar, India, on the dry-matter accumulation in different plant parts, leaf area index (LAI), time of silking and grain yield components.Different patterns of dry-matter accumulation in various plant parts was observed. Silking was delayed by increasing plant density. Defoliation (even partial) at the 16th fully expanded leaf stage resulted in substantial reduction in LAI and such yield components as number of ears, ear length, ear diameter and 1000-grain weight. On the other hand, partial defoliation done at the 10th fully expanded leaf stage to simulate an ‘erectophile canopy’ led to yield increases even under high plant density (90000 plants/ha) in the Kharif (rainy season), mainly through an increase in number of ears, 1000-grain weight and grain to stover ratio coupled with a reduction in barrenness and percentage of lodging. It is suggested that an increase in the photosynthetic efficiency per unit area of leaf resulting from the ‘erectophile canopy’ is the reason for these effects.

scholarly journals Effects of plant density and nitrogen fertilization in winter wheat (Triticum aestivum L.). 1. Production pattern and grain yield.

1987 ◽  
Vol 35 (2) ◽  
pp. 137-153
Author(s):  
J. Ellen
Keyword(s):  
Winter Wheat ◽  
Leaf Area ◽  
Plant Density ◽  
N Uptake ◽  
Triticum Aestivum L ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Plant Parts ◽  
Water Soluble Carbohydrates ◽  
Production Pattern

Winter wheat cv. Arminda sown on 8 Oct. 1979 at 45 or 125 kg seed/ha was given 60 kg N/ha between 29 Mar. and 23 May at Zadoks growth stage 22, 27, 30, 31, 32 or 37, and a further 80 kg N/ha on 6 June at Zadoks stage 45. Delay in applying N reduced the number of tillers/plant and increased the number of grains/ear but had little effect on number of grains/msuperscript 2, progressively decreased 1000-grain wt and decreased leaf area per plant, per tiller and per msuperscript 2. Higher shoot wt before anthesis was more closely correlated with final grain wt than with grain number. Main stems and side tillers differed in development, growth rate, leaf area, specific leaf area and ear DM content. N uptake was faster the later the N was applied but the efficiency of that N in DM production was reduced and the N content of vegetative plant parts, particularly at low plant density, and of grain was considerably increased. Contents and amounts of water-soluble carbohydrates in stems, leaves and chaff were generally lower at low plant density. Differences in date of N application resulted in different levels and amounts of water-soluble carbohydrates at ripening. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Biomass, fruit yield, water productivity and quality response of processing tomato to plant density and deficit irrigation under a semi-arid Mediterranean climate

2015 ◽  
Vol 66 (2) ◽  
pp. 224 ◽  
Author(s):  
Cristina Patanè ◽  
Alessandro Saita
Keyword(s):  
Deficit Irrigation ◽  
Plant Density ◽  
Water Productivity ◽  
Fruit Yield ◽  
Full Irrigation ◽  
Yield Losses ◽  
Processing Tomato ◽  
High Plant Density ◽  
Dry Biomass ◽  
Semi Arid

A 2-year study was conducted to examine the impact of deficit irrigation on dry biomass, water-use efficiency (WUE), fruit yield and quality in open-field processing tomato at high plant density in a semi-arid environment. Three irrigation treatments (nil; and 100% (full) and 50% (deficit) restoration of crop evapotranspiration (ETc), respectively) and two plant densities (2.5 (P1) and 5.0 (P2) plants m–2) were studied. Dry biomass and fruit yield per plant were lower in P2 than in P1, but at high plant density the crop compensated for biomass and yield decrease at the plant level. Fruit yield in P2 was greater than that in P1, by 36% in 2004 and 33% in 2005. Water limitation improved quality traits compared with full irrigation. Deficit irrigation, especially in P2, enhanced WUE and allowed a water saving of >45% relative to full irrigation, while keeping high levels of fruit quality. The yield response factor, Ky, which correlates relative fruit yield losses to relative ETc reduction, was higher (0.63) than Kss (0.44), which correlates relative total dry biomass losses to relative ETc reduction, revealing a greater crop sensitivity to soil-water deficit in terms of fruit yield than dry biomass. Therefore, Ky may of use in identifying the plant density at which water productivity is maximised or yield losses are minimised.

scholarly journals Optimizing Planting Density and Impact of Panicle Types on Grain Yield and Microclimatic Response Index of Hybrid Rice (Oryza sativa L.)

2021 ◽  
Author(s):  
Guotao Yang ◽  
Xuechun Wang ◽  
Farhan Nabi ◽  
Hongni Wang ◽  
Changkun Zhao ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Light Intensity ◽  
Grain Yield ◽  
Hybrid Rice ◽  
Plant Density ◽  
Oryza Sativa L ◽  
Planting Density ◽  
Response Index ◽  
Lower Position ◽  
High Plant Density

AbstractThe architecture of rice plant represents important and complex agronomic traits, such as panicles morphology, which directly influence the microclimate of rice population and consequently grain yield. To enhance yield, modification of plant architecture to create new hybrid cultivars is considered a sustainable approach. The current study includes an investigation of yield and microclimate response index under low to high plant density of two indica hybrid rice R498 (curved panicles) and R499 (erect panicles), from 2017 to 2018. The split-plot design included planting densities of 11.9–36.2 plant/m2. The results showed that compared with R498, R499 produced a higher grain yield of 8.02–8.83 t/ha at a higher planting density of 26.5–36.2 plant/m2. The response index of light intensity and relative humidity to the planting density of R499 was higher than that of R498 at the lower position of the rice population. However, the response index of temperature to the planting density of R499 was higher at the upper position (0.2–1.4%) than at the lower position. Compared with R498, R499 at a high planting density developed lower relative humidity (78–88%) and higher light intensity (9900–15,916 lx) at the lower position of the rice population. Our finding suggests that erect panicles are highly related to grain yield microclimatic contributors under a highly dense rice population, such as light intensity utilization, humidity, and temperature. The application of erect panicle rice type provides a potential strategy for yield improvement by increasing microclimatic conditions in rice.

scholarly journals Survival and Inoculum Production of Gibberella zeae in Wheat Residue

Plant Disease ◽  
2004 ◽  
Vol 88 (7) ◽  
pp. 724-730 ◽  
Author(s):  
S. A. Pereyra ◽  
R. Dill-Macky ◽  
A. L. Sims
Keyword(s):  
Management Strategies ◽  
Soil Surface ◽  
Triticum Aestivum L ◽  
Gibberella Zeae ◽  
Effective Management ◽  
Head Blight ◽  
Fusarium Spp ◽  
Residue Decomposition ◽  
Inoculum Production ◽  
Mesh Bags

Survival and inoculum production of Gibberella zeae (Schwein.) Petch (anamorph Fusarium graminearum (Schwabe)), the causal agent of Fusarium head blight of wheat and barley, was related to the rate of wheat (Triticum aestivum L.) residue decomposition. Infested wheat residue, comprising intact nodes, internodes, and leaf sheaths, was placed in fiberglass mesh bags on the soil surface and at 7.5- to 10-cm and 15- to 20-cm depths in chisel-plowed plots and 15 to 20 cm deep in moldboard-plowed plots in October 1997. Residue was sampled monthly from April through November during 1998 and every 2 months through April to October 1999. Buried residue decomposed faster than residue placed on the soil surface. Less than 2% of the dry-matter residue remained in buried treatments after 24 months in the field, while 25% of the residue remained in the soil-surface treatment. Survival of G. zeae on node tissues was inversely related to the residue decomposition rate. Surface residue provided a substrate for G. zeae for a longer period of time than buried residue. Twenty-four months after the initiation of the trial, the level of colonization of nodes in buried residue was half the level of colonization of residue on the soil surface. Colonization of node tissues by G. zeae decreased over time, but increased for other Fusarium spp. Ascospores of G. zeae were still produced on residue pieces after 23 months, and these spores were capable of inducing disease. Data from this research may assist in developing effective management strategies for residues infested with G. zeae.

Nitrogen reduction in high plant density cotton is feasible due to quicker biomass accumulation

2021 ◽  
Vol 172 ◽  
pp. 114070
Author(s):  
Zhao Zhang ◽  
Muhammad Sohaib Chattha ◽  
Shoaib Ahmed ◽  
Jiahao Liu ◽  
Anda Liu ◽  
...  
Keyword(s):  
Plant Density ◽  
Biomass Accumulation ◽  
Nitrogen Reduction ◽  
High Plant Density
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