Physiological studies of competition in Zea mays L: I. Vegetative growth and ear development in maize

1969 ◽  
Vol 72 (2) ◽  
pp. 185-193 ◽  
Author(s):  
Maurice Eddowes

SUMMARYPreliminary field studies were carried out to obtain an understanding of the progress of dry-matter accumulation in maize and its end-point at harvest. Dry-matter accumulation and its partition between morphological parts was affected, at various stages of growth, by competition. For maximum total yield per unit area of land, early and rapid development of leaf area was needed to exploit the relatively high net assimilation rate early in the season. This leaf area should persist as long as possibleto maximize leaf area duration. A high total plant yield, and high yield of the important ear component, by the individual plant, was obtained at a plant population of about 40000 per acre. The photosynthetic area of the ear made no significant contribution to cob weight.

2020 ◽  
Vol 203 ◽  
pp. 02008
Author(s):  
Baifeng Cang ◽  
Hao Jiang ◽  
Rong Ma ◽  
Yunzhe Li ◽  
Jingjing Cui ◽  
...  

In order to study the application of light and simplified cultivation mode in straw returning field. In the experiment, two treatments of straw returning and non-straw returning were used under the light simplified cultivation mode, and the differences of tiller number, dry matter accumulation, leaf area index, chlorophyll and yield were studied. Field cultivation experiments were carried out with Jihong 9 and Jinongda 138. The results showed that the yields of Jihong 9 and Jinongda138 straw returning to the field under the light and simplified cultivation mode were 2.00% and 3.63% higher than those under the non-straw returning mode. The total grain number in the yield components increased by 3.35% and 11.60% respectively. Dry matter increased by 19.70% and 7.66% in mature period. The leaf area index (LAI) and SPAD value in the later period of straw returning were higher than those in the non-straw returning, and the number of effective tillers was lower. Light and simplified cultivation can be used as a new mode of rice high-yield cultivation under straw returning, which improves the total grain number, leaf area index, SPAD value and dry matter in the later stage, and increases rice yield. The yield advantage of Jinongda 138 under straw returning (SJ138) is more significant.


Weed Science ◽  
1993 ◽  
Vol 41 (1) ◽  
pp. 38-45 ◽  
Author(s):  
David T. Patterson

Goatsrue, a perennial legume, is an exotic noxious weed currently found in the United States only in Cache County, Utah. It infests irrigated pastures, alfalfa fields, and noncropland areas. In order to compare their responses to temperature, goatsrue and alfalfa were grown in artificially illuminated controlled-environment chambers in 16 day/night temperature regimes ranging from 15/4 to 36/25 C. Growth analysis was used to evaluate effects of temperature on dry matter accumulation, leaf area production, and biomass allocation. Both species grew best at day/night temperatures of 22/25, 29/ 18, and 29/25 C. Leaf appearance rates were linearly related to mean daily temperature. Goatsrue produced fewer but larger leaves and a greater total leaf area than alfalfa. Biomass partitioning to leaves was greater in goatsrue, whereas partitioning to stems was greater in alfalfa. Response of vegetative dry matter production to temperature closely paralleled response of leaf area duration in both species. Alfalfa generally had a higher net assimilation rate, but the greater leaf area duration of goatsrue resulted in greater dry matter accumulation in this species after 50 d of growth. Overall responses to temperature were similar in the two species. Thus it seems likely that goatsrue could become a much more widely distributed weed in alfalfa.


2013 ◽  
Vol 409-410 ◽  
pp. 314-317
Author(s):  
Heng Jia Zhang

An experiment was conducted to determine the effect of limited water supply on plant height, leaf area, dry matter and net assimilation rate (NAR) of spring maize. The results indicated that limited water supply had little effect on plant height of maize at six-leaf, twelve-leaf, heading and early grain filling except the end of filling. Leaf growth and leaf area expansion were effectively increased at middle and late maize growth stages under limited water supply and the maximum leaf area was maintained at early grain filling to middle filling. In addition, dry matter accumulation of maize in reproductive organs may be promoted by limited water supply. Finally, limited water supply also had great effect on net assimilation rate of maize and the maximum was maintained at six-leaf to twelve-leaf, followed by heading to silking.


2019 ◽  
Vol 48 (4) ◽  
pp. 1001-1010
Author(s):  
Liu Ming ◽  
Bi Ying-Dong ◽  
Li Wei ◽  
Liu Miao ◽  
Wang Ling ◽  
...  

Effects of the interaction of biochar and nitrogen fertilizer on the growth, yield and yield components of soybean were studied in cylindrical tube cultivation. The results showed that proper application of biochar promoted dry matter accumulation and LAI regulation of individual plant, and the regulating effect was greater in the later stage of growth than in the early stage. The dry matter weight per plant and LAI were the highest in C1 treatment with different amount of biochar application. However, with the further increase of the amount of carbon application, the dry matter weight per plant and LAI decreased gradually. The plant height of soybean was reduced by the application of biochar. 750 kg/hm2 of biochar and 42 kg/hm2 of nitrogen were found to be the best combinations for high yield of soybean and the theoretical yield was found to be 3546.9 kg/hm2. The combination of biochar and nitrogen fertilizer affects yield mainly by regulating the number of seed per plant.


Author(s):  
Muhammad Zeeshan Mehmood ◽  
Ghulam Qadir ◽  
Obaid Afzal ◽  
Atta Mohi Ud Din ◽  
Muhammad Ali Raza ◽  
...  

AbstractSeveral biotic and abiotic stresses significantly decrease the biomass accumulation and seed yield of sesame crops under rainfed areas. However, plant growth regulators (such as Paclobutrazol) can improve the total dry matter and seed production of the sesame crop. The effects of the paclobutrazol application on dry matter accumulation and seed yield had not been studied before in sesame under rainfed conditions. Therefore, a two-year field study during 2018 and 2019 was conducted with key objectives to assess the impacts of paclobutrazol on leaf greenness, leaf area, total dry matter production and partitioning, seed shattering, and seed yield of sesame. Two sesame cultivars (TS-5 and TS-3) were treated with four paclobutrazol concentrations (P0 = Control, P1 = 100 mg L−1, P2 = 200 mg L−1, P3 = 300 mg L−1). The experiment was executed in RCBD-factorial design with three replications. Compared with P0, treatment P3 improved the leaf greenness of sesame by 17%, 38%, and 60% at 45, 85, and 125 days after sowing, respectively. However, P3 treatment decreased the leaf area of sesame by 14% and 20% at 45 and 85 days after sowing than P0, respectively. Compared with P0, treatment P3 increased the leaf area by 46% at 125 days after sowing. On average, treatment P3 also improved the total biomass production by 21% and partitioning in roots, stems, leaves, capsules, and seeds by 23%, 19%, 23%, 22%, and 40%, respectively, in the whole growing seasons as compared to P0. Moreover, under P3 treatment, sesame attained the highest seed yield and lowest seed shattering by 27% and 30%, respectively, compared to P0. This study indicated that by applying the paclobutrazol concentration at the rate of 300 mg L−1 in sesame, the leaf greenness, leaf areas, biomass accumulation, partitioning, seed yield, and shatter resistance could be improved. Thus, the optimum paclobutrazol level could enhance the dry matter accumulation and seed production capacity of sesame by decreasing shattering losses under rainfed conditions.


1978 ◽  
Vol 90 (3) ◽  
pp. 569-577 ◽  
Author(s):  
G. O. Iremiren ◽  
G. M. Milbourn

SummaryTotal dry-matter yield of maize silage rose asymptotically as density was increased up to 17 plants/m2. Over the range 11–17 plants/m2, which is generally higher than is used in the U.K., the increase in yield was 1–1·6 t dry matter/ha which can justify the higher seed cost and although there was no adverse affect on time of maturity the risk of lodging increased at the highest density. During the harvest period whilst whole crop dry-matter percentage was rising from 23 to 28%, the ear dry-matter content rose steadily from 29 to 35%, whereas the leaf and stem dry-matter content remained essentially constant and only dried out at a later stage after a frost.Caldera 535 had a higher leaf area index and net assimilation rate than the earlier variety Julia which it outyielded by 15%. The additional yield was mainly stem tissue and the greater vegetative production caused an 11-day delay in reaching the silage stage of maturity (25% crop D.M.). NO differences occurred between density treatments and varieties in the forage quality components considered, namely percentage drymatter digestibility, modified acid-detergent fibre, crude protein and ash. Thus in U.K. conditions, total dry-matter yield exerts an overriding influence on the yields per unit area of these quality constituents. This contrasts with reports from the U.S.A. in which a reduced grain/stover ratio adversely influences silage quality.Removal of the whole ear (including husk and rachis) at an early stage in ear development resulted in a 50% reduction in the final dry-matter yield. In the earless plants, leaf area and net assimilation rate was lower, but the dry-matter content of the leaves and stem was considerably higher, and a marked purple coloration developed indicative of excess starch concentration. These results emphasize the need in maize silage not only for an adequate leaf canopy, best obtained early in the growing season by using high planting density and subsequently by using late maturing varieties, but also for sufficient sink capacity in the ear as well as in the stem fraction.


2011 ◽  
Vol 59 (1) ◽  
pp. 35-45
Author(s):  
E. Sugár ◽  
Z. Berzsenyi

The effect of nitrogen (N) fertilisation on the growth of winter wheat varieties was examined in three diverse years using the functional method of growth analysis. The main plot in the two-factorial, split-plot experiment was the N treatment and the subplot the variety. The wheat varieties Mv Toborzó (extra-early), Mv Palotás (early) and Mv Verbunkos (mid-early) were treated with N rates of 0, 80, 160 and 240 kg N ha−1 (N0, N80, N160, N240). The Hunt-Parsons (HP) program fitted a third-degree exponential function to the dry matter and leaf area data. In 2007 and 2008 dry matter accumulation continued up to the N240 rate and in 2009 to the N160 rate. In all three years the highest value was recorded for Mv Verbunkos (4.62 g plant−1 in 2007, 4.63 g in 2008 and 4.51 g in 2009). The highest value of maximum leaf area (237.5 cm2) was found for Mv Verbunkos in the N240 treatment. The maximum values of leaf area in each N treatment, averaged over years and varieties (cm2 plant−1), were as follows: N0: 86.2; N80: 141.0; N160: 164.0; N240: 173.1. The parameter AGRmean exhibited the highest value (8.04 g day−1 102) in the N160 treatment, while among the varieties Mv Verbunkos had the highest mean value (7.18 g day−1 102). The highest value of RGRmean was achieved by Mv Toborzó in the N160 treatment in 2009 (3.94 g g−1 day−1 102). The value of NARmean increased up to fertiliser rates of N160 and N240, with mean values (g m−1 day−1) of N0: 2.35, N80: 2.44, N160: 2.53 and N240: 2.47. The highest value of NAR (3.29 g m−1 day−1) was obtained for Mv Palotás in the N160 treatment in 2008. On average the greatest value of LARmax was recorded in the N160 treatment (172.8 cm2 g−1), while the highest absolute value (213.6 cm2 g−1) was achieved by Mv Toborzó in 2008. The unfavourable effect of the drought in 2007 was clearly reflected in the values of the growth parameters.


1969 ◽  
Vol 72 (2) ◽  
pp. 203-215 ◽  
Author(s):  
Maurice Eddowes

SUMMARYCompetition among maize plants in the vegetative stage of growth was postponed by application of nitrogen to the seed bed and by maintaining soil moisture near field capacity. The amount of available nitrogen was a critical factor in determining the effect of the competitive balance between nitrogen and light on maize yield. The supply of either affected the capacity of the crop to utilize the other, but ultimately light became the dominant factor.Soil moisture deficits of up to 1.0 in from field capacity, in the early stages of vegetative growth, did not reduce dry-matter accumulation and uptake of nitrogen, but in the absence of weed competition and post-planting cultivation soil moisture losses in the early stages of crop growth may be small.In 1966, maize responded quicker to surface applied than to deep-placed nitrogen and utilized the surface applied nitrogen for dry-matter accumulation more effectively.Provided that there was initially an adequate supply of nitrogen in the seed bed, there appeared to be no advantage to total yield from application of nitrogen top dressings to maize. In the West Midlands, under conditions of adequate nutrient and soil moisture supply, the optimum plant population for commercial production of forage maize was about 40000 per acre.


2017 ◽  
Vol 5 (4) ◽  
pp. 423-429 ◽  
Author(s):  
Mohan Mahato ◽  
Bishnu Bilas Adhikari

A field experiment was conducted under humid subtropical agro-climatic condition of Nepal during rainy season of 2014. The experiment was laid out in to two factor Randomized Complete Block Design with  three replications consisting three drought tolerant rice varieties (Sukhadhan-4, Sukhadhan-5 and Radha-4) and four planting geometry (15 cm × 10 cm, 15 cm × 15 cm, 20 cm × 15 cm and 20 cm × 20 cm). The results revealed that the highest plant height and maximum leaf area index was recorded in planting geometry 15 cm × 10 cm in all growth stages. Whereas, planting geometry 20 cm × 15 cm produced the maximum number of tiller m-2 in all growth stage.  While planting geometry 20 cm × 15 cm and 20 cm × 20 cm produced statistically similar crop growth rate and dry matter accumulation in all stage of growth. Regarding the varieties, Sukhadhan- 4 showed highest plant height up to 75 DAT and plant height was statistically similar to Radha - 4 in 60 and 75 DAT. But maximum number of tiller m-2, leaf area index, crop growth rate and dry matter accumulation were recorded in Sukhadhan – 5 varieties. Int. J. Appl. Sci. Biotechnol. Vol 5(4): 423-429


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