RESPONSE OF SOYBEAN TO LOWER-CANOPY DEFOLIATION DURING SEEDFILL

1989 ◽  
Vol 69 (1) ◽  
pp. 17-22 ◽  
Author(s):  
B. L. VASILAS ◽  
J. FUHRMANN ◽  
L. E. GRAY
Keyword(s):  
Yield Components ◽  
Field Experiments ◽  
Total Yield ◽  
Brown Spot ◽  
Yield Losses ◽  
Growing Seasons ◽  
Naturally Occurring ◽  
Yield And Yield Components ◽  
Yield Responses ◽  
Pod Number

One of the effects of Septoria brown spot on soybean is accelerated lower-canopy defoliation. Field experiments were conducted in 1986 and 1987 to determine the response of soybean yield and yield components to progressive lower-canopy defoliation during seedfill. Soybean cultivar Williams 82 was machine planted in rows 76 cm wide and hand thinned to a uniform stand of 23 plants m−1. Three treatments were used: controls; defoliated, starting at R5 (beginning seed stage; DEF1), and defoliated, starting 7 d past R5 (DEF2). Defoliation treatments were applied by removing the leaflets and petioles from the lowest three or four leaf-bearing nodes four times at 4-d intervals so that only three or four nodes at the top of the plant remained leaf-bearing when defoliation ceased. Yield and yield components were determined for upper, lower and total nodes. Although the two growing seasons were very different, yield responses to defoliation were similar in both years. On the average, DEF1 reduced seed yield by 18% which is similar to losses that occur when brown spot is induced by inoculation; DEF2 reduced yields by 9% which is similar to yield losses reported for naturally occurring brown spot. Yields of DEF2 exceeded yields of DEF1 because of differences in pod number in 1986 and seeds/pod in 1987. Controls out-yielded DEF2 because of differences in seeds/pod in 1986 and seed size in 1987. The proportion of the total yield contributed by pods found on the upper nodes averaged 76% and was not affected by defoliation.Key words: Glycine max, Septoria glycines, brown spot, leaf loss

CROP-WEED COMPETITION STUDIES IN FABA BEAN (Vicia faba L.) UNDER RAINFED CONDITIONS

2001 ◽  
Vol 49 (3) ◽  
pp. 299-303 ◽  
Author(s):  
A. M. Tawaha ◽  
M. A. Turk
Keyword(s):  
Vicia Faba ◽  
Faba Bean ◽  
Yield Components ◽  
Field Experiments ◽  
Maximum Yield ◽  
Weed Competition ◽  
Growing Seasons ◽  
Yield And Yield Components ◽  
Vicia Faba L ◽  
Crop Weed Competition

Field experiments were conducted during the two growing seasons of 1999 and 2000 at the research farm of the Jordan University of Science and Technology (JUST) to study the effect of the time of weed removal on the yield and yield components of faba bean (Vicia faba L.). Removing weeds from 25 to 75 days after crop sowing led to significantly larger yields than on plots which were not weeded. Maximum yield was obtained in both years when weeds were removed thrice at 25, 50 and 75 days after crop sowing.

scholarly journals Potato (Solanum tuberosum L.) Tuber Yield and Yield Components as Influenced by Different Levels of Nitrogen, Phosphorus and Potassium in Rwanda

2019 ◽  
Vol 39 (03) ◽  
Author(s):  
Adrien Turamyenyirijuru ◽  
Guillaume Nyagatare ◽  
Robert Morwani Gesimba ◽  
Rhoda Jerop Birech
Keyword(s):  
Yield Components ◽  
Field Experiments ◽  
Tuber Yield ◽  
Solanum Tuberosum L ◽  
Block Design ◽  
Yield Potential ◽  
Ecological Zones ◽  
Growing Seasons ◽  
Yield And Yield Components ◽  
Phosphorus And Potassium

Despite potato yield potential, its intensification level remain low in Rwanda, translating into low yield occasioned mainly by the decline in soil fertility. Field experiments were conducted in Birunga, Mudende [L1]) and Buberuka, Rwerere [L2] highlands Agro-Ecological Zones (AEZs), during September- December 2016 and March-June 2017 crop growing seasons to determine the effects of varying rates of N, P and K on potato tuber yield and yield components. The experiments were laid out using randomized complete block design with factorial arrangement, with four replicates. Factors were N rates (NX) i.e N1-0 kg ha-1, N2 – 50 kg ha-1, N3 – 100 kg ha-1 ; P2O5 rates (PX) i.e P1-0 kg ha-1, P2 – 50 kg ha-1, P3 – 100 kg ha-1and K2O rates (Kx) i.e K1- 0 kg ha1and K2- 50 kg ha-1. Number of tubers per plant, fresh tuber weight, small tuber yield, medium tuber yield, large tuber yield and total tuber yield were measured. Analysis of variance, performed using SAS-version 9.2, revealed that interaction effects of N×P×K were very highly significant on all parameters. Generally, N3×P3×K2 performed better than other treatments and recorded highest tuber yields in all situations: (32.73 ± 0.43) t ha-1[L1] and (29.36 ± 0.41) t ha-1 [L2] and (31.05 ± 0.52) t ha-1for pooled ANOVA. Contrarily to what happened at L2, N3P3K2 andN2P3K2 were not significantly different at L1. N2P3 K2 is recommended to L1 whereas N3P3K2 is recommended to L2.

scholarly journals Rattail fescue (Vulpia myuros) interference and seed production as affected by sowing time and crop density in winter wheat

Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Seed Production ◽  
Yield Components ◽  
Field Experiments ◽  
Growing Season ◽  
Sowing Time ◽  
Growing Seasons ◽  
Crop Density ◽  
Wide Range

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.

scholarly journals Changes in Number and Weight of Wheat and Triticale Grains to Manipulation in Source-Sink Relationship

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
E. Ballesteros-Rodríguez ◽  
C. G. Martínez-Rueda ◽  
E. J. Morales-Rosales ◽  
G. Estrada-Campuzano ◽  
G. F. González
Keyword(s):  
Yield Components ◽  
Genetic Improvement ◽  
Wheat Cultivar ◽  
Experimental Manipulation ◽  
Grain Weight ◽  
Agricultural Technology ◽  
Growing Seasons ◽  
Yield And Yield Components ◽  
The Individual ◽  
Source Sink

The source-sink ratio experimental manipulation has helped to define whether a crop is limited by source or sink or co-limited by both. There is no evidence in triticale of source-sink manipulations effects on yield and yield components. Two experiments were accomplished during 2008 and 2009 growing seasons at the Universidad Autónoma del Estado de México, México, and one in 2010 at the National Institute of Agricultural Technology in Pergamino, Argentina. Two triticale cultivars (line 4 and 7) and one wheat cultivar (Tollocan) were used. Source-sink relations were modified at anthesis by thinning, degraining, shading, and total defoliation procedures. Changes in the source-sink relation affected yields in both species differentially. The changes in yield due to cultivars and treatments were explained mainly by the number of grains rather than by their individual grain weight. The number of grains was affected by all treatments in both species, while the individual grain weight was increased by thinning and degraining mainly in triticale. A greater number of fertile florets in triticale were associated with their higher rate of abortion compared to wheat. These results could help to better understand crop management and genetic improvement.

Assessing barley (Hordeum vulgare) response to clipping in the semi-arid Mediterranean climate

2004 ◽  
Vol 44 (1) ◽  
pp. 37
Author(s):  
M. K. J. El-Shatnawi ◽  
N. I. Haddad
Keyword(s):  
Grain Yield ◽  
Yield Components ◽  
Field Experiments ◽  
Grain Weight ◽  
Growing Seasons ◽  
North Eastern ◽  
Pot Trials ◽  
Tiller Density ◽  
Induced Changes ◽  
1000 Grain Weight

Greenhouse pot trials and field experiments were carried out under rain-fed condition in north-eastern Jordan during 1997–98 and 1998–99 growing seasons, to test 3 barley genotypes for their suitability for both forage and grain production. The varieties Rehani and ACSAD176 produced higher forage yields than Rum. In the field, clipping reduced subsequent grain yield per plant by about 18%, lowering grain weight of the main spike from 2.3�g in the control to 1.8 g in the clipped plants. Clipping increased tiller density of barley plants in the field. Decreases in grain yield following clipping could also be attributed to reductions in the number of grains per spike. Clipping decreased the number of grains per spike by about 9% by reducing the number of spikelets per spike. Cutting reduced 1000-grain weight by about 9%. Clipping induced changes in the relative importance of yield components influencing subsequent grain yield. The yield components reduced by clipping were the most important contributors to loss of grain yield.

Yield responses of oats and alfalfa to common hemp-nettle (Galeopsis tetrahit) interference

1991 ◽  
Vol 71 (1) ◽  
pp. 141-147 ◽  
Author(s):  
Anne Légère ◽  
Jean-Marc Deschênes
Keyword(s):  
Field Experiments ◽  
First Year ◽  
Weed Competition ◽  
Yield Losses ◽  
Weed Interference ◽  
Medicago Sativa L ◽  
Lower Height ◽  
Carry Over ◽  
Yield Responses ◽  
Early Harvest

Effects of various densities of hemp-nettle (Galeopsis tetrahit L.) on yields of oats (Avena sativa L.) and first year alfalfa (Medicago sativa L.) were investigated in field experiments. In both crops, emergence of hemp-nettle seedlings occurred after plot establishment such that final densities were generally greater than initial densities. Hemp-nettle plants within a stand were distributed normally over no more than seven 15-cm height classes. Very few plants were found in the lower height classes. Weight distribution according to the same height classes showed that average to tall individuals produced a large proportion of the weed biomass. Oat yields decreased as hemp-nettle density increased. In the density range of 28–248 hemp-nettle plants m−2, oat grain yield losses varied between 12 and 50%. Alfalfa was cut according to either a two-cut regime, or a three-cut regime which included an early harvest. Alfalfa yields decreased with increase in hemp-nettle density regardless of cutting regime, whereas effects of cutting regime on alfalfa yield varied with year of experiment. In each regime, timing of first harvest determined the duration of hemp-nettle interference and may have affected the degree of carry-over effects to later harvests. Key words: Hemp-nettle, Galeopsis tetrahit, weed competition, weed interference, crop losses

EFFECT OF DATES AND RATES OF SOWING ON YIELD AND YIELD COMPONENTS OF NARBON VETCH UNDER SEMI-ARID CONDITIONS

2001 ◽  
Vol 49 (1) ◽  
pp. 103-105 ◽  
Author(s):  
A. M. Tawaha ◽  
M. A. Turk
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Yield Components ◽  
Field Experiments ◽  
Grain Weight ◽  
Arid Conditions ◽  
Yield And Yield Components ◽  
1000 Grain Weight ◽  
Semi Arid ◽  
Northern Jordan

Field experiments were conducted during the winter seasons of 1998–1999 and 1999–2000 at Houfa in northern Jordan, to study the effect of the date and rate of sowing on the yield and yield components of narbon vetch (Vicia narbonensis L.). Progressive delays in sowing beyond 1 st January led to yield reductions of 11.1 and 17.9 at successive 15-day intervals. Plant height, pods stem –1, stems m –2 and 1000-grain weight followed the same trend as the yield. Grain yield was not significantly affected by the sowing rate.

Floret survival in wheat: significance of the time of floret initiation relative to terminal spikelet formation

1982 ◽  
Vol 98 (2) ◽  
pp. 257-268 ◽  
Author(s):  
E. E. Whingwiri ◽  
W. R. Stern
Keyword(s):  
Triticum Aestivum ◽  
Yield Components ◽  
Field Experiments ◽  
Treatment Time ◽  
Vascular System ◽  
Sowing Date ◽  
Nitrogen Application ◽  
Yield And Yield Components ◽  
Individual Grains ◽  
Initiation Period

SUMMARYWheat (Triticum aestivum L.) cv. Gamenya was grown in a Mediterranean type environment in two separate field experiments, to determine the effects of nitrogen application and date of seeding on floret survival. One treatment, intermediate in nitrogen level and sowing date, was common in both experiments. Rates and durations of spikelet initiation and durations of the floret initiation period were estimated. At maturity, yield and yield components were measured and occurrence of individual grains at each floret position on odd-numbered spikelets were recorded. The time of floret initiation relative to terminal spikelet formation and the subsequent occurrence of grain were examined.Florets developed first in spikelets 5-13 and last in spikelet 1. Added nitrogen hastened the initiation of florets but did not affect the number initiated; it also increased the numbers of grains per spikelet. In the last sowing date treatment, time to floret initiation decreased, but the sequence of floret initiation was unaffected.Numbers of florets and grains on tillers were less than on main shoots. Only about 28% of all florets initiated developed into grain.The main conclusion was that the florets which initiated before the terminal spikelet formed grain and those that initiated afterwards did not; we accordingly postulate that the vascular system between the rachis and the floret develops as the floret is initiated, but that after terminal spikelet formation, this is inhibited and further grains then fail to develop.

scholarly journals Shading of the fruit zone to reduce grape yield and quality losses caused by sunburn

OENO One ◽  
2014 ◽  
Vol 48 (3) ◽  
pp. 179 ◽  
Author(s):  
Manuel Oliveira ◽  
José Teles ◽  
Pedro Barbosa ◽  
Francisco Olazabal ◽  
Jorge Queiroz
Keyword(s):  
Water Availability ◽  
Yield Components ◽  
Cost Effective ◽  
Meteorological Conditions ◽  
Yield Losses ◽  
Partial Shading ◽  
Growing Seasons ◽  
Yield And Quality ◽  
Cost Effective Method ◽  
Grape Yield

<p style="text-align: justify;"><strong>Aim</strong>: To test the hypothesis that shading of the fruiting zone of the plants might reduce yield losses caused by excessive exposure to sun while avoiding the most damaging effects associated with reduced radiation.</p><p style="text-align: justify;"><strong>Methods and results</strong>: A number of grapevine rows were shaded with a double layered white plastic netting on their south-facing side, from the ground to about 20 cm above the cluster zone. Data on meteorological conditions, plant growth, plant water availability, yield components and must characteristics were recorded during three growing seasons. Shading significantly increased yield but did not alter significantly the must characteristics.</p><p style="text-align: justify;"><strong>Conclusion</strong>: Partial shading of the grapevine canopy reduced yield losses attributable to excessive radiation. The must obtained from shaded berries had a lower concentration of anthocyanins, and the wines made from these musts had a lighter colour which may be detrimental to their quality.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: The study highlights the effects of solar radiation on the composition of grape musts and suggests a potentially cost-effective method to control excessive radiation in vineyards.</p>

scholarly journals Synergistic effect of P and K interaction on yield and yield components of mungbean (Vigna radiata (L.) Wilczek) varieties

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
E. M. Abd El Lateef ◽  
Asal M. Wali ◽  
M. S. Abd El-Salam
Keyword(s):  
Synergistic Effect ◽  
Seed Yield ◽  
Yield Components ◽  
Field Experiments ◽  
Fertilizer Application ◽  
Yield Component ◽  
Beneficial Effects ◽  
Yield And Yield Components ◽  
Component Traits ◽  
Yield Component Traits

Abstract Background The relation between the macronutrients P and K seems to be synergistic due to the beneficial effects of the interaction between (P × K) and varies according to the variety used. Therefore, two field experiments were conducted during 2018 and 2019 summer seasons to study the effect of interaction of phosphatic fertilization at 0, 37.5 and 75 kg P2O5 ha−1 and potassic fertilization at 0 and 57.6 kg K2O ha−1 on the yield and yield components of two mungbean varieties, viz. Kawmy-l and V2010, as well as determining the relationship between the two nutrients interaction. Results The results showed that there were varietal differences in yield and yield components regardless fertilizer application. Either phosphatic or potassic fertilization significantly increased mungbean yield and yield components traits. Significant effects due to the interaction (V × P) were reported on yield component traits in both seasons. Furthermore, the triple interaction (V × P × K) indicates that synergistic effect was reported for the two varieties and was more clearer for V2010 where it needed both of P and K nutrients to out yield the greatest seed yield ha−1, while Kawmy-1 gave the greatest seed yield ha−1 without K application. Conclusion It could be concluded from this study that mungbean varieties differ in their response to the synergistic interaction effect of P and K and the combination of 75 kg P2O5 + 57.6 kg K2O is preferable for V2010 and 75 kg P2O5 alone for Kawmy-1 to produce the greatest yield.

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