Growth and yield of highland maize in Mexico

1974 ◽  
Vol 83 (2) ◽  
pp. 213-221 ◽  
Author(s):  
P. R. Goldsworthy ◽  
M. Colegrove
Keyword(s):  
Growth Rate ◽  
Grain Growth ◽  
Growth Rates ◽  
Dry Weight ◽  
Grain Filling ◽  
Growth And Yield ◽  
Weight Changes ◽  
Highland Maize ◽  
Grain Filling Period ◽  
Tropical Varieties

SUMMARYThe growth and yield of five highland varieties of tropical maize were studied. Grain yields were between 4·7 and 8·8 t/ha. Crop growth rates (C) increased to a maximum of between 25 and 35 g/m2/day at silking and then declined. Grain growth rates (maximum 21 g/m2/day) exceeded current C during most of the grain-filling period.After silking, when C exceeded grain growth rate, dry matter accumulated in the stem and husk, resulting in an increase of from 200 to 600 g/m2. Later, as grain growth rate increased and exceeded current C, some of this accumulated material was incorporated into the grain, and stem weight decreased. A comparison of the dry weight changes after flowering in these varieties with those reported for a hybrid that yielded 12 t grain/ha indicates that the smaller yield of the Mexican varieties was associated with smaller grain growth rates and the incorporation into the grain of a smaller fraction of the dry weight produced after flowering. These results suggest that the capacity of the grain ‘sink’ to utilize assimilates limited yields in the tropical varieties.

Growth and yield of lowland tropical maize in Mexico

1974 ◽  
Vol 83 (2) ◽  
pp. 223-230 ◽  
Author(s):  
P. R. Goldsworthy ◽  
A. F. E. Palmer ◽  
D. W. Sperling
Keyword(s):  
Grain Growth ◽  
Growth Rates ◽  
Dry Weight ◽  
Grain Filling ◽  
Growth And Yield ◽  
Weight Increase ◽  
Tropical Maize ◽  
Growing Period ◽  
Grain Filling Period ◽  
Tropical Varieties

SUMMARYThe growth and yield of three tropical varieties of maize were studied at two elevations in Mexico: Poza Rica (60m) and Tlaltizapan (940m). Grain yields were between 3·5 and 8·5 t/ha. The growing period was longer and the crop produced more dry weight and yield at Tlaltizapan than at Poza Rica. Crop growth rates (C) increased to a maximum of about 35 g/m2/day at both sites and then declined. Grain growth rates (maximum 35 g/m2/day) exceeded current C during most of the grain filling period. After silking when C exceeded grain growth, dry matter accumulated in the stem. Later as grain growth increased and exceeded C, some of the accumulated material was incorporated into the grain and stem weight decreased. The dry weight increase after flowering was similar at the two sites, but the grain yield at Tlaltiapan was larger because a larger proportion of the dry weight increase was incorporated into the grain than at Poza Rica. The results indicate that at both sites grain ‘sink’ capacity was limiting yield.

Factors Influencing the Rate and Duration of Grain Filling in Wheat

1977 ◽  
Vol 4 (5) ◽  
pp. 785 ◽  
Author(s):  
I Sofield ◽  
LT Evans ◽  
MG Cook ◽  
IF Wardlaw
Keyword(s):  
Growth Rate ◽  
Grain Yield ◽  
Grain Growth ◽  
Dry Weight ◽  
Grain Filling ◽  
Close Relation ◽  
Grain Number ◽  
Lag Period ◽  
The Difference ◽  
Leaf Photosynthetic Rate

Controlled-environment conditions were used to examine the effects of cultivar and of temperature and illuminance after anthesis on grain setting and on the duration and rate of grain growth. After an initial lag period, which did not differ greatly between cultivars, grain dry weight increased linearly under most conditions until final grain weight was approached. Growth rate per grain depended on floret position within the ear, varied between cultivars (those with larger grains at maturity having a faster rate), and increased with rise in temperature. With cultivars in which grain number per ear was markedly affected by illuminance, light had relatively little effect on growth rate per grain. With those in which grain number was less affected by illuminance, growth rate per grain was highly responsive to it, especially in the more distal florets. In both cases there was a close relation between leaf photosynthetic rate as influenced by illuminance, the rate of grain growth per ear, and final grain yield per ear. The duration of linear grain growth, on the other hand, was scarcely influenced by illuminance, but was greatly reduced as temperature rose, with pronounced effects on grain yield per ear. Cultivars differed to some extent in their duration of linear growth, but these differences accounted for less of the difference in final weight per grain than did those in rate of grain growth. Under most conditions the cessation of grain growth did not appear to be due to lack of assimilates.

The development of barley grain: comparisons between cultivars for growth rate and α-amylase activity

1976 ◽  
Vol 86 (3) ◽  
pp. 603-608 ◽  
Author(s):  
T. J. Riggs ◽  
P. G. Gothard
Keyword(s):  
Growth Rate ◽  
Grain Growth ◽  
Growth Rates ◽  
Amylase Activity ◽  
Spring Barley ◽  
Dry Weight ◽  
Barley Grain ◽  
Absolute Level ◽  
Barley Cultivars ◽  
Days After Anthesis

SummaryGrains from ears of known anthesis time in seven spring barley cultivars were measured for dry weight and α-amylase activity at regular intervals during grain maturation. During the period 10–31 days after anthesis, dry weight increase of the grain was found to be substantially linear in all the cultivars. Comparisons between linear slopes fitted for this phase of growth were found to provide an objective means of comparing grain growth rates in different cultivars.α-Amylase activity per grain reached a peak in all except one cultivar at between 10 and 16 days after anthesis but declined rapidly during the linear phase of grain growth. α-Amylase activity per gram grain dry weight decreased exponentially during this period and transformation of the data to logarithms allowed a substantially linear fit to be made. Slopes for each of the cultivars were compared.Differences were found between cultivars in grain growth rates, total α-amylase activity and rates of fall of α-amylase activity per gram for the period 10–31 days after anthesis. No relationship could be found between grain growth rate and either the absolute level of α-amylase activity achieved in the grain or the rate of fall in activity during development.

Ear branching as a means of increasing grain uniformity in wheat

1972 ◽  
Vol 23 (4) ◽  
pp. 551 ◽  
Author(s):  
HM Rawson ◽  
KN Ruwali
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Grain Growth ◽  
Growth Rates ◽  
Grain Filling ◽  
Size At Maturity ◽  
Grain Number ◽  
Photosynthetic System ◽  
Temperature Changes ◽  
The Relationship

Grain growth was compared in two field-grown wheats, Kalyan Sona, a high-yielding, seinidwarf line with few spikelets per ear and many grains per spikelet, and a branched-eared cultivar with many spikelets, each with few grains. The basis of comparison was the spikelet in Kalyan Sona and the branch in the branched material. Within the central spikelets of the main ear in Kalyan Sona, grain growth rates for the greater part of filling were b > a = c > d > e; final weights per grain for these florets were 42, 40, 37,26, and 12 mg respectively. The gradation in growth rate for the eight grains along the branch in the branched-eared cultivar was relatively small with the consequence that all grains were similar in size at maturity (range 39–43 mg); peak growth rates for all positions were at least as high as for grains a, b, and c in Kalyan Sona. In another cultivar, Triple Dirk, increasing competition for assimilates by reducing the light intensity during grain filling had a differential effect on grains within the spikelet but scarcely on the pattern between spikelets. The relationship between all grains was unaffected by temperature changes. The results are discussed in relation to competition for assimilates between grains, and the suggestion made that a high number of grains per spikelet may not use the available assimilates most efficiently. Ear branching is proposed as a preferable alternative, as this also provides abundant grain sites to utilize assimilates to the potential of the photosynthetic system, yet ensures grain uniformity per ear, regardless of grain number, by having few grains in each spikelet.

scholarly journals Effects of nitrogen on crop development and grain growth of winter wheat in relation to assimilation and utilization of assimilates and nutrients.

1978 ◽  
Vol 26 (2) ◽  
pp. 210-231 ◽  
Author(s):  
J.H.J. Spiertz ◽  
J. Ellen
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Grain Growth ◽  
Grain Filling ◽  
Growth And Yield ◽  
Growth Duration ◽  
Crop Development ◽  
Grain Filling Period ◽  
Growing Conditions ◽  
High Level

Grain growth and yield components of winter wheat cv. Lely were studied in a field experiment in 1976 with 4 rates of N (50, 100, 100 + 50 or 100 + 100 kg N/ha). Growing conditions were characterized by a high level of solar radiation, warmth, ample nutrient supply and no damage by diseases. N raised grain number/m2 from 16 700 to 20 600 and grain yield from 640 to 821 g dry wt./m2. Grain growth duration was short, due to warmth, but the rate of the grain filling was very high (from 24.0 to 29.2 g/m2 day during the effective grain-filling period). A high grain yield was associated with a high grain N content which resulted in a grain protein yield ranging from 63.8 to 107.1 g/m2 with increased N rate from 50 to 200 kg/ha. The carbohydrate demand of the grains was provided by current photosynthesis and relocation of stem reserves. The latter was reflected in a decline of the stem wt. after the mid-kernel filling stage. N and P demands of the grains were supplied by withdrawal from the vegetative organs (leaves, stem, chaff) and to a large extent by post-floral uptake and assimilation. Under the prevailing growing conditions the grains turned out to be very strong sinks for carbohydrate, N and P as shown by the harvest indices. Additional N dressings increased the harvest indices of DN, N and P from 0.40 to 0.48, from 0.75 to 0.81 and from 0.91 to 0.93 resp. It was suggested that a more restricted vegetative crop development at high N levels and a longer duration of root activity, photosynthesis and grain growth after anthesis would considerably favour grain yield. (Abstract retrieved from CAB Abstracts by CABI’s permission)

GRAIN FILLING OF DURUM WHEAT THROUGH ASSIMILATE REMOBILISATION UNDER SEMI-ARID CONDITIONS

2012 ◽  
Vol 49 (2) ◽  
pp. 197-211 ◽  
Author(s):  
K. LATIRI ◽  
J. P. LHOMME ◽  
D. W. LAWLOR
Keyword(s):  
Durum Wheat ◽  
Grain Growth ◽  
Field Experiments ◽  
Grain Filling ◽  
Growth And Yield ◽  
Short Term ◽  
Grain Number ◽  
Growing Seasons ◽  
Grain Filling Period

SUMMARYIn a context of understanding the physiological mechanisms and cultivar traits which could improve durum wheat (Triticum durum) yield in water limited conditions, the paper focuses on the contribution of stored assimilates to grain growth and yield. A conceptual model describing the different fluxes of assimilate during the grain filling period is used together with a dataset from field experiments made in northern Tunisia during two growing seasons and under different conditions of water and nitrogen supply. Three types of behaviour have been encountered in relation to the balance between demand for assimilate and supply. Remobilisation of stored assimilates provides a buffer enabling grain growth to be maintained. Conditions at anthesis play an important role in determining the type of fluxes of assimilates. Grain number also plays a major role in short- or long-term remobilisation and grain number per ear increases short-term remobilisation. In rain-fed conditions, short-term remobilisation allows faster grain growth.

scholarly journals Effect of Time of Tiller Separation on Grain Growth and Seed Yield of Transplant Aman Rice

2013 ◽  
Vol 10 (1) ◽  
pp. 12-19 ◽  
Author(s):  
MA Alam ◽  
MS Sheuly
Keyword(s):  
Growth Rate ◽  
Grain Yield ◽  
Grain Growth ◽  
Seed Yield ◽  
Growth Parameters ◽  
Block Design ◽  
Dry Weight ◽  
Growth And Yield ◽  
Plot Size ◽  
Randomized Complete Block Design

An experiment was carried out to study the effect of time of tiller separation on grain growth and yield of transplant aman rice. The experiment consisted of 3 times of tiller separation viz. tiller separation at 25 (T1), 35 (T2) and 45 (T3) days after transplanting (DAT); and 5 levels of number of tillers kept hill-1 viz. intact hills (K0), 1 tiller kept hill-1 (K1), 2 tillers kept hill-1 (K2), 3 tillers kept hill-1 (K3) and 4 tillers kept hill-1 (K4). The experiment was conducted in randomized complete block design with three replications. The unit plot size was 4 m 2.5 m. With a few exceptions, the highest grain growth parameters like number of panicles hill-1, dry weight panicle-1, number of grains panicle-1, dry weight grain-1 and grain growth rate were observed when tillers were separated at 25 DAT but the lowest values were found at 45 DAT. The grain growth rate decreased with the advance of time. The highest grain yield (5.25 t ha-1) was obtained from tillers separated at 25 days after transplanting (DAT) but the lowest values (4.13 t ha-1) were recorded when tillers were separated at 45 DAT. The maximum grain yield (5.88 t ha-1) was found in intact hills, while the lowest values (2.64 t ha-1) were obtained when 1 tiller kept hill-1. DOI: http://dx.doi.org/10.3329/jsf.v10i1.16274 J Sci Foundation, January-June 2012;10(1):12-19

Effect of Timing of Heat Stress During Grain Filling on Two Wheat Varieties Differing in Heat Tolerance. II. Fractional Protein Accumulation

1996 ◽  
Vol 23 (6) ◽  
pp. 739 ◽  
Author(s):  
PJ Stone ◽  
ME Nicolas
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Grain Growth ◽  
Heat Tolerance ◽  
Grain Filling ◽  
Size Exclusion ◽  
Protein Accumulation ◽  
Wheat Varieties ◽  
Grain Filling Period ◽  
Very High

Short periods of very high temperature (> 35�C) are common during the grain filling period of wheat, and can significantly alter mature protein composition and consequently grain quality. This study was designed to determine the stage of grain growth at which fractional protein accumulation is most sensitive to a short heat stress, and to examine whether varietal differences in heat tolerance are expressed consistently throughout the grain filling period. Two varieties of wheat differing in heat tolerance (cvv. Egret and Oxley, tolerant and sensitive, respectively) were exposed to a short (5 day) period of very high temperature (40�C max, for 6 h each day) at 5-day intervals throughout grain filling, from 15 to 50 days after anthesis. Grain samples were taken throughout grain growth and analysed for protein content and composition (albumin/globulin, monomer, SDS-soluble polymer and SDS-insoluble polymer) using size-exclusion high-performance liquid chromatography. The timing of heat stress exerted a significant influence on the accumulation of total wheat protein and its fractions, and protein fractions differed in their responses to the timing of heat stress. Furthermore, wheat genotype influenced both the sensitivity of fractional protein accumulation to heat stress and the stage during grain filling at which maximum sensitivity to heat stress occurred.

scholarly journals Growth and yield of wheat at different dates of sowing under chrland ecosystem of Bangladesh

2017 ◽  
Vol 14 (2) ◽  
pp. 147-154 ◽  
Author(s):  
MM Kamrozzaman ◽  
MAH Khan ◽  
S Ahmed ◽  
N Sultana
Keyword(s):  
Growth Rate ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Matter ◽  
Block Design ◽  
Grain Filling ◽  
Crop Growth ◽  
Growth And Yield ◽  
Area Index ◽  
Crop Growth Rate

An experiment was conducted at Sadipur charland under Farming System Research and Development Site, Hatgobindapur, Faridpur, during rabi season of 2012-13 and 2013-14 to study the growth and yield performance of cv. BARI Gom-24 as affected by different dates of sowing under Agro-ecological Zone-12 (AEZ-12) of Bangladesh. The experiment was laid out in randomized complete block design with six replications, comprising five different dates of sowing viz. November 5, November 15, November 25, December 5 and December 15. Results reveal that the tallest plant, leaf area index, total dry matter, and crop growth rate were observed in November 25 sown crop and leaf area index, total dry matter and crop growth rate were higher at booting, grain filling, and tillering stages of the crop. Maximum effective tillers hill-1 (3.49), spikes m-2, (311), number of grains spike-1 (42.20) and 1000-grain weight (52.10 g) were produced by November 25 sown crop exhibited the highest grain (4.30 t ha-1) and straw yield (4.94 t ha-1) as well as harvest index (46.88%) of the crop. Lowest performance was observed both in early (November 5) and late sown crop (December 15). The overall results indicated that November 25 sown crop showed better performance in respect of growth and yield of wheat under charland ecosystem of Bangladesh.J. Bangladesh Agril. Univ. 14(2): 147-154, December 2016

Relationships Between RNA–DNA Ratio, Prey Density, and Growth Rate in Atlantic Cod (Gadus morhua) Larvae

1979 ◽  
Vol 36 (12) ◽  
pp. 1497-1502 ◽  
Author(s):  
L. J. Buckley
Keyword(s):  
Growth Rate ◽  
Nutritional Status ◽  
Growth Rates ◽  
Prey Density ◽  
Gadus Morhua ◽  
Slow Growth ◽  
Atlantic Cod ◽  
Larval Fish ◽  
Dry Weight ◽  
Dna And Rna

The protein, DNA, and RNA content of larvae maintained at 1.0 plankter/mL increased at the rates of 9.3, 9.9, and 9.8% per day, respectively, for the 5 wk after hatching. Protein reserves of larvae held at 0 or 0.2 plankters/mL were depleted by 45 and 35%, respectively, prior to death 12–13 d after hatching. Starved larvae had similar protein concentrations (percent of dry weight), lower RNA concentrations, and higher DNA concentrations than fed larvae. Larvae held at higher plankton densities had higher RNA–DNA ratios and faster growth rates than larvae held at lower plankton densities. The RNA–DNA ratio was significantly correlated (P < 0.01) with the protein growth rate. The RNA–DNA ratio appears to be a useful index of nutritional status in larval Atlantic cod (Gadus morhua) and may be useful for determining if cod larvae were in a period of rapid or slow growth at the time of capture. Key words: RNA–DNA ratio, starvation, protein, nucleic acids, growth, larval fish, Atlantic cod

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