SEASONAL DRY-WEIGHT DISTRIBUTION OF SINGLE-STALKED AND MULTI-TILLERED CORN HYBRIDS GROWN AT THREE POPULATION DENSITIES IN SOUTHERN ALBERTA

1977 ◽  
Vol 57 (4) ◽  
pp. 1041-1047 ◽  
Author(s):  
D. J. MAJOR

Dry weights of component parts of the main stalk and tillers of corn (Zea mays L.) were determined for a multi-tillered hybrid, Stewart Multi G, and single-stalked hybrids, United UH 106 and Warwick SL 209, in 1974 and 1975. The hybrids were grown under irrigation at 35, 70, and 115 thousand plants/ha at Lethbridge, Alberta. Intrarow spacings equalled interrow spacings. At the end of the season, the multi-tillered hybrid had higher total yields at 35,000 plants/ha man single-stalked hybrids because of its large tillers but the single-stalked hybrids had a higher grain content than the multi-tillered hybrid. Tillers developed early in the season, but the number of tillers per plant decreased after reaching a maximum in late July, presumably due to population-density stresses. Decreases in tiller and stalk dry weight at the end of the season may have been due to translocation of carbohydrates to the main stalk and kernels.

1992 ◽  
Vol 72 (4) ◽  
pp. 1163-1170 ◽  
Author(s):  
B. C. Liang ◽  
A. F. MacKenzie ◽  
M. Remillard

The increase in area for corn production in eastern Canada has stimulated the search for improvements in corn management practices to obtain higher yields. The purpose of this study was to investigate the effects of maize (Zea mays L.) hybrids, plant population density, rates of fertilization and irrigation on grain yield. A field experiment was conducted on a Chicot sandy clay loam soil in Quebec from 1984 to 1986. Corn attained grain yields of 10.9–15.2 Mg ha−1. These yields were attained only when all management inputs were at optimum levels. No single hybrid was superior over the 3-yr-period. High plant population densities, if not accompanied by other inputs, decreased yields. In moist, cooler years, effects of management factors were reduced, and only high plant population densities seemed to increase production. High rates of fertilization increased yields only when other management levels were high.Key words: Population density, irrigation, fertilization, hybrid, Zea mays, grain


1988 ◽  
Vol 68 (4) ◽  
pp. 935-940 ◽  
Author(s):  
M. TOLLENAAR ◽  
T. W. BRUULSEMA

The response of rate and duration of kernel dry matter accumulation to temperatures in the range 10–25 °C was studied for two maize (Zea mays L.) hybrids grown under controlled-environment conditions. Kernel growth rates during the period of linear kernel growth increased linearly with temperature (b = 0.3 mg kernel−1 d−1 °C−1). Kernel dry weight at physiological maturity varied little among temperature treatments because the increase in kernel growth rate with increase in temperature was associated with a decline in the duration of kernel growth proportional to the increase in kernel growth rate.Key words: Zea mays L, period of linear kernel dry matter accumulation, controlled-environment conditions, kernel growth rate


2015 ◽  
Vol 67 (3) ◽  
pp. 993-1000 ◽  
Author(s):  
Lydia Shtereva ◽  
Roumiana Vassilevska-Ivanova ◽  
Tanya Karceva

An experiment was carried out hydroponically under laboratory conditions to investigate the effect of salt stress on several physiological and biochemical parameters of three sweet corn (Zea mays L. var. saccharata) genotypes: lines 6-13, C-6 (pollen source) and their heterotic F1 hybrid ?Zaharina?. The degree of salinity tolerance among these genotypes was evaluated at three different sodium chloride (NaCl) concentrations: 0 mM, 100 mM, 125 mM and 150 mM. Seed germination, plant growth and biochemical stress determining parameters such as malondialdehyde (MDA), proline content and hydrogen peroxide (H2O2) levels were compared between seedlings of lines and hybrid. The obtained results indicated that both lines and hybrid have similar responses at different salinity levels for all examined traits. All the seedlings? growth parameters, such as germination percentage, root length, shoot length, root and shoot fresh and dry weight, decreased with increasing salinity level. MDA, proline and H2O2 increased at different saline conditions in comparison to the control. Based on the results, of the three genotypes examined, the hybrid Zaharina, followed by line C-6, was more salt-sensitive than line 6-13 in salt stress condition.


1977 ◽  
Vol 28 (4) ◽  
pp. 417 ◽  
Author(s):  
R Marchant ◽  
WD Williams

Quantitative samples of P. zietziana were taken monthly for two years from Pink Lake and Lake Cundare. Shrimps were usually contagiously distributed. To reduce error, samples were stratified resulting in confidence limits of 40-50% for the mean population density. Despite this variability, stable trends emerged, and variation was not so great as to mask significant differences. Length-frequency analyses distinguished cohorts; a regression was established between length and dry weight, enabling growth to be estimated from samples. By combining growth with population densities in Allen curves, production was computed. In Pink Lake and Lake Cundare mean pro- duction was 11.3 and 1.0 g dry weight m-2 year-1 respectively. Generally there were two or three generations per year, but time and extent of recruitment were not predictable. Each generation suffered continuous mortality, the death of young shrimps accounting for most of the production. This mortality remains unexplained; there are no significant predators and salinity and temperature stress would occur only during summer.


2019 ◽  
Vol 50 (7) ◽  
pp. 811-826 ◽  
Author(s):  
Hakan Çelik ◽  
Murat Ali Turan ◽  
Barış Bülent Aşık ◽  
Sencer Öztüfekçi ◽  
Ali Vahap Katkat

1977 ◽  
Vol 4 (6) ◽  
pp. 857 ◽  
Author(s):  
MF Beardsell

Maize (Zea mays L. cv. XL45) plants were grown from seed in controlled-environment rooms. Twice-daily weighings of the plants and containers for 7 days reduced height, and removing plants from the rooms for two 20-min periods daily for 7 days gave significant reductions in stem and leaf dry weights and total leaf area. Transpiration rates were not affected by either of these treatments. Short-term removal from the rooms (up to 10 min daily) produced no significant reductions in plant characteristics. Measuring leaf lengths daily for 10 days resulted in significant reductions in stem dry weight and plant height. It is suggested that control plants should always be subjected to the same degree of handling as treated plants.


1999 ◽  
Vol 62 (10) ◽  
pp. 1218-1222 ◽  
Author(s):  
FILMORE I. MEREDITH ◽  
OLGA R. TORRES ◽  
SANDRA SAENZ de TEJADA ◽  
RONALD T. RILEY ◽  
ALFRED H. MERRILL

Fumonisin B1 (FB1) is a common contaminant of corn worldwide and is responsible for several diseases of animals. In the preparation of tortillas, corn is treated with lime (producing nixtamal) that when heated hydrolyzes at least a portion of the FB1 to the aminopentol backbone (AP1), another known toxin. This study analyzed the amounts of FB1 and AP1 in tortillas and nixtamal from two communities in the central highlands of Guatemala where corn is a major dietary staple (Santa Maria de Jesus, Sacatepequez, and Patzicia, Chimaltenango). The amounts of FB1 and AP1 in tortillas from Santa Maria de Jesus were, respectively, 0.85 ± 2.0 and 26.1 ± 38.5 μg/g dry weight (mean ± SD), and from Patzicia were 2.2 ± 3.6 and 5.7 ± 9.4 μg/g dry weight. Less than 6% of the tortillas from both locations contained ≥10 μg FB1/g dry weight; whereas, 66% of the samples from Santa Maria de Jesus and 29% from Patzicia contained ≥10 μg AP1/g dry weight. The highest amount of AP1 (185 μg/g dry weight) was found in tortillas from Santa Maria de Jesus. The highest amounts of FB1 were 6.5 and 11.6 μg/g dry weight in tortillas from Santa Maria de Jesus and Patzicia, respectively. The mean concentration of FB1 in nixtamal was significantly higher in Santa Maria de Jesus compared to Patzicia. Surprisingly, AP1 was not detected in any of the nixtamal samples. The human impact of exposure to these amounts of fumonisins is not known. However, based on findings with other animals, where corn is a dietary staple, long-term consumption of FB1 and AP1 (especially at ≥10 μg/g of the diet) may pose a risk to human health.


1984 ◽  
Vol 64 (3) ◽  
pp. 487-496 ◽  
Author(s):  
ROBERT J. NAVRATIL ◽  
JOSEPH S. BURRIS

Seed produced on three widely grown public corn (Zea mays L.) inbreds were tested for tolerance to drying injury. Inbred parents A632, B73, and Mo17 were grown in 1979 and 1980. The single cross H99 × H95 was used as a pollinator both years. Random ear samples were collected, to obtain ears with moisture percentages ranging from approximately 50 to 20%, and dried to 12% moisture at 35 °C, 40 °C, 45 °C, and 50 °C. Inbred parents were found to differ in tolerance to high drying temperatures. A632 was the most tolerant to high drying temperatures whereas B73 and Mo17 were relatively intolerant. Field performance of dried seed was similar to that observed in laboratory tests. Combined analyses yielded significant inbred-parent by harvest-moisture by drying-temperature interactions for germination and cold-test emergence percentages. These interactions do not allow for simple recommendations of safe harvest moistures and drying temperatures. Components from the combined analysis that had a P > F of 0.30 or less were then used to predict mean values for A632, B73, and Mo17 germination, cold-test emergence, seedling dry weight and the ratio of shoot to root dry weight. Values for the ratio variable indicated that root development is more susceptible to injury than is shoot development. These predicted values provide seed producers with information on the quality responses that they could expect when seed of A632, B73, or Mo17 is harvested at different moisture contents and dried at different drying temperatures.Key words: Drying, seed quality, Zea mays L.


1974 ◽  
Vol 54 (1) ◽  
pp. 71-78 ◽  
Author(s):  
R. B. HUNTER ◽  
L. A. HUNT ◽  
L. W. KANNENBERG

The open-pollinated corn (Zea mays L.) cult Gaspé Flint and three hybrids, Guelph GX122, Harrow 691, and Pioneer X306, were selected to examine the effects of photoperiod and temperature on the number of days to tassel initiation. The range of maturity of this material varied from extremely early to subtropical. The experiments, conducted in growth cabinets, examined photoperiods of from 10 to 20 h in 21/2-h increments. Constant day–night temperatures examined were 20, 25, and 30 C. Photoperiod and temperature affected number of days to tassel initiation. The response was not consistent for each genotype. As daylength increased from 10 to 20 h all but the earliest genotype, Gaspé Flint, took longer to reach tassel initiation. The latest hybrid, Pioneer X306, was affected relatively more by photoperiod. The delay in tassel initiation with longer photoperiods was apparent at all temperatures; however, the magnitude of the response was less at the high temperature. With longer photoperiods, there was an increase in the amount of vegetative growth and development prior to tassel initiation. This was apparent from the greater number of emerged leaves, the longer stem length, and the greater plant dry weight at tassel initiation.


2013 ◽  
Vol 37 (1) ◽  
pp. 177-187 ◽  
Author(s):  
Michelli Fernandes Batista ◽  
Ismar Sebastião Moscheta ◽  
Carlos Moacir Bonato ◽  
Marcelo Augusto Batista ◽  
Odair José Garcia de Almeida ◽  
...  

Aluminum (Al) toxicity is one of the most limiting factors for productivity. This research was carried out to assess the influence of Al nutrient solution on plant height, dry weight and morphoanatomical alterations in corn (Zea mays L.) roots and leaves. The experiment was conducted in a greenhouse with five treatments consisting of Al doses (0, 25, 75, 150, and 300 µmol L-1) and six replications. The solutions were constantly aerated, and the pH was initially adjusted to 4.3. The shoot dry matter, root dry matter and plant height decreased significantly with increasing Al concentrations. Compared to the control plants, it was observed that the root growth of corn plants in Al solutions was inhibited, there were fewer lateral roots and the development of the root system reduced. The leaf anatomy of plants grown in solutions containing 75 and 300 µmol L-1 Al differed in few aspects from the control plants. The leaf sheaths of the plants exposed to Al had a uniseriate epidermis coated with a thin cuticle layer, and the cells of both the epidermis and the cortex were less developed. In the vascular bundle, the metaxylem and protoxylem had no secondary walls, and the diameter of both was much smaller than of the control plants.


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