Plant Ear Height Research Articles

Early plant height: A defining factor for yields of silage maize with contrasting phosphorus supply

AbstractSilage maize (Zea mays L.) is an important crop for forage on Northwestern European dairy cattle farms. We examined the effect of readily available soil phosphorus (P) on early maize growth and linked in‐season height growth to final harvest yield using field plots with contrasting P supply in a one‐year study embedded in a long‐term experiment. Water‐extractable P (Pw) was used as a proxy for readily available P in soil. Plant height, dry matter (DM) accumulation, P and nitrogen (N) uptakes were determined eight times from the two‐leaf stage until final whole‐crop harvest and fitted to logistic growth models. The models revealed that the final yield was significantly related to the time required to reach the maximum rate of height growth (occurring from 330 to 485 accumulated growing degree units, GDU), but not the time required to reach the maximum rate of DM accumulation (occurring from 561 to 649 GDU). Furthermore, plant height at the four‐leaf stage and onwards was significantly related to the final harvest yield. Soil Pw linked closely to height growth parameters; higher levels of Pw gave earlier peaks in height growth. For this light sandy loam with a wide gradient in P content, we conclude that suboptimal P supply postpones height growth and reduces final yields. A sufficient P supply links to an early rapid increase in plant height and forms the potential for optimum nutrient uptake and high forage yields. Thus, early‐season plant height may serve as a simple morphometric indicator for final yields.

Genetic Architecture of Early Vigor Traits in Wild Soybean.

A worldwide food shortage has been projected as a result of the current increase in global population and climate change. In order to provide sufficient food to feed more people, we must develop crops that can produce higher yields. Plant early vigor traits, early growth rate (EGR), early plant height (EPH), inter-node length, and node count are important traits that are related to crop yield. Glycine soja, the wild counterpart to cultivated soybean, Glycine max, harbors much higher genetic diversity and can grow in diverse environments. It can also cross easily with cultivated soybean. Thus, it holds a great potential in developing soybean cultivars with beneficial agronomic traits. In this study, we used 225 wild soybean accessions originally from diverse environments across its geographic distribution in East Asia. We quantified the natural variation of several early vigor traits, investigated the relationships among them, and dissected the genetic basis of these traits by applying a Genome-Wide Association Study (GWAS) with genome-wide single nucleotide polymorphism (SNP) data. Our results showed positive correlation between all early vigor traits studied. A total of 12 SNPs significantly associated with EPH were identified with 4 shared with EGR. We also identified two candidate genes, Glyma.07G055800.1 and Glyma.07G055900.1, playing important roles in influencing trait variation in both EGR and EPH in G. soja.

Strong temporal dynamics of QTL action on plant growth progression revealed through high-throughput phenotyping in canola.

SummaryA major challenge of plant biology is to unravel the genetic basis of complex traits. We took advantage of recent technical advances in high‐throughput phenotyping in conjunction with genome‐wide association studies to elucidate genotype–phenotype relationships at high temporal resolution. A diverse Brassica napus population from a commercial breeding programme was analysed by automated non‐invasive phenotyping. Time‐resolved data for early growth‐related traits, including estimated biovolume, projected leaf area, early plant height and colour uniformity, were established and complemented by fresh and dry weight biomass. Genome‐wide SNP array data provided the framework for genome‐wide association analyses. Using time point data and relative growth rates, multiple robust main effect marker–trait associations for biomass and related traits were detected. Candidate genes involved in meristem development, cell wall modification and transcriptional regulation were detected. Our results demonstrate that early plant growth is a highly complex trait governed by several medium and many small effect loci, most of which act only during short phases. These observations highlight the importance of taking the temporal patterns of QTL/allele actions into account and emphasize the need for detailed time‐resolved analyses to effectively unravel the complex and stage‐specific contributions of genes affecting growth processes that operate at different developmental phases.

Influence of Manure and Nitrogenous Fertilizer Applications on Corn Yield and Quality Characteristics

Two field experiments were conducted at Sids research station, BeniSuef Governorate during 2014 and 2015 seasons, to study the effect of three manure levels (M1= zero, M2= 10 and M3= 20 m3 fed-1) and four nitrogen (N) application times (T1= 1/5 N at planting, 2/5 N at 1st irrigation and 2/5 N at 2nd irrigation, T2= 1/5 N at planting, 2/5 N at 1st irrigation and 2/5 N at 3rd irrigation, T3= 1/3 N at 1st irrigation, 1/3 N at 2nd irrigation and 1/3 N at 3rd irrigation and T4= 1/2 N at 1st irrigation and 1/2 N at 2nd irrigation) on white corn (hybride single cross 130) growth, yield components and grain yield. The resultant corn grains were estimated with respect to some physicochemical and technological properties. Manure levels and N application times significantly affected days to 50% tasseling, plant and ear height, ear length, rows per ear and kernels per row in both seasons. Manure levels significantly affected days to 50% silking in season 2015 while, N application times significantly varied days to 50% silking, grain yield in both seasons and earbdiameter in season 2015. The highest grain yield was obtained with M3 in both seasons while, T2 reached floweringbstage earlier than the other N application times and it had the highest value in plant ear height, yield components and grain yield. Results of interaction indicated that M3 had the highest grain yield when it was used with T2. 1000-grain weight significantly increased with increasing manure levels. M3T2 and M3T3 had the highest values in 1000-grain weight for both seasons. The endosperm and germ percentages were significantly increased in M3T2 and M3T3. Protein, ash, iron and zinc slightly higher in season 2014 at different manure levels. While, fat contents were higher in season 2015. Protein digestibility and availability of iron and zinc increased with increasing manure levels in both seasons. The lightness (L*) values of muffins crumb color insignificantly decreased while, yellowness (b*) values increased with increasing manure levels. In general, it could be concluded that, corn flour could be used to produce good quality gluten-free muffins with acceptable physical and sensory characteristics.

Genetic variation of height growth rhythm between clones of Larix kaempferi × L. gmelini based on logistic models

Fifty-three larch interspecific hybrid clones (Larix kaempferi × L. gmelini) and their parent clones were used for growth curve analysis of height variations. The growth curves of the 55 clones were ‘S’-shaped and 36 exhibited similar curves as the male parent. The coefficients of the logistic models were higher than 0.943, indicating that our results were effective in the simulation of the growth curves. ANOVA analysis showed significant differences in height of different clones (P < 0.01). Average date of maximum height growth was Day 173, and average duration of rapid growth lasted for 50 days. Annual average increase in height was 9.7 cm d−1 and daily average increase was 0.2 cm. The ratio of GR to the total annual increase in height ranged from 51.2 to 68.8%, with the average being 59.8%. There was a positive correlation between k values and plant heights which benefited from the evaluation of early plant height. There was also a positive correlation between GR (growth stage), GD (plant height) and annual increase in height. These results are informative to the evaluation of the elite clone selection and provide a theoretical basis for breeding and management.

Seeding rate and genotype effects on weeds and yield of dry-seeded rice

Weeds are the main biological constraint to wide spread adoption of dry-seeded rice (DSR). Research analyzing the effects of seeding rate on weeds and yield of DSR using newly developed genotypes adapted to DSR is not well documented in Asia. The objective of this study was to investigate the relative performance of selected genotypes in relation to seeding rate and weed infestation levels on weeds and yield of DSR in the rainy seasons of 2014 and 2015. Four selected genotypes [two cultivars (PR-115 and Dhan-202), and two recombinant inbred lines (RIL-367 and RIL-1646)], were grown in a split-split plot arrangement in a randomized complete block, with weed infestation levels (weed-free and partial weedy) in the main plots, seeding rate (100 and 200 seeds m−2) in the subplots, and genotypes in the sub-subplots. Total weed biomass was lower at the high seed rate (HSR; 200 seeds m−2) as compared to the low seeding rate (LSR; 100 seeds m−2), and the reduction in weed biomass varied from 40 to 72% depending on genotypes. At the LSR, the weed-competitive index (WCI) of RIL-1646 (1.13) was higher than PR-115 (0.44), but remained similar to RIL-367 and Dhan-202. At the HSR, the WCI of RIL-367 (1.57), RIL-1646 (2.24), and Dhan-202 (2.89) was higher than PR-115 (0.95). The WCI of newly developed genotypes (RIL-367, RIL-1646 and Dhan-202) increased with increased seeding rate, while for PR-115; no such increase was found. In the weed-free plots, RIL-367 at both the seeding rates had higher grain yield (5.97 t ha−1) than other genotypes and the lowest yield was recorded with Dhan-202, and the trend was similar at both the seeding rates. However, in the partial weedy plots, at both the seeding rates, the lowest yield was recorded for PR-115. In the partial weedy plots, the grain yield of RIL-367 was increased using the HSR. In the partial weedy plots, the plant height of RIL-367 at HSR was higher than that at LSR, and a similar trend was observed for panicle weight. There was a negative relationship between early plant height and relative grain yield loss due to weed infestation. This study indicates that the newly developed genotypes for DSR have variations in WCI, and weed control in DSR could be improved by increasing the seeding rate for these genotypes.

Analysis of Growth Characteristics and Yield Components According to Rice Varieties Between on Irrigated and Partially Irrigated Rice Paddy Field

국내 가뭄 조건에서의 벼 품종별 재배안정성을 평가하기 위한 인위적인 가뭄 처리 조건(수리불안전답 조건)에서 생육 특성과 쌀수량 조사하고 쌀수량 감소 요인을 분석한 결과는 다음과 같다. 1. 수리불안전답 조건에 의한 경수 및 이삭수 감소율은 품종에 따라 각각 10.7%에서 33.1%와 10.5%에서 30.1%였으며, 공시품종 중 '새일미', '일미'가 경수 및 이삭수 변화가 적었으며, '오대'와 '운광', '추청' 품종에서 경수와 이삭수 감소가 크게 나타났다. 2. 수리불안전답 조건에서의 쌀수량은 품종에 따라 수리안전답 조건보다 9.9%에서 33.3% 감소하였으며, 쌀수량 감소가 적은 품종은 '새일미'와 '주남', '일미'였으며, 감소율이 큰 것으로 조사된 품종은 '오대'와 '칠보', '호품' 등 이였다. 3. 수리불안전답 조건에 의한 생육초기 경수 발달 부진과 이의 영향에 의한 이삭수 감소가 쌀수량 감소에 가장 큰 영향을 준 것으로 분석되었다. 4. 본 연구에서 수리불안전답 조건에서의 쌀수량 감소를 분석한 결과, 국내 기상조건에서 발생할 수 있는 가뭄은 생육후기보다 생육초기의 경수 발달에 크게 영향을 주는 것으로 확인되었다. 따라서 농업용수 공급이 원활하지 않는 수리불안전답의 경우 가뭄에 대비하기 위하여 '새일미'와 '일미', '일품' 품종 같은 가뭄에 대한 재배안정성이 우수한 품종을 재배하는 것이 적당하다고 판단된다. Drought caused by global climate change is one of serious problems for rice cultivation. However, it was little reported the impact of drought on rice cultivation in Korea. In here, to assess impact of drought on rice varieties in Korean climate condition, growth characteristics and yield components of rice were compared on irrigated and partially irrigated rice paddy field. First, we have chosen 11 rice varieties including 'Saeilmi' and 'Shindongjin' which are widely cultivated in Korea. For partially irrigated rice paddy treatment, we have withheld irrigation from 25 days after transplanting and water supply was totally dependent on rainfall for rice cultivation. When we examined early plant height and tiller number of these varieties on partially irrigated rice paddy were reduced 1.6% to 18.4% and 10.4% to 33.1%, respectively, and these reduction rate were highly correlated with yield loss in our experimental conditions. Among rice yield components, panicle number was decreased 10.5% to 30.1% according to rice varieties and reduced panicle number was highly correlated with yield loss. Grain number per panicle, grain filling rate and 1,000 seeds weight did not have correlation with yield loss of rice varieties. These result means that growth stage, especially the tillering stage, is seriously affected by drought on rice cultivation in Korea. And we suggest that 'Saeilmi', 'Ilmi' and 'Ilpum' are good for rice cultivation on drought prone rice field in Korea.

Variation in Early Plant Height in Wild Soybean

It is difficult to evaluate plant height at maturity in wild soybean (Glycine soja Sieb. &amp; Zucc.) and no research about plant height at early growth stages has been reported. The objective of this study was to identify variation for plant height at early growth stages in wild soybean accessions. On the basis of the data collected in 1999, five accessions were selected from each height class (tall, intermediate, and short) for each of three maturity groups (00, II, and IV). These 45 accessions were planted in a completely randomized design with six replications in 2000 and 2003. Three height measurements (H1, H2, and H3) were taken at 10‐d intervals beginning 20 d after planting. A multiple comparison t test by Fishers Least Significant Differences (LSD) was used to test the differences among means of three early plant height classes. Highly significant differences were found among years, height classes, accessions within height classes and within maturity groups, and year × accession interaction for H2 measurement, but there were no significant differences among maturity groups and no significant interaction between year and height classes. The optimum time for evaluating differences in early plant height is 30 d after planting. This rapid growth trait in wild soybean could be beneficial for cultivated soybean and a useful trait for evaluating wild soybean germplasm.

DRILL FURROW OPENER EFFECTS ON WHEAT AND SORGHUM ESTABLISHMENT IN NO-TILL FIELDS

Further investigations on no-till openers are needed to better understand their effects on crop performance. Fivedifferent furrow opener points on shank-type drill units, a triple-disc opener, and three types of presswheels were evaluatedin terms of wheat and grain sorghum stand establishment and early plant height, for the no-till field conditions of drylandfarming and over-wintered partially deteriorated corn stubble residues. The field experiment was conducted with eighttreatments and five replicates for wheat or sorghum. The results of the analysis of covariance (ANCOVA) indicated that thedifferent types of no-till openers had statistically significant effect on wheat emergence and sorghum early growth height onthe Texas Blackland Prairie. Significantly higher wheat emergence percentage was obtained using a 95-mm wide openerpoint rather than using narrow points of 25- and 35-mm widths. In contrast, the narrow opener point of 35-mm width hadbetter performance on sorghum early growth height than the wide point of 95-mm width. Hoe-type drill furrow openersproduced equivalent or higher wheat emergence percentages and sorghum height than a comparison disc-type furrow opener.A single presswheel provided equivalent or improved seeder performance over dual angled presswheels. The considerationof the effect of the width of an opener point on early plant performance is recommended for the selection or design of no-tilldrill openers.

QTLs conditioning early growth in a soybean population segregating for growth habit

There are both economic and environmental reasons for reducing the use of herbicides for weed control in soybean [Glycine max (L.) Merr.] fields. Optimizing crop competitiveness can reduce reliance on chemical weed control. Fast and vigorous early growth and rapid canopy development can be effective in suppressing weed infestation of crop plants. The purposes of this study were to identify and molecularly map the quantitative trait loci (QTLs) conditioning soybean plant height and canopy width during the early vegetative stages of soybean growth. A restriction fragment length polymorphism (RFLP) linkage map was created using 142 markers and 116 F2-derived lines from a cross of ‘S100’בTokyo’. The parents and the 116 F2-derived lines were evaluated in the greenhouse and in the field at Athens, Ga., in 1996 and 1997. Combined over environments, Tokyo averaged 41 and 17% taller plants than S100 at the V7 and V10 stages of development. Transgressive segregation was observed among the progeny at both stages. Based on single-factor analysis of variance (ANOVA), three and four independent RFLP loci were associated with plant height at the V7 and V10 stages, respectively. All three loci detected [on linkage groups (LGs) C2 and F, and unlinked] at the V7 stage were also detected at the V10 stage along with one additional independent locus on LG E. The Tokyo allele contributed to increased plant height at all loci except at the unlinked locus. Three QTLs (on LGs C2, E, and F) were consistent across environments, three (on LGs C2 and F, and unlinked) were consistent across stages of plant development, and two (on LGs C2 and F) were consistent both across environments and stages of plant development. Within each stage of development, there was no interaction among the independent loci, and the respective loci together explained most of the variation in the traits. Three independent RFLP loci were associated with canopy width at the V10 stage, of which one was unique to the trait, while the remaining loci (on LGs C2 and F) were in common with the independent loci for plant height. Canopy width had a strong correlation (r=0.87) with plant height at the V10 stage. However, mature plant height, lodging, or seed weight had no phenotypic or QTL association with early plant height or canopy width.

Effects of Seed Vigor on Crop Characters in Uniform and Reduced Populations of Corn (Zea mays L.)

AbstractThe relationship between seed corn vigor and some crop characters in uniform and reduced plant populations is poorly defined. This study, was designed to define the crop characters through which seed vigor is expressed in reduced and uniform populations of corn and to clarify which experimental technique should be used in seed vigor studies. Seeds of two corn hybrids, A632 x (H99 x H95) and B73 x (H99 x H95), were dried at two temperatures, 35 °C and 50 oC, and planted near Ames, Iowa, in 1983. The two drying temperatures created differential vigor levels between the seed lots. There were 21 crop characters measured in two populations, reduced populations due to lack of seed vigor and uniform population (thinning to stand). Early vegetative growth was influenced by seed vigor, but as the plant aged, the influence of seed vigor decreased. Increased early plant height, up to 6 weeks old, small stem diameter, low shoot dry‐matter content, delay in days from sowing to 50 % tasseling and to 50 % silking, narrow penultimate and ear leaf, and reduction in the number of ears and tiller production were observed in the uniform population. The differences in population density due to seed vigor did not have a significant effect on final grain yield inasmuch as plants in the reduced populations were able to compensate completely for missing stands.

Seed Grade Effect on Corn Performance1

AbstractSmall‐sized or ungraded corn (Zea mays.) seed usually costs less than large‐graded seed. Since planters can now uniformly plant ungraded and/or small seed, we conducted trials at Waseca and Lamberton, Minn., in 1973 and 1974 to determine the effect of seed size and shape on performance of early compared to late‐planted corn.Four seed grades — large round (LR), large flat (LF), small round (SR), small flat (SF), and mixed (M) — were evaluated each year. The M category was an equal mixture of the four grades. In 1973, the single cross hybrid ‘A639 × A638’ was used; in 1974 we used ‘DeKalb XL45A’ and ‘DeKalb XL43.’ Early plant height, early plant dry weight, and tassel dates were recorded at the Waseca location and grain yield was measured at both locations.Seed grades did not affect corn yields when data were averaged over years, locations, and hybrids. In only one of 12 comparisons was there a seed grade effect with higher yields from graded vs. ungraded seed, from large vs. small seed, and from round vs. flat seed. Seed grade did not affect early plant height or tassel dates. Early plant dry weight for plots seeded with SR and SF seeds was lower than that of plots seeded with LR or LF seeds in 1973; only very small plant dry weight differences occurred in 1974.Grain yields from the early May planting were higher than from late May planting for all location‐years except Waseca in 1973. Interactions of seed grade with planting dates or hybrids were not statistically significant for three of the four location‐years of the study. Soil temperature at the 10‐cm depth for the 2 weeks post planting was 8 to 10 C colder for early vs. late planting dates, yet yields from SR and SF seed were equal to those from LR or LF.

RELATIONSHIP BETWEEN SPRING VIGOR AND GRAIN YIELD IN CORN

In an experiment designed to study the relationship between seedling vigor and grain yield in corn (Zea mays L.), 25 single-cross hybrids, of a range in spring vigor (6 involved crosses between inbred parents of high seedling vigor, 6 were crosses between parents of low seedling vigor, and 13 were crosses between inbreds of high and low vigor) were grown in test for 2 yr near Woodstock, Ontario. In the 1st yr, hybrids were evaluated for differences in: rate of emergence; visual vigor rating; plant height, dry weight, and leaf number at several dates during early vegetative development; leaf area index (measured after pollination); and final grain yield. In the 2nd yr, hybrids were evaluated for differences in seed size (weight/kernel), visual vigor rating, and grain yield. No differences were detected among hybrids in rate of emergence. In the 1st yr, the visual vigor score was positively related to early plant height, but not to any of the other measures of seedling vigor. A positive relationship between seed weight and visual vigor rating was observed in the 2nd yr. The mean grain yield of the three groups of hybrids corresponded directly with their initial vigor rating in the 1st yr (i.e., crosses among high vigor inbreds outyielded high × low crosses; high × low crosses outyielded low × low), but not in the 2nd yr. Among individual genotypes, no relationship was evident between any measure of spring vigor and grain yield, in either year.

Flight Habits of the Maize Weevil, Sitophilus zeamais12

A 3-year study of the dispersal of the maize weevil, Sitophilus zemais Motschulsky, from a corn storage bin was made at Baton Rouge. Dispersal was determined by the use of sticky traps. Beginning in January and continuing through December adult weevil emergence occurred on days when the temperature reached 23.3°C. Weevil dispersal reached a peak about July 7 (average of 3 years) after which it declined. Dispersal practically ceased hy the end of the year. Greatest emergence occurred during the warmer months. Dates of peak emergence, however, differed for each of the 3 years. The sex ratio of the trapped weevils was approximately 1: 1. Almost 100% of the females leaving the bin had been mated. Time of greatest dispersal flight occurred between 4 and 6PM. This period followed the warmest part of the day. More maize weevils were found to enter a field of corn at average plant ear height than at a level between 1 and 2 feet elevation.