Sowing

About: Sowing is a research topic. Over the lifetime, 33888 publications have been published within this topic receiving 273438 citations. The topic is also known as: seeding.

Genetic gain × management interactions in soybean: I. Planting date

Abstract: planting date is a commonly manipulated man - agement practice in soybean ( Glycine max (L.) Merr.) production; however, the impacts of past and ongoing agronomic improvements, such as earlier planting, on genetic yield improvement and associated changes in seed protein and oil have not been evaluated. The objectives of this study were to determine if a 30-d difference in planting date affected measured rates of genetic improvement in (i) yield, (ii) seed mass, and (iii) seed protein and oil in the midwestern United States. research was conducted at Arlington, WI, Urbana, IL, and Lafayette, IN, during 2010 and 2011, using 59 Maturity Group (MG) II cul - tivars (released 1928-2008) at Wisconsin, and 57 MG III cultivars (released 1923-2007) at Illi - nois and Indiana, with targeted planting dates of 1 May and 1 June. Earlier planting provided higher yields (+3.1 kg ha −1 yr −1 ) than late planting in MG III soybean. Seed protein concentration decreased linearly over cultivar year of release at a rate of 0.191 (± 0.069) g kg −1 yr −1 for MG II, and 0.242 (± 0.063) g kg −1 yr −1 for MG III. Seed oil concentration increased over year of release at a rate of 0.142 (± 0.037) g kg −1 yr −1 for MG II, and 0.127 (± 0.039) g kg −1 yr −1 for MG III. The interaction between planting date and cultivar year of release for MG III yield suggested that the trend toward earlier planting is one agro - nomic improvement that, when coupled with genetic improvement, has provided a syner - gistic increase in on-farm soybean yields in the midwestern United States.

Effect of proximity factors on competition between winter wheat (triticum aestivum) and italian ryegrass (lolium multiflorum)

Abstract: Density and spatial arrangement (rectangularity) effects on the competitive relationships, yield performance, and dynamics in canopy dominance of winter wheat and Italian ryegrass were evaluated using two addition series experiments. In experiment 1, combinations of six densities of each species formed the treatment matrix of addition series. In experiment 2, each species was tested at four densities and three rectangularities (RE) of winter wheat. In monocultures, crop density (plants per square meter) explained 82 to 85% of the total variation in the per-plant biomass of winter wheat in experiment 1. In mixtures of crop and weed, initial wheat density (N1) and initial ryegrass density (N2) and interaction of N1 and N2 explained 74 to 80% of the total variation in the per-plant biomass of winter wheat and 68 to 79% of Italian ryegrass in experiment 1. Intraspecific competition was apparent between 15 and 90 days after emergence (DAE) in winter wheat and between 90 and 170 DAE in Italian ryegrass. In mixtures, RE influenced plant size of Italian ryegrass up to 50 DAE only. Maximum winter wheat intraspecific competition occurred at 170 DAE, but maximum interspecific competition occurred during reproductive stages in mixtures. High RE increased seed yield, seed size, and harvest index of winter wheat and reduced biomass of Italian ryegrass. Grain yield of winter wheat was reduced up to 92% by competition from ryegrass. Even nine ryegrass plants in 100 winter wheat plants m−2 reduced winter wheat grain yield by 33%. However, the extent of loss in winter wheat grain yield was less in RE 16 (wider spacing) than in RE 1 (square planting) or 4 (close row spacing). Winter wheat was the stronger competitor during vegetative stages, but Italian ryegrass became the stronger competitor during the reproductive stages of development. Winter wheat leaves dominated at the top canopy during the vegetative stage, but ryegrass dominated at the top canopy during the reproductive stages. In the top canopy of mixtures at 200 DAE, the leaf area indices (LAI) of ryegrass was 6.6 times greater than winter wheat at RE 1 compared to only 1.6 times at RE 16. Greater LAI of Italian ryegrass in the top canopy reduced photosynthetically active radiation available to winter wheat by 68% at booting stage.

The yield of sugar beet in relation to weather and length of growing season

Abstract: An experiment at Sutton Bonington in 1971 tested the effects of sowing and harvesting dates on yield of sugar beet. Seed sown on 28 March germinated slowly in the cold soil and crop establishment was poor. From early April until the beginning of May the loss in yield of sugar consequent upon delaying sowing by 1 week was 0·4 t/ha. For later sowings the yield loss was greater. During the harvest period the rate of increase in sugar yield was the same for all sowings. Yields of crops sown and harvested on different dates were closely correlated withthe amount of solar radiation intercepted by the leaf canopy.