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.

Short-Season Soybean Yield Compensation in Response to Population and Water Regime

Abstract: Short-season soybean [Glycine max (L) Merr.] production systems, such as double cropping and late sowing, require high populations to optimize yield, but effects of high populations on seed number and seed mass are unknown. We evaluated plant population effects on yield compensation, stability of harvest index, assimilate partitioning for seed number, and seed-filling characteristics for 2 yr near Keiser, AR. The study had two cultivars, two levels of irrigation, and three row spacings that each had five levels of population ranging from 6 to 134 plants m -2 . Increasing population reduced yield per plant but increased yield per unit area. Harvest index was relatively constant across populations for a given year and irrigation regime, and yield was closely associated with biomass at maturity. At high populations, plants maintained individual seed mass by reducing the proportion of shell mass per pod. Final individual seed mass, seed growth rate (SGR), and the length of effective filling period did not change with increasing population for irrigated or nonirrigated treatments. Reductions in yield caused by low population density were due to low seed number. Seed number per square meter was directly proportional to the ratio of crop growth rate (CGR) to SGR. For short-season production, high populations ensured early canopy coverage and maximized light interception, CGR, and crop biomass, resulting in increased seed number and yield potential.

Short duration chickpea to replace fallow after aman rice: the role of on-farm seed priming in the high barind tract of bangladesh

Abstract: Chickpea (Cicer arietinum) is a promising post-wet-season crop to follow rainfed rice (Oryza sativa) in the High Barind Tract of northwestern Bangladesh. Yields in farmers' fields, however, remain low (<1 t ha-1) primarily due to factors such as poor crop establishment, late sowing, and terminal drought and heat stress. Having been shown to improve plant stand and yield of chickpea in other environments, seed priming - soaking the seed overnight before surface drying and sowing the next day - of chickpea cv. Barichola-2 was tested for its efficacy under Barind conditions. In the 1998-99 season, 30 trials, grown entirely on residual soil moisture were conducted in farmers' fields in districts of Rajshahi and Nawabganj. A statistically significant mean yield response to priming of 47% was obtained. In 1999-2000, 105 on-farm trials (in Rajshahi, Nawabganj, Noagaon and Niamatpur) and 15 demonstrations (in Godagari) comparing presence and absence of priming were conducted. The crop received rain during this growing season. In a randomly chosen subset of 35 trials, scientists recorded a mean yield increase due to priming of 20%; it was 22% (from 1.02 to 1.25 t ha-1) in the remaining 64 trials (6 of the 105 trials were abandoned) where farmers recorded yields. Using a different cultivar (Barichola-5), the mean yield response to priming in 15 demonstrations was 17% (from 1.25 to 1.46 t ha-1). The priming response was attributed mainly to rapid seedling establishment, with higher plant stand and earlier crop maturity allowing escape from end-of-season stresses. Priming also reduced the incidence of stem and root diseases, and increased nodulation by native rhizobia. This simple technology can substantially increase chickpea yields to remunerative levels for the resource-poor farmers in this difficult environment. Furthermore, it is suggested that this technology can act as a catalyst for the introduction of further technologies that will permit reliable and profitable cultivation of post-rainy-season crops and thus improve the livelihoods of the rural population

Exploiting weed seed dormancy and germination requirements through agronomic practices

Abstract: Many common agronomic practices affect weed seed dormancy and germination by influencing the microen- vironmental and edaphic conditions surrounding seeds in soil. Factors such as light penetration, soil water content, soil fertility, and temperature are modified by tillage, planting, harvesting, and other production practices, resulting in en- hanced or depressed weed seed germination. Changes in these environmental factors may also indirectly lead to al- terations in phytohormone concentrations during seed devel- opment, which can subsequently affect dormancy status of the mature seed. Integrated approaches that place priority on depleting weed seed banks through interfering with dor- mancy or germination requirements have strong potential to enhance weed management aspects of agricultural sys- tems. Nomenclature: Mouseearcress (Arabidopsis thaliana L. Heynh), barley (Hordeum vulgare L.), common lambsquar- ters (Chenopodium album L.), curly dock (Rumex crispus L.), giant foxtail (Setariafaberi Herrm.), hairy vetch (Vicia villosa Roth), rough stalk bluegrass (Poa trivialis L.), prostrate knot- weed (Polygonum aviculare L.), red brome (Bromus rubens L.), red rice (Oryza sativa L.), red sorrel (Rumex acetosella L.), redroot pigweed (Amaranthus retroflexus L.), rye (Secale cereale L.), silvergrass (Vulpia spp.), sulfur cinquefoil (Poten- tilla recta L.), wild oats (Avenafatua L.), witchweed (Striga asiatica (L.) Kuntze). Additional index words. Cultivation, edaphic factors, seed physiology.