Kernel Weight (kernel + weight)

Distribution by Scientific Domains

Selected Abstracts

Yield Responsiveness in Two- and Six-Rowed Barley Grown in Contrasting Nitrogen Environments

S. Arisnabarreta
Abstract Two- and six-rowed barley with different intrinsic ability to produce tillers and kernels per ear, would differ in responsiveness to nitrogen availability with environmental improvements. Two field experiments were carried out to elucidate how nitrogen supply (N40 and N150) affects yield and its components in two- and six-rowed barley. High nitrogen increased aboveground dry matter at anthesis, by improving cumulative solar radiation intercepted by the crop, determining an increased dry-matter production at maturity without changes in harvest index. In both barley types, variations in grain yield were explained by changes in kernels per unit land area rather than by differences in the average kernel weight. However, changes in the number of kernels were due to variations in the number of ears per m2 in two-rowed barley and the number of kernels per ear in six-rowed barley. Ears per unit area showed a greater responsiveness in two- than in six-rowed barley due to a higher nitrogen supply treatment, associated with their intrinsic higher tillering capacity, while the number of kernels per ear was more responsive in six- than in two-rowed types. The fact that responses to nitrogen by the number of kernels per unit land area in two- and six-rowed barley is better explained by different yield sub-components, allows the speculation that the critical period for yield determination would differ between barley types. [source]

Growth and Yield Response of Facultative Wheat to Winter Sowing, Freezing Sowing and Spring Sowing at Different Seeding Rates

A. Ozturk
Abstract Growth and yield of wheat are affected by environmental conditions and can be regulated by sowing time and seeding rate. In this study, three sowing times [winter sowing (first week of September), freezing sowing (last week of October) and spring sowing (last week of April)] at seven seeding rates (325, 375, 425, 475, 525, 575 and 625 seeds m,2) were investigated during the 2002,03 and 2003,04 seasons, in Erzurum (Turkey) dryland conditions, using Kirik facultative wheat. A split-plot design was used, with sowing times as main plots and seeding rates randomized as subplots. There was a significant year sowing time interaction for grain yield and kernels per spike. Winter-sown wheat produced a significantly higher leaf area index, leaf area duration, spikes per square metre, kernel weight and grain yield than freezing- and spring-sown wheat. The optimum time of sowing was winter for the facultative cv. Kirik. Grain yields at freezing and spring sowing were low, which was largely the result of hastened crop development and high temperatures during and after anthesis. Increasing seeding rate up to 525 seeds m,2 increased the spikes per square metre at harvest, resulting in increased grain yield. Seeding rate, however, was not as important as sowing time in maximizing grain yield. Changes in spikes per square metre were the major contributors to the grain-yield differences observed among sowing times and seeding rates. Yield increases from higher seeding rates were greater at freezing and spring sowing. We recommended that a seeding rate of 525 seeds m,2 be chosen for winter sowing, and 575 seeds m,2 for freezing and spring sowing. [source]

Effect of Water Stress at Various Growth Stages on Some Quality Characteristics of Winter Wheat

A. Ozturk
Abstract A field experiment was carried out in Erzurum (Turkey) on winter wheat to analyse the effect of water stress at different growth stages , fully irrigated (FI), rainfed (R), early water stress (EWS), late water stress (LWS) and continuous water stress (CWS), on some quality characteristics , in the 1995,96 and 1996,97 cropping seasons. Water stress had a substantial effect on most of the quality characteristics. As averages of cropping seasons, CWS, EWS, R and LWS treatments decreased grain yields by 65.5, 40.6, 30.5 and 24.0 %, respectively, compared with the FI treatment. CWS increased grain protein content by 18.1 %, sedimentation volume by 16.5 %, wet gluten content by 21.9 % and decreased 1000-kernel weight by 7.5 g compared with FI treatment. LWS caused an increase of 8.3 % in grain protein content, 8.7 % in sedimentation volume, 10.8 % in wet gluten content and a reduction of 3.8 g in 1000-kernel weight compared with FI. EWS and R increased sedimentation volume and wet gluten content, but decreased 1000-kernel weight compared with FI. The effect of LWS on grain quality was more significant than that of EWS. The results suggest that soil moisture conditions increase grain yield and kernel weight of winter wheat but decrease its quality. [source]

Yield Responses of Barley to Leaf Stripe (Pyrenophora graminea) under Experimental Conditions in Southern Syria

M. I. E. Arabi
Abstract The seed-borne pathogen, Pyrenophora graminea is the causal agent of barley leaf stripe disease. Field trials were undertaken to investigate the impact of leaf stripe on barley yield in two growing seasons in Southern Syria, by comparing plots with and without artificial inoculation. Ten barley cultivars originating from widely dispersed areas were used. The overall response to leaf stripe differed with the differences in susceptibility levels of the cultivars. Grain yield, the number of tillers, kernel weight and plant biomass decreased as disease severity increased. Diseased plants had fewer tillers, and as a consequence a reduced grain yield per plant. High yield losses resulted from leaf stripe in susceptible cultivars in Arrivate, Furat 1, WI2291 and Arabi Abiad with 44%, 50%, 73% and 92%, respectively. The cultivar Banteng had the best level of resistance to the disease, and is a candidate donor for resistance in future breeding programmes. As leaf stripe can dramatically reduce barley yields under favourable conditions, the disease should be considered by crop improvement programmes in Mediterranean and similar environments. [source]

Effect of harvest time and storage conditions on almond kernel oil and sugar composition

Ioannis Kazantzis
Abstract The effect of storage for 6 months at 5,C (80% RH) versus 20,C (60% RH) of shelled versus in-shell almonds was studied on early versus late harvested nuts from ,Ferragnes' and ,Texas' trees. Kernel quality characteristics, oil composition and sugar composition were determined initially and after 6 months of storage. Early harvested almonds had similar kernel weight to but higher moisture content than late harvested almonds after 6 months of storage. Early harvested almonds also had similar oil quality (based on ultraviolet absorption coefficient measurements) and oil composition but lower sugar content and modified sugar composition compared with late harvested almonds. Storage of shelled almonds resulted in kernels with higher oil content, better oil quality, similar oil composition, similar sugar content and some modifications in sugar composition compared with in-shell stored almonds. Finally, storage for 6 months at either 5 or 20,C resulted in lower moisture content, higher oil content, similar oil quality and composition, similar sugar content and some modifications in sugar composition compared with freshly harvested almonds. Almonds stored at 5,C retained higher kernel weight and moisture content than almonds stored at 20,C. 2003 Society of Chemical Industry [source]

Effect of sowing date and straw mulch on virus incidence and aphid infestation in organically grown faba beans (Vicia faba)

H. Saucke
Abstract The effect of sowing date on aphid infestation and the incidence of aphid-transmitted viruses were investigated in organically managed, small-scale field experiments with two faba bean cultivars over 3 years (2002,04). As an additional factor, straw mulch was applied in 2 of the 3 years shortly before the start of vector activity in May. Virus incidence was determined using enzyme-linked immunosorbent assay and immunoelectron microscopy. Aphid flight activity was monitored using standard yellow water traps. Bean colonising aphids were assessed throughout the vegetation period by counting the number of plants infested with Acyrthosiphon pisum, Megoura viciae and Aphis fabae. Pea enation mosaic virus and bean yellow mosaic virus were the most abundant aphid-transmitted viruses, being detected in 22,54% and 9,69%, respectively, of the total number of virus-infected plants analysed per year. Further aphid-transmitted viruses found in faba bean were bean leaf roll virus, beet western yellows virus, clover yellow vein virus (in 2002) and soybean dwarf virus (in 2004). A. pisum was the predominant aphid species colonising faba bean plants. Early sowing compared with late sowing led to a significant reduction of the total virus incidence in faba bean in all 3 years. However, significantly decreased levels of A. pisum colonisation as a result of early sowing were observed only in 1 year and one cultivar. Irrespective of sowing date, straw mulching had no significant effects on virus incidence and aphid colonisation. Compared with late sowing, early sowing significantly increased bean yield in all 3 years and kernel weight in 2 years, whereas straw mulching had no effect on yield. [source]