New forage crop introductions for the semi-arid highland areas of Kenya as a means to increase beef production.

A UNDP/FAO Development Project has initiated and aided the establishment of a commercial beef cattle finishing sector in Kenya. The feeding systems developed utilize surplus cattle from rural areas which are fed on rations based on maize silage. The project has now initiated a search for forage crops suitable for cultivation under highland conditions, but more drought-resistant than the presently used maize. It appeared in a trial at 3 sites at 1850-1920 m alt. that new introductions of cold-tolerant sorghum cv. from the high-alt. areas of Uganda and Ethiopia produced consistently good yields which were comparable to, or better than, maize. Some of the high-alt. sorghum cv. were completely free from diseases which are typically encountered when 'lowland' cv. are grown above 1600 m in Kenya. In contrast with maize and sunflower, the new sorghum introductions were highly resistant to lodging. Correlation analysis showed that the unwanted tallness of crops is highly associated with the yield of maize and sunflower, whereas with cold-tolerant sorghum cv. there is scope for selection or breeding of high-yielding material which is shorter. The single highest-yielding entry for cold-tolerant sorghum, sunflower and maize produced 30.5, 29.5 and 26.6 t DM/ha, resp. (Abstract retrieved from CAB Abstracts by CABI’s permission

Leaf area determinations in sorghum and maize by the length-width method.

5 plant population trials were carried out in 1974 and 1975 with 5 sorghum and 4 maize cv. Each trial was sample harvested several times during the growing period. In 6080 leaves the leaf area was carefully determined and related to its length and width. By regression calculations an examination was made regarding the construction of the best calibration lines for the estimation of the product of length and width from leaf area. Plant population had no significant effect on the regressions. Drawing the regression lines through the origin was sometimes statistically rejected but if the regression lines were forced through the origin in spite of this, the loss of precision was very small. It is therefore concluded that forcing the regression lines through the origin involves an acceptable estimation error. The resulting regression lines which were established separately for each cv. and harvest proved to estimate the leaf area accurately. The values of the regression coefficients varied between 0.65 and 0.77. The lowest correlation coefficient was 0.968, but 55% of all correlation coefficients were >0.990. If data from different harvests were pooled (although not allowable statistically) the highest mean error of estimation of leaf area at any harvesting date was 8.5%. (Abstract retrieved from CAB Abstracts by CABI’s permission

The forage and grain yield of cold-tolerant sorghum and maize as affected by time of planting in the highlands of Kenya.

In trials with sorghum and maize in the highlands of Kenya the effects of sowing date on the forage and grain yields were studied. Yields were regressed on sowing date in days after the start of the wet season, mean air temp. during the 1st 5 wk post-em. and sowing date index in a yield stability analysis. Grain yields varied more than total DM yields, indicating that correct sowing date was more important if crops were harvested for grain than for forage. Sorghum cv. E 1291 gave the highest grain yields and sorghum cv. E 6518 the highest DM yields under all conditions. The grain yield of E 1291 was less affected by delayed sowing than the grain yield of maize cv. H 613. In a dry yr delayed sowing was beneficial because it allowed a certain soil moisture reserve to be built up, but this beneficial effect disappeared if the duration of crop development exceeded the length of the wet season. If rainfall was heavy immediately after the dry season, delayed sowing had a pronounced negative effect on yields. Under such conditions DM yields decreased by 1.0 t/ha for each wk delay in sowing for both E 6518 and H 613; grain yields decreased by 0.41 t/ha wk and 0.47 t/ha wk for E 1291 and H 613, resp. All grain yields were positively correlated with av. mean air temp. and regression coeff. varied from 0.77 to 3.67 t/ deg C, but temp was confounded with rainfall and more work was needed to separate temp. and rainfall effects. (Abstract retrieved from CAB Abstracts by CABI’s permission

Fertilizer response of cold-tolerant sorghums under semi-arid high-altitude conditions.

5 fertilizer trials were carried out in 1974-5 at 3 different high-alt. locations in Kenya. In 3 of the 5 trials the yield response of a grain-type sorghum cv. was compared with the response of a forage-type cv. to N and P. In the other 2 trials the yield response of a grain-type sorghum to N, P, K and Mg + Zn, B and Cu was studied. Rainfall during the field period of the crop varied from 225 mm to 811 mm. There was no interaction with yr, but the responses varied greatly with trial site. Although DM yields obtained from the grain type in the driest trials were considered good (4.9 t DM/ha on 255 mm and 7.2 t DM/ha on 294 mm), no response to N or P was observed. Under wetter conditions it appeared that N increased the total DM yield of the forage-type cv. and the grain yield of the grain-type cv.; the type was accentuated. P increased the grain yield and total DM yield of the grain-type cv. Both N and P increased the CP content of the forage sorghum, but with the grain sorghum only N increased CP content whereas P decreased it. K and trace elements had a positive influence on yield in 2 experiments, but more work is needed to evaluate this effect in detail. Yield and forage quality differences resulting from different fertilizer applications were small. One possible reason for this is N-fixation in the soil, but more research is needed to substantiate this. In the trials with the lowest rainfall, the earlier maturing grain type outyielded the forage type, but if rainfall was less limited the forage type had a clear advantage over the grain type. (Abstract retrieved from CAB Abstracts by CABI’s permission

The forage and grain yield of sorghum and maize as affected by soil moisture conservation, lodging and harvesting losses.

The effects of early ploughing (before the start of the dry season) and late ploughing on the grain and DM yields of a forage maize and cold-tolerant forage and grain sorghum crops are reported. It appeared that on a shallow soil no significant effects on crop production could be shown, but on a deep soil with good water-holding capacity, crop yields were increased considerably by reducing soil moisture evaporation in the dry period prior to the growing season. In DM yield forage sorghum outyielded maize, a difference which was accentuated when mechanized harvesting systems were used in lodged crops. Forage sorghum proved to be more lodging-resistant than maize but, even when lodged, was harvestable without too much difficulty. The use of small-plot maize yield trials is considered to have limited applicability to mechanized harvesting systems when presently available Kenyan maize hybrids are used. Lodging was the major limiting field factor for the harvesting of heavy maize crops. The highest net yields recorded for maize and sorghum were 12.0 and 23.7 t DM/ha, resp. The higher yield of sorghum was probably not due to better drought resistance but to lower lodging susceptibility and a longer growing period. (Abstract retrieved from CAB Abstracts by CABI’s permission

The identification and introduction of a new crop in the highlands of Kenya

African range cattle respond well to intensive feeding in feedlots, when maize silage based rations are fed. Maize is not drought-tolerant and is lodging-susceptible, which makes it less attractive as a forage. In a search for alternative forages, a new group of plant material is introduced: high-altitude, cold-tolerant sorghum. Some of the cultivars in this group appear to outyield maize both in terms of total dry matter and grain yield, over a large range of environmental conditions in the Kenyan highlands. Crop husbandry trials with the new sorghums and maize are reported. In an animal feeding trial the cattle performance of maize and sorghum silage based rations is compared. The introduction of new high-altitude, cold-tolerant grain type sorghums may eventually lead to a substantial increase of the area under arable agriculture in Kenya, because it will make grain production feasible in areas which were previously considered too dry for reliable grain production. A discussion of the typical problems of working on agricultural development in a developing country is given

Hanny's Voorwerp: a nuclear starburst in IC2497

We present high and intermediate resolution radio observations of the central region in the spiral galaxy IC 2497, performed using the European VLBI Network (EVN) at 18 cm, and the Multi-Element Radio Linked Interferometer Network (MERLIN) at 18 cm and 6 cm. The e-VLBI observations detect two compact radio sources with brightness temperatures in excess of 105 K, suggesting that they are associated with an AGN located at the centre of the galaxy. We show that IC2497 lies on the FIR-radio correlation and that the dominant component of the 18 cm radio flux density of the galaxy is associated with extended emission confined to sub-kpc scales. IC 2497 therefore appears to be a luminous infrared galaxy that exhibits a nuclear starburst with a total star formation rate (assuming a Salpeter IMF) of ~ 70 M*/yr. Typically, vigorous star forming galaxies like IC2497 always show high levels of extinction towards their nuclear regions. The new results are in-line with the hypothesis that the ionisation nebula "Hanny's Voorwerp", located ~15-25 kpc from the galaxy is part of a massive gas reservoir that is ionised by the radiation cone of an AGN that is otherwise obscured along the observer's line-of- sight.Comment: Paper presented at the 10th EVN Symposium in Manchester, Sep. 201

High-pressure structural, elastic and electronic properties of the scintillator host material, KMgF_3

The high-pressure structural behaviour of the fluoroperovskite KMgF_3 is investigated by theory and experiment. Density functional calculations were performed within the local density approximation and the generalized gradient approximation for exchange and correlation effects, as implemented within the full-potential linear muffin-tin orbital method. In situ high-pressure powder x-ray diffraction experiments were performed up to a maximum pressure of 40 GPa using synchrotron radiation. We find that the cubic Pm\bar{3}m crystal symmetry persists throughout the pressure range studied. The calculated ground state properties -- the equilibrium lattice constant, bulk modulus and elastic constants -- are in good agreement with experimental results. By analyzing the ratio between the bulk and shear modulii, we conclude that KMgF_3 is brittle in nature. Under ambient conditions, KMgF_3 is found to be an indirect gap insulator with the gap increasing under pressure.Comment: 4 figure

Genomic characterization and linkage mapping of the apple allergen genes Mal d 2 (thaumatin-like protein) and Mal d 4 (profilin)

Four classes of apple allergens (Mal d 1, ¿2, ¿3 and ¿4) have been reported. By using PCR cloning and sequencing approaches, we obtained genomic sequences of Mal d 2 (thaumatin-like protein) and Mal d 4 (profilin) from the cvs Prima and Fiesta, the two parents of a European reference mapping population. Two copies of the Mal d 2 gene (Mal d 2.01A and Mal d 2.01B) were identified, which primarily differed in the length of a single intron (378 or 380 nt) and in one amino acid in the signal peptide. Both Mal d 2.01A and Mal d 2.01B were mapped at identical position on linkage group 9. Genomic characterization of four Mal d 4 genes (Mal d 4.01A and B, Mal d 4.02A and Mal d 4.03A) revealed their complete gDNA sequences which varied among genes in length from 862 to 2017 nt. They all contained three exons of conserved length: 123, 138, and 135 nt. Mal d 4.01 appeared to be duplicated in two copies and located on linkage group 9. Mal d 4.02A and Mal d 4.03A were single copy genes located on linkage group 2 and 8, respectivel

Endogenous Viral Genes in Thirteen Highly Inbred Chicken Lines and in Lines Selected for Immune Response Traits

Thirteen highly inbred lines of chickens of Leghorn, Spanish, and Egyptian Fayoumi origin, four partly inbred Leghorn lines selected for MHC alleles and immune response to GAT (Ir-GAT), and two replicated, noninbred Leghorn lines divergently selected for multiple immune response traits were subjected to molecular genotyping for endogenous viral (ev) gene sequences. In all highly inbred lines of Leghorn origin, ev 1 alone or both ev 1 and ev 2 were observed. The Spanish and Fayoumi lines had three and five ev genes, respectively, most of which were not readily identifiable with standard Leghorn ev gene loci. The Leghorn lines selected for MHC and Ir-GAT had ev 1 fixed in the population. Differences in ev 3 and ev 5 gene frequency were associated with Ir-GAT in the B1 haplotype, but not in the B19 haplotype. In the noninbred lines, which were divergently selected for multiple traits of immune responsiveness, ev 6 and ev 9 differed in frequency between lines, and both were in lower frequency in the lines selected for high immunoresponsiveness. These two ev genes are the only ones known in White Leghorns that have the gs– chf+ phenotype [expressing chicken helper factor (chf) but not expressing group-specific antigen (gs)]