Effect of sowing rate of glycine and green panic mixtures on establishment and survival under dry conditions

Glycine javanica cv. Tinaroo and green panic were sown together in May 1962 in all possible sowing-rate combinations of 2, 4, 8 and 16 lb/ac for the former and of 0, 0.5, 1, 2 and 4 lb/ac for the latter, and survival was followed for 2.5 years. Plant density of each species was dependent solely on the sowing rate of that species. There was no evidence of interspecific competition under these conditions, where neither species made sufficient growth to warrant yield samplings. Sparse stands of both species were present at the end of the study, though green panic at lower rates showed an increase in plant density; G. javanica stands gradually declined at all sowing rates

Effect of grazing management on persistence of Priebe prairie grass in an irrigated pasture

Lengthening the regrowth interval from 4 to 6 weeks, with or without extra deferment of grazing in autumn and spring, did not significantly improve the persistence of the grass component of an irrigated prairie grass (Bromus unioloides)

Effect of renovation and nitrogen fertilization on an old stand of buffel grass (Cenchrus ciliaris) in sub-coastal central Queensland

The effect of adding N as urea at 1 cwt/ac with or without cultivation with disk harrows was studied as a means of restoring vigour to an old buffel-grass pasture. Rainfall over the 2 years of the trial was below average

Perspectives on global leadership and the Covid-19 crisis

As the world struggled to come to grips with the Covid-19 pandemic, over twenty scholars, practitioners, and global leaders wrote brief essays for this curated chapter on the role of global leadership in this extreme example of a global crisis. Their thoughts span helpful theoretical breakthroughs to essential, pragmatic adaptations by companies

Evolutionary significance of inversions in legume chloroplast DNAs

Cloned genes from tobacco, spinach, and pea were used as hybridization probes to localize 36 protein genes on the chloroplast chromosomes of four legumes — mung bean, common bean, soybean, and pea. The first three chloroplast DNAs (cpDNAs), all of which retain a large inverted repeat, have an identical gene order with but one exception. A 78 kb segment encompassing nearly the entire large single copy region is inverted in mung bean and common bean relative to soybean and non-legumes. The simplest evolutionary explanation for this difference is a 78 kb inversion, with one endpoint between rps8 and inf A and the second between psb A and rpl2 . However, we can not rule out a two-step re-arrangement (consisting of successive expansion and contraction of the inverted repeat) leading to the relocation of a block of six ribosomal protein genes ( rps 19- rps 8) from one end of the large single copy region to the other. Analysis of gene locations in pea cpDNA, which lacks the large inverted repeat, combined with cross-hybridization studies using 59 clones covering the mung bean genome, leads to a refined picture of the position and nature of the numerous rearrangements previously described in the pea genome. A minimum of eight large inversions are postulated to account for these rearrangements. None of these inversions disrupt groups of genes that are transcriptionally linked in angiosperm cpDNA. Rather, the end-points of inversions are associated with relatively spacer-rich segments of the genome, many of which contain tRNA genes. All of the pea-specific inversions are shown to be positionally distinct from those recently described in a closely related legume, broad bean.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46965/1/294_2004_Article_BF00405856.pd

Effect of nitrogen fertilization and slashing on the Priebe prairie grass (Bromus uniofoides) component of an irrigated pasture

The effect of 200 lb/ac/annum of nitrogen applied as urea in split applications, and of regular slashing after each grazing, was studied for 3 years on an irrigated sward. The pasture initially consisted of 20% Priebe prairie grass and 75% Ladino white clover. Inadequate summer irrigation caused the clover to largely disappear from the sward in the first 15 months of the study. This was accompanied by summer grass invasion. Very marked responses by the prairie grass occurred as the clover disappeared from the sward and the rate of cool season nitrogen application was increased. Over the 1966 season, nitrogen increased the total yield of prairie grass from 1,105 lb/ ac oven-dry matter to 7,618 lb/ac. Nitrogen depressed clover yield on one occasion. At the end of the trial the nitrogen fertilized sward was composed of 7 5 % prairie grass and equal proportions of clover and weeds. Slashing after each grazing decreased yield of prairie grass on only three occasions