Greenhouse evaluation of the potential of sorghum, pearl millet and crotalaria in the management of Meloidogyne javanica

Crop rotation can play a valuable role in managing plant parasitic nematodes, depending on the availability of profitable non-host or poor host crops. Alternatively, non-host cover crops or green manures can be used in succession to summer cash Crops for this Purpose. The aim of the current study was to evaluate, under greenhouse conditions, the host status of commercial hybrids and cultivars of grain and silage sorghum (Sorghum bicolor) for Meloidogyne javanica, and to assess the effect of sorghum on nematode population in comparison with pearl millet (poor host for M. javanica), showy crotalaria and sunn hemp (both non-hosts). Based on two experiments, it was stated that, as a rule, grain sorghum is a poor host for M. javanica, but silage sorghum is a good host. Silage sorghum `BRS 601` was an exception. In other experiments, grain sorghum, pearl millet (Pennisetum glaucum `BN 2`), showy crotalaria (Crotolaria spectabilis `Comum`) and sunn hemp (C. juncea `IAC-KR-1`) reduced M. javanica population level, while silage sorghum increased the nematode density.

Production of finger millet (Eleusine coracana (L.) Gaertn.) dry matter under anticipated fertilization of soybeans

Due to the lack of information about the effects of soybean fertilization anticipation and the use of Eleusine coracana (L.) Gaerm. (ANSB Pe-de-galinha 5352) as cover culture, and the need for new techniques for the management of the agro-ecosystem in a more conservationist, sustainable and functional manner the goal of this research was to study the effects of anticipated fertilization on the production of dry matter in E. coracana. The experiments were carried out in an Oxisol, during the growing seasons of 200112002, 200212003 and 200312004, in Piracicaba, SP Brazil (22`50`25""S and 48`01`65""W). The experimental design was of totally randomized blocks and twelve treatments (lev- els of anticipated fertilization) were used with three repetitions. The base fertilization of soybean culture was partially anticipated, in the sowing for the finger-millet crop. Approximately 70 days after sowing, samples of the finger millet plants were collected in order to evaluate the dry matter production and to desiccate them thereafter It is concluded that the anticipation of phosphorus and potassium fertilization of soybean increases the dry matter production of E. coracana; in addition, E. coracana holds a great potential for the production of plant residues and it can be used in culture rotation or in no-tillage production systems.

Simulating growth, development, and yield of tillering pearl millet. III. Biomass accumulation and partitioning

Pearl millet landraces from Rajasthan, India, yield significantly less than improved cultivars under optimum growing conditions, but not under stressed conditions. To successfully develop a simulation model for pearl millet, capable of capturing such genotype x environment (G x E) interactions for grain yield, we need to understand the causes of the observed yield interaction. The aim of this paper is to quantify the key parameters that determine the accumulation and partitioning of biomass: the,light extinction coefficient, radiation use efficiency (RUE), pattern of dry matter allocation to the leaf blades, the determination of grain number, and the rate and duration of dry matter accumulation into individual grains. We used data on improved cultivars and landraces, obtained from both published and unpublished sources collected at ICRISAT, Patancheru, India. Where possible, the effects of cultivar and axis (main shoot vs. tillers) on these parameters were analysed, as previous research suggested that G x E interactions for grain yield are associated with differences in tillering habit. Our results indicated there were no cultivar differences in extinction coefficient, RUE, and biomass partitioning before anthesis, and differences between axes in biomass partitioning were negligible. This indicates there was no basis for cultivar differences in the potential grain yield. Landraces, however, produced consistently less grain yield for a given rate of dry matter accumulation at anthesis than did improved cultivars. This was caused by a combination of low grain number and small grain size. The latter was predominantly due to a lower grain growth rate, as genotypic differences in the duration of grain filling were relatively small. Main shoot and tillers also had a similar duration of grain filling. The low grain yield of the landraces was associated with profuse nodal tillering, supporting the hypothesis that grain yield was below the potential yield that could be supported by assimilate availability. We hypothesise this is a survival strategy, which enhances the prospects to escape the effects of stress around anthesis. (C) 2002 E.J. van Oosterom. Published by Elsevier Science B.V. All rights reserved.

Osmoregulative capacity in birdseed millet under conditions of water stress. I. Variation in Setaria italica and Panicum miliaceum

Experiments involving 14 accessions of Panicum miliaceum L. (Proso millet) and 11 accessions of Setaria italica L. (Foxtail millet) have demonstrated variability in the degree of osmoregulative capacity among these accessions. Birdseed millet is generally claimed to be sensitive to drought stress, apparently because of a shallow root system. Accessions with high osmoregulative capacity demonstrate at least some drought tolerance. Osmoregulative capacity was measured on flag leaves of headed millet plants in pots undergoing water stress in a controlled environment chamber. Osmoregulative capacity was determined from the relationship between osmotic potential and leaf water potential; and the logarithmic relationship between osmotic potential and relative water content. The group of accessions of S. italica showed an overall level of osmoregulative capacity which was greater than that observed for the group of P. miliaceum accessions. Four accessions of S. italica (108042, 108463, 108541 and 108564) and one accession of P. miliaceum (108104) demonstrated high osmoregulative capacity. Differences of 1.05 MPa or more between observed and estimated osmotic potential were found at relative water contents of 80 % among these accessions. The extent of osmoregulative capacity was associated with osmotic potential at full turgor and the rate of decline in osmotic potential as leaf water potentail declined.

A yield architecture framework to explain adaptation of pearl millet to environmental stress

Functional knowledge of the physiological basis of crop adaptation to stress is a prerequisite for exploiting specific adaptation to stress environments in breeding programs. This paper presents an analysis of yield components for pearl millet, to explain the specific adaptation of local landraces to stress environments in Rajasthan, India. Six genotypes, ranging from high-tillering traditional landraces to low-tillering open-pollinated modern cultivars, were grown in 20 experiments, covering a range of nonstress and drought stress patterns. In each experiment, yield components (particle number, grain number, 100 grain mass) were measured separately for main shoots, basal tillers, and nodal tillers. Under optimum conditions, landraces had a significantly lower grain yield than the cultivars, but no significant differences were observed at yield levels around 1 ton ha(-1). This genotype x environment interaction for grain yield was due to a difference in yield strategy, where landraces aimed at minimising the risk of a crop failure under stress conditions, and modem cultivars aimed at maximising yield potential under optimum conditions. A key aspect of the adaptation of landraces was the small size of the main shoot panicle, as it minimised (1) the loss of productive tillers during stem elongation; (2) the delay in anthesis if mid-season drought occurs; and (3) the reduction in panicle productivity of the basal tillers under stress. In addition, a low investment in structural panicle weight, relative to vegetative crop growth rate, promoted the production of nodal tillers, providing a mechanism to compensate for reduced basal tiller productivity if stress occurred around anthesis. A low maximum 100 grain mass also ensured individual grain mass was little affected by environmental conditions. The strategy of the high-tillering landraces carries a yield penalty under optimum conditions, but is expected to minimise the risk of a crop failure, particularly if mid-season drought stress occurs. The yield architecture of low-tillering varieties, by contrast, will be suited to end-of-season drought stress, provided anthesis is early. Application of the above adaptation mechanisms into a breeding program could enable the identification of plant types that match the prevalent stress patterns in the target environments. (C) 2003 E.J. van Oosterom. Published by Elsevier Science B.V. All rights reserved.

Répartition en Suisse et en France de Sorex araneus L., 1758 et de Sorex coronatus Millet, 1828 (Mammalia, Insectivora)

La répartition en Suisse et en France de Sorex coronatus et de Sorex araneus est étudiée au moyen de l'analyse ostéométrique des mandibules mise au point récemment (Hausser et Jammot, 1974). Nous discutons la mise en pratique de cette méthode. 1 101 exemplaires provenant de 207 localités ont été étudiés. Ces données s'ajoutent aux informations cytologiques obtenues antérieurement pour 65 localités. Les résultats indiquent que S. coronatus et S. araneus ne sont pas sympatriques, sauf éventuellement sur la frange nord-est de l'aire de répartition de la première espèce. Celle-ci semble progresser vers l'est et éliminer peu à peu S. araneus, sauf en montagne, où demeurent des populations isolées et, dans une moindre mesure, dans les lieux humides.

Le type chromosomique A des Sorex du groupe araneus: Sorex coronatus Millet, 1828 (Mammalia, Insectivora)

Après avoir complété la nomenclature par lettres des différents caryotypes des musaraignes du genre Sorex rattachées au groupe araneus, lequel est caractérisé par un trivalent sexuel, les auteurs discutent le statut taxonomique du type A. Sur la base de l'examen cytologique et morphologique de 3 individus, récoltés dans la localité type de Sorex coronatus Millet, 1828,ils proposent ce nom pour désigner l'espèce chromosomique A. Sorex gemellus Ott, 1968 tombe alors en synonymie. L'espèce est décrite et le statut des sous-espèces reconnues dans son aire de distribution examiné.

Cycling of nutrients and silicon in pigeonpea and pearl millet monoculture and intercropping

In a no-tillage system, cover crops must be used that combine shoot dry matter production and nutrient recycling. The aim of this study was to evaluate shoot dry matter production, decomposition rate and macronutrient and silicon release from pigeonpea and pearl millet in monoculture and intercropping systems. A randomized block design was used with a 3 x 6 factorial arrangement, with four replications. The first factor consisted of three cover crops (pigeonpea, pearl millet and intercropping of these cover crops) and the second consisted of six sampling times [0, 18, 32, 46, 74 and 91 days after desiccation (DAD)]. Pearl millet produced greater amounts of shoot dry matter and content of N, P, K, Ca, Mg, S, C and Si and had a higher decomposition rate and macronutrient and Si release than the other cover crops. The rates of decomposition and daily nutrient release from shoot dry matter were highest in the first period of evaluation (0-18 DAD). Over time, the C/N, C/P and C/S ratios increased, while C/Si and the decomposition rate decreased. Potassium was the nutrient most quickly released to the soil, especially from pearl millet residue. Silicon had the lowest release rate, with 62, 82 and 74 % of the total content in the shoot dry matter remaining in the last evaluation of pearl millet, pigeonpea and in the intercrop system, respectively. The shoot dry matter from the intercrop system had a different decomposition rate than that from the pearl millet monoculture and pigeonpea. Plants with greater shoot dry matter production and lower C/Si ratio are more effective in a no-tillage system for providing a more complete and persistent soil cover.

Habitat selection in zones of parapatric contact between the Common shrew Sorex araneus and Millet's shrew S. coronatus

(1) The common shrew Sorex araneus and Millet's shrew S. coronatus are sibling species.They are morphologically and genetically very similar but do not hybridize. Their parapatric distribution throughout south-western Europe, with a few narrow zones of distributional overlap, suggests that they are in competitive parapatry. (2) Two of these contact zones were studied; there was evidence of coexistence over periods of 2 years as well as habitat segregation. In both zones, the species segregated on litter thickness and humidity variables. (3) A simple analysis of spatial distribution showed that habitats visible in the field corresponded to the habitats selected by the species. Habitat selection was found throughout the annual life-cycle of the shrews. (4) In one contact zone, a removal experiment was performed to test whether habitat segregation is induced by interspecific interactions. The experiment showed that the species select habitats differentially when both are present and abandon habitat selection when their competitor is removed. (5) These results confirm the role of resource partitioning in promoting narrow rangesof distributional overlap between such parapatric species and qualitatively support the prediction of habitat selection theory that, in a two-species system, coexistence may be achieved by differential habitat selection to avoid competition. The results also support the view that the common shrew and Millet's shrew are in competitive parapatry.

La Topografía médica de Vic de Antonio Millet: 1798

En primer lloc, aquest llibre conté una traducció i transcripció de la Topografia Mèdica de Vic, d'Antoni Millet, de 1798. Aquesta transcripció es completa amb una investigació analítica i detallada del context cultural en què sorgiren les primeres topografies mèdiques al nostre país.El present document suposa el redescobriment d'una figura rellevant de la medicina catalana, Antoni Millet, de qui també es recull una segona obra entorn a una epidèmia que afectà la ciutat de Ripoll l'any 1790.

Habitat selection in zones of parapatric contact between the common shrew Sorex araneaus and Millet's shrew S. coronatus

(1) The common shrew Sorex araneus and Millet's shrew S. coronatusare sibling species.They are morphologically and genetically very similar but do not hybridize.Their parapatric distribution throughout south-western Europe, with a few narrow zones of distributional overlap, suggests that they are in competitive parapatry. (2) Two of these contact zones were studied; there was evidence of coexistence over periods of 2 years as well as habitat segregation. In both zones, the species segregated on litter thickness and humidity variables. (3) A simple analysis of spatial distribution showed that habitats visible in the field corresponded to the habitats selected by the species. Habitat selection was found throughout the annual life-cycle of the shrews. (4) In one contact zone, a removal experiment was performed to test whether habitat segregation is induced by interspecific interactions. The experiment showed that the species select habitats differentially when both are present and abandon habitat selection when their competitor removed. (5)These results confirm the role of resource partitioning in promoting narrow ranges of distributional overlap between such parapatric species and qualitatively support the prediction of habitat selection theory that, in a two-species system, coexistence may be achieved by differential habitat selection to avoid competition. The results also support the view that the common shrew and Millet's shrew are in competitive parapatry.