Alternate Selection Indices for Leaf Photosynthetic Rate in Greengram (Vigna radiata [L.] Wilczek) Cultivars

Significant differences were observed for leaf net photosynthetic rate, chlorophyll content, soluble protein content, nitrate reductase activity, stomatal frequency and specific leaf mass among ten greengram cultivars. Leaf net photosynthetic rate had significant positive correlation with soluble protein, nitrate reductase activity, stomatal frequency and specific leaf mass. Leaf net photosynthetic rate had no relationship with leaf chlorophyll content in greengram.     

Temporal-Spectral Profile Characteristics of Certain Rice Cultivars

The spectral variables have been found to be useful in distinguishing high and low yielding rice cultivars under different growing seasons. Transverse shift in the spectral profile served as a tool for identification of these cultivars.     

Allelopathic Potential of Shoot and Root Leachates of Certain Weed Species

The allelopathic potential of shoot and root leachates of seven weed species was assessed using sorghum and blackgram as test crops. Weeds differed significantly among themselves in their allelopathic effect. Shoot leachates of weeds, in general, showed more allelopathic effect than their root leachates. Phenolic content of weed leachates has positive association with the allelopathic potential of the weed species.     

Weather and land cover create a predictable “stress-scape” for a winter-adapted bird

Landscape Ecology - Variability in temperature and snow cover are characteristics of high-latitude environments that impose significant pressures on overwintering species. To cope with increased...     

The pathology of E. ovis

Abstract

Extract

Sir, — In your September issue, Sutton (3) Sulton, R. H. 1978. N.Z. vet. J., 26: 224–230.  [Google Scholar] suggests that the anaemia of E. ovis infection is due to intravascular haemolysis. The pathology he describes is almost identical to that described by Dacie(l) Dacie, J. V. 1963. The Haemolylic Anaemias, 2nd ed., 382–382. London: Churchill.  [Google Scholar] in autoimmune haemolytic anaemia in man; sheep recently exposed to active E. ovis infection are usually positive to the Coombs test(2) Sheriff, D. 1967. Nature, 215: 101–101.  [Google Scholar] and show spherocytosis; in my experience, haemoglobinuria is rarely, if ever, seen in E. ovis infection but is common in intravascular haemolytic conditions in sheep; and, finally, what appears to be haemoglobinaemia in sheep infected with E. ovis may be due to the rupture of abnormally fragile red cells during, or after, collection of the blood. On this evidence, it seems likely that incomplete antibodies are involved in the red cell destruction that characterises E. ovis infection, and that the process takes place extravascularly, by phagocytosis.     

Influence of Seasonality on Certain Leaf Characteristics in Rice Cultivars

Higher growth and grain yield in rice was obtained in February planting as compared to July and October plantings. This was achieved through favourable leaf characteristics. In all the three plantings, leaf number monitored the leaf area rather than ILS which showed minimal alterations by the seasonality. There was a considerable variation in the attainment of critical leaf area index (LAI) among cultivars in different seasons. Thus, attainment of critical LAI would be necessary to influence the sink strength positively.