Vitreousness is an important quality characteristic that affects the yield of semolina during milling of durum wheat. It has been observed that kernel vitreousness seems to be lower when durum is exposed to damp conditions just before harvest. The main objective of this research was to determine the effect of high relative humidity (RH) on kernel vitreousness of ten durum wheat cultivars. Spikes were exposed to 88% RH at room temperature for 1 and 3 days. This resulted in increased spike moisture, kernel moisture and kernel size. Vitreous kernel content (vitreousness) decreased 23.6% after spikes were exposed to high relative humidity for 3 days. Exposure to 88% RH caused the greatest decline in vitreousness with the cultivar ‘Ben’.
Seed moisture content is a well-recognised index of safe storage. However, when in equilibrium with the storage environment it is merely an indicator of the relative humidity of the air, which is the primary regulator of the growth of moulds and insects. The relationship is influenced by the profile of the seed components. During the 1990s, significant increases in the seed oil content of evening primrose were achieved through plant breeding. This paper shows that the equilibrium moisture content of evening primrose seeds declines significantly with increasing oil content. Hence, the moisture isotherm is altered and newer cultivars must be stored at slightly lower seed moisture contents to ensure that seed and oil quality are maintained.
Authors:B. Abou-Awad, A. Metwally, and M. Al-Azzazy
Abou-Elella, G. M. (2003): Effect of eriophyid prey species and relativehumidity on some biological aspects of the predatory mite,
Proprioseiopsis (Amblyseius) lindiquisti
(Acari: Phytoseiidae). Egypt. J. Biol. Pest Cont. 13, 31
Marin , J. A.
( 2003 ): High survival rates during acclimatization of micropropagated fruit tree rootstocks by increasing exposures to low relativehumidity . — Acta Hortic. 616 : 139 – 142 . https://doi.org/10.17660/actahortic.2003
In order to examine the complex role of the vegetation
structure determining microclimate, the authors carried out temperature and
relative humidity measurements in beany fens, drying fens, semidry grasslands,
hayfields, steppe grasslands, rocky grasslands and open sandy grasslands of the
Transdanubian mountains. In the course of this process, measurement and data
recording took place annually with four repetitions (June, July, August,
September) per sampling area in identical weather conditions, resulting in
altogether 162 sampling occasions in 84 sampling areas on the ground surface
and at a height of 10, 20, 30 and 120 cm in the grassland. In the present paper
measurement data concerning the humidity of grasslands researched to a lesser
extent in previous works are assessed. The comparative study ascertains that
based on the relative humidity curves depicting microclimate, the samples of
the examined types of grassland should be handled as separate groups in each
sampling period. A further result to be seen is that in the case of several
grasslands (semidry grasslands, drying fens) aspect change can also be detected
in the change of microclimate (decrease of the relative humidity). The shift in
relative humidity curves towards drying can be most conspicuously seen in the
case of semidry grasslands.
An impact of temperature, light and relative humidity were studied on root colonisation by mycorrhizal fungi and on pine seedling growth. Moderate and high light intensities favoured mycorrhizal colonisation and seedling growth. Pine seedlings inoculated with
compared to other fungi attained maximum growth. Survival of pine seedlings was higher under moderate light intensity than low and high light intensity. Seedling growth and mycorrhizal colonisation was better at 25°C than 10°C. Variation in humidity did not show much difference in mycorrhizal colonisation and seedling growth. However, seedling survival was greater at high than at low humidity. Pine seedlings showed best survival with 0.5 P level (46.153 mg P/kg soil) of phosphorus at 25 °C temperature and under moderate light intensity. Among the mycorrhizal fungi used
was the most effective endophyte and was followed by
Laccaria laccata, Rhizopogon luteolus
under various physical factors.
Authors:K. Viswajyothi, N. Aggarwal, and J. Jindal
The biology of Sesamia inferens (Walker) was studied at 25±1 °C
and 70±5 per cent relative humidity on PMH 1 maize hybrid. The incubation period
was 6.82±0.05 days. There were six larval instars and the larval development was
completed in 29.95±0.16 days. The duration of instars I-VI was 4.17±0.09,
3.60±0.08, 4.47±0.02, 4.40±0.03, 6.18±0.06 and 7.13±0.05 days, respectively. The
pre-pupal period was 2.83±0.02 days. The male and female pupa had duration of
8.05±0.12 days and 10.33±0.16 days, respectively. The adult emergence was
93.02±0.01 per cent, with a sex ratio of 1:1.05. The males had shorter longevity
of 3.92±0.23 days, while females had 5.05±0.28 days. The pre-oviposition,
oviposition and post-oviposition period was 1.11±0.10, 2.96±0.19 and 0.79±0.10
days, respectively. The fecundity was 211.92 ±11.92 eggs with 53.69±10.78 eggs
per cluster. The egg hatchability was 92.19±0.01 per cent. The total life cycle
was completed in 47.65±0.24 days (Male) and 49.93±0.21 days (female). The
observations on the biology will help in developing efficient strategies to
manage S. inferens on maize in the north western plains of
Authors:D. S. G. Henriques, P. A. V. Borges, and R. Gabriel
How are bryophyte alpha and beta diversities distributed across spatial scales along an elevational gradient in an oceanic island? Which mechanisms and drivers operate to shape them? Starting from a multiscale hierarchical sampling approach along an 1000 m elevational transect, we used additive diversity partitioning and null modeling to evaluate the contributions of the alpha and beta diversity components to overall bryophyte diversity in Terceira Island, Azores. Substrate-level diversity patterns were explored by means of the Sørensen Similarity Index and the Lloyd Index of Patchiness. Elevation-level beta diversity was decomposed into its replacement and richness differences components, with several environmental variables being evaluated as diversity predictors. Bryophyte diversity proved to be primarily due to beta diversity between elevation sites, followed by diversity among substrates. Compositional differences between neighboring sites decreased with elevation, being mainly caused by species replacement and correlating with differences in relative humidity and disturbance. At the substrate level, we found a great homogeneity in terms of species composition, coupled with a low substrate specialization rate. We conclude that, in Terceira’s native vegetation patches, regional processes, such as environmental gradients associated with elevation, play a greater role in shaping bryophyte diversity than local processes. Moister and less disturbed areas at mid-high elevation harbor a richer bryoflora, consistently more similar and stable between neighbouring sites. Simultaneously, the different substrates available are somewhat ecologically redundant, supporting few specialized species, pointing to these areas providing optimal habitat conditions for bryophytes. Our findings provide a better understanding of how bryophyte diversity is generated in Terceira Island, indicating that management and conservation measures should focus on island-level approaches, aiming to protect and rehabilitate additional natural vegetation patches at different elevations, especially in the severely disturbed lowlands.
The work presents the role of the abiotic factors in the development of the thrips populations in the mountainous meadows. We have calculated the correlation coefficients between thrips numerical abundance obtained throughout three years, and two main weather factors. 93 correlation coefficients higher than 0.5 were obtained in the case of the correlation between the abundance of 12 Thrips species and air relative humidity; 218 in the case of correlation abundance - air temperature; 411 in the case of multiple correlation coefficients. Taeniothrips picipes, Frankliniella intonsa, Aeolothrips intermedius, Thrips pelikani and Chirothrips manicatus had the highest number of significant values of multiple correlation coefficients.