Determination of Exchangeable Ca and Mg Contents in Tobacco Growing Area by Atomic Absorption Spectrometry

[Objective] A method for the determination of exchangeable Ca and Mg contents in tobacco growing area by atomic absorption spectrometry was established. [Method] Factors in the extraction process, sample weight, ammonium acetate volume, extraction time and strontium chloride volume were tested, and the stability, precision and accuracy of the method were also investigated. Meanwhile, samples at different pH values were determined by this method. [Result] The results showed that this method operation has simple operation with good stability and high precision. [Conclusion] This method could be applied to determine exchangeable Ca and Mg contents in tobacco growing area.

Influence of the Year and Growing Area on Maize (Zea mays L.) Production in the Central and North-Central Zones of Côte d’Ivoire (Departments of Bouake and Katiola)

Several studies conducted in recent years in Côte d’Ivoire reveal that agriculture is increasingly affected by the adverse effects of climate variability. The present study aims at evaluating the effect of the zone and the year of cultivation on the productivity of maize in the Central and North-Central zones of Cote d’Ivoire. It was carried out for two years (2020 and 2021). The experimental design used was a completely randomized block design with three replications. Observations were made on 12 agronomic parameters (plant size, internode size, collar diameter, number of leaves, number of internodes, cob insertion level, cob length, cob diameter, total kernels, cob dry weight, kernel dry weight, yield). The results showed that all agronomic traits of maize were significantly influenced by locality, except for the number of leaves. The highest values of the traits were observed in the locality of Bouaké. However, the year of cultivation did not influence the agronomic parameters of maize. This study will help to avoid yield decreases due to rainfall disturbances as a consequence of climate change.

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments

Clustering Analysis of the Climate in Tobacco Planting Zone of Yunnan

[Objective] The research aimed to study clustering of the six climatic factors in Yunnan tobacco planting zone. [Method] 6 meteorological elements in 89 tobacco-growing counties and 12 sub-prefectures were conducted clustering analysis. According to indicator and climate characteristics of the each type, climate in tobacco planting area of Yunnan Province was divided. [Result] Climate in tobacco planting area of Yunnan Province could be divided into eight types: Jiangchuan (24 counties, belonged to northern and central subtropical climate belts), Songming (27 counties, belonged to northern subtropical and central, south, north temperate climate belts), Tengchong (3 counties, belonged to northern subtropical climate belt), Mile (12 counties, belonged to central and southern subtropical climate belts), Qiubei (11 counties, belonged to southern subtropical climate belt), Yanjin (4 counties, belonged to central subtropical humid climate belt), Yuanjiang (4 counties, belonged to southern subtropical and northern tropical climate belts), Zhenxiong (3 counties, belonged to warm temperate and northern subtropical climate belts) were eight representatives. Among 1-8 eco-zones, domestic and foreign cities where climate reached level-one similarity were respectively 3, 1, 1, 0, 1, 1, 0 and 1, up to level-two similarity, respectively 12, 15, 3, 13, 13, 1, 5 and 3. Among 8 major ecological zones, similar distance of the city reaching level-one similarity was in the range of 0.28 to 0.45, and similar degree was the highest. Variety introduction among these places would be successful. Similar distance of the city reaching level-two similarity was between 0.51 and 1.00, and similar degree was higher. Mutual variety introduction had high successful rate in these places. [Conclusion] The research provided theoretical basis for selecting new suitable tobacco variety and optimizing tobacco variety layout in different zones.

Seasonality in the occurrence of two lepidopterous olive pests in Egypt

Prays oleae Bern, （OM） andPalpita unionalis Hfib., （JM） are two of the most important pests in olive groves in Egypt. A 3-year monitoring study using sex pheromone traps in semi-arid and arid olive groves was performed. In the semi-arid grove, flight pattern of the OM was the same as in other Mediterranean countries, but in dates concordating plant phenology. The moth completes three generations annually： the first flight is in March to April, the second is in May to June and the third occurs in August to October. In the arid olive grove, an interesting flight pattern was observed. First flight was always very close or overlapped with the second one with no male catches during August to October. However, eggs were present most of the season, indicating unusually high female presence and oviposition activity of the OM during the absence of males in the traps. Generally, moth densities were significantly lower in low fruiting years than in higher ones and were also lower in the arid olive grove than in the semi-arid one. In contrast, JM males were present all season, exhibiting six to seven and three to four overlapping flight peaks in arid and semi-arid olive groves, respectively. Moth densities were significantly higher in the arid olive grove than those in the semi-arid one. This study shows that trapping location and fruit beating year are characteristics that strongly affect the grove-specific information needed to estimate correctly adult emergence and thus the timing of control measures.