Resistance of Scots pine (Pinus sylvestris L.) wood modified with functionalized commercial silicone emulsions against subterranean termites

Scots pine (Pinus sylvestris L.) sapwood was treated with quat-silicone micro-emulsion (<40?nm), amino-silicone macro-emulsion (110?nm), alkyl-modified silicone macro-emulsion (740?nm) and solutions of inorganic water glass. Three treatment concentrations of 5, 15 and 30% (w/w) were used for the impregnation of the test specimens. Termite resistance was assessed following a 16-week field trial conducted in northern Queensland, Australia. Two different field sites were chosen for exposure to feeding by Coptotermes acinaciformis (Froggatt) and Mastotermes darwiniensis (Froggatt). Following exposure, the test and feeder specimens were inspected and assessed for termite damage using a visual rating system (from 10 sound to 0 completely destroyed) and individual mass losses. The specimens treated with quat- and amino-silicone emulsions resisted damage by both termite species, even at less than 15% weight percent gains (WPGs). Alkyl-modified silicone macro-emulsion and water glass treatment induced somewhat less resistance to termite damage, but imparted protection at higher WPGs.     

Remote sensing and machine learning for crop water stress determination in various crops: a critical review

Precision Agriculture - The remote sensing (RS) technique is less cost- and labour- intensive than ground-based surveys for diverse applications in agriculture. Machine learning (ML), a branch of...     

Seasonal and biological interactions between the parasitoid, <Emphasis Type="Italic">Aenasius arizonensis</Emphasis> (Girault) and its host, <Emphasis Type="Italic">Phenacoccus solenopsis</Emphasis> Tinsley on cotton

Aenasius arizonensis (Girault) (Hymenoptera: Encyrtidae) is an important solitary endoparasitoid of mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae). Studies on seasonal and biological interactions between host and parasitoid are important to optimize the mass production and field release of high-quality females. We investigated the influence of different crop seasons viz., pre-monsoon, monsoon and post-monsoon and host stages viz., three nymphal instars (1st, 2nd and 3rd) and adult stage of P. solenopsis on the development, longevity, fecundity and sex ratio of its parasitoid, A. arizonensis. A. arizonensis female parasitized all life stages of its host except the 1st instar nymphs. Only males emerged from parasitized 2nd instar nymphs, while the sex ratio in the later host instars was strongly female-biased. The adult host stage was most suitable for A. arizonensis in terms of shorter development time, while the 3rd instar nymphal stage was most suitable with respect to higher fecundity, proportion of adults emerged and more females in the progeny. Among different seasons, post-monsoon season (September–October) with temperature (25 to 29 °C) and relative humidity (68 to 73%) was most suitable for the overall fitness of the parasitoid. The findings of this study have implications in designing mass rearing of this parasitoid and devising an effective biological control strategy for P. solenopsis on cotton.     

Soil failure associated with crack propagation for an agricultural tillage tool

Tillage loosens soil to depths of 75–150 mm (3–6 in.). As the soil is tilled, the failure path precedes the motion of the tillage tool. Previous studies have examined soil forces acting on a tine by predicting different soil failure patterns. This paper quantifies the rate and the path of the cracks associated with soil failure front. The propagation of the soil failure path by observing the temporal profile of the leading edge of the failure crack with respect to the tool motion was examined. Crack propagations were analysed for sweep operating at 4 km h⁻¹ speed, and two operating depths of 75 and 100 mm using high-speed digital videography. Higher depth of operation showed distinct phases for crack development and propagation. Short and intermittent soil crack propagation with lower propagation growth rates was observed for shallow depth of operation. Crack growth rate has been observed to have a sinusoidal relation with time.     

Histopathological changes and tissue residue concentrations of monosex Nile tilapia (Oreochromis niloticus,L) fries exposed to oxytetracycline

Aquaculture International - The current study evaluated the biosafety of oxytetracycline (OTC) exposure for 30&nbsp;days in monosex Oreochromis niloticus fries. The fries were exposed to OTC...     

Hermaphrodite inbreds with better combining ability improve antioxidant properties in ridge gourd [Luffa acutangula (Roxb.) L.]

An experiment was conducted with the objectives to evaluate the breeding potential of hermaphrodite lines and to suggest suitable breeding approaches following half-diallel mating design for genetic improvement of antioxidant content and activity in ridge gourd [Luffa acutangula (Roxb.) L.] fruits. Twenty-eight genotypes, including seven parental lines and 21 crosses, were grown in randomized block design with three replications for fruit sample collection. The highly significant mean squares due to parents, hybrids and parents versus hybrids; and GCA and SCA for yield and antioxidants (ascorbic acid, total carotenoids, total phenolics, DPPH-RSA, ABTS-RSA and CUPRAC assay) indicate the existence of abundant genetic variation. The per se performance and combining ability of hermaphrodite parents (Satputia Long and Satputia Small) and hybrids of “monoecious × hermaphrodite” cross were found to be superior for antioxidants along with yield potential. The cross combinations with superior per se performance coupled with high SCA estimates and having at least one hermaphrodite parent would be useful for concentrating desirable alleles to improve the antioxidants and yield simultaneously. Thus, hermaphrodite lines in combination with monoecious counterpart have enormous potential to breed “genotypes for higher antioxidants” without compromising yield in ridge gourd.     

Development of expert system modeling based decision support system for swine manure management

Animal waste has always been considered as a resource for agricultural input as biofertilizer. However, the management is becoming more stringent due to environmental regulations. Livestock producers are faced with different manure management options that may be implemented into their operations. Given the expansion of the livestock industry, the implementation of environmental regulations, and the increasing importance of social and health issues, the selection of optimal manure management systems is becoming a strategically important task. Increasingly, integrated decision support systems (DSSs) are becoming necessary to assist decision makers in their evaluation of different manure management alternatives, like, liquid system, semi-solid system, solid system and bio-gas or bio-energy system based on combinations of different manure management sub-systems (collection, storage and application). To address this situation, a user-friendly computer program called Integrated Swine Manure Management (ISMM) is being developed for the Canadian Prairie provinces. Decision criteria including environmental, agronomic, social and health, greenhouse gas emission, and economic factors have been considered for the selection, design, and operation of the DSS. The expert system modeling is based on Visual Basic programming. Decision on adopting a particular combination of systems components is based on performance rating of the overall system. The program is interactive so that weighting factors for the different decision criteria can be varied to suit site-specific considerations. In this paper, the systems approach for development of an integrated liquid manure management system is discussed. Using a case study, sensitivity analysis of different combinations of management components is also reported for systems performance. The decision software compared satisfactorily with other available DSS packages.     

孟加拉吉大港地区丘陵森林有机物积累

在孟加拉吉大港丘陵地区,调查了热带季风气候条件下的3种人工林(7年生大叶相思(Acacia auriculiformis)林、15年生大叶相思林和18年生混交林)和1种天然林的森林凋落物及其对土壤性质的作用.结果表明,总的有机质积累随人工林树龄增加而增加,但是年积累量随之降低.在同一植被类型内,不同坡位新鲜或部分分解的凋落物有机质累计量变化较大,坡底部有机质积累量最高,沿着山坡向上逐渐减少.在15年生大叶相思人工林内,土壤整合有机物积累量变化趋势与新鲜或部分分解有机质积累量变化趋势相反.在7年生和15年生的大叶相思林以及18年龄的阔叶混交人工林内,新鲜、部分分解和完全分解(含土壤整合有机质)有机质总生产速率分别是2554.31、705.79和1028.01kg.ha-1·a-1,新鲜凋落物有机质在3种林分中的生产速率分别是38.23,19.40和30.48 kg·ha-1·a-1.3种人工林和自然林内,平均新鲜凋落物的有机质积累占有机质产出总量的32.45%,部分分解凋落物占13.50%,而全分解整合土壤有机质占54.56%.森林土壤酸度随凋落物分解阶段的深入而增加.     

Bt cotton producing Cry1Ac and Cry2Ab does not harm the parasitoid Aenasius arizonensis (Girault): a host-mediated tritrophic assay

Phytoparasitica - Transgenic crops with genes from Bacillus thuringiensis (Bt) Berliner, a soil bacterium producing δ-endotoxin that is lethal to several phytophagous insects. Concerns related...