Current and Emerging Pests and Diseases of Cucumber (Cucumis sativus L.) in Africa

The place of cucumber (Cucumis sativus L.) in Africa was considered insignificant for years due to its previously assumed limited uses. However, it has now gained recognition as one of the important market vegetables in the tropics because of the continued awareness of the numerous health benefits attached to its consumption. This has progressively affected its cultivation and thereby, increased outbreak of diseases and insect pests of the crop. High incidence of insect and disease infestations occur in Cucumis sativus L. due to extreme temperatures, heavy rainfall and high humid condition resulting there from, causing huge losses through reduction in yield, lowered quality of harvested produce and increased cost of production. More than 30 pests and diseases are known to contribute to the losses recorded on the crop in Africa, some of which will be discussed in this chapter.

Rasgulla—the ethnic Indian sweetmeat delicacy and its evolutionary journey through contemporary research

West Bengal and Odisha, two distinguished provinces of India, are consecrated with prosperous animal resources. Both territories have substantially affluent traditional dairy-based products. Rasgulla is one of such kind of traditional Indian dessert made from milk casein with attractive white colour having a spongy, porous structure and spherical shape, popular all over the world for its taste, flavour and unique texture. It is mainly originated in the West Bengal and Odisha, through a cascade of ethnic gastronomic phenomena. Both the traditional and cutting-edge practice of rasgulla preparation has its own impact on the sensory attributes of the product. Researchers’ approach to improve textural, colour and sensory qualities of this astonishing dairy product has an appulse on overall acceptability of the product. Different types of milk and coagulant have a tremendous effect on the final quality of the product in terms of nutritional, textural and palatability characteristics of rasgulla. To make this traditional sweetmeat more nutritious, fortification and enrichment of functional features have been studied. Anti-diabetic rasgulla has been prepared to conquer the diabetes mellitus through re-modulation in the extent of sugar used to process this sweetmeat. Shelf-life of casein based products is one of the main concerns for researchers, due to abundance of ample amount of nutrients for optimum growth of microorganisms, along with the warm and humid condition of Indian subcontinent which accelerates the microbial propagation. Though the product has immense nutritional and sensory idiosyncrasy as well as folk medicinal importance, it is yet to be explored in coetaneous medical sciences.

A General Strategy towards Superhydrophobic Self-Cleaning and Anti-Corrosion Metallic Surfaces: An Example with Aluminum Alloy

Corrosion and contamination of metallic structures can cause loss of their functionality as well as aesthetic values. In this study, we describe a general strategy to prepare superhydrophobic self-cleaning and anti-corrosion surfaces for metallic structures. As a specific example, a superhydrophobic coating (SHC) on aluminum alloy was prepared by a simple etching combined with the decoration of a low-surface-energy material. The optimal SHC has a water contact angle (CA) at ~157.4° and a sliding angle (SA) of ~8.3° due to the synergy of binary hierarchical structures and chemical modification. The SHC showed low adhesion to dry contaminants and a series of liquids, displaying a good self-cleaning effect. The SHC maintained superhydrophobicity after exposure to air and humid condition at 60 °C for 7 days. In addition, the electrochemical measurements reveal that the anti-corrosion performance was enhanced by reducing the corrosion current density (Jcorr) by 1 order of magnitude and increasing the corrosion potential (Ecorr) by 0.527 V as compared to the bare Al alloy substrate after immersion for 168 h.

First report of seedling damping off in forage ryegrass caused by Pythium aphanidermatum and P. periilum in Japan

Italian ryegrass (Lolium multiflorum Lam.) and perennial ryegrass (L. perenne L.) are important for hay fields and grazing lands across Japan, with nearly 70,000 ha production, the largest share in forage grass cultivation. In August 2018, damping off of seedlings of both species was observed about 2wk after seeding in Tochigi Prefecture, central region of Japan. Roots were brown and decayed drastically with browning of basal stem. Nearly 90% of the row seedling stands were eradicated in some fields, especially ones seeded from August to early September, when the soil and air temperatures were around 25-30 ˚C. Six Pythium-like isolates were obtained by isolation from surface-sterilized diseased hypocotyls (1-2cm) placed on water agar. Six isolates were purified as single hyphal tips and deposited at the NARO genebank (https://www.gene.affrc.go.jp/index_en.php), with accession no. MAFF101946-101951. Two of them, MAFF101946 and 101948 were used for detailed study. The isolates were grown in the dark on clarified V8 juice agar for 10 days to produce oogonia. The oogonia of MAFF101946 were globose, colorless, smooth, 21 to 30 µm in size, and had 1(- 2) antheridia. Oospores were mostly aplerotic, and oogonia walls were 1.1 to 2.3 µm thick. The oogonia of MAFF101948 were globose, colorless, smooth, 19 to 27 µm in size, and had 2-5 antheridia. Oospores were mostly plerotic, and oogonia walls were 1.7 to 4.2 µm thick. The morphology of the MAFF101946 matched that of P. aphanidermatum (Edson) Fitzp.(abbr. PA) and the MAFF101948 matched P. periilum Drechsler (abbr. PP) (Van der Plaats-Niterink, 1981). DNA sequences of cox1 (Robideau et al, 2011) and rDNA-ITS regions (White et al,1990) of each isolate were analyzed. The cox1 sequences of the MAFF101946 and 101948 (GenBank Accession No. LC548774 and LC548775) matched 100% (680/680 bp) with that of PA (HQ708486) and PP (HQ708781), respectively. The rDNA-ITS sequence of the MAFF101946, LC592700, matched PA (772/777 bp; HQ643439), and the MAFF101948 (LC592701) matched PP (HQ643740), with 99% similarity (764/773 bp). The optimal growth temperature was 35 ˚C for both. Their pathogenicity was confirmed by seeding two Italian (cv. Inazuma and Minamiaoba) and perennial (cv. Yatsuyutaka and Natsugoshi-pere) ryegrasses cultivars in cell trays containing commercial potting mixture inoculated with the isolates. Barley grains autoclaved with a half volume of water and incubated with each isolate at 25 ˚C for about 2 wk were added to inoculate the potting mixture (5%, v/v). Separate trays were used for each isolate to avoid cross-contamination, sown with 60 seeds were sown per cv. and the trays were placed in a light thermostat chamber under the daily cycle of 16 hr light at 30 ˚C and 8 hr dark at 25 ˚C. About 3 wk later, seedlings on the inoculated soil exhibited the symptoms, but not in control (no inoculum) plots. Both inoculated organisms were re-isolated from the diseased plants to confirm their pathogenicity. PA was more aggressive with grater percent damping off compared to PP. Both species are known as pathogens of diverse plants including grasses and legumes (Abad et al, 1994; Ao et al, 2018), but to our knowledge, this is the first report of seedling damping off caused by these Pythium species in forage ryegrass in Japan. With the increased duration of hot, humid condition across temperate regions due to global warming, the damping off may become a problem in hay fields and pasture and resistance breeding for these pathogens may be needed.

Potential CO2 forcing and Asian summer monsoon precipitation trends during the last 2,000 years

Holocene records for the Asian Summer Monsoon (ASM) indicate that, apart for the last 2,000 years (“2 kyr shift”), solar insolation was the dominant factor controlling the monsoon climate. The aim of this review is to provide a synopsis of climate characteristics over the last 2 kyr, clarifying mechanisms for the diverse trend with Northern Hemisphere Summer Insolation (NHSI) records. Here, we initially review proxy-based climate reconstructions for the last 2 kyr, and then compare them with records from the last five interglacial periods. Finally, we examine potential physical mechanisms responsible for the “2 kyr shift.” Findings from this review indicate that the “2 kyr shift” is a representative pattern of Holocene climate change within the core area of the ASM, and the “2 kyr shift” could be mainly controlled by changes in atmospheric CO2 concentration. In addition, suggestions to address a more humid condition dominating the Asian monsoonal margin zones are offered.

Highly stable and efficient α-phase FA-based perovskite solar cells prepared in ambient air by strategically enhancing the interaction between ions in crystal lattices

FAPbI3 perovskite is an ideal candidate for efficient and stable perovskite solar cells (PSCs). Unfortunately, attaining photoactive α-phase FAPbI3 under humid condition is rather difficult due to the structural and...

Fluorinated metal organic frameworks, MFFIVE-Ni-L (M = Fe/Al, L = pyr), with coordinatively unsaturated metal site for CO2 separation from flue gas in the presence of humidity by computational methods

CO2 capture from flue gas compositon (i.e. CO2/N2 = 15/85) under humid condition in coordinatively unsaturated (CUS) square pillared fluorinated metal organic framework (MOF) is computationally investigated with newly derived specific forcerfield.