Antibiotics Contaminated Irrigation Water: An Overview on Its Impact on Edible Crops and Visible Light Active Titania as Potential Photocatalysts for Irrigation Water Treatment

Sub-therapeutic levels of antibiotics (ABs) are given to animals and poultry to promote growth and reduce disease. In agricultural environments, ABs reach croplands via animal manure used as fertilizer and/or ABs-contaminated water used for irrigation. The continuous discharge of ABs into the ecosystem raises growing concerns on the ABs contamination of edible crops. Tetracyclines (TCs) are among the most widely used ABs around the world. In this review, we discuss the contamination of irrigation water with TCs, its impact on edible crops, and the potential risks of crop contamination with TCs on human health. We propose solar-mediated photocatalytic degradation using Titania (TiO2) photocatalyst as a promising method to remove TCs from irrigation water. The photocatalytic activity of TiO2 can be enhanced by chemical modification to expand its activity under visible light irradiation. Herein, we aim for providing literature-based guidance on developing a visible light–active TiO2-based system to degrade TCs and other ABs in water streams. We include a summary of recent advances on this topic based on three main modification methods of Titania: metal/non-metal/mixed doping, composite formation, and heterojunction construction. Among the investigated photocatalysts, Fe2O3-TiO2/Fe-zeolite and the N-doped TiO2/rGO immobilized composite catalysts were found to be very efficient in the degradation of TCs under visible light irradiation (i.e., 98% degradation within 60 min). Most immobilized TiO2 based composite systems exhibited improved performances and hence we highlight these as efficient, cost effective and ecofriendly photocatalysts for the degradation of TCs in irrigation water.

Management for Paddy, Oil Palm, and Pineapple Plantations in Malaysia: Current Status and Reviews

Heavy rainfall causes a loss of fertiliser to the environment, and it leads to environmental issues such as eutrophication. Replenishment of fertiliser to replace the loss imposes a financial impact since frequent applications are costly and labour intensive. Therefore, investigations on proper fertiliser application in maintaining good soil pH, improving plant growth, and increasing crop yield from various plantations across Malaysia are of paramount importance. Meanwhile, limited agricultural-related studies about crop management in Malaysia have been done. This study presents a state-of-the-art review of Malaysia’s paddy, oil palm, pineapple plantations, and the existing nutrient management and fertilisation practices throughout the crop cycle. A systematic study of the existing crop management in terms of farming practices, nutrient management, and fertiliser application on the plantations of paddy, oil palm, and pineapple in Malaysia was carried out. Industry overviews for these three crop types based on past situations and future directions are also included. Recommendations on how to better manage these plantations are also outlined to promote a better understanding of the past, current, and future direction of the agricultural activities and management for principal edible crops like paddy, oil palm, and pineapple in Malaysia.

Silicon Foliar Spray and Substrate Drench Effects on Plant Growth, Morphology, and Resistance to Wilting with Container-Grown Edible Species

The objective of this study was to evaluate silicon (Si) foliar spray and substrate drench effects on plant growth and morphology for container-grown edible crops during greenhouse production, as well as resistance to plant wilting during post-production. In the first greenhouse experiment, basil received Si foliar sprays at 0, 50, 100, 200, and 400 mg∙L–1 Si. In the second greenhouse experiment, Si was applied as either a foliar spray (500 mg∙L–1 Si) or substrate drench (100 mg∙L–1 Si) with six edible crop species. Supplemental Si increased shoot Si levels but had minimal effects on plant growth and morphology, except for parsley, which resulted in distorted growth and phytotoxicity. In the first experiment, 200 and 400 mg∙L–1 Si foliar sprays increased plant resistance to wilt by 2.2 and 2.5 d, respectively; however, this was not observed in the second experiment. All species accumulated Si with the control (no Si) treatments, indicating trace amounts of Si were taken up from the substrate, fertilizer, spray surfactant, and irrigation water. Only cucumber was classified as a Si “accumulator” with a high capacity for Si uptake. Results emphasize the need to conduct preliminary trials with supplemental Si to avoid issues of phytotoxicity.

Three Selected Edible Crops of the Genus Momordica as Potential Sources of Phytochemicals: Biochemical, Nutritional, and Medicinal Values

Momordica species (Family Cucurbitaceae) are cultivated throughout the world for their edible fruits, leaves, shoots and seeds. Among the species of the genus Momordica, there are three selected species that are used as vegetable, and for medicinal purposes, Momordica charantia L (Bitter melon), Momordica foetida Schumach (Bitter cucumber) and Momordica balsamina L (African pumpkin). The fruits and leaves of these Momordica species are rich in primary and secondary metabolites such as proteins, fibers, minerals (calcium, iron, magnesium, zinc), β-carotene, foliate, ascorbic acid, among others. The extracts from Momordica species are used for the treatment of a variety of diseases and ailments in traditional medicine. Momordica species extracts are reputed to possess anti-diabetic, anti-microbial, anthelmintic bioactivity, abortifacient, anti-bacterial, anti-viral, and play chemo-preventive functions. In this review we summarize the biochemical, nutritional, and medicinal values of three Momordica species (M. charantia, M. foetida and M. balsamina) as promising and innovative sources of natural bioactive compounds for future pharmaceutical usage.

DISEASE INCIDENCE AND SEVERITY OF SCLEROTIUM ROLFSII ON ARACHIS HYPOGEA L

Groundnut or peanut (Arachis hypogea L.) is an important oilseed and edible crops of the world. It is affected by many diseases, among which stem rot disease caused by Sclerotium rolfsii is major fungal disease that cause severe yield losses up to 80%. An experiment wasconducted in Tamil Nadu during 2019-2020, to study the cultural, morphological and pathogenicity of different isolates of S. rolfsii infecting groundnut in major cultivating areas of Tamil Nadu. The overall disease severity ranges from 9.82 to 36.83 percent. The highest disease incidence 36.83 per cent was noticed in the Kalpadai village and the least incidence 9.82 per cent was recorded in Pattukotttai village. All the isolates varied their ability to produce abundant mycelium and sclerotial production. The pathogenicity test was conducted to all the twenty isolates and the isolate Sr6 exhibited the maximum disease incidence and proved to be more virulent.