Rice is the staple crop for more than half the world’s population, but there is a lack of high-resolution maps outlining rice areas and their growth stages. Most remote sensing studies map the rice extent; however, in tropical regions, rice is grown throughout the year with variable planting dates and cropping frequency. Thus, mapping rice growth stages is more useful than mapping only the extent. This study addressed this challenge by developing a phenology-based method. The hypothesis was that the unsupervised classification (k-means clustering) of Sentinel-1 and 2 time-series data could identify rice fields and growth stages, because (1) the presence of flooding during transplanting can be identified by Sentinel-1 VH backscatter; and (2) changes in the canopy of rice fields during growth stages (vegetative, generative, and ripening phases) up to the point of harvesting can be identified by Normalized Difference Vegetation Index (NDVI) time series. Using the proposed method, this study mapped rice field extent and cropping calendars across Peninsular Malaysia (131,598 km²) on the Google Earth Engine (GEE) platform. The Sentinel-1 and 2 monthly time series data from January 2019 to December 2020 were classified using k-means clustering to identify areas with similar phenological patterns. This approach resulted in 10-meter resolution maps of rice field extent, intensity, and cropping calendars. Validation using very high-resolution street view images from Google Earth showed that the predicted map had an overall accuracy of 95.95%, with a kappa coefficient of 0.92. In addition, the predicted crop calendars agreed well with the local government’s granary data. The results show that the proposed phenology-based method is cost-effective and can accurately map rice fields and growth stages over large areas. The information will be helpful in measuring the achievement of self-sufficiency in rice production and estimates of methane emissions from rice cultivation.

An assessment of morphological variation among 70 accessions of greater yam (Dioscorea alata L.) collected throughout Malaysia was made. Data of 47 morphological variables measured from the accessions were subjected to multivariate analysis using principal component (PCA) and cluster analysis (CA). The PCA results indicated that the characters contributing largely to the species variability were those related to the shape, size and flesh colour of underground tubers; shape and colour of aerial tubers; position, shape, size and vein colour of the leaves; petiole colour; shoot growth rate; and number of days for shoots to germinate. The two-dimensional plot of the first two PCs showed a separation between accessions of purple tuber groups and those of white tuber groups, but was unable to distinguish accessions according to tuber shape groups, i.e. irregular, oblong and round, as revealed by visual observation. The dendrogram of CA revealed four major groups of D. alata in Malaysia, which supported the PCA grouping. This study demonstrated that D. alata in Malaysia consists of numerous genotypes revealing wide inter- and intra-group variability.

Momordica cochinchinensis (Gac fruit) grows as perennial climbers and dioecious plants, where it can be cultivated from seeds, root tubers, and root vine cuttings. Rooted vine cuttings are more reliable than seed propagation, which can be affected by dormancy and delay production. The application of auxin group of hormones such as Indole acetic acid (IAA), Indole-3- butyric acid (IBA), and Naphthaleneacetic acid (NAA) in certain concentrations shown good results in inducing root initiation faster and effective. However, experimental data and information on the plant growth hormone application on M. cochinchinensis vine cuttings propagation are not very extensive, especially in Malaysia. Thus, the objective of this study was to determine the effect of different concentrations of IAA, IBA, and NAA on M. cochinchinensis vine cutting propagation. The design of the experiment is a randomized complete block design in a factorial experiment, with five replications. The treatments comprised three types of plant growth hormone, IAA, IBA, and NAA with 0, 500, 1000, and 3000 ppm concentrations. Data recorded were surviving rate or percentage of rooting, root numbers per rooted cutting, means of root length, length of longest root, total root length per rooted cuttings, sprouting percentage, and sprouting length. The vine cutting treated with IBA and NAA 1000 ppm has shown a considerably positive effect in root formation and sprouting.

Organic fertilisers are of biological origin and the amount of nutrients they produce varies greatly. Besides providing the essential macro and micro nutrients, they also provide an array of plant growth-promoting substances. Organic agronomy is a relatively recent technique of farming in developed countries. While several studies were conducted on the impact of organic fertilisers on soil properties and crop production, further research is needed to determine comparative results between organic fertilisers. This paper aims to review some of the influences and impacts of poultry manure, cow dung, goat manure, vermicomposter and seaweed extracts. Much-needed characteristics of numerous crops were enhanced with the appropriate application of these organic fertilisers. Organic fertilizer applications influences the increase of plant heights, vegetative growth, yields and yield attributes. The application of adequate fertilisers also influences the qualitative parameters and post-harvest traits of most crops. Selecting the best organic fertilisers at an optimal application rate that could be the best source of nutrient supplement in cultivating qualitative crops, is a gap that needs to bridge. Therefore, different application rates of the above organic fertilisers were also studied.

The improper disposal of agricultural waste leads to soil degradation and environmental harm, but this issue can be addressed by converting the waste into nutrient-rich fertilizer, promoting soil health and sustainable farming practices. This study evaluates mineral content in fish bones waste which may support plant growth. FBM was prepared from fish bones collected from the local food processing industry in Terengganu, Malaysia, and nutrient composition was analyzed using the ICP-OES and CHNS equipment. Macronutrient and micronutrient content were compared among Sardinella fimbriata commonly known as Tamban fish, Decapterus tabl, commonly known as Selayang fish, and Chirocentrus dorab, commonly known as Parang fish. Among the species studied, Tamban fish had the highest phosphorus content of 105.59 g/kg, important for energy storage in plants, while Parang fish had the highest potassium content of 2.99 g/kg, important for root development. The Selayang fish expressed the highest values of calcium at 125.05 g/kg, which helps to mitigate soil salinity; other nutrient contents such as magnesium, iron, zinc, manganese, and boron were highly variable. These findings highlight the potential of FBM as a sustainable alternative to synthetic fertilizers, supplying critical nutrients for plant growth as well as offering solutions to challenges related to waste management. To optimize its use, further research on blending FBM with other organic materials is recommended in order to balance nutrient availability for improved crop development, and thus support sustainable agriculture and circular economy.