No abstract

A field investigation was run to ascertain the critical period of weed control in jute (Corchorus olitorius). The study consisted of two distinct sets of treatments, with one set of weeds being left to invade the crop for a longer period of time, specifically, for 15, 30, 45 and 60 days after sowing (DAS) and up to harvest. In the other set of treatments, the plants remained weed-free for progressively longer periods, i.e., 15, 30, 45 and 60 DAS, and until harvest. The reduction in fibre yield (FY) was recorded as 53.39% when weed interference was permitted from the beginning to harvest, as opposed to the season-long weed-free period. The critical period for weed competition (CPWC) of jute was calculated as being 11 to 68 DAS and 19 to 59 DAS, based on results of 5% and 10% yield loss, respectively. Under the 5% yield loss condition, although yield was higher (3.36 t ha−1), the benefit cost ratio (BCR) was lower (1.65), whereas yield was slightly lower (3.19 t ha−1) but BCR was higher (1.73) with respect to 10% yield loss. Therefore, jute fields should be kept weed free from 19 to 59 days after sowing, and a weed management strategy should be undertaken accordingly.

This paper presents the formulation of dynamic stiffness matrix for the natural vibration analysis of porous power-law functionally graded Levy-type plate. In the process of formulating the dynamic stiffness matrix, Kirchhoff-Love plate theory in tandem with the notion of neutral surface has been taken on board. The developed dynamic stiffness matrix, a transcendental function of frequency, has been solved through the Wittrick–Williams algorithm. Hamilton’s principle is used to obtain the equation of motion and associated natural boundary conditions of porous power-law functionally graded plate. The variation across the thickness of the functionally graded plate’s material properties follows the power-law function. During the fabrication process, the microvoids and pores develop in functionally graded material plates. Three types of porosity distributions are considered in this article: even, uneven, and logarithmic. The eigenvalues computed by the dynamic stiffness matrix using Wittrick–Williams algorithm for isotropic, power-law functionally graded, and porous power-law functionally graded plate are juxtaposed with previously referred results, and good agreement is found. The significance of various parameters of plate vis-à-vis aspect ratio ( L/b), boundary conditions, volume fraction index ( p), porosity parameter ( e), and porosity distribution on the eigenvalues of the porous power-law functionally graded plate is examined. The effect of material density ratio and Young’s modulus ratio on the natural vibration of porous power-law functionally graded plate is also explained in this article. The results also prove that the method provided in the present work is highly accurate and computationally efficient and could be confidently used as a reference for further study of porous functionally graded material plate.

With a view to creating an inventory of the existing climatic and nutritional condition of the haor (low-lying land) areas along with their cropping systems, this research was carried out in the Dingaputa haor of the Netrakona district of Bangladesh. The main objective was to study the farmers’ concept of climate change issues and their responses in respect to cropping systems and nutrition. This study is crucial for comparing the existing situation and taking future decisions. The feasibility and strategic direction of the present haor agriculture were evaluated using strengths, weaknesses, opportunities, and threats (SWOT) analysis and matrices. The results showed that the farmers’ understanding of climate change was much lower than expected; a maximum of 73.2% farmers pointed out that climate change means frequent flooding, and more than 90% of farmers opined that temperature, early flooding, and lightning have increased over time. They strongly agreed that boro (dry-season-irrigated) rice is affected more frequently by natural hazards than in previous times. Very few farmers (only 14.4%) have taken adaptation strategies, which are less climate-smart and nutrition-sensitive. Only 10.8% of farmers cultivated oilseeds, pulses, and vegetables other than boro rice. A lack of technological knowledge is the main obstacle to practicing climate-resilient, modern cultivation practices. The trends of cultivation and consumption of vegetables by haor farmers are very low, whereas they are agreeable to cultivating nutrition-sensitive and high-value crops if they have technical support. The major strengths of haor agriculture are fertile soil and rice surplus, whereas weaknesses are monocropping and malnutrition.

No abstract