“WaterMan”: an on-farm water management game with heuristic capabilities

A modern computer-based simulation tool (WaterMan) in the form of a game for on-farm water management was developed for application in training events for farmers, students, and irrigators. The WaterMan game utilizes an interactive framework, thereby allowing the user to develop scenarios and test alternatives in a convenient, risk-free environment. It includes a comprehensive soil water and salt balance calculation algorithm. It also employs heuristic capabilities for modeling all of the important aspects of on-farm water management, and to provide quantitative performance evaluations and practical water management advice to the trainees. Random events (both favorable and unfavorable) and different strategic decisions are included in the game for more realism and to provide an appropriate level of challenge according to player performance. Thus, the ability to anticipate the player skill level, and to reply with random events appropriate to the anticipated level, is provided by the heuristic capabilities used in the software. These heuristic features were developed based on a combination of two artificial intelligence approaches: (1) a pattern recognition approach and (2) reinforcement learning based on a Markov decision processes approach, specifically the Q-learning method. These two approaches were combined in a new way to account for the difference in the effect of actions taken by the player and action taken by the system in the game world. The reward function for the Q-learning method was modified to reflect the suggested classification of the WaterMan game as what is referred to as a partially competitive and partially cooperative game.     

Differential Response of Southern US Rice (Oryza sativa L.) Cultivars to Ultraviolet‐B Radiation

Elevated ultraviolet‐B (UV‐B; between 290 and 320 nm) radiation, because of depletion of the stratospheric ozone layer, is one of the major environmental factors influencing plant metabolic processes and yield. The southern US rice cultivars contribute greatly towards US rice production, but the effects of elevated UV‐B radiation on these cultivars are not well known. The objective of this study was to determine the effects of elevated UV‐B radiation on leaf photosynthetic rate (P_n), membrane stability, pollen viability, phenolic concentration and yield of eight commercially popular southern US rice cultivars (five inbred cultivars and three hybrids). Plants were grown in a temperature‐controlled greenhouse in Beaumont, TX, USA, and were exposed to UV‐B radiation of 0, 8 or 16 kJ m^?2 day^?1 for 90 days. For most of the cultivars, plants grown under 8 or 16 kJ UV‐B radiation showed significant decreases in P_n, membrane stability, pollen viability, and yield compared with the plants grown under an UV‐B‐free environment, whereas there was a significant increase in leaf phenolic concentration under 16 kJ UV‐B radiation. The hybrid ‘Clearfield XL729’ performed best among the selected southern US rice cultivars under 16 kJ UV‐B radiation.     

智能氮肥在干湿交替灌溉下对水稻产量与水分利用率的影响

为探究智能氮肥(pH响应性控释氮肥)在干湿交替灌溉模式下的适宜性,设置3种程度的干湿交替灌溉W1(灌水下限100％饱和含水率)、W2(灌水下限90％饱和含水率)、W3(灌水下限70％饱和含水率),3种施肥形式智能氮肥(SF)、普通无机氮肥(MF)以及不施氮肥(NF)的桶栽试验,分析其对水稻产量及水分利用效率的影响.结果...     

Comparative field performance of some agricultural crops under a canopy of Populus deltoides and Ulmus wallichiana

The performance of maize, beans and sunflower was evalu-ated under a canopy of Populus deltoides and Ulmus wallichiana at Fac-ulty of Agriculture, Wadura. The germination, growth and yield of the three...     

Are composts from shredded leafy branches of fast-growing forest species suitable as nursery growing media in arid regions?

The morpho-physiological quality of seedlings is negatively affected by the wide scale use of forest soils as substrates in developing countries. With the objective of finding long-term sustainable supply of growing media, compost was produced from shredded branches of three fast growing species (Acacia cyanophylla (AA), Acacia cyclops (AS) and Eucalyptus gomphocephala (EG). The composting process covered three different periods over the course of a year. Pile temperatures were monitored daily and the composts were routinely sampled and analyzed for 19 chemical variables. Although composting is feasible year-round in arid climates, compost produced in the humid cool conditions of autumn, winter and early spring reaches the maturation phase more quickly than compost produced under hot, dry summer conditions. It also requires less turning and water. The evolution of the composting process and quality of the final product can be assessed using three chemical variables (C/N, pH, EC). Seed germination rates in the three types of compost were similar to that in a peat:vermiculite substrate and vigorous high quality seedlings were produced in the two acacia composts. However, compost-grown seedlings had significantly smaller shoots and root systems than those produced in peat substrate. Principal components analyses showed that the quality of a compost-based substrate is reproducible and that its final chemical composition can be predicted from its raw organic materials. The EG composts had higher pH than the acacia composts, whereas the AA and EG composts were higher in mineral salts than the AS.     

Relaxant effect of aqueous extract of Cistus ladaniferus on rodent intestinal contractions

The effects of the aqueous extract of Cistus ladaniferus leaves and stems were studied on the rodent isolated jejunum. The extract produced a reversible concentration dose-dependent (0.1-3 mg/ml) inhibition of the spontaneous motility of the rabbit jejunum. The inhibitory effects of the extract were not affected by pretreatment with the inhibitors of the alpha and beta adrenergic receptors yohimbine, prazosin or propranolol. The extract also inhibited K(+)-induced contractions in rabbit and rat jejunum at a similar concentration range. This result suggests that the antispasmodic action of the extract is mediated through calcium channel blockade. The results confirm the traditional use of C. ladaniferus in treating intestinal ache.     

Production, Economics, Employment Generation and Marketing Pattern of Rattan-Based Cottage Enterprises: A Case Study from an Urban Area of North-Eastern Bangladesh

Rattan, an important non-timber forest product, is a flexible palm used in weaving baskets or furniture. Rattan is light yet sturdy, making it suitable for furniture that can be moved often. Bangladesh has a large number of rattan-based enterprises. This paper reports a case study carried out in Sylhet City Corporation of north-eastern Bangladesh, exploring the production, financial profitability and marketing of rattan-based products, and the problems and priorities of rattan-based enterprises as well as their potential contribution to employment opportunity. A sample survey was conducted of 58 randomly selected rattan-based enterprises with entrepreneurs personally interviewed using a semi-structured questionnaire. Based on the total investment, the enterprises were divided into large, medium and small categories. Three origins of rattan (Local, Myanmar and Indonesia) and five species were used by the enterprises to produce 29 rattan-based product types. Rattan products were divided into three basic categories, viz. domestic utensils, domestic decorative articles and others for which uses are not specific. Among the three rattan origins, processing cost of local and Myanmar rattan species products was less and more articles were sold than for Indonesia rattan species. Financial analysis indicated that rattan-based enterprises are a profitable and attractive option for local socio-economic development. Entrepreneurs’ views on major problems and issues in rattan-based product trading and suggested measures to improve the condition of rattan-based enterprises also collected. Rattan-based enterprises will generate more domestic revenue, foreign exchange and employment if policies are adopted to provide the enterprises with a reliable source of raw materials and technical and financial assistance from Government to NGOs to sell the products, and expand market facilities in both local and international markets.     

雨豆树播种前预处理对种子发芽和种苗发育的影响

播种前对雨豆树(Albizia saman (Jacq.) F. Muell.)的种子进行了5 种预先处理,研究种子预先处理对种子发芽和苗圃种苗发育的影响。实验是在孟加拉吉大港大学林业与环境研究所的苗圃进行。研究结果表明,在种子末端修剪(处理4)提高种子发芽率50%,在冷水中浸泡24 小时(处理1)提高种子发芽率42%,在开水中浸30 秒后再在冷水中浸泡24 小时(处理2),种子发芽完全被抑制。处理4 和处理1 的种子发芽率、种苗初期形态生长和生物量都明显高于对照组。因此,这2 种播种前的种子预处理方法,可用于提高雨豆树种子发芽率和促进早期壮苗生长。图2 表3 参30。     

Lure-and-infect and lure-and-kill devices based on <Emphasis Type="Italic">Metarhizium brunneum</Emphasis> for spotted wing Drosophila control

In the current study, we have designed two experimental devices to study the potential of Metarhizium brunneum (Petch) and its crude extract (filtered growth medium) for the control of Drosophila suzukii (Matsumura). An experimental autoinoculation device impregnated with conidia of EAMa 01/58-Su strain was designed for a lure-and-infect strategy. D. suzukii adult mortality resulted in a 62.2% with an average survival time of 3.6 days, with no significant differences among attractiveness to adults of red and black colours used in the devices. Nevertheless, a 48.0% mortality of untreated males was obtained after being coupled with inoculated females, whereas only 24.0% of untreated females was killed after being coupled with inoculated males, thereby revealing the horizontal transmission potential of the strain in these inoculation devices. We observed an 84.7% reduction in fecundity in M. brunneum-challenged D. suzukii females. Finally, we designed a lure-and-kill device to dispense a crude extract of the EAMb 09/01-Su strain that had previously shown acute mortality in D. suzukii, with an exposure time of 6.9 h required to achieve 50.0% mortality. Mixing the extract with feeding attractant caused a 61.6% D. suzukii adult mortality rate. These results show the high potential of using M. brunneum in lure-and-infect and lure-and-kill strategies contributing to an integrated pest management program for D. suzukii control.