Leaf senescence constitutes the last stage of leaf development in plants and proceeds through a highly regulated program in order to redistribution of micro- and macro-nutrients from the senescing leaves to the developing/growing plant organs. Initiation and progression of leaf senescence is accompanied by massive sequential alterations at various levels of leaf biology including leaf morpholog...

There is a need to optimize water-nitrogen (N) applications to increase seed cotton yield and water use efficiency (WUE) under a mulch drip irrigation system. This study evaluated the effects of four water regimes [moderate drip irrigation from the third-leaf to the boll-opening stage (W1), deficit drip irrigation from the third-leaf to the flowering stage and sufficient drip irrigation thereaf...

Silicon in forage reduces dry matter digestibility and may reduce grazing preference. Two studies were conducted with the following objectives: (1) to evaluate a method of determining grazing preference, and (2) to characterize the distribution and solubility of silicon in 31 accessions of C-3 grasses and relate these traits to grazing preference and estimated forage digestibility. Forage sampl...

Since 1988, cucurbit crops, particularly watermelon, cantaloupe, and squash, grown in Oklahoma and Texas have experienced devastating losses from cucurbit yellow vine disease (CYVD), caused by the phloem-limited bacterium Serratia marcescens Bizio. Squash bug, Anasa tristis (De Geer), is a putative vector of the pathogen. In 2000-2001, overwintering populations of squash bug collected from DeLe...

The low average grain yield (0.7 ton ha(-1)) of tef in Ethiopia is mainly attributed to low soil fertility, and inappropriate tillage and weeds control practices. Despite this, limited scientific information has been documented so far on their interaction effects on tef crop productivity in northern Ethiopia. The objective of this study was to assess the separate and interaction effects of till...

The glossy varieties (A14 and Jing 2001) and glaucous varieties (Fanmai 5 and Shanken 99) of wheat (Triticum aestivum L.) were selected for evaluation of developmental changes in the composition and morphology of cuticular waxes on leaves and spikes. The results provide us with two different wax development patterns between leaf and spike. The general accumulation trend of the total wax load on...

data envelopment analysis is a nonparametric technique checking efficiency of dmus using math programming. in conventional dea, it has been assumed that the status of each measure is clearly known as either input or output. kao and hwang (2008) developed a data envelopment analysis (dea) approach for measuring efficiency of decision processes which can be divided into two stages. the first stag...

data envelopment analysis (dea) is a method for measuring the efficiency of peer decision making units (dmus) which uses a set of inputs to produce a set of outputs. in some cases, dmus have a two-stage structure, in which the first stage utilizes inputs to produce outputs used as the inputs of the second stage to produce final outputs. one important issue in two-stage dea is the sensitivity of...