3 Lentil (Lenus culinaris Medik) is a major grain legume crop in many developing countries in West Asia, North Africa and many other areas of the world. The effects of sowing date (1 January, 15 January and 2 February), plant density (80, 100 and 120 plants m )2 ), phosphorus level (0, 17.5, 35.0 and 52.5 kg P ha )1 ) and ethephon application [(1500 p.p.m. 4 ethephon (2-chloroethel phosphonic acid) applied 30 days after sowing] were investigated in the semiarid region in the north of Jordan. High yields were obtained for early sowing (1 January), high plant density (120 plants m )2 ), and high phosphorus application rate (52.5 kg P ha )1 ). Yield and yield components were not affected by ethephon application 30 days after sowing.

The rhizosphere is the site of organic deposition and the generator of habitat and resource heterogeneity for soil organisms. Plants can modify their rhizosphere through nutrient, moisture and O2 uptake from the rhizosphere, rhizo‐deposition and production of root exudates. As a result, rhizosphere chemical (pH, nutrient solubility, O2, CO2 and other chemicals), physical (moisture and aeration), and biological (soil pathogens, beneficial microorganisms and allelopathy) characteristics will be changed or modified. Rhizosphere microorganisms have positive or negative effects on plant growth and morphology by affecting the plant hormone balance, plant enzymatic activity, nutrient availability and toxicity, and competition with other plants. Plants modify the rhizosphere and as a result will modify the community.

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SummaryThe influence of aphid, Aphis gossypii, feeding on photosynthesis and transpiration in cotton plants was investigated under greenhouse conditions. Four population densities of 0, 5, 10, and 25 aphids were used to infest individual cotton leaves. Gas exchange rates were determined for single attached cotton leaves after 9, 18, and 27 days of aphid infestation. Aphid feeding changed photosynthetic rates and transpiration rates. These changes were proportional to the number of aphids and the length of infestation period. Photosynthetic rates were significantly reduced in infested leaves with 25 aphids over 18 days, whereas significant reduction in photosynthetic rates was recorded within 27 days in infested leaves with 5, 10, and 25 aphids in comparison to their respective control. Initial population of 10 aphids increased significantly the transpiration rate of infested leaves over 9 and 27 days. Leaves of plants with 25 aphids had significantly greater transpiration rate than the control at all times.

Pods and seeds from carob Ceratonia siliqua L. trees growing in Ajloun Mountainous forests and rangelands in Jordan were analyzed for their proximate analysis, Ca and P contents, and also the effects of ingestion of seeds by sheep and goat on the germination were investigated. Carob seed has hard seed coat dormancy, and seed scarification increased germination from 10.2% in non-scarified to 85.4% after scarification. Germination percentages for seeds that were ingested by sheep were 73.5, 61.8, 39.3, and 0.0% for ingestion periods of 24, 48, 72, and 96 hours, respectively; whereas, it was 56.8, 79.9, 50.1, 13.7, and 1.1 % for seeds dispersed from goat after 24, 48, 72, 96, and 120 hours. Carob seeds contained higher amounts of protein, fiber, fat and Ca than deseeded pods. However, the latter contained more carbohydrates and P than seeds. Carob pods and seeds contained sufficient crude protein and energy to meet the maintenance and lactation requirements of ewes, but Ca and P contents were not adequate by themselves.