Orobanche aegyptiaca is a chlorophyll-lacking holoparasite that subsists on the roots of plants, inflicting severe damage to legumes and other crops in the Mediterranean region. Common vetch and purple vetch are important legume forage crops in Israel and the Middle East. Experiments in pots containing soil inoculated with O. aegyptiaca seeds have shown that common vetch genotypes ‘Yovel’ and ‘473-A’ are susceptible to the parasite, whereas purple vetch genotypes ‘Popany’ and ‘Sadot’ are resistant. When grown in association with O. aegyptiaca in polyethene bags, purple vetch genotypes stimulated a significantly higher rate of parasite seed germination than that stimulated by common vetch genotypes. However, the number of successful Orobanche attachments developed on the host root was lower on resistant genotypes compared to susceptible ones. This differential response between purple and common vetch genotypes was evident at diverse temperature regimes (17/12, 22/17, and 27/22 C day/night). Microscopic observations revealed that resistant genotypes rapidly developed necrotic lesions surrounding the contact point of the parasite radicle (germ tube) with the host root, hence preventing further development of the parasite. In the sensitive genotypes, attachments developed without necrotic lesions. These data may indicate involvement of host defense mechanisms induced by the parasite attachment.

Organic cotton is a new industrial crop product. Field experiments were conducted to determine the effects of cultural systems and varieties on the growth, fiber quality and yield components of cotton crop (Gossypium hirsutum L.). The experiments, conducted during 2006 and 2007, were laid out in a split plot design with four replicates, two main plots (organic and conventional system) and two sub-plots (cotton varieties: Athena and Campo). There were no significant differences between the organic and conventional system for cotton growth, yield and fiber quality. The results suggest that the soil N released from both the inorganic (80:40:40 kg ha−1 N:P2O5:K2O) and organic pool (green manure) were sufficient to maintain good growth. Inferior-quality fiber was produced in the variety. Campo, which had the lowest fiber fineness (micronaire), strength, length and reflection. In addition, this variety had the highest fiber elongation and yellowness. There were no significant differences between varieties as far as uniformity and leaf trash ratio are concerned. A positive correlation was observed between fiber strength and length. However, a negative correlation was found between lint yield and fiber strength.

Energy analysis provides a measure of the effectiveness of sustainable agricultural systems in reducing inputs purchased from off-farm sources. This study compares the total (direct plus indirect) energy costs of growing corn for silage using manufactured N fertilizer or N-fixing legume cover crops. The cover crop either was killed with herbicide in a no-till system or disked in the spring. Economically competitive alternative crop production practices are identified.

In both the no-till and the disked versions, cover-cropped treatments used about half as much energy per hectare as the corresponding winter fallow N-fertilizer treatments. Using vetch to provide N significantly lowered energy use per unit of crop output compared with the N-fertilized treatments. For the treatments that used hairy vetch, either alone or in combination with big/lower vetch, net revenue was statistically equivalent to that of standard-practice treatments in each year of the study.