When glyphosate [N-(phosphonomethyl)glycine] at 0.075 kg/ha, DCPA (dimethyl tetrachloroterephthalate) at 10 kg/ha, and H 26905 [O-ethyl-O-(3-methyl-6-nitrophenyl)-N-sec-butyl phosphorothioamidate] at 0.25 and 0.5 kg/ha were sprayed on foliage of alfalfa (Medicago sativaL. ‘Vernal’) on which field dodder (Cuscuta campestrisYunck.) and largeseed dodder (Cuscuta indecoraChoisy) were attached and growing vigorously, almost all visible dodder tissue was killed and alfalfa was not injured noticeably. Some dodder recovered from haustoria within the alfalfa stems and from remnants of twined tendrils, but devastation of the alfalfa by uncontrolled dodder was prevented. PP 009 (butyl 2-[4-(5-trifluoromethyl-2-pyridyloxy)phenoxy] propionate), BAS 9052 (2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one) and RO 13-8895 (acetone-O-[D-2-[p-[(α,α,α-trifluoro-p-tolyl)-oxy] phenoxy] propionyl] oxime) at 0.25, 0.50, or 1.0 kg/ha did not control dodder.

A field study was conducted on dry land to determine the contribution of different plant parts to the kernel development of wheat and barley. Shading of the spike proved to be the most effective treatment in reducing the grain yield and 1000‐kernel weight of wheat and barley. The least significant effect was obtained by the removal of the lower leaves. Treatments made 1 week before anthesis caused maximum reductions in grain yield and 1000‐kernel weight. Plant height was least affected by shading or removal of the different plant parts. Clipping full awns at anthesis had the most significant effect on the grain yield and 1000‐kernel weight of wheat, reducing the yield 20.8% and the weight 13.4%. This reduction corresponded to the proportion of the awns clipped and the advancement of the stages of growth studied. The plant height was not affected by clipping the awns.

The North American species of Allium exclusive of A. schoenoprasum and A. tricoccum of Old World affinity are grouped on the basis of morphological similarity into eight discontinuous species alliances typified by A. acuminatum, A. campanulatum, A. canadense, A. cernuum, A. falcifolium, A. kunthii, A. sanbornii, and A. validum, respectively. Representatives of each of these alliances were compared with respect to volatile constituents responsible for characteristic odors by means of gas chromatography. Results indicate that these volatiles provide evidence of relationship useful in the classification of alliums. Uniformity was found in composition of volatiles in the representatives of the A. canadense, A. cernuum, A. kunthii, and A. sanbornii alliances. Variation was observed in the A. acuminatum, A. campanulatum, and A. falcifolium alliances. A. validum was the only species of its alliance studied. Vapors of A. validum contain mostly n‐propyl sulfides (onion‐like odor) as does the cultivated A. cepa. Methyl sulfides (cabbage‐like odor) predominate in the A. sanbornii alliance. A few species of the A. acuminatum and A. falcifolium alliances contain mainly allyl sulfides (garlic‐like odor).

Field studies were conducted in 1991 and 1992 at the Faculty Farm of the U.A.E. Univ., Al-Ain, to evaluate the effectiveness of soil solarization for weed management in naturally infested plots of lettuce, and on subsequent planting of garlic. Solarization for 2 mo during the hottest summer period effectively suppressed weeds during the growing season of head lettuce. In subsequently-planted garlic, no significant effect was observed between solarized and nonsolarized treatments.