.Feddes Repertorium zyxwvutsr 105 (1994) 5-6,383-386 National Botanical Research Institute, Environmental Botany Laboratory, Lucknow. India Berlin, September 1994 J. MISRA; V. PANDEY; K. J. AHMAD Effect of cement dust on petal morphology of zyxw Brassica campestris L. With 2-Tables and one Plate Summary Effect ofcement dust on petal morphology ofBrassica campestris L. was studied under light and scanning electron microscopes. In control (undusted) plants, papillae were striate and coronulate with clear boun- daries unlike dusted plants where they were shrunken and collapsed. Number of papillae was also reduced. Cement dust absorbed moisture from petal surface causing water loss and subsequent loosening of the arrangement of papillae. Damage to flower petals will affect the quality of flowers thus causing serious losses in floriculture. Key words: Cement dust, petalmorphology, 3rassi- ca campestris. Introduction Different types of dusts are known to affect plant growth and yield by altering morphologi- cal structures and biochemical processes of the plants. Dust deposited on plant surfaces causes changes in the structure and composition of the cuticles (MARTIN zyxwvuts & JUNIPER, 1970; CUTLER et als., 1982; Y u m s & AHMAD, 1983). EVELING (1967, 1984), SHARMA (1977). EVELING & BA- TAILLE (1984) and GUPTA & GHOUSE (1986) studied the effect of different types of dusts zyxwv on the foliar cuticle and petal morphology. Studies on the effects of cement dust are not well documented and there are only a few reports on the effect of cement dust on leaf surface. JAFRI et al. (1979) and Yws & AHMAD (1980) found changes in leaf architecture due to cement dust deposition. There is, however, no informa- tion on the effect of cement dust on petal Zusammenfassung Die Auswirkung von Zementstaub auf die Morpho- logie der Bliitenblatter von Brassica campestris L. wurde licht- und elektronenmikroskopisch unter- sucht. Bei Kontroll (Staubbeeinflul3t)-Pflanzen waren die Papillen striat und koronulat mit deutlich ausge- pragten Rlndern, wogegen bei den staubbefallenen Pflanzen diese reduziert und zusammengefallen wa- ren. Gleichzeitig wurde die Anzahl der Papillen reduziert. Der Zementstaub absorbiert die Feuch- tigkeit von der Bliitenblatt-Oberfllche, was zu Was- serverlusten fiuhrt und als Folge dessen kommt es zur Verinderung in der Anordnung der Papillen. Die Beschadigung der Bliitenblltter verringert die Quali- tiit der Bliitenblatter und verursacht zyx so einen be- trlchtlichen Verlust in der Pflanzenkultur. morphology. Cement-kiln dust released by ce- ment factories, settles on the plants and due to its highly hygroscopic nature forms a hard crust on the surface. In India, a large number of cement manufacturing units have been set up and they release enormous amount of cement dust into the atmosphere. The present study has been undertaken to study the effect of cement dust on the petal morphology of zyx Brassica campestris L. which is one of the most important oil yielding plants of India. Material and methods Cement dust was obtained from Chunar Cement Factory, which is one of the biggest factories of North India, located in Mirzapur district of Uttar Pradesh. Its chemical composition is given in Table 1. Seedlings of 3. campestris L. were planted 15 cm apart in rows spaced 25 cm in 1 m2 plots. At 4-6