ABSTRACT

The observations of foliage around a glass factory indicated damage symptoms like leaf tip and margin burning, chlorosis, bleaching, spotting etc.. which reflected decreasing intensities of pollutants with increasing distance from the source of the pollutants. The preliminary study indicated that Mangifera indica and Polyalthia longjfolia plants were found to be more susceptible in comparison with Erythrina indica and Moringa oliefera.

INTRODUCTION

Fluorides which are present in raw materials go into the glass (80%) or are emitted from the process (20%) along with mineral dusts. .Plant-fluoride relationships and field monitoring of plant responses to fluoride have been studied. by Le Blanc et al., (1971) in Canada, Rao & Pal (1978) in India and Doley (1986) in Australia. The work presented in this paper deals with the observations of damage to leaves of many plants growing in the vicinity of a glass manufacturing industry at OgaleWadi (near Karad, in Maharashtra State)

MATERIALS AND METHODS

A belt transect of the width of 3 m and length of 500 m was laid from the outskirts of a glass industry in the north-east direction. Plants growing in this region, cultivated or otherwise, were observed for their foliage. Since the transect covered roads and houses,

The author is thankful to Shri R. Salvi, D. B. Shinde, and Ms. J. M. Garud for their help infield work and Prof.R. M. Raverkar for his keen interest and encouragement.

Plants encountered are few in numbers but are of large variety, shade and ornamentals, trees, shrubs, herbs, kitchen-garden plants as also ruderals.

Observations were made after the monsoon, in January, 1980. The extent of damage to leaves of plants was classified as 'S' (slight less than 25% leaf area damaged), 'M' (mode-rate-26 to 50 % leaf area damaged) and -C (comp!ete-75% and more leaf area damaged). The damaged and total leaf areas were noted by using transparent graph papers and percentage leaf area damage was calculated, For practical convenience, approximate estimations regarding the number of leaves affected are made. Type of damage to leaves was recorded simultaneously. Samples of leaves collected were brought to the laboratory for further observations and preservation.

OBSERVATIONS AND DISCUSSION

The extent and type of damage observed in different plant species at different places on the transect is shown in Table I. The mar-g'n and tip burning was commonly seen in many plants like Mangifera indica, Datura alba, Pongamia glabra, Bougainvillea spectabilis, Miche-lia champaca, Polyalthia longifolia var. pendulosa etc Degree of burning of the leaves seem to be determined by the proximity of the plants to the source of pollution. Some individuals of these plants as well as Carina indica show chlorosis on their leaves being confined to the direction of wind blast carrying gaseous effluents. Ruderals like Cassia tora and Amaranthus spinosus seem to have met with similar fate under similar conditions

Beyond the above mentioned zone of the transect many plants are seen with distinct signs of injury due to atmospheric pollution. Spotting and margin burning is common in Pongamia glabra, the ornamentals like fasminum pubescens, Canna indica and Syzygium cumini show burning of leaves at tips and margins extending inwards. Bougainvillea specta;bilis, Musa paradisica and Cocos nucifera show margin burning.

Bleached white spots and/or marginal and interveinal chlorosis seen in Cucurbita maxima, Tinospora cordifolia, Pongamia glabra, Canna indica, Parthenium hysterophorus, Colocasia, antiquorum, Ipomea fistu'.ata, etc. at far distance from the pollutant source suggest their susceptibility of the fluoride pollution.

Plants like Moringa pterygosperma, Cassia, fistula, Erythrina indica, Euphorbia neriifolia, Vitex negundo,fatropha sps., Cynodon dectylon, %ea mays etc. through covered-over oily black coloured dust like, most other plants seem to show little response to atmospheric pollutants by way of visible injury. It was interesting to note that the canopy of the trees of Mangifera indica and Ficus sp. could not grow in the direction of the glass factory.

The preliminary study indicate that the plants have different responses to chemical airborne pollutants. Some plants are more resistant than others. More extensive work is required to understand the effects of air pollutants in this area and the same has been undertaken in this laboratory among other things, (I) the indicator species of plants as an easy aid in understanding air quality and (2) deciding the type of species that can be profitably cultivated in this area which is under the influence of air pollution.

1	2	3	4
Moringa oleifira	300—400	None	Nil
Cassia fistula	300—400	None	Nil
	400—500	None	Nil
Erythrina indica	300-400	None	Nil
Cassia tora	100—200	Tip burning and chlorosis	M
	400-500	Tip burning	S
Tamarindus indica	400—500	Margin and tip burning	M
Zea mays	400—500	None	Nil
Achyranthes aspera	400-500	None	Nil
Vitex negundo	400- 500	None	Nil
Fatropha sp	400—500	None	Nil
Cynoaon dactylon	400—500	None	Nil
Svzygium cumini	100—200	Margin and tip burning	M
Legend :
S	25% leaf area damaged,
M	26% to 50% leaf area damaged, and
H	51% to 74% leaf area damaged.