Meteorological considerations in determining the permissible time for cotton spraying from the air in Israel

✍ Scribed by J. Lomas; H. Frankel; I. Hirsch

• Publisher: Elsevier Science
• Year: 1964
• Weight: 426 KB
• Volume: 1
• Category: Article
• ISSN: 0002-1571
• DOI: 10.1016/0002-1571(64)90031-7

✦ Synopsis

Five years' practical experience of the aerial spraying with insecticides of cotton in the Beit Shean Valley, Israel, has shown empirically that, with the application techniques used in Israel, the best and most economical results are obtained when the operation is confined (in mid-summer) to the period from sunrise to 08.30 hours. The recent introduction of cotton in other regions of Israel, with more temperate climates, poses the question of the extent to which the spraying period might be safely and economically extended in these regions. In a nation-wide plan for the application of insecticides, such an extension would materially lower the cost of aerial spraying by increasing the utilisation of each aircraft and thus reducing the total number of aircraft required.

The physical and meteorological principles which govern aerial applications are reviewed. Climatological data of temperature, relative humidity and wet-bulb depression from a number of representative observing stations with long-term records are used to divide Israel into three fairly homogeneous climatic zones. The empirical findings for mid-summer in the Belt Shean Valley are then extrapolated, on the basis of consideration of the meteorological data (supplemented by radiation figures), to other months and other regions. These considerations indicate that in the semi-arid zone (Area 3), which includes the Beit Shean Valley, spraying should be confined to four hours after sunrise, but in the interior of the country (Area 2), this period might be extended to 41/2 hours, and in the coastal region (Area l) to 51/2 hours.

It is suggested that the methods used in this study might usefully be applied in other areas and for other crops.