Assessment of citrus crop condition in Umling block of Ri-Bhoi district using RS and GIS technique

Orange orchards of Meghalaya are small in size and are found together with other plants on the slopes of hills. It is also reported that the productivity of orchards is declining in some parts of the state. Therefore in this study, we have attempted to map areas prone to citrus productivity decline based on the integrated effect of soil erosion, vegetation condition and moisture stress. It is difficult to identify orchards on hilly terrain using standard FCC of IRS-P6 LISS III data. Hence, an enhanced color composite image was prepared from three images generated from indices namely SBI, NDWI and NDVI. This enhanced color image was classified using the maximum likelihood classification method and enabled identifying villages prone to citrus decline. The study shows that orchards of 29 villages which are suffering from moisture stress and mostly located on steep slopes that cause heavy soil loss leading to nutrient imbalances are prone to citrus decline. These data will be useful in mapping potential citrus decline areas over zones having similar climatic conditions so that the concerned state horticulture/agriculture departments and citrus growers can take necessary remedial actions.