ISHS Acta Horticulturae 696: VII International Symposium on Temperate Zone Fruits in the Tropics and Subtropics - Part Two
EFFECT OF HOST PLANT NUTRITION ON DEVELOPMENT AND POPULATION BUILD-UP OF EUROPEAN RED MITE [PANONYCHUS ULMI (KOCH)] ON APPLE |
| Authors: | S.P. Bhardwaj, S. Sharma, S. Bhardwaj |
| Keywords: | apple, european red mite, nutrition, Panonychus ulmi |
| Abstract:
Host plant nutrition plays vital role in sustaining pest population. Impact of nitrogen, phosphorus, and potassium on the development of different life stages and population build up of P. ulmi population was determined. Three levels of NPK each at recommended dose (N1, P1, K1), 25 per cent above (N2, P2, K2) and 25 per cent below the recommended dose (N3 P3, K3) was studied on potted plants of Delicious cultivars of apple. Among various levels of N, P, and K minimum incubation period (5.80 days) and total duration of immature stages (11.40 days) was recorded in N2 and maximum in K2 treatments (13.40 and 22.40 days, respectively). The female longevity was higher than males in all the nutritional treatments including control. Highest adult longevity was observed in N2 treatment being 14.80 days and 7.00 days for female and male, respectively, as against 11.00 days in females and 5.80 days in males in control. The mean fecundity was minimum in K2 (10.80 eggs/female) and maximum in N2 treatment (49.40 eggs/female). The mean population of adults, immatures and eggs of P. ulmi was minimum in plants given different levels of K followed by P with highest number in N treatments. The respective mean population of adults, immatures and eggs was minimum in K2 (21.59, 25.56, 117.80/leaf) and maximum in N2 treatment (77.44, 102.00, 414.80/leaf). Among P treatments, P2 supported minimum population of adults (35.67/leaf), immatures (38.11/leaf) and eggs (144.60/ leaf). The studies suggest that application of N at 25 per cent less dose (525 g/tree) and that of P (440 g/tree) and K (875 g/tree) 25 per cent higher than the recommended dose extend the life span and reduce the European red mite population to a significant level. | |
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