Temperate Vegetables

PESTS

PESTS Aphids : (Myzus persicae , Brevicoryne brassicae) This is most important insect harming radish crop. Both adults and nymphs suck the sap of leaves. The cloudy and humid atmospheric conditions are favourable for rapid increase of aphid population. Control measures: Remove and destroy affected plant parts and spray malathion (0.05%). Harvesting should be done 7-10 days after application of insecticides. Flea Beetle : (Phyllotreta spp.) Flea beetle attacks leaves and makes small circular holes. They are active in sunny weather during spring. Control measures: Remove weeds hosts, follow the phytosanitary measures and spray carbaryl (0.1%). Repeat spray if attack persists. Mustard saw fly : (Athalia promixa) It sometimes causes severe damage to radish and turnip. Affected leaves and fruits show holes. It attacks crop in both flowering and vegetative phase. Control measures: Follow hand picking in kitchen garden and spray malathion (0.05%) or Endosulfan (0.05%). PHYSIOLOGICAL DISORDERS 1. Akashin It is is a disorder of radish caused due to boron deficiency. Also caused due to high day and night temperature (30/20oC) as well as by low soil moisture. Management: Spray 1-2 ppm of boron to rectify this disorder. 2. Pore extent or pithiness: It does much damage to the quality of the radish destroying the commercial value. Pores are formed by the collapse of parenchymatous cells in root tissues caused by excessive root growth in comparison with the corresponding assimilation ability of leaf tissue. Pore development is a sign of senescence and its degree differ among cultivars. Possible reasons: Delay in harvesting is the main reason to cause this disorder Management: Harvesting should be done at appropriate time. 3. Elongated root or Forking: i.e. secondary elongating growth in the root. Possible Reasons: Excess moisture during the root development, occurs on heavy soils due to soil compactness Management: Use of undecomposed organic manure is recommended.