• Protect your lemons from fungal, bacterial or viral diseases by spraying them.LEMONS image by brelsbil from Fotolia.com
  
  It's always nice to have lemonade as a cool-down drink during the summer. Not only are lemons tasty, but they are also a nutritious fruit that contains a lot of vitamins. Problems arise when diseases such as fungus or bacteria attack lemon trees, slowing down fruit production and, in some instances, causing lemons to be inedible. Use the right sprays to disinfect lemon trees and keep lemons healthy.
  
  

Sulfur and Copper Sulfate Sprays

• A sulfur spray is effective in controlling the spread of powdery mildew, which is produced by several fungal diseases. It should be sprayed on the lemon trees before disease occurs to be effective. Copper sulfate spray is the remedy for anthracnose. If not treated beforehand, fungal diseases can cause lemon-tree leaves to drop, leaving black spots on the fruit.
  
  

Copper Oxycholoride

• Copper oxychloride spray controls a fungal disease called "Scab." Scab causes rough bumps on lemon-tree leaves and fruit, and can potentially damage the fruit so it is no longer edible. Copper oxychloride is a chemical fungicide that needs to be used with care, as it can cause the skin, eyes and respiratory system to become irritated and can also cause nausea, vomiting and stomach pain if overexposure occurs.
  
  

Liquid Copper Fungicide

• Liquid copper fungicide is used to control "greasy spot" fungal disease, or melanose. Melonose causes yellow or brown blisters on the bottoms of lemon leaves and causes the rind of the fruit to look like it has scabs. Liquid copper fungicide is effective in controlling these greasy spots and stopping the melonose fungal disease. Precautions must be taken to prevent irritation to respiratory areas, so make sure to follow the label instructions if you are using this product.
  
  

Insecticidal Soap

• Common insect pests on lemon trees are aphids and scales. They can have a detrimental effect on a lemon tree by sucking the plant's juices and contributing to the citus tristeza virus. Ants are responsible for transporting aphids because they harvest a sticky substance called "honeydew" that is excreted by aphids. This aphid-produced honeydew substance can cause diseases like powdery mildew and make lemons inedible. Keep ants away by spraying your tree with insecticidal soap and continue to spray every few days until there are no more indications of insect invaders.
  
  

Oil Spray

• In recent years, red-and-black scale insects have been attacking citrus trees and have developed an increasing immunity to cyanide gas sprays. One of the sprays that has been effective in protecting the trees from these insects are oil sprays. Oil sprays are characterized by high viscosity and low volatility, meaning that they can leave an oil film on the tree for many weeks. These sprays are most effective in breaking through the armored and unarmored scales and red spiders, when used in sufficient concentrations. Do not use heavy applications of oil spray on plants as it can produce certain undesirable effects on the plant itself and prevent the overall maturity of citrus fruits.