Q: Several people I've talked to are worried about the safety of their pets when household rat and mice killers are used. Is their worry justified?--D.H., Van Nuys A: University of California experts recently reviewed the safety record of the anti-coagulant rodent baits most commonly used in the home. Such materials, which are applied by pest-control operators and sold in nurseries and hardware stores, account for about 95% of all rodent control in the United States. The study indicates that the relative safety of anti-coagulants is due to the fact they are selective to rodents and require multiple feedings over a period of several days to cause death. Label instructions on these materials refer to pet safety; it's important to follow the precautions and place rodent bait where it's inaccessible to pets. The study also recommends using tamper-proof bait boxes. Once you've controlled the rodent population, remove remaining bait. In situations where pets could gain access to such bait, you'd be wise to choose another approach.
Q: For some time now, we've been trying to grow disease-free peach trees. Some years, the leaves that emerge in the spring are more of a red and yellow than a healthy green. In other years, leaves have had brown and purple spots. Why is that?--T.N., Covina A: Several of our more popular deciduous fruit trees--such as peaches and nectarines--are susceptible to diseases indicated by the symptoms you have described. When leaves produced in the spring are thickened and red or yellow, peach-leaf curl is probably responsible. Dormant fungicide applications--anytime after leaf fall--will provide protection. Use Bordeaux, fixed copper or Ziram. What is called shothole disease, or peach blight, will cause the leaf lesions you describe as having light-brown centers and dark-purple margins. The disease gets its name because the lesions become corky and ultimately fall out of the leaves, leaving pinhead-size holes. To control the affliction, spray with Bordeaux, fixed copper, Ziram or Ferbam after leaf fall and before the end of December. Shothole disease is caused by prolonged wetness, so untreated trees are more subject to infection during wetter winters.