■%i- 



m PLANT INSPECTIONS CAN HELP. Plant inspections 

 took more time than stici<y card counts, but gave us 

 important information. We learned what benches were 

 hotspots, so that control efforts could be concentrated 

 there. IVlost hotspots tended to stay hot over the sea- 

 son, while large sections of bench area were free of 

 whiteflies. We learned that it can be very effective to 

 spot-treat. Without plant examinations, we would have 

 wasted treatments where they were not needed. 

 Plant examinations also told us what stages the white- 

 flies were in. We know that the 

 adults and young larvae are easiest 

 to control; the eggs and pupae are ^**'' 



the most difficult. Knowing what ^"i" 



stages were present allowed us to ^^.^ 



select the most effective control op- ^^ 



tions, as well as anticipate where 

 and when adults would appear. On 

 several occasions, plant inspections 

 proved that an influx of adult white- 

 flies seen on that week's sticky 

 cards had actually come from nearby 

 plants, not the poinsettias. 



most serious 



the undersides of the leaves was critical when spray- 

 ing was done. Although adults are sometimes found 

 elsewhere, all other stages are exclusively found on 

 leaf undersides. On one occasion, the manager inten- 

 tionally selected a pesticide that gave easy-to-see 

 white deposits, so that we could better evaluate cov- 

 erage. We also tried water-sensitive paper (turns blue 

 where touched by droplets) attached to leaf under- 

 sides, to help us see if we were getting good cover- 

 age. It worked well if the strips were placed just be- 

 fore spraying and evaluated just af- 

 ter spraying. If watering took place 

 fl'** before the strips could be exam- 



■■■ ined, they just turned solid blue! 



1,^ Controls were not limited to 



just spraying. In a few cases, a very 

 few well-infested leaves were 

 threatening otherwise uninfested 

 benches. Removal of those infested 

 (lower) leaves improved the ap- 

 pearance of the plants and elimi- 

 nated the whiteflies, too. 



pest problems 



■ FLAGGING INFESTED SPOTS 

 CAN HELP. We learned how effec- ^^^^_^ 

 tive treatments had been by mark- 

 ing well-infested leaves with blue 



flagging and checking on them the following week. By 

 returning to the same leaves, we could tell if sprays 

 had done their job. If they had not, the pattern of 

 coverage and the records of rate and past choices of 

 materials helped us determine if the problem was 

 caused by poor coverage, too low a rate, or perhaps 

 resistance. 



■ MARK THE BENCHES/BAYS WITH IDENTIFYING 

 NUMBERS. We made maps of the greenhouses and 

 bench numbers, so that managers could identify which 

 benches or areas were hotspots, from the data sheets. 

 Anyone looking at the data could then figure out what 

 was going on, not just the person(s) doing the 

 scouting. 



■ SPRAYS MUST BE DIRECTED AT THE LEAF UN- 

 DERSIDES. It was clear that getting good coverage to 



poinsettia growers face. 



■ PUTTING IT ALL TOGETHER. It 

 is not necessary for you to employ 

 all of these practices to improve 

 ~'^^~^^^~ your management of whiteflies. I 



hope you already use some! The 

 challenge is to fit together a program of practices that 

 will help you in your silualion. For some, this means 

 getting better coverage. For others, monitoring is the 

 principal need. In some situations, it is clear that 

 preventative measures (starting clean, staying clean) 

 are of key importance. My experiences with sprays on 

 fruit and vegetable crops indicate that growers are 

 very quick to assume that poor control means the 

 pesticide was ineffective. In fact, most of the time 

 poor coverage, calibration or poor timing are the rea- 

 sons. My limited work with greenhouse pests sug- 

 gests the same patterns. 



In the coming months, the Extension IPM program 

 will specifically target management of pests in poin- 

 settias. Keep in touch with your County Extension 

 staff or me if you are interested in help. 



Dr. Eaton is an Extension Specialist in Integrated Pest Man- 

 agement, with UNH. He can be reached at 603-862- 11 59. ^ 



75 CHESTNUT HILL, RTE 190 

 STAFFORD SPRINGS, CT 06076 



W. H. MILIKOWSKI, INC. 



GREENHOUSE SUPPLIES & EQUIPMENT 



PLANTS BULBS SEEDS 



ALL YOUR GREENHOUSE NEEDS 



GROW verm US 



Conn. 203-684-5811 

 Out ol State 800-243-7170 



JOSEPH GIANNINO 



Greenhouse Plants 



Unrooted • Rooted 



Preflnlshed 



Finished 



Nursery Stock 



B&B 

 Container 

 Bare Root 



56 Tuscano Avenue 



Revere. MA 02151 



Home: 617-286-6541 



Fax: 617-289-9412 



From Start to Finnh 



D. A. POSOCCO, Inc. 



