•To avoid development of resistance in the packing- 

 house do not use Benlate or other benzimidazole fungi- 

 cides in the orchard. Resistance to Benlate will reduce 

 the effectiveness of other postharvest fungicides in- 

 cluding Mertect 340-F and Deccosalt No. 19. 



Harvest 



•Harvest at proper maturity. Late-picked fruit is more 

 susceptible to decay than fruit of optimum maturity. 



•Clean bins thoroughly before filling. Steam is most 

 effective. 



•Reduce bin contact with dust and dirt which contain 

 spores of decay fungi. Keep the bottom of bins as clean 

 as possible. Keep staging areas mowed. Suppress dust. 



•Avoid picking fruit when it is wet. 



• Keep grounders (fallen fruit) out of bins. 



•Do not allow bins of fruit to remain inthesun. Trans- 

 fer fruit quickly to the packinghouse and cold storage. 



•Handle fruit gently. Avoid bruising and stem punc- 

 tures. Smooth orchard roads and driving forklifts and 

 bin trailers slowly may reduce fruit injury. 



Postharvest 



•After harvest, remove fallen fruit from orchard to 

 prevent buildup of decay spores. 



•Apply copper at leaf-fall to help reduce bull's eye rot. 



Bin Drench 



• Use a fungicide and change solution regularly to avoid 

 buildup of fungal spores such as Mucor that are not 

 controlled by fungicides. 



Packing Line 



• In the dump tank use sodium hypochlorite or calcium 

 hypochlorite at 100 ppm available chlorine or SOPP 

 (Steri-Seal D or Stop Mold F) at 0.3 to 0.5% to kill 

 spores of decay fungi. For pears, use sodium sulfate 

 flotation salt with chlorine or lignin sulfonate (Orzan, 

 Lignosite 458, Lignosite 50) with SOPP. Do not mix 

 chlorine with SOPP. Do not use chlorine with lignin 

 sulfonate. 



•Monitor concentration of chlorine many times each 

 day. Add chlorine continuously with a pump rather 

 than just once a day. Keep chlorinated dump tank at 

 Ph 6 to 8 for best results, but do not acidify solutions 

 containing sodium silicate. 



• The surfactant AG98 (Rohm and Haas) improves the 



effectiveness of chlorine. Use 0.3% AG98 and increase 

 the initial chlorine charge by about 10X to obtain 100 

 ppm chlorine. For pears, allow about 1 hour for flota- 

 tion salt to dissolve and tank specific gravity to stabilize 

 between adjustments. Do not use surfactants with 

 Topsin, Captan, or Mertect. 



•If using SOPP, dump tank water may be sterilized 

 with heat. Remove all fruit from tank, cover tank with 

 styrofoam or canvas, heat to 130°F and hold at that 

 temperature for 25 minutes. Allow water to cool before 

 dumping fruit into it. Ensure good ventilation during 

 heating. Approximately 10%waterlossand25% SOPP 

 loss occur during heating and need to be replaced. Do 

 not heat water containing chlorine. 



•Minimize depth of immersion of fruit when dumping 

 bins. Immersion forces contaminated water into 

 wounds and cores and increases rot. 



•Fruit should receive a thorough fresh water rinse 

 after leaving the dump tank and flumes. 



•Design line to minimize damage to fruit. Avoid sharp 

 edges and drops that wound or bruise fruit. 



•Apply fungicide prior to storage. 



Storage 



• Clean cold room thoroughly with a high pressure hose 

 and a commercial disinfectant labelled for food han- 

 dling areas. Several formulated products are available 

 for this purpose. Most of these products contain so- 

 dium or calcium hypochlorite, chlorine dioxide, or- 

 ganic acids such as phosphoric or acetic acid or quater- 

 nary ammonia compounds often referred to as 

 "quats". 



•Do not pack and store wet fruit. Dry thoroughly 

 before storage. Do not wrap wet pears in copper- 

 treated paper or staining may result. Keep relative 

 humidity in storage only high enough to avoid shrivel. 



• Keep temperature in cold room as low as possible. 



Packaging 



• Copper-treated wraps reduce spread of gray mold and 

 Mucor rot. 



•Use packaging material that minimizes bruising and 

 injury of fruit during transit. 



Shipping 



•Handle fruit gently and carefully. 



• Keep fruit cold. 



Fruit Notes, Summer, 1990 



19 



