Bruce Bordelon

Professor of Horticulture
Department of Horticulture and Landscape Architecture
Area(s) of Interest: Grapes and Small Fruit
Bruce Bordelon's website

111 articles by this author

Article List

grapes turning color

Early grapes are just beginning to soften and color (veraison). Summer raspberry harvest if winding down and fall bearing types are flowering. Blueberry harvest continues. Japanese beetle numbers continue to be relatively high in the Lafayette area. Peach harvest (for those fortunate to have a crop) has begun. Early apple cultivars are approaching harvest.


An Indiana Pesticide Clean Sweep Project designed to collect and dispose of suspended, canceled, banned, unusable, opened, unopened or just unwanted pesticides (weed killers, insecticides, rodenticides, fungicides, miticides, etc.) is being sponsored by the Office of Indiana State Chemist (OISC).  This disposal service is free of charge up to 250 pounds per participant.  Over 250 pounds there will be a $2.00 per pound charge.  This is a great opportunity for you to legally dispose of unwanted products at little or no cost. WHO:         All public and private schools, golf courses, nurseries, farmers, ag dealers, cities, towns, municipalities and county units of government or others receiving this notice are eligible to participate. WHEN/       9:00am to 3:00pm Local Time WHERE:     August 14, 2018: Steuben County Fairgrounds in Angola, IN August 15, 2018: Jasper County Fairgrounds in Rensselaer, IN                   August 16, 2018: Henry County Fairgrounds in New Castle, IN                   August 21,[Read More…]


Japanese beetles appear to be especially abundant this year. They started showing up a couple of weeks ago and are now numerous in many areas. This past year Japanese beetle populations were higher than they have been for a number of years and this year looks to be a repeat.  We’ve seen severe damage to small fruits, grapes, as well as the Pristine apples, plums, etc. Adult beetles are relatively easy to control, but after insecticide treatment to knock them down, populations reappear as the insecticide wears off. So, it may require more than one application to control them. Sevin and the pyrethroids will provide the best control, although Sevin may only give about 3 days of protection. Watch pre-harvest intervals (PHIs) in small fruits if harvest is on-going. And note that the REI for Sevin can be 2 to 6 days in grapes. One note about damage: It often[Read More…]


Plant nutritional status is important for all phases of plant growth and has a direct effect on vigor, fruitfulness, cold hardiness, and other factors. Tissue analysis is the most reliable means of determining plant nutritional status. Combined with soil testing, tissue analysis can help pinpoint the source of problems and determine what measures may be needed to insure proper nutrition of the crop. Tissue analysis samples should be collected at the appropriate time to give the most meaningful results. For strawberry, sample the first fully expanded leaves after renovation, usually in mid to late July. For brambles, sample leaves on non-fruiting canes (primocanes) between August 1 and 20. For blueberries sample leaves during the first week of harvest. For grapes, samples should be taken about 70 days after full bloom, usually early to mid August. Samples should be adequate in size. Collect 30-60 leaves for strawberries, brambles, and blueberries, and[Read More…]



By now almost everyone has heard about dicamba, the volatile growth regulator herbicide that has garnered so much attention the past couple of years. It is being used over the top of dicamba-tolerant soybeans on thousands of acres in the state this year. We are trying to keep track of off-target damage so we would like to hear from growers that see any typical symptoms. Grapes are one of the most sensitive crops to dicamba, though there is a wide range of sensitivity among varieties. But they are not the only fruit crops that are sensitive. Raspberries, blackberries, blueberries, and tree fruit are also sensitive. Dicamba typically causes upward leaf rolling on new growth (see pictures below). If you see this type of damage in your fruit plantings, please contact your local Purdue Extension Educator or one of the specialists that write this newsletter. The more we know about the[Read More…]


This was a very short year for strawberries due to the record warmth in May. By now, most harvest is over. As soon as harvest is done, it’s time to begin the renovation process. Matted row strawberry plantings must be renovated each year to establish new crowns for the following year’s crop. For best results, renovation should be started immediately after the harvest is completed to promote early runner formation. This is especially important in the northern part of the state with its shorter growing season. The earlier a runner gets set, the higher its yield potential. Growers should begin renovation as soon as the last marketable berries are harvested. Delaying renovation is one of the most common mistakes growers make. Renovation should be completed by the end of July in normal years. The following steps describe renovation of commercial strawberry fields. Weed control: Post emergent application: Annual broadleaf weeds[Read More…]


Now that we are past fruit set, it is easy to tell what level of crop we are carrying. With the fairly extensive winter injury this year, many varieties will have a light crop borne on secondary or tertiary shoots. Little if any crop control will be needed in those. However, many of the plantings I’ve seen have a very good crop and some crop control will be necessary to balance the vines. A crop load ratio (yield to pruning weight) of 8 to 12 is a good rule of thumb for vine balance. This means we need to leave only enough clusters to produce 8 to 12 lb of fruit on low to medium vigor vines with 1 lb of prunings. For large clustered varieties such as Vidal and Chambourcin, clusters can weight 0.40 lb. So 10 clusters will contribute 4 lb of yield and we would need 25[Read More…]


Grapes across the state are post bloom a week or more. As berries reach 3 to 5 weeks post bloom they become naturally resistant to infection by black rot and powdery mildew fungi. So our spray program can relax a bit. Growers normally extend to a 14 to 21 day schedule supported by regular scouting. At that time we can begin to focus on leaf diseases such as downy and powdery mildew. Downy is likely to be a big problem this year because it favors hot, humid conditions, exactly what we’ve been experiencing. There are a number of excellent fungicides specifically for downy mildew as well as older products such as Captan and phosphorous acid products. Scout your most susceptible varieties twice a week and make an application as soon as any downy mildew lesions are noted. Another concern is insect pests. Japanese beetles have emerged and adults are present[Read More…]