Hope everyone has a safe and wonderful 4th! Some food safety tips from our Food and Nutrition educators: hot days above 90F means we need to keep warm foods 140F or warmer. Perishable food should stay in the fridge or on ice before and after eating. Leave perishable food out an hour or less in hot weather. For more picnic and bbq tips, check out https://bit.ly/3xjYWwz.
ET and GDD: Also praying for rain; pics of drought monitor map at my blog. Our CropWatch GDD and ET resources if you don’t have your own ET gage are at: https://cropwatch.unl.edu/gdd-etdata.
From CropWatch: The forages team shared more detail on summer annual forage options at: https://go.unl.edu/7z5p. A team of Extension and Industry professionals led by Dr. Amit Jhala shared info. regarding herbicide options for soybean after the June 30 RUP dicamba restriction: https://go.unl.edu/2i5a.
Hail Damaged Trees: Evergreen trees have rapidly turned brown on the hail-damaged sides of trees the past 7-10 days. We don’t recommend applying anything to them; just water them to help them with healing. Next spring, they may be more sensitive to fungal disease and insects. Sarah Browning, Extension horticulture educator shares, “Hailstone damage to a tree’s vascular system limits its ability to move water up from the roots and into the secondary branches and leaves. Movement of nutrients throughout the tree is also reduced. Over the next few years, previously healthy vigorous trees will produce callus tissue to seal off bark wounds and re-establish vascular function. Until then, they have a reduced ability to move water and cope with dry conditions….In most cases, homeowners should take a “wait and see” attitude. Trees and shrubs should be kept well-watered throughout summer and fall to avoid drought stress. Keep plants well mulched to prevent secondary injury from mowers and string trimmers.”
Japanese Beetles: The adult beetles are ½” in length with metallic green heads and white ‘tufts’ of hair that look like spots on the abdomen. Don’t use Japanese beetle traps! Research shows they attract beetles to the landscape.
Organic control options: Wait till 7-9 p.m. then knock beetles off plants into a bucket of soapy water to drown them. This method takes diligence but is effective. You can also spray trees with water to knock them down to the ground and then drown in soapy water. Neem and Pyola are organic options that will protect for 3-7 days. Applying these products once per week can be effective as a repellent. Bt provides 7 days protection and is safe for bees.
Conventional control options: Japanese beetles impact flowering plants that other pollinators visit. Avoid spraying insecticides on windy days or when pollinators are present (best to spray late in day near dusk) and follow label instructions and harvest intervals (for cherries, plums, vegetables, etc.). Chlorantraniliprole (Acelepryn®) provides two to four weeks protection and is low risk to bees. Pyrethroids, including bifenthrin, cyfluthrin, lambda cyhalothrin, and permethrin, last about two to three weeks. Carbaryl (Sevin) or acephate will provide one to two weeks’ protection. Pyrethroids, carbaryl, and acephate are toxic to bees and other pollinators.
Corn and Soybean Thresholds: Soybean thresholds are 20% defoliation in the reproductive stages. In talking with Dr. Bob Wright, Extension Entomologist, we’re going with a 30% defoliation threshold for corn prior to tassel (same as soybean prior to flowering). Tasseled corn threshold: three or more Japanese beetles per ear, silks have been clipped to less than ½ inch, AND pollination is less than 50% complete. Pyrethroids are very effective against beetles. If one is concerned about flaring spidermites, a product like bifenthrin can be used.
Japanese beetle feeds on 300 different plant species preferring ones like roses, lindens, birch, and fruit trees. Early on, they can be managed by knocking them off plants in the evening and drowning in soapy water.
Concerning. Drought monitor maps: June 30, 2022 on the left compared to June 26, 2012 on the right.