This Spring has presented plenty of challenges, and another is coming in from the south. Potato leafhoppers (PLH) are being carried into Ohio fields on southern winds and can quickly become a concern. PLH arrives around the time of first cutting and can be a pest of alfalfa into September. PLH can reach maturity in three weeks, and multiple generations can be present at the same time, being very damaging.
PLH is relatively easy to identify; the adults are lime green, wedge-shaped, and are roughly 1/8 of an inch in length. The immature nymph stages look similar but are smaller and lack wings. PLH feeding damage, commonly called hopper burn, is seen as the yellowing of alfalfa leaf tips in a V-shaped orientation.
For a video on identifying PLH, follow this link: PLH Identification and Damage in Alfalfa
Just like every pest, scouting is critical to know when spraying is an economically sound decision. To scout PLH, a 16-inch diameter sweep net, and a yardstick are needed. Be sure that the sweep net is 16 inches in diameter; if not, the control thresholds will not be accurate. With the sweep net, take 10 pendulum swings, making solid contact with the field canopy. After 10 swings, count the adults and nymphs collected, and be sure to check the seams around the rim for PLH nymphs. Take multiple samples from around the field for more accurate estimates. It is best to sample in dry and calm conditions.
For a video demonstration of PLH scouting, follow this link: Scouting for PLH in Alfalfa
The threshold for when control should be considered is 1 PLH for 1 inch of stand height. For example, if the alfalfa is 16 inches in height, the threshold for control would be 16 PLH adults and nymphs per 10 swings.
If a field has reached the threshold where action is needed, there are some extra considerations to give thought to. If the alfalfa is close to harvest, be sure to account for the preharvest interval restrictions for insecticides; there may be instances where an early or timely harvest is the better choice. Be sure to monitor the following cuttings for continued PLH pressure. PLH is most damaging to young stands, fresh regrowth, and stressed stands, since feeding can remove a great percentage of leaf area compared to a healthy mature stand.
For more information on potato leafhopper, see this factsheet: Potato Leafhopper on Alfalfa
weather this spring especially over the last couple of weeks has rapidly progressed forage maturity. Harvesting forages at the proper time for the livestock you are feeding is critical to farm profitability. Poor quality forages must be supplemented to maintain livestock. In the southern part of the state, many forage grasses are in head while in the northern part of the state, some varieties of Orchard grass and barnyard grass are in head but most are still in the vegetative stage but will be in head within a week.
Last week’s warm days and mostly fair weather supported crop progress but left some counties excessively dry, according to Ben Torrance, State Statistician, USDA NASS, Ohio Field Office. Topsoil moisture conditions were rated 9 percent very short, 19 percent short, 68 percent adequate, and 4 percent surplus. Statewide, the average temperature for the week ending on September 10 was 72.5 degrees, 4.6 degrees above normal. Weather stations recorded an average of 0.27 inches of precipitation, 0.27 inches below average. There were 5.6 days suitable for fieldwork during the week ending September 10.
Ninety-five percent of corn was in or past dough, 53 percent was in or past dent, and 11 percent was mature. Corn for silage was 27 percent harvested. Eight percent of soybeans were dropping leaves. Corn and soybean condition were 82 and 75 percent good to excellent, respectively. Third cuttings of alfalfa hay and other dry hay were 88 and 58 percent complete, respectively. Fourth cuttings of alfalfa hay were 38 percent complete. Pasture and range condition was rated 68 percent good to excellent, down from the previous week.
2nd cutting is well underway. Potato leafhoppers are very active. If you haven’t cut yet, continue to monitor, where damage is increasing, cut as soon as weather permits.
Our corn growth varies greatly throughout the county. Some fields are beginning to tassel and some field are at V8.
Soybeans are starting to look a little bit better, however, there are still a lot of “yellow” beans throughout the county. Two possible reasons are 
Wheat harvest has come to an end and most of the straw is in the barn. From what I hear, wheat yields were pretty good with little to no disease issues.
Recent weather has delayed 2nd cutting in many fields. Potato leafhoppers are very active. Continue to monitor, where damage is increasing, cut as soon as weather permits.
Plenty of moisture and some welcome warm weather – What a difference a week makes!
V3 through V6 – The third trifoliolate (V3) stage takes place when three trifoliolates are unrolled. In case of damage to the growing point, axillary buds permit the plants to compensate for yield or final productivity. The unrolling of six trifoliolates indicates the V6 stage. The root system continues to grow, even expanding across a 30-inch row spacing. The V growth stages continue as long as a plant continues to produce trifoliolates. Determinate soybean plants complete most of their vegetative growth when flowering begins. Indeterminate plants produce trifoliolates until the beginning of the seed formation stage (late reproductive period).
The time for 2nd cutting is getting closer, for some fields 2nd cutting has happened. Continue to monitor fields for potato leafhopper.
Our corn growth varies greatly throughout the county. Most of the county is between V2 and V6. However, there are some fields at V8 and beyond.
Most of our first cutting is complete. If you have not mowed yet continue to monitor for alfalfa weevil. As regrowth starts begin to monitor for potato leafhopper.
What a difference a week makes. Most of our corn is now planted and about 50% has emerged.
Like corn, bean planting is coming to an end. Soil crusting is also an issue in many of our bean fields. Continue to scout these fields for emergence problems. 
