Topics of this newsletter includes corn irrigation and the southern rust situation, boron in cotton and peanuts, weed control issues, bermudagrass stem maggot and the pasture mealy bug.
Current situation: The local cotton crop ranges from just emerged to first bloom. The corn crop ranges from blister to 80% milk line. The peanut crop ranges from 14 days old to blooming. Fields are starting to dry out, and weed control in cotton and peanuts has been the topic of discussion. Bermudagrass stem maggot populations are being noticed in some hay fields. The Drought Monitor this week shows that we have improved over the last month.
Corn: The corn crop ranges from blister to 80% milk line. I have received a question or two about water requirements during kernel development. Corn irrigation needs to be terminated when the crop reaches black layer stage of development. Early irrigation termination on corn is a common mistake and it can hurt your yield depending on when you cut the water off. Although kernels outwardly appear mature and corn water use begins declining at the dent stage, this is far too early to terminate irrigation. Potential kernel weight is only about 75% complete at the dent stage. Thus, termination of irrigation at the dent stage can reduce grain yields as much as 15-20% when hot, dry conditions persist. Early irrigation termination will also likely reduce stalk strength and promote lodging, because plants will cannibalize energy from vegetative organs to fill kernels when they are stressed. So water corn until black layer…
Boron on Peanuts: Growers should also remember to apply boron to support plant development, pollination, and seed formation. Two applications of boron at 0.25 pounds per acre each are recommended between 30 and 60 days after planting. As an example, one quart of a 10% boron product supplies approximately 0.25 pounds of boron where 6 oz of a 5% only provides roughly 0.025 pounds of boron.
What about manganese on peanut? Another fertility situation growers need to be aware of is manganese deficiency. In many of our peanut fields we are pushing soil pH into the upper 6’s which will tie up manganese. Therefore, growers need to think about addressing these high pH fields with 2 applications of foliar manganese to help reduce potential deficiency problems later in the growing season. Typically, growers will apply the two applications between 45 and 80 days.
Source : uga.edu