We received some precipitation across much of Wisconsin over the past weekend. Although soil moisture had been adequate for crop planting and establishment across much of the state, the recent rains should improve conditions for most crops and is likely critical for recently transplanted crops. Soil temperatures have cooled considerably with the recent rain events and cloud cover. Bare ground maximum soil temperatures the end of last week were greater than 115 F at Arlington which can be damaging to newly transplanted crops if there is inadequate moisture. Maximum bareground soil temperatures at Hancock were 80 F last Thursday and Friday, but are 15 degrees cooler with recent rains, canopy development, and cooler night time temperatures. 

 

Potato- Conditions continue to be ideal for early season potato growth. Canopy development has progressed rapidly in Central Wisconsin with row closure likely occurring in most of the crop by the end of the week. Canopy closure of several slower growing varieties such as Bannock Russet may be 5 to 7 days behind. Canopy closure should help lower soil temperatures which is critical as tuber bulking is impaired at soil temperatures > 75 F. Many potato varieties have developed flower buds already.

 

We are also seeing differences in canopy development within different seedlots of the same variety. Physiologically younger seed emerged several days later than older seed and some minor differences in canopy development occurred as a result. We intend to continue to monitor differences in canopy health as well as tuber bulking between different aged lots throughout the year.

 

Early developing varieties have entered early tuber bulking stage of development. Red Norland tubers in Central Wisconsin are ½ to 3/4” in diameter. Russet Norkotah tubers are 1” in diameter. Russet Burbank tubers have begun to develop with stolon tips swelling to 1/4” or more.   Bannock Russet have developed stolons, but there is little sign of tuber development yet. Most of the crop has been side-dressed with the second application of nitrogen based on stage of development.

 

Early planted Red Norland potatoes on the Muck are approaching 30% canopy closure and tubers have begun initiating on the stolons. Stands appear to be good, but hills still feel dry even with the rains over the past weekend. Early planted potatoes in Langlade County have emerged as well. We planted potatoes the week of May 14th and they have just begun to emerge. 

 

ET has dipped under 0.15”/day over the weekend and early part of this week due to the cooler temperatures, cloudy days, and precipitation events. Up until this week the crop was requiring irrigation and fields are starting to need irrigation again today. Actual ET is similar to the reference ET because the crop has reached 80 to 85% canopy closure.

 

Processing vegetables – Sweet corn planted the first week of May has reached 7 leaves and is over 14” tall. Sweet corn planted 5 to 10 days later has 5 leaves and is 8 to 10” tall. The growing point of sweet corn has emerged above the surface of the soil and the tassel forms when corn reaches the 5 leaf stage. Sweet corn planting is just starting in earnest and should be done before mid June. Sweet corn stands appear to be good. Warm soil temperatures through much of May have promoted good germination and emergence leading to good stands across both sweet corn types. Soil temperatures of at least 50 F are necessary to promote and ensure good sweet corn germination and conditions have been nearly ideal for the past 5 to 6 weeks. 

 

Pea planting is nearly finished, with the earliest planted peas beginning to bud and bloom. Snap bean planting began over the past 10 to 14 days in the southern part of Wisconsin. Cucumber planting has also begun across Central Wisconsin. Soil temperatures of 60 F and higher should promote rapid crop establishment for snap bean and cucumber especially when considering the recent moisture.

 

Stands of carrot and other small seeded and shallow planted crops should be inspected and monitored to make sure of good emergence. High winds, lack of precipitation, and sunny weather led to dry conditions in the top inch or so of soil. The recent moisture should help promote early carrot growth, but inspect fields to make sure you have a satisfactory stand.