Growing Degree Days through June 2

Jarrod O. Miller, Extension Agronomist,

Steady warm weather and periodic rainfalls have moved corn along pretty well. Most corn planted here in Georgetown in late April is at V6-7 and has been sidedressed. Fields planted through mid-May are at V5/V6, matching the predicted GDD pretty well.

The next milestone to watch for would be tasseling (VT), which occurs at 1135 GDD. At this stage just consider how weather may determine pollination and later grain fill as another determinant of final yield.

Table 1: Accumulated growing degree-days based on planting dates through May 20th.

If you planted

Sussex Kent New Castle
Apr 14 805 760 723
Apr 21 713 669 636
Apr 28 632 593 556
May 5 532 512 484
May 12 431 414 393
May 19 361 350 333

V6 = 475 GDD, V12 = 870 GDD, VT = 1135 GDD, R1 = 1400 GDD

Statewide Temperatures Since April 1st

Statewide Rainfall Accumulation Since April 1st

Corn Leaf Stages and Growing Degree Days

Jarrod O. Miller, Extension Agronomist,

With the fluctuation in temperatures since mid-April, corn emergence and growth has shifted week to week. At the research station, we have observed corn emergence take up to ten days planted April 24th, but only five when it was planted May 8th. Rising temperatures accumulate growing degree days (GDD) in less time, so that would be expected. Looking across the region, any corn planted on May 12th should have already emerged in Sussex, or be close to emerging in New Castle (as of May 20th).

Following emergence, the next important stage to manage is V6-V8, where you would typically sidedress corn. The V stage means six leaf collars, which can be identified as the white circle around the base of a corn leaf (Figure 1). Emerging, or recently emerging corn leaves will not have a collar yet. In Figure 1, counting the collars puts this field at V3. As you scout fields, some plants may be at the next stage, while the rest will catch up in a day or two.

Statewide temperatures and rainfall since April 1st can be seen in Figures 2 and 3. The rapid increase in temperature over the last week should have sped up emergence as well as advancing corn to the next stages. Rainfall over the weekend mostly hit the southern part of the state, increasing totals around Dagsboro and Delmar, but we have seen total rainfall of 6-9 inches since April 1st across the state.

Figure 1. Locating leaf collars on corn (left). Counting these collars will get you the corn stage (V3 in this case) to compare to GDD (right).

Table 1. Accumulated growing degree-days based on planting dates through May 20th.

If you planted

Sussex Kent New Castle
14-Apr 498 465 441
21-Apr 407 372 354
28-Apr 325 297 274
5-May 225 216 202
12-May 125 118 112

Emergence = 120 GDD, V6 = 475 GDD.

Figure 2. Statewide temperatures since April 1st.

Figure 3. Statewide rainfall accumulation since April 1st.

Growing Degree Days (GDD) and Rainfall through May 14th

Jarrod O. Miller, Extension Agronomist,

Since the rainfall this weekend, cooler temperatures have slowed the accumulation of growing degree days. Since April 14th we had observed a steady trend in GDD accumulation, keeping emergence on track between 7-10 days. Any planting done since May 6th may see delayed emergence, compared to previously planted fields. For those fields planted mid-April you may be at V4-V5. As temperatures warm back up, be prepared to sidedress between V6-V8.

The cooling trend is more apparent when you look at statewide temperatures and rainfall. Compared to nighttime lows, daytime temperatures had a significant drop since the weekend. Rainfall accumulation was between 1.5-2 inches, with the Harrington area still leading the state with 8 inches since April 14th. However, compared to last year these intermittent rainfalls are allowing fields to drain and not leaving all the duck ponds we had in 2018.

Figure 1. Growing degree days in the Dover area since April 14th.

Figure 2. Statewide temperatures since April 14th.

Figure 3. Statewide rainfall accumulation since April 14th.

2019 Weather Summary


Week Rainfall Range of Daily Highs Range of Daily Lows Average Soil Temp*
May 30-Jun 5 0.85 in 89 – 75°F 68 – 49°F 76.1
May 23-May 29 1.01 in 91 – 68°F 74 – 56°F 74.1
May 16-May 22 0.04 in 89 – 73°F 73 – 48°F 70.1
May 9-May 15 1.60 in 80 – 56°F 62 – 45°F 66.0
May 2-May 8 1.82 in 80 – 60°F 60 – 50°F 68.8
Apr 25-May 1 1.02 in 81 – 56°F 59 – 43°F 63.6
Apr 18-Apr 24 1.20 in 81 – 55°F 67 – 48°F 63.8
Apr 11-Apr 17 1.04 in 77 – 55°F 66 – 43°F 60.7
Apr 4-Apr 10 0.39 in 81 – 52°F 61 – 37°F 57.3
Mar 28-Apr 3 0.08 in 76 – 48°F 50 – 26°F 50.6
Feb 28-Mar 6 1.86 in 44 – 30°F 34 – 20°F 40.4

2018 Seasonal Rainfall and Temperature

Jarrod O. Miller, Extension Agronomist,

We have enough days in September to get a good average to finish out the season. The graphs below have rainfall (precipitation) as bar graphs, with the typical average in blue and this year’s rainfall in green. Average temperatures are yellow lines and this year’s temperatures are in red.

Newark had a drier June than normal, but most other months have 1-2 inches more rain than normal. Average temperatures in 2018 were warmer in May and throughout September, but were otherwise normal.

Dover had similar summer temperatures to Newark, but received higher than average rainfall every month between May-September. If you went to DEOS ( after most storms this summer, it was apparent that many storms seemed to move across the center of the state.

Georgetown was saturated in May, with 10.23 inches of rain compared to the normal of 4 inches. Through the summer, rainfall steadily fell until going far below normal in August with only 2 inches. Temperatures were not so kind in the southern half of the state, with both May and late summer having higher averages. Hopefully farmers in Sussex County kept the irrigation going in August. The rains have returned in September, delaying some of the corn harvest.

Extension Disaster Education Network

Nancy Gregory, Plant Diagnostician;

The Extension Disaster Education Network (EDEN) is a resource for all farmers, Extension personnel, landscapers, landowners, families, and citizens for information regarding disaster preparedness and recovery. The national website provides tips and resources for families in preparation of natural disasters. Delaware has a web page under UD Cooperative Extension with links to resources, reports, opportunities and more:

USDA Prepared to Respond to Hurricane Florence

WASHINGTON, Sept. 12, 2018 – The U.S. Department of Agriculture (USDA) reminds rural communities, farmers and ranchers, families and small businesses potentially impacted by Hurricane Florence of programs to provide assistance in the wake of disasters. USDA staff in the regional, State and county offices stand ready and eager to help. Additionally, USDA’s Operations Center will function around the clock.

“Our farmers and ranchers take financial risks every year to help feed and clothe the U.S. and the world, and a hurricane makes their situations even more perilous,” U.S. Secretary of Agriculture Sonny Perdue said. “At USDA, it’s our job to be there for them when they need help. All of our relevant agencies are ready to assist when natural disasters strike.”

USDA has important roles in both response to hurricanes and recovery efforts. USDA also is staffing the Regional Response Coordination Center in the Federal Emergency Management Agency’s (FEMA) Region IV, which covers eight states including North Carolina, South Carolina, and Georgia. USDA is providing 24-hour staffing to the FEMA National Response Coordination Center, and has personnel supporting the North Carolina and South Carolina State Emergency Operations Centers. USDA also is supporting FEMA Region II Regional Response Coordination Center in New Jersey to assist response efforts for Tropical Storm Isaac and Hurricane Florence. Additionally, personnel from the U.S. Forest Service and USDA Office of the Inspector General are pre-staging in Charlotte, North Carolina to assist with public safety and security efforts.

USDA recently launched a disaster assistance discovery tool through its new website that walks producers through five questions to help them identify personalized results of which USDA disaster assistance programs can help them recover after a natural disaster.

In a continuing effort to serve the public, USDA also partnered with FEMA and other disaster-focused organizations and created the Disaster Resource Center website, located at This central source of information utilizes a searchable knowledgebase of disaster-related resources powered by agents with subject matter expertise. The Disaster Resource Center website and web tool now provide an easy access point to find USDA disaster information and assistance.

USDA also encourages residents and small businesses in impact zones to contact USDA offices which meet their individual needs.

Food Safety and Food Assistance
Severe weather forecasts often present the possibility of power outages that could compromise the safety of stored food. The USDA Food Safety and Inspection Service (FSIS) recommends consumers take necessary steps before, during, and after a power outage to reduce food waste and minimize the risk of foodborne illness. FSIS offers tips for keeping frozen and refrigerated food safe and A Consumer’s Guide to Food Safety: Severe Storms and Hurricanes brochure that can be downloaded and printed for reference at home. Owners of meat and poultry producing businesses who have questions or concerns may contact the FSIS Small Plant Help Desk by phone at 1-877-FSIS-HELP (1-877-374-7435), by email at, or 24/7 online at:

The USDA Food and Nutrition Service (FNS) coordinates with state, local and voluntary organizations to provide food for shelters and other mass feeding sites. Under certain circumstances, states also may request to operate a disaster household distribution program to distribute USDA Foods directly to households in need. As disaster response moves into the recovery phase, FNS may approve a state’s request to implement a Disaster Supplemental Nutrition Assistance Program (SNAP) when the President declares a major disaster for individual assistance under the Stafford Act in areas affected by a disaster. State agencies also may request a number of disaster-related waivers to help provide temporary assistance to impacted households already receiving SNAP benefits at the time of the disaster, and to provide flexibilities in administering school meals, the Special Supplemental Nutrition Program for Women, Infants, and Children, and other programs. Resources for disaster feeding partners as well as available FNS disaster nutrition assistance can be found on the FNS Disaster Assistance website.

Crop and Livestock Loss
The USDA Farm Service Agency (FSA) administers many safety-net programs to help producers recover from eligible losses, including the Livestock Indemnity Program, the Emergency Assistance for Livestock, Honeybees, and Farm-Raised Fish Program, Emergency Forest Restoration Program (PDF, 257 KB) and the Tree Assistance Program. The FSA Emergency Conservation Program provides funding and technical assistance for farmers and ranchers to rehabilitate farmland damaged by natural disasters. Producers located in counties that receive a primary or contiguous disaster designation are eligible for low-interest emergency loans to help them recover from production and physical losses. Compensation also is available to producers who purchased coverage through the Noninsured Crop Disaster Assistance Program, which protects non-insurable crops against natural disasters that result in lower yields, crop losses or prevented planting. USDA encourages farmers and ranchers to contact their local FSA office to learn what documents can help the local office expedite assistance, such as farm records, receipts and pictures of damages or losses.

Producers with coverage through the federal crop insurance program administered by the Risk Management Agency should contact their crop insurance agent. Those who purchased crop insurance will be paid for covered losses. Producers should report crop damage within 72 hours of damage discovery and follow up in writing within 15 days.

Community Recovery Resources
For declared natural disasters that lead to imminent threats to life and property, the USDA Natural Resources Conservation Service (NRCS) can assist local government sponsors with the cost of implementing recovery efforts like debris removal and streambank stabilization to address natural resource concerns and hazards through the Emergency Watershed Protection Program. NRCS had made available nearly $2 million in advance funding under the Emergency Watershed Protection program to help local communities immediately begin relieving imminent hazards to life and property caused by floods and is coordinating with state partners to complete damage assessments in preparation for sponsor assistance requests. NRCS also can help producers with damaged agricultural lands caused by natural disasters, such as floods.

The NRCS Environmental Quality Incentives Program (EQIP) provides financial assistance to repair and prevent excessive soil erosion that can result from high rainfall events and flooding. Conservation practices supported through EQIP protect the land and aid in recovery, can build the natural resource base, and might help mitigate loss in future events.

USDA National Institute of Food and Agriculture provides support for disaster education through the Extension Disaster Education Network (EDEN). EDEN is a collaborative multi-state effort with land-grant universities and Cooperative Extension Services across the country, using research-based education and resources to improve the delivery of services to citizens affected by disasters. EDEN’s goal is to improve the nation’s ability to mitigate, prepare for, prevent, respond to and recover from disasters. EDEN equips county-based Extension educators to share research-based resources in local disaster management and recovery efforts. The EDEN website offers a searchable database of Extension professionals, resources, member universities and disaster agency websites, education materials to help people deal with a wide range of hazards, and food and agricultural defense educational resources.

Many of USDA Rural Development programs can help provide financial relief to rural communities hit by natural disasters by offering low-interest loans to rural community facilities, rural businesses and cooperatives and to rural utilities. More information can be found on the Rural Development website, located at

For complete details and eligibility requirements regarding USDA’s disaster assistance programs, contact a local USDA Service Center. More information about USDA disaster assistance, as well as other disaster resources, is available on the USDA Disaster Resource Center website, located at

2018 Summer Rain and Temperatures

Jarrod O. Miller, Extension Agronomist,

Corn shelling has been rolling where fields have been dry enough. Due to the highly variable rainfall and temperatures we have had since April, every field will probably be a little different. Many corn fields planted in late April should have started silking around July 9th, with other fields following. During the month of July, daytime temperatures fluctuated above 86°F several times, which may have reduced pollination. This may be more prevalent in fields that were planted in early May. Fields planted late May through mid-June may have been luckier; they should have been pollinating near the end of July, when daytime temperatures stayed out of the 90s.

When temperatures at night remain above 72°F, corn plants are stressed and consume some of the energy they had built up from the sun. There are several nights where this occurred over the summer, typically also associated with high daytime temperatures. This will reduce the amount of energy corn plants have to develop grains. This is not a doom and gloom statement, it is simply a way for Delaware farmers to asses any differences they may find across all of their planting dates.

Georgetown represents the southern end of the state, and typically had the highest night and daytime temperatures, but not by much. There are a few times (April 30, July 16) that Dover was a little warmer. There is a lot more variability in rainfall across the state than temperatures.

As most readers are aware, we are receiving high rainfall again, some which may have come from tropical storm Gordon over the weekend. Unlike temperature, there is high variability across the state. The earlier predictions from Hurricane Florence projected that our region may get 2-6 inches, but after this summer that seems normal. Current tracking as put us in a better position that our southern neighbors, but we are not done with hurricane season yet.

Growing Degree Days (GDD) and Rainfall Through September 4th

Jarrod O. Miller, Extension Agronomist,

There is some shelling going on in Sussex County this week, with word that many fields will start on Monday. Any field planted between April 22 and May 20 should be in blacklayer, and the high temperatures this week should really help in reducing moisture content. If you planted over a range of dates, you should be able to roll through your fields week to week, depending on your variety. Most fields planted in early to Mid-June should be in R5 (dent), which you can check by watching the milk line (

R5 (Dent): 2190-2450
R6 (Blacklayer): 2700

Table 1: Accumulated growing degree days based on planting dates through September 4th.

If you planted
Sussex Kent New Castle
22-Apr 3179 3109 3000
29-Apr 3126 3062 2966
6-May 3018 2952 2868
13-May 2914 2846 2771
20-May 2803 2740 2676
27-May 2645 2580 2528
3-Jun 2492 2429 2378
10-Jun 2370 2312 2265
17-Jun 2234 2185 2136

To match most of the season, rainfall around the state over the last week was scattered with variable intensity. From the graph below, it appears that Dover took a pretty hard hit (2.47” on Aug 31st), but most of the state received about an average of 0.5” over the weekend. On DEOS I did observe at 5.39 inch rainfall in Oakley and 4.20 inches at the Prime Hook Wildlife Refuge.

Growing Degree Days (GDD) and Rainfall Through August 28th

Jarrod O. Miller, Extension Agronomist,

If spring weather caused you to plant fields spaced out from April to June, you may get a good idea of what the weather can do to a crop. Considering the varying planting dates, flooding, drought, and high temperatures, we have about three years’ worth of weather in one summer to observe the effects on growth, pollination, and kernel abortion.

Most later planted fields (mid-June) probably saw decent temperatures and rainfall for pollination, while earlier planted fields may have more tipback during the mid-July heatwave. Kernels forming under stress may also abort, which could certainly be seen with temperatures above 90 the week of August 17th and our current heat wave. Still, nighttime temperatures have often been below 72°F, so that should help.

Looking at GDD, any fields planted in April (that survived) should be starting or at blacklayer. Most fields planted in May across the state should be starting or full within R5 (dent). The only way you can be sure is to walk out and check your corn.

R1 (Silking): 1400 GDD
R2 (Blister): 1660 GDD
R4 (Dough): 1925 GDD
R5 (Dent): 2190-2450
R6 (Blacklayer): 2700

Table 1: Accumulated growing degree days based on planting dates through August 28th.

If you planted Sussex Kent New Castle
22-Apr 2956 2895 2794
29-Apr 2903 2848 2760
6-May 2795 2738 2662
13-May 2691 2632 2564
20-May 2580 2525 2470
27-May 2422 2366 2322
3-Jun 2270 2215 2171
10-Jun 2147 2098 2058
17-Jun 2011 1971 1929


We still cannot complain about rainfall too much. There have been a few storms popping up across the state, enough that dryland should have received a little moisture. Since mid-August, we have received less than an inch in most parts of the state, and the heat this week will probably stress corn and beans.