Texas fruit crops are behind on chill hours necessary to trigger optimal blooms and good fruit sets, according to Texas A&M AgriLife Extension Service experts.

a hand holding part of a tree limb with a poorly developed peach bud due to inadequate chill hours
A peach grower shows a bud that developed poorly due to inadequate chilling hours during the 2017 growing season when Texas fruit crops were very short on chill hours. (Texas A&M AgriLife photo by Adam Russell)

If Punxsutawney Phil was right, there are still enough winter days ahead, but experts said Texas’ fruit crops need cold, clouds and rain.

Fruit trees, such as peaches, apples and even blackberries depend on cool, cloudy weather in the winter to promote proper physiological growth in the spring, said Larry Stein, Ph.D., AgriLife Extension horticulturist, Uvalde. If plants do not receive the required number of chill hours, plants can be slow to leaf out, which typically leads to poorly developed fruit or no fruit at all.

“Growers in different regions of the state have plants with different chilling requirements,” he said. “Orchards in the Rio Grande Valley might have trees that require 200-300 chill hours, whereas the varieties that perform well in North Texas might require 900-1,000 hours.”

Clouds, cold equal chill hours

Chill hours begin to add up after the first freeze each fall, he said. Trees go dormant for the winter, but chill hours promote hormones that dilute growth inhibitors throughout the winter and prepare the plant to break dormancy and begin new growth, bloom and set fruit.

Growers want the timing of new growth and bloom to coincide with avoiding the average final spring frost, which would damage budding fruit.

Proper chill hours trigger good and well-timed leaf and bud development, Stein said. A lack of chill hours can lead to poorly developed buds and flowers that can have a cascading effect leading to stunted or misshaped fruit to no fruit at all.

Leaves help trees produce energy and protect limbs from sun scald, but multiple seasons of inadequate chill hours can kill plants, Stein said.

Damp, cloudy conditions and temperatures between 32-45 degrees are ideal for accruing chill hours, Stein said. Temperatures have been relatively cool, but drought and sunny days have inhibited the process.

Stein said there is still time to make up significant chill hours. Last year, chill hours were behind until Winter Storm Uri delivered cold temperatures across the state. The storm hurt some individual fruit growers and produced generally negative effects on agriculture, but the cold temperatures helped most tree varieties around the state, Stein said.

“Last year was marginal up to this point and then Uri arrived,” he said. “There were some low chill varieties that were becoming active, and they got hammered. But for the most part, that cold front put us over the top with the chill hours necessary to make a good crop.”

Blue bird days, go away

Jim Kamas, AgriLife Extension fruit specialist, Fredericksburg, said chill hours accumulation got off to a late start and remain behind. He does not expect chill hours to be as short as 2016-2017 when Central Texas received a little over 450 hours total. But more cloudy, cold weather is needed with chill hours just surpassing 600 at this point in the season.

Kamas said chemical growth regulators can mimic chill hours, but that availability could be an issue because the products are imported from Europe. And the product must be applied 30 days before full bloom, which on average is March 17.   

Unless producers have growth regulators to apply, or Mother Nature delivers cold, wet weather soon, Texas fruit crops from peaches to grapes could be at risk of lower yields, misshaped fruit with lower market appeal, delayed and inconsistent fruit harvests and stressed trees, Kamas said.  

“We have a saying that there are only two types of people who like 36-degree days that are gray, cloudy, misty, rainy and just plain icky to be out in – duck hunters and fruit growers,” he said. “Most people would disagree, but winter days like that bring a smile to their faces because they know good things are happening.”

AgriLife Extension district reporters compiled the following summaries:

A map of the 12 Texas A&M AgriLife Extension districts.
A map of the 12 Texas A&M AgriLife Extension districts.


No rainfall was reported following heavy rainfall last week. Some areas were showing signs of soil erosion from heavy runoff. Stock tanks were filling nicely. Wet conditions halted fieldwork. Frosty conditions continued to impact winter oats and limited potential recovery for late winter grazing. Winter wheat was showing good hardiness to nightly freezes. The cold was limiting weed development. Overall, crops were in poor to fair condition. Livestock were in fair shape, and producers were supplemental feeding heavily.


Weather was pleasant but remained dry with very little farming activity. The ground dried after last week’s snowfall. Some areas reported almost 1 inch of moisture from the snow, but most areas reported the snow delivered very little moisture. Wildfires were still a concern. Row crop tillage was postponed due to overly dry conditions. Winter forage crops that were planted either never germinated or died after germination. Irrigated wheat looked good. Dryland winter wheat looked very poor, and cattle producers were supplemental feeding livestock heavily. Stock tank water was becoming an issue in some areas. Hay supplies were tightening.


Some areas reported a hard freeze for three nights this week. Soil moisture conditions were adequate and even wet in some areas, but conditions were drying quickly with windy conditions. Row crop field preparation continued. Fertilizer and pre-emergence herbicides were being applied. There was a small amount of corn planted. Rangeland and pasture conditions continued to be poor. Frosty mornings throttled back winter forage growth, but producers were hopeful to see some accelerated green-up soon. Livestock were in good condition, and many herds were starting spring calving. Supplemental feeding of livestock continued with hay and protein. Hay supplies were available. Cattle market prices were exceptional.


Drought conditions continued across most of the district. Subsoil and topsoil conditions were adequate to short. Ponds and creeks were low. Much more rainfall was needed to relieve current conditions. Winter forages were performing very poorly compared to a normal year. Pasture and rangeland conditions were very poor. Cattle market prices were up from last week, but head numbers remained low due to weather. Livestock were in fair to good condition with supplemental feeding taking place. Wild pigs remained a problem for producers.


Conditions were still extremely dry, and rain was needed for all aspects of agriculture. Cattle looked good.


Light snow events added small amounts of topsoil moisture, however, extreme drought conditions persisted. Overall soil moisture levels were very short to short, and rangeland and pasture ratings were very poor to poor in nearly all counties. 


Topsoil moisture throughout the district was short to adequate. Parts of some counties reported small amounts of rain but that more was needed going into spring. Temperatures dropped into the 20s and 30s at night, and sustained winds continued to dry the little soil moisture received. Winter wheat improved slightly across the district. Livestock were in good condition, but water tanks were becoming a concern and pond levels were significantly low for this time of year.


Average daytime temps reached a high of 64 degrees with average nighttime lows at 31 degrees. Trace amounts of rain was reported. The little moisture was gone with the warm and breezy days over the past week. Moisture conditions were extremely dry. Some fieldwork was done after the snow. There was a very small amount of irrigated wheat that had not grown much due to cold temperatures and a lack of moisture. Pastures were completely bare of forage for livestock. Cattle were looking thin, and producers were still feeding them heavy rations/ They also continued to sell off cull cows and younger calves at lighter weights. A few producers were considering reducing herd size due to high feed costs. Ranchers were busy preparing to bring in newborn calves. 


Area conditions were still extremely dry despite some winter mix of precipitation. Even with the recent moisture, fire danger remained high. Moisture and warm weather were needed for grazing. Winter wheat was very poor. Calving season began, and producers were busy feeding cows and putting out hay. Stock tank levels were reaching critical levels.


Some areas reported heavy rains and saturated soils whereas other areas remained dry. Prescribed burning of pastures was being done on land that had dried out. Livestock were in fair condition. Rangeland and pasture ratings were very poor to fair. Multiple nights of light freezing temperatures were reported. Warmer daytime temperatures may allow winter wheat and oats to grow, but some fields showed freeze burn. Crawfish were being harvested, and the cooler weather did not seem to affect them. Some work was done in rice fields, but most areas were still too wet.


Cold and dry weather conditions continued for most of the district. Some snow and sleet were reported but more moisture was needed overall. Hay fields were burned in preparation for the growing season. Row crop producers were preparing for planting. Winter forages planted for grazing were in poor to fair condition. Rangeland and pasture conditions were fair, but stocking rates were reduced due to dry conditions. Livestock were in fair condition, but prices were down. Livestock and wildlife were being heavily supplemented, and water availability was being monitored closely.


Northern, eastern and western parts of the district reported very short to short soil moisture levels while southern areas reported adequate moisture. Conditions were drier than normal. Temperatures were cold but stayed above freezing. Precipitation varied from trace amounts of mist up to 1.5 inches of rainfall. Fields were dusty and dry. Producers were expressing skepticism about spring planting without significant moisture, but some irrigated farmers were planting some vegetables. Some vegetables were being harvested and onions looked good. Citrus and sugarcane harvests continued. Producers continued to rehabilitate citrus groves. Rainfall delayed access to some fields, but there were some reports of corn and sorghum planting. A few canola fields were harvested. Mesquite trees were putting on leaves. Soil temperatures were below adequate planting levels. Pastures looked dry and dormant, and livestock producers were providing heavy supplemental feed. Stock tanks were low. Cattle sales were above normal, but prices were steady. Round bale hay prices were $50-$95. Some producers were performing prescribed burns.

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