Central Valley enduring heat wave
Central Valley enduring heat wave
FRESNO, CA -- An extended heat wave in the Central Valley, which began June 30 and continued with a string of triple-digit temperatures through most of the month, has affected various crops currently being harvested in the valley. The nature of the effect differs with the type of crop.
With tomatoes, for example, the immediate effect appears to have been minor, but the heat caused a bloom drop that could reduce yields in four to six weeks.
With grapes, the heat has caused Flame seedless varieties to be slow to develop color and has delayed the maturity of Thompsons, according to some sources.
Stone fruit maturity has also been delayed by the extreme heat, but the fruit is expected to come on quickly as soon as temperatures moderate. Cantaloupe maturity, on the other hand, appears to have been accelerated by the heat.
In general, most Central Valley crops harvested in July do not seem to mind temperatures under 105 degrees, particularly if temperatures cool down in the evenings. But several successive days with highs over 105 degrees, with night-time lows staying above 80 degrees, do cause some problems for most crops.
"Extremes of anything are never any good," Mike Aiton of Sun World International LLC said July 19. "The heat we have had the past 10 days makes it very difficult.
Apart from the effect on the crops themselves, "there is the whole people issue, he said. Field workers become fatigued, and "working conditions are just miserable. That causes a loss in productivity. "You have to make sure you are doing everything you can to accommodate the people. That is the foremost priority with us and, I think, with anyone else in agriculture. It is important to be sure that workers get "plenty of breaks and plenty of water, he said.
The heat "to some degree affects the quality of the crops also, he said. "In a lot of ways, that extreme heat will just slow everything down. The plants are just struggling to survive, he said, "so you are really pouring the water to it, doing everything you can to keep the vine or the tree or the bush or whatever healthy and active.
Unprotected fruit, whether it is "a plum or a pepper or a bunch of grapes, is very susceptible to burning from extreme heat, Mr. Aiton continued. That results in "a little bit of a crop loss. With colored grapes, the heat tends "to slow down the coloring process.
Sun World's Thompson seedless grapes in the Bakersfield, CA, area "are being affected somewhat, he said. "They are having a hard time finishing off. The Flame harvest, however, in spite of problems with color, "is going great guns.
With stone fruit, condition is a concern. "You have to be careful of that, Mr. Aiton said. "You have to watch your pressures and stay in front of the harvest and make sure everything is getting harvested in a timely manner. Once harvested, "you can't leave the product sitting out in the field. You need to rush it into the cooler and get the field heat out of it as quickly as possible. It requires a lot of diligence on the part of a lot of people to make it work right. It is not insurmountable, but it certainly is difficult.
"For us so far, we are a little ahead of the curve, so it is really not affecting us as much as it would be [some] other people, said John Harley of Anthony Vineyards, whose Flame seedless grape harvest in the Arvin district at the southern end of the valley was within about a week of being finished as of July 19. The heat accelerated the start of the Flame harvest by about a week, which was actually a good thing, since the desert Flame deal had finished early and there was a lot of unsatisfied demand in the market for Flames.
Anthony's early start on Arvin Flames made for a smooth transition from Coachella, he said. However, coloration problems are contributing to a reduction in per-acre yields on Flames.
But the heat has "actually delayed the green [grape] harvest, Mr. Harley said. "Thompsons right now are probably about four or five days later than originally anticipated. "This is kind of an odd situation.
Up to a point, Thompsons like heat, he said. But "maybe not this much heat and this prolonged. "Pouring the water to them helps. Still, we really haven't seen a whole lot of [adverse] effect on the crop yet.
Anthony expected to start the Thompson harvest on Wednesday, July 20, "in a small way, but didnt expect any real volume until the following week. "We have good sugar content, he said.
Mike Watts of Kingsburg Orchards in Kingsburg, CA, told The Produce News that the effect of the heat differs on various crops. "I think it is a case-by-case and variety-by-variety situation, he said. It also has a lot to do with cultural practices.
In stone fruit, for example, orchards that have mowed grass between the rows of trees will experience less sunburn than those on bare, dry ground, which can reflect hot sun back up into the trees.
"Any time there has ever been extended heat for days over 105 degrees, there is always something that gets damaged, he said. Usually, only the exposed fruit is affected. "The fruit that is underneath the canopy and in the shade [has] no problem.
With certain varieties, the extreme heat can also affect internal quality. "The heat kind of stews them a little inside, Mr. Watts said. "Some are more susceptible than others.
Dale Janzen of the Reedley-based California Tree Fruit Agreement said that the extreme heat has slowed the maturity on some stone fruit varieties. With Friar plums, for example -- the state's No. 2-producing plum -- the fruit "is really taking its time. The anticipated harvest start date for Friars "has come and passed, he said July 19, "but we have not had that big harvest like we were expecting. Because of the heat, the trees are just hunkered down to survive through the hot spell.
Once temperatures cool down a few degrees, with highs in the low 100s or high 90s, he said, "Then things are gong to really speed up and there is going to be a lot of activity.
Mr. Janzen said that he has seen some sunburn in the fruit, but "not anything wholesale. The fruit being harvested and packed is "really strong fruit with good color, sugar and flavor, he said. "One good thing about all this heat is that heat does develop sugar, so the fruit really is eating great. Fruit movement is "really good, he said.
With cantaloupe, the high temperatures are helping bring the fruit on faster, according to Gil Vasquez of Fordel Inc. in Mendota, CA. "Everything ripens faster, he said. As long as the melons are harvested on time and brought into the cooler quickly, "there is no problem, he said.
Tomatoes have not suffered any significant short-term damage from the heat, according to Joe Bernardi of Bernardi & Associates Inc. in Turlock, CA. "Everybody is doing a really good job with the pack, so the quality in the box is good, he said.
However, the extreme heat has been causing bloom drop. It "knocks blooms off the plants, Mr. Bernardi said. That will result in reduced yields about 30 to 45 days from now, he said..
With tomatoes, for example, the immediate effect appears to have been minor, but the heat caused a bloom drop that could reduce yields in four to six weeks.
With grapes, the heat has caused Flame seedless varieties to be slow to develop color and has delayed the maturity of Thompsons, according to some sources.
Stone fruit maturity has also been delayed by the extreme heat, but the fruit is expected to come on quickly as soon as temperatures moderate. Cantaloupe maturity, on the other hand, appears to have been accelerated by the heat.
In general, most Central Valley crops harvested in July do not seem to mind temperatures under 105 degrees, particularly if temperatures cool down in the evenings. But several successive days with highs over 105 degrees, with night-time lows staying above 80 degrees, do cause some problems for most crops.
"Extremes of anything are never any good," Mike Aiton of Sun World International LLC said July 19. "The heat we have had the past 10 days makes it very difficult.
Apart from the effect on the crops themselves, "there is the whole people issue, he said. Field workers become fatigued, and "working conditions are just miserable. That causes a loss in productivity. "You have to make sure you are doing everything you can to accommodate the people. That is the foremost priority with us and, I think, with anyone else in agriculture. It is important to be sure that workers get "plenty of breaks and plenty of water, he said.
The heat "to some degree affects the quality of the crops also, he said. "In a lot of ways, that extreme heat will just slow everything down. The plants are just struggling to survive, he said, "so you are really pouring the water to it, doing everything you can to keep the vine or the tree or the bush or whatever healthy and active.
Unprotected fruit, whether it is "a plum or a pepper or a bunch of grapes, is very susceptible to burning from extreme heat, Mr. Aiton continued. That results in "a little bit of a crop loss. With colored grapes, the heat tends "to slow down the coloring process.
Sun World's Thompson seedless grapes in the Bakersfield, CA, area "are being affected somewhat, he said. "They are having a hard time finishing off. The Flame harvest, however, in spite of problems with color, "is going great guns.
With stone fruit, condition is a concern. "You have to be careful of that, Mr. Aiton said. "You have to watch your pressures and stay in front of the harvest and make sure everything is getting harvested in a timely manner. Once harvested, "you can't leave the product sitting out in the field. You need to rush it into the cooler and get the field heat out of it as quickly as possible. It requires a lot of diligence on the part of a lot of people to make it work right. It is not insurmountable, but it certainly is difficult.
"For us so far, we are a little ahead of the curve, so it is really not affecting us as much as it would be [some] other people, said John Harley of Anthony Vineyards, whose Flame seedless grape harvest in the Arvin district at the southern end of the valley was within about a week of being finished as of July 19. The heat accelerated the start of the Flame harvest by about a week, which was actually a good thing, since the desert Flame deal had finished early and there was a lot of unsatisfied demand in the market for Flames.
Anthony's early start on Arvin Flames made for a smooth transition from Coachella, he said. However, coloration problems are contributing to a reduction in per-acre yields on Flames.
But the heat has "actually delayed the green [grape] harvest, Mr. Harley said. "Thompsons right now are probably about four or five days later than originally anticipated. "This is kind of an odd situation.
Up to a point, Thompsons like heat, he said. But "maybe not this much heat and this prolonged. "Pouring the water to them helps. Still, we really haven't seen a whole lot of [adverse] effect on the crop yet.
Anthony expected to start the Thompson harvest on Wednesday, July 20, "in a small way, but didnt expect any real volume until the following week. "We have good sugar content, he said.
Mike Watts of Kingsburg Orchards in Kingsburg, CA, told The Produce News that the effect of the heat differs on various crops. "I think it is a case-by-case and variety-by-variety situation, he said. It also has a lot to do with cultural practices.
In stone fruit, for example, orchards that have mowed grass between the rows of trees will experience less sunburn than those on bare, dry ground, which can reflect hot sun back up into the trees.
"Any time there has ever been extended heat for days over 105 degrees, there is always something that gets damaged, he said. Usually, only the exposed fruit is affected. "The fruit that is underneath the canopy and in the shade [has] no problem.
With certain varieties, the extreme heat can also affect internal quality. "The heat kind of stews them a little inside, Mr. Watts said. "Some are more susceptible than others.
Dale Janzen of the Reedley-based California Tree Fruit Agreement said that the extreme heat has slowed the maturity on some stone fruit varieties. With Friar plums, for example -- the state's No. 2-producing plum -- the fruit "is really taking its time. The anticipated harvest start date for Friars "has come and passed, he said July 19, "but we have not had that big harvest like we were expecting. Because of the heat, the trees are just hunkered down to survive through the hot spell.
Once temperatures cool down a few degrees, with highs in the low 100s or high 90s, he said, "Then things are gong to really speed up and there is going to be a lot of activity.
Mr. Janzen said that he has seen some sunburn in the fruit, but "not anything wholesale. The fruit being harvested and packed is "really strong fruit with good color, sugar and flavor, he said. "One good thing about all this heat is that heat does develop sugar, so the fruit really is eating great. Fruit movement is "really good, he said.
With cantaloupe, the high temperatures are helping bring the fruit on faster, according to Gil Vasquez of Fordel Inc. in Mendota, CA. "Everything ripens faster, he said. As long as the melons are harvested on time and brought into the cooler quickly, "there is no problem, he said.
Tomatoes have not suffered any significant short-term damage from the heat, according to Joe Bernardi of Bernardi & Associates Inc. in Turlock, CA. "Everybody is doing a really good job with the pack, so the quality in the box is good, he said.
However, the extreme heat has been causing bloom drop. It "knocks blooms off the plants, Mr. Bernardi said. That will result in reduced yields about 30 to 45 days from now, he said..
