Wednesday, April 27, 2011

Fruit Thinning of Apples and Pears

   Tree fruits generally bloom heavily, so some fruits will develop even if some blooms are killed by frost.  When many fruit set, as they did this year, fruit trees naturally shed some of the developing fruit, so the fruit left on the trees will grow better and ripen their seeds.  Most  years, such as this one, fruit growers need to take nature a step further and thin tree fruits, by removing excess fruits while they are still small, so the remaining fruits will get larger and sweeter.
    Apples and pears can be thinned chemically, which saves huge amounts of labor compared to peaches, which must be hand-thinned.  We use a carbaryl spray between 10 and 25 days after full bloom to thin apples and pears.  The pears reached the thinning stage a few days ago.
These young pears are at the stage for fruit thinning.  The thinning sprays will cause some fruit to drop, ideally leaving one fruit per cluster remaining.

   Apples are at the thinning stage now.  We'll apply an apple thinning spray in a few days, whenever the winds calm enough to allow it.
Some of these young apples are developing well, while others are naturally failing to develop and will fall off.  The crop needs further thinning to produce large, sweet fruit.

Thursday, April 21, 2011

Strawberry Bloom

   Strawberries are in full bloom now.  They started blooming about 10 days ago, and will keep blooming for the next couple weeks.  So strawberries will be ripe about May 10 to June 4 or so.
   Each year in mid-Dec. I place straw mulch over the strawberry plants to protect the crowns from winter freezing and thawing.  (That's why they're called strawberries.)  The mulch prevented winter damage, so we didn't lose any strawberry fruit to the -17 F winter.  In mid-March, I remove the mulch from the tops of the strawberry plants so they can grow, and place it in the aisles to provide a soft material for harvest, and to keep berries off the ground so they don't develop fruit rots.
   Since strawberries bloom for almost a month, from early April to early May, some of the first blossoms always get killed by late spring frosts.  The closed buds can take temperatures down to the lower 20's F without damage, but open blossoms are injured at 32 F or below.
The blossom at lower left, with the dark center, was killed by a frost so won't produce a fruit.  Thankfully, many more flowers open over several weeks, and all the others will produce fruit.
    Our strawberry planting is small, so strawberries are pick-your-own only, by appointment only.  If you'd like to arrange a time to pick strawberries, call 620-597-2450 and leave a message, or e-mail  We grow 'Earliglow' strawberry, which has fantastic flavor -- MUCH better than grocery-store strawberries! 

Friday, April 15, 2011

Breeding New Fruit Varieties

   Besides growing fruit for sale, I'm also conducting an apple breeding program.  (We got some needed rain last evening, and it's in the low 40's this morning, so I have time to post this, after working outside 11 hours a day for the past 3 weeks.)  We grow apple varieties immune to apple scab disease, such as 'Enterprise' and 'GoldRush', so they don't need to be sprayed for apple scab.  This means the scab-immune apples need only half the sprays (7 or 8 per year) that scab-susceptible varieties such as 'Jonathan' or 'Fuji' do (they need 15 or 16 sprays per year).
   These scab-immune apple varieties came from a breeding program that started back in the 1940's.  I'm continuing this work by crossing some of these varieties and numbered selections that haven't been named yet.  This year I made crosses between 'GoldRush' and Coop 27, a numbered selection with fruit that tastes similar to 'Jonathan'.
    To make controlled crosses, I first remove the anthers, petals and sepals from some flower buds on the tree I'm going to cross.  Bees won't visit a flower with no petals, so it won't get pollinated by unknown pollen, and I'll later transfer known pollen I've collected from the variety I want to cross with. Fruit I've pollinated will develop without sepals, so I can tell my crosses from all the other fruit on the tree.
I'm removing the anthers, petals and sepals from a flower bud here.

   I  pick out and dry the anthers I've removed, and use the pollen they contain to pollinate the stigmas on the tree I'm crossing.

   In the fall, I'll look for fruit with no sepals on the trees I crossed, and save those.  I save the seeds, and stratify them by placing them in plastic bags of moist vermiculite in the fridge, to give them a moist, cold treatment so they'll germinate in spring.  In late April I plant the seeds from last year's crosses in small pots, grow them over the summer, then plant in the field in the fall.  Seedling trees take longer to start fruiting than grafted trees, so it'll be 7 or 8 years before I can evaluate fruit, discard trees with inferior fruit or disease susceptibility, and hopefully get a few selections worthy of testing and possibly eventually naming as new varieties.  Crosses I made 9 years ago have just bloomed well this year, so I'll evaluate them this fall.

Tuesday, April 12, 2011

Apple & Pear Bloom and Pollination

Apples are in full bloom now, and pears just finished blooming.  We'll have full crops of both apples and pears this year -- they're quite hardy, so weren't bothered by the -16 F winter.
Our apple orchard in bloom is a beautiful sight.

People sometimes ask if we raise honeybees to provide pollination for our fruit crops.  No -- we don't need to.  There are plenty of wild bees in our area that provide lots of pollination.  Most years, the bees provide too much pollination, and we'll need to thin off about 80% of the young fruits, so the remaining fruits get large enough and develop good flavor.
Wild bees are plentiful in our apple trees now.