How much exactly does planting affect the flowering period?

The flowering time of campanula is also closely related to the planting time. Campanula likes a cool environment, so planting in spring or autumn is most suitable. But different planting times lead to earlier or later flowering.

Under natural conditions (open-field planting), if sown in January or February with a suitable environment, campanula will grow to full size by summer. But flowering still requires waiting until after winter.

If sown at the end of summer, after temperatures drop, the plant goes through the long winter, continues growing in spring, and can flower in the same year.

How do you manage pear trees during the flowering period? Key technical points for flowering-period management in pear cultivation

In pear cultivation, the flowering period is a very important stage that directly affects fruit yield and quality. In the flowering-period management of pear trees, issues such as improving the fruit-setting rate, protecting flowers and fruits, and thinning flowers and fruits must not be underestimated. So how do you manage pear trees during the flowering period? Below is an introduction to the key technical points for flowering-period management in pear cultivation. Let's take a look.

I. Hand pollination to improve the fruit-setting rate

Most pear varieties require cross-pollination before they can set fruit. If the pollinizer trees planted in the pear orchard are too few or improperly arranged, hand pollination must be carried out to improve the fruit-setting rate.

1. Pollen collection:Pollen collection is generally done together with flower thinning. When the flowers of the pollinizer variety are at the initial flowering stage, collect the flowers, remove the anthers from the collected flowers. You can hold one flower in each hand and rub the two flowers together, and the anthers will fall off. Place the anthers at room temperature of 20°C-25°C to dry, do not sun-dry or roast over fire, and store after drying.

Image: Flowering-period management of pear trees

2. Pollination methods:

(1) Hand pollination in the field:When the variety to be pollinated reaches full bloom, carry out hand dot pollination. Tools such as a writing brush, a pencil with an eraser tip, a gauze ball, or a paper stick can be used. Each dip of pollen can pollinate 5-10 flowers, with 1-2 flowers pollinated per inflorescence; pollinate more when there are many flowers, and more when there are few flowers.

(2) Feather duster pollination:In a pear orchard with pollinizer trees, during full bloom, tie a feather duster to a bamboo pole, first roll it over the pollinizer trees to pick up pollen, then gently roll it over the trees of the variety to be pollinated, repeating 1-2 times from top to bottom and inside to outside. This method is not suitable in strong wind or rainy weather.

(3) Releasing bees during the flowering period:Although this method is not hand pollination, it is also a good pollination method. Generally, one bee can carry 5000-10000 grains of pollen, and each box of bees can ensure pollination for 10 mu of pear orchard.

(4) Dusting or liquid pollination:For large pear orchards, to improve work efficiency, a small duster or sprayer can be used for pollination. When dusting, add 20-30 parts dry starch to each part of pollen and use immediately; for liquid pollination, a pollen suspension can be prepared. The preparation method is: 5 kg water, 10 g pollen, 250 g white sugar, 15 g borax and 15 g urea, mix and filter before spraying, and use immediately after preparation.

Image: Flowering-period management of pear trees

II. Frost prevention during the flowering period to protect flowers and fruits

Pear trees bloom early and their flowers are uniform, so frost during the flowering period causes great losses, even total crop failure, and frost prevention work must be done well. Irrigation before flowering can lower soil temperature and delay the flowering period, reducing or avoiding frost damage; or whitewashing the trunk before flowering can make the tree temperature rise slowly and delay the flowering period by 2-3 days, avoiding or reducing frost damage; or using smoke to prevent frost, as smoke can reduce the radiant evaporation of soil heat, while smoke particles can absorb moisture, causing water vapor to condense into liquid and release heat, raising the air temperature.

III. Thinning flowers and fruits to improve quality

Thinning flowers and fruits means removing an appropriate amount of flowers and fruits from trees with excessive flower and fruit loads. Reasonable thinning of flowers and fruits can save nutrients, improve the fruit-setting rate, increase yield, restore tree vigor, and overcome and reduce alternate bearing. It is an important measure to ensure high, stable yield and good quality in pear trees. The earlier the thinning of flowers and fruits, the better. Thinning buds is better than thinning flower buds, thinning flower buds is better than thinning flowers, and thinning flowers is better than thinning fruits; the earlier it is done, the more nutrients are saved. Bud thinning should be carried out when the buds begin to swell, flower thinning should be carried out at full bloom, and fruit thinning should be completed within one month after flowering.

Image: Pear cultivation

1. Interval flower thinning:After determining the yield per tree, leave one inflorescence and remove one alternately, leaving empty branches, exchanging flowers for flowers, to bear fruit the next year. Generally, remove inflorescences on weak branches, keep inflorescences on strong branches, and then carry out appropriate fruit thinning;

2. Leaving fruit by distance:Generally, leave one fruit every 15-20 cm on a pear tree. For strong trees and vigorous branches, the fruit spacing can be slightly closer, leaving one fruit every 10-15 cm; for weak trees and weak branches, leave fruit slightly farther apart, leaving one fruit every 20-25 cm;

3. Leaving fruit based on the secondary shoots at the fruit cluster base:If the secondary shoots at the fruit cluster base are strong, leave double fruits for two secondary shoots; for one secondary shoot or medium to weak secondary shoots, leave a single fruit; for inflorescences without secondary shoots, do not leave fruit;

4. Leaving fruit based on inflorescence position:Within one inflorescence, choose to keep the 1-2 lower fruits, whose fruit stalks are long and thick and can grow into large fruits with standard shape. Remove the flowers and fruits in the upper part of the inflorescence;

5. Coordinating the layout of the whole tree:Leave appropriately more inside the canopy and in the lower layers, and less on the periphery and in the upper layers; leave more on auxiliary branches and less on scaffold branches; leave more in the middle part of scaffold branches and less in the lower part; for trees in full fruit-bearing stage, leave more on upward-growing branches and less on backward-growing branches; when there are many flowers and the tree is weak, leave less. The overall principles of thinning flowers and fruits are: ensure yield, improve quality, select the superior and remove the inferior, and regulate distribution.

[Editor's concluding remarks]Doing a good job in flowering-period management in pear cultivation directly affects the fruit yield and quality of pear trees, and fruit growers should pay attention to it in cultivation. The above has introduced the key technical points for flowering-period management in pear cultivation, and we hope it will be helpful to everyone.

The effect of light during the forcing period on Rhododendron

There are still many technical issues in the methods used for cultivating imported varieties of Rhododendron in China. If you want to cultivate Rhododendron with large flowers and bright colors, paying attention to light during the forcing period is key. So how should light be provided to Rhododendron during the forcing period?

Rhododendron

After 2 to 3 weeks, provide artificial supplemental light to the plants to force flowering. The light intensity should be around 3000 lux, and the specific value should be adjusted according to the Rhododendron variety. In terms of light selection, it is best to choose a high-density sodium light source, as this helps produce brightly colored flowers. The supplemental lighting time should be about 6 hours per day, and 3 hours of light can be added before and after natural light respectively. In the three weeks before flowering, increase the supplemental lighting time, and if necessary, provide 24-hour supplemental lighting.

Experts remind growers that although artificial supplemental lighting is important, natural light is even more critical for Rhododendron, and sunlight must be fully utilized during cultivation. When sunlight is seen, open the windows, and close the windows when there is no sunlight. Some producers do not open the windows until around 11 a.m. because they worry that keeping the windows open for a long time will lower the indoor temperature, thereby increasing heating costs. I strongly disagree with this method, because although it can save production costs, it will keep product quality from improving. To cultivate high-quality Rhododendron, sufficient sunlight must never be lacking.