Agriculture Reference
In-Depth Information
take place. Night temperatures of 65°F (18°C) or greater and daytime temper-
atures of 85°F (29°C) or greater during the 3 to 5 days after applying sprays
can increase the thinning response. If you observe or expect temperatures in
these ranges, consider using the lower application rates.
Loquats
For commercial production, you must thin loquat fruits to produce fruits of
acceptable size. Loquats also tend to develop an alternate year bearing pat-
tern like apples. You can thin clusters to help reduce alternate bearing and
remove flowers and fruits to increase loquat fruit size.
Loquats set about nine or ten fruits per cluster. By leaving three to five
fruits per cluster, you will increase fruit size and the percentage of market-
able fruits. In Chinese trials, enclosing the fruits in bags (bagging) after thin-
ning reduced the amount of sunburned and rusty fruit from about 48 per-
cent to less than 1 percent and greatly increased the percentage of premium-
quality fruits. Bagging tree fruits in fabric or weather-resistant paper to pro-
tect the fruits from pest, disease, and environmental damage and increase
the percentage of premium-grade fruit is a common practice in parts of the
Orient.
There is a trade-off to thinning loquats, however. Worldwide, purple spot
is the most serious physiological disorder affecting loquat, causing the rind
to discolor and dry out. In Spanish trials, thinning to leave five fruits per
cluster when the fruits were
⅜
inch in diameter increased the incidence of
purple spot from about 2 percent to about 6 percent. Leaving three fruits
per cluster increased purple spot to 12 percent of the fruits, and leaving one
fruit per cluster increased purple spot to 36 percent of the fruits. The cause
of purple spot is not yet known, but it correlates with the amount of mineral
nutrients in the fruits. Thinning alters the concentrations of mineral nutri-
ents in the fruit. In short, be careful not to overthin.
You can use several approaches to thin loquats. One approach is to thin
out the flower clusters, usually at or shortly after full bloom. Clip off about
50 percent of the flower clusters, leaving the remaining clusters evenly dis-
