12 
CARL SALBACH 
1936 
THRIPS CONTROL MADE EASY 
It is with pleasure that we can report after last season’s experimentation, that definite 
and easy methods for controlling gladiolus thrips are now known. This new pest has been 
known in the United States for several years, but only recently reached California. 
In general, three objectives must be kept in mind. First, all bulbs must be free from thrips 
when planted; second, flowers should be brought to bloom before thrips move in from 
neighboring gardens to start their rapid increase; and, third, weekly sprayings are a very 
wise safeguard. 
To protect the bulbs—Cut and destroy the stalks of the plants as soon as dug, but other¬ 
wise cure in the regular way. Store bulbs in the natural manner. When thoroughly dry, 
sprinkle naphthalene flakes among the bulbs. Approximately one pound to each 1,000 large 
bulbs is sufficient. As a final measure, use either gas or hot water treatment. Commercial 
growers, and others with large plantings should use two Cyanogas fumigations at intervals 
of ten days, with a temperature of 65° to 70° during fumigations. Further details can be 
obtained from the local agricultural commissioner. The ordinary amateur should peel his 
bulbs, not more than twenty-four hours before planting, and dip them in approximately 
120° of hot water for about two minutes. In the absence of a thermometer, the water should 
be as hot as the average person can stand with his hand fully immersed. 
Our advice is to plant early. December and January are the safest months in southern 
California; January and February in central California; and February and March further 
north. This does not apply in places completely isolated miles away from other gladiolus 
plantings, but is essential in urban regions. Most thrips die out in the winter, but a few 
will winter over on untreated bulbs that will be grown in neighborhood gardens. If, how¬ 
ever, your own plantings are early, migratory thrips are not likely to reach your flowers in 
time to injure them. The damage is not from the first few thrips, but from their thousands 
of offspring that develop after several weeks of breeding. 
Ordinarily, gladiolus planted early, as mentioned above, if treated to assure thrips free 
bulbs at the start, will bloom with no injury. Those who wish to avoid the slightest chance 
of thrips damage, or who wish gladiolus blooming from later plantings, should adopt a 
program of spraying. Thrips may eventually injure regularly sprayed plantings, but not 
until very late in the season. In our own exhibition plantings at Berkeley, by starting with 
thrips free bulbs, and by regular sprayings, we were able to cut unblemished blooms as late 
as August 1. By August 15, many of the flowers were showing slight signs of injury. After 
September 1, we had a few good blossoms, but most varieties were in poor or fair shape. 
Our stock plantings, grown in isolated places, were not infested, and blooms were perfect 
throughout the season. 
It is impossible to reclaim the flowers, even by spraying, once there are enough thrips to 
“blight” the blossoms, but regular weekly sprayings started when the plants are two or 
three inches tall will insure perfect early blooms, and will prevent noticeable injury until 
very late in the season. To protect the foliage from spray-burning, never spray until evening 
during spells of warm weather. The best spray in the Pacific Coast regions is mixed as follows: 
M lb. manganese arsenate, 4 lbs. brown sugar, and 6 Ms gallons of water. The methods given 
above are particularly applicable for the Pacific Coast, but may be used to advantage any¬ 
where. 
To make spraying easier, we offer cans of specially prepared “Manganar” (Manganese 
arsenate and brown sugar) ready to mix with water for spraying. Not mailable—we send 
Manganar express collect. Express charges range as follows: Two pound can: 25c in Berke¬ 
ley, 37c to Oakland, 85c to New York; eight pounds in cans: 25c in Berkeley, 42c to Oakland, 
$2.10 to New York. 
Two pound can (via express collect).$1.25 
Eight pounds (4 cans) (via express collect). 4.00 
NOTE: Two pounds mixes to make three gallons of spray. 
