The Birmingham age-herald., 1920-07-15

The season is at hand when the cot ton farmer will watch his profits falling to the ground in punctured squares" the work of the boll weevil. Fortunately however the farmer is less helpless than he used to be. It is possible to control the boil weevil, the United States depart ment of agriculture has found after long experimentation. by dusting the plants with calcium arsenate. An adequate sup ply of the chemical is obtainabie tnls year. and considerable dusting machin- cry is available, though not suIIlcleHt eo meet the needs.
 It should be borne in mind, the spe- cialists say, that in poisoning for bot weevil control, extermination IS not se cured and should not be attempted. The result aimed at is a sufficient reduction of the weevil infestation to permit matur- ing a full crop of cottos. About 50 per cent of the squares fall before reaching maturity even in the absence of weevlis. The present system of weevil poisoning is expected to keep the weevils con- trolled to such an extent that they Will no more than offset the normal shedding win puncture only about as many squares as would have fallen in any event. This means usually, that the weevils are permitted to multiply unmo- tested until they become sufficiently nu- merous to puncture more forms than would shed normally. Poisoning is then started and continued until the plants have had time to develop as many poiis as they will be able to mature. Poison ing is then stopped and the weevils are allowed to resume multiplication ns- markably large increases in yield frs quently result from a comparativety slight degree of control for short time. The effect is cumulative. however. ana
 lxxr ctn rtf tfv,O plications at the right time and repeat ing them at the correct intervals The specialists urge planters to conduct the operation thoroughly or not to attempt 1t at all.
 The right kind of poison is dry pow dered calcium arsenate containing nor less than 40 per cent arsenic pentoxlo, not more than three -fourths of 1 per cent water soluable arsenic pentoxid and hav- ing a density of not less than 80 and not more than 100 cubic inches to the pound. To be sure that it is right, samples should be sent to the departments deta laboratory at Tallulah. La An imme- diate report will be furnished showing whether or not the material is satisfac- tory for cotton dusting. It IS Of the greatest importance to be sure that the material is right. If it contains too littls arsenic, it will not kill the weevils. If it contains too much water soluble arse nic, 1t will kill or injure the plants. Mix lures of all kinds are condemned. Cal cium arsenate may be kept as long as four years if it is stored in dry place.
 There is always the possibility of pol soning both men and horses working in calcium arsenate dust. Though no se- rious injury has ever been reported. the specialists urge the taking of all reason able precautions. Personal cleanliness IS the most important Operators should bs required to bathe as soon as they have completed the dusting work and under no circumstances should they be permit ted to eat or drink without washing their hands and faces with soap and water. Horses and mules used to pull the dusting machines should be muzzied to prevent the possibility of poisoning by eating grass and weeds along the rows.
 Generally speaking. at least five pounds of calcium arsenate per acre should bs used