. Bulletin. Agriculture. 16 THE CURLY-TOP OF BEETS. from one side and the edge of the cover raised. The hoops of iron rod are especially useful for cages, covers, etc., and may readily be made by bending lengths of the rod over the edge of a board that has been cut to the proper size and shape, as shown in figure 6. It will be noted that the sides of this board are convergent. This is done to take up the resilience of the iron rod; otherwise the hoops would straddle too much. In cages 1 and 2 a standard strain of beet seed was sown on July 18, and more on August 4. This germinated and grew und
. Bulletin. Agriculture. 16 THE CURLY-TOP OF BEETS. from one side and the edge of the cover raised. The hoops of iron rod are especially useful for cages, covers, etc., and may readily be made by bending lengths of the rod over the edge of a board that has been cut to the proper size and shape, as shown in figure 6. It will be noted that the sides of this board are convergent. This is done to take up the resilience of the iron rod; otherwise the hoops would straddle too much. In cages 1 and 2 a standard strain of beet seed was sown on July 18, and more on August 4. This germinated and grew under isola- tion conditions. Red spiders and aphides were excluded, but a few thrips gained en- trance through the soil. Cage 1 was carefullv CD « partitioned into three insect-proof chambers. Colonies of thrips were introduced into cham- ber a; into b six adult beet leaf hoppers were placed, and into c red spiders from the beets in the open field. Aphides Ay ere placed on beets in cage 3. Cage 2 was reserved as a " ; This was done on August 25; from that time the rec- ord of cage 1 is as fol- lows : Four more. Fig. A simple method of preparing iron hoops for cages, etc. August 2S. placed in b. September 7. (a) Plants made good growth: leaves dark green, many of inner ones badly distorted, some being " savoyed " and some cup shaped by thrips' attacks, (b) Scarcely any growth made; leaves dull, leathery, and somewhat blotched or faintly mottled when seen by trans- mitted light; some leaves strongly concave; no vein symptoms, (c) Condi- tions similar to a. September S. Placed a few more hoppers in b. September 12. (6) Four of the earliest sprouting seedlings show some curl on margin of inner leaves. September 17. (b) Several more hoppers introduced. One leaf completely curled. 181. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrati
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