PLANT HORMONES 



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flower cluster Avith an atomizer. When two or more flowers are open, the 

 entire cluster may be treated to set the fruit on both buds and open flowers. 

 The recommended concentration for the chemical in solution is shown in 

 Table 26. Spreaders may be used in the solution but they are not necessary. 



FiGUKE 81. Induced fruit set and seedlessness. A, Left to right: normal tomato fruit 

 resulting from pollinated flowers; parthenocarpy and seedlessness resulting from treat- 

 ment of flower cluster with 2,4-dichlorophenoxyacetic acid (5 mg/liter) when three 

 flowers were open; parthenocarpy and seedlessness resulting from treatment of flower 

 clusters with 2,5-dichlorobenzoic acid (100 mg/hter). B, Left to right: cross section of 

 normal control with seeds; cross section of seedless tomato induced with /3-naphthoxy- 

 acetic acid (100 mg/liter). 



Also lanolin emulsion has been tested and found effective, but is no more 

 satisfactory than water solution. In fact there is some indication that the 

 emulsion brings about some undesirable effects, such as scarring the surface 

 of the tomato or increasing blossom end rot. Carbowax (polyethylene- 

 glycol 0.5 to 1 per cent) is a good spreader and is fully as effective as lanolm 

 emulsion. It has been recommended for fruit sprays. In spraying the 

 flower cluster it is well to apply the solution to the peduncle as well as to 

 the open side and back of the flowers. For a high percentage of fruit set it 



