318 FORCING VEGETABLES 



QUESTIONS 



1. What is meant by the forcing of vegetables? 



2. What different kinds of glass structures may be used for the forcing of 



vegetables? 



3. What are the leading hothouse vegetable crops? 



4. Why is there little competition on the market between hothouse vegetables 



and outdoor products shipped in from the South? 



5. How can the temperature of a greenhouse be controlled at different 



seasons of the year, and in sudden changes of weather conditions? 



6. Can the temperature requirements of a given crop be more fully met in 



a greenhouse or out-of-doors? Why and how? 



7. Are plants more or less subject to disease in a greenhouse as compared 



with out-of-doors? Why? 



8. What precautions should be taken in the care of greenhouse crops in 



cloudy weather? 



9. What is the chief means of controlling insects in greenhouses? 



10. What considerations should govern the selection of crops for forcing? 



11. How is lettuce handled as a greenhouse crop? 



12. Why are radishes and leaf lettuce comparatively easy crops to grow in a 



forcing house? 



13. What difficulties are encountered in growing head lettuce in a greenhouse? 



14. Why are cucumbers and tomatoes more difficult to grow in a greenhouse 



than'radishes and lettuce? 



15. How are greenhouse tomatoes trained? 



16. What combination of greenhouse crops is suitable for fall, winter, and 



spring, to get the longest use of the houses in profitable crops? 



