12 



of early planted cauliflower ^d-ll be very high. 



Relay intercropping which is another method of crop intensifi- 

 cation, can save time in the cropping sequence, permit the first crop 

 to protect the second crop during the early stages of growth by acting 

 as a "nurse crop" and distribute labor peaks throughout the cropping 

 year (92, 11?). In relay interplanting, the primary limiting factor 

 seems to be competition for light, whereas moisture and nutrients are 

 less critical (S^) . For example , experiments at IREI demonstrated that 

 mungbean and radish were least tolerant to shading because these crops 

 can stand only two to three days of dense shade, whereas sweet potato 

 ( ipomoea batatas L. ) can stsuid four to five weeks of dense shade with 

 little yield reduction when relay intercropped with rice (8^) . 



Several vegetable crops relay interplanted into auinual field 

 crops or vegetable crops benefited small-scale farmers (?, 84). For 

 instance, relay interplanting tomato, cabbage, bush snap bean, ajid 

 sweet potato as early as 20 days before haxvest of sweet corn did not 

 reduce yield (7) . Helay intercropping vegetables into rice increased 

 total production, yet maintained critical planting dates for the main 

 rice crop within the cropping pattern. For instance, small-scale 

 faxmers in central Taiwan relay interplant short duration vegetable 

 crops d-uring a 60 to 100-day period between two rice crops (96) . 

 Vegetable crops that require 10 to 30 additional days to mature c-an be 

 planted and harvested before the critical rice planting dates. Summer 

 melon (Cucumis melo L, ) , pickling melon (Cucumis melo L. Var. Gonomon ) , 

 or watermelon [ Citrullus lanatus (Thumb.) Mansf.J are planted on small 

 mounds of soil two weeks before rice harvest during the summer season. 



