39 



the fall months, whereas yield of about 6,7 metric tons/ha were harvested 

 vfhen planted from January to March in Gainesville. 



Yields of southern pea were not significantly different "between 

 years except in cropping pa,ttern HM-MM-IM (Table 4) . High residual 

 nutrients in the soil from previous squash (126) and earlier planting 

 dates resulted in hi^er yields in 1977-73 than in 1 978-79. In general, 

 the third crop of southern pea produced low yields. Several reports (60, 

 63) 6^1 lOl) indicated that yields from fall plantings were lower compared 

 to spring plantings of southern peas. Lorz (lOl) repcr-ed that crops 

 planted in late spring produced excessive vines at the expense of yield. 



Planting squash in early summer in cropping pattern KM-MM-M 

 resulted in yields equivalent to 2.1 metric tons/ha (Table 4). Halsey 

 and Koste^'ri.cz (66) har'/ested comparable yields when squash >:as planted 

 in early summer because of foliar disease incidence associated with 

 high humidity and temperature . 



Biological stability . Biological stability is defined as the 



2 

 degree to which the outcome of any event is predictable. One method 



of increasing the degree of biological stability in cropping patterns 



is to plant crops at the proper time. In cropping patterns HM-HM-KM 



and HK-MM-LT'I, the inclusion of pole becin and squash resulted in unsta,ble 



yields due to improper time of planting. Cropping pattern LiVI-LM-M 



provided some stability, but yields of southern pea decreased with 



successive plantings. A high degree of biological stability was 



K. R. Harwcod. 197^1. Stability in cropping systems (raimeo) . 

 International Hice Research Institute, Los Bancs, Philippines, 



