but this technique is too slow for larger plantings. A faster method was 

 developed which utilized the same two-wheel garden tractor, equipped with 

 dual wheels, which was used for harvesting seed to pull a cultivator that 

 consisted of six small sweeps about 25 centimeters apart (Fig. 27). 

 Furrows were opened with the sweeps, seed were broadcast and covered by 

 a second trip over the seeded area. 



e. Seeding Date . Seed germination under natural conditions begins 

 as early as March on the North Carolina coast. However, when seeding 

 S. alterni flora , delaying the planting date until mid-April lessens the 

 chance of damage due to weather. The probability of storms which produce 

 damaging wave action decreases later in the spring. Earlier plantings 

 produce more growth by the end of the growing season, but a compromise 

 must be made between early planting and increasing the risk of being 

 washed out or buried by wave action. 



A comparison of two planting dates was made at Beaufort in 1972. 

 About 0.5 hectare was seeded 11 April, but part of the seedlings were 

 washed out by a storm in May. A second seeding was made 21 June. Samples 

 of aboveground and belowground standing crops harvested 5 October 1972 

 from an area about in the middle of the tide range, indicate that the 

 April seeding was more productive the first growing season (Tab. 16 and 

 Fig. 28) . After the second growing season, differences were less 

 striking. 



Table 16. Mean Aboveground and Belowground Standing Crops Produced from 

 Two Seeding Dates at Beaufort, North Carolina in 1972 



Seeding Date 



Aboveground Standing 

 Crop (g/m 2 ) by Year 



Belowground Standing 

 Crop (g/m 2 ) by Year 





5 Oct. 1972 



11 Sept. 1973 



5 Oct. 1972 



11 Sept. 1973 



11 April 1972 

 21 June 1972 



354 

 56 



644 

 527 



541 

 176 



1,077 

 869 



Three seeding dates were compared in the spring of 1972 at Snow's Cut. 

 Seed were planted on 16 March, 10 April, and 10 May; yields of shoots 

 were 388, 304 and 116 grams per square meter, respectively. These results 

 indicate that there is very little difference in growth between the March 

 and April seeding; therefore, risk of weather damage can be reduced by 

 delaying planting until April without sacrificing growth potential. 

 Delaying until May reduced first season growth greatly. 



f. Seeding Rate . Since the number of viable seed produced varies 

 from year to year and between locations, it is desirable to estimate the 

 number of viable seed per unit volume for each lot of seed that is avail- 

 able for planting. This can be done by simply measuring a small volume 

 of seed, germinating them, and counting the number of seedlings produced. 



59 



