Florida Agricultural Experiment Station


 Where all cover crops consisted of legumes the yield increase
of Frotscher trees amounted to more than 660 and 350 pounds
per acre with and without sulfate of ammonia, respectively,
over that in the unplanted plot. Where oats and C. spectabilis
were grown in Plot 4 the nut production was less than where
no cover crops were planted.
 The Stuart trees produced 100 to 200 percent more nuts with
winter and summer legumes than without cover crops. How-
ever, it will be noted in Table 4 that owing to light yields the
increase amounted to only 171 to 205 pounds per acre during
the second period. As with Frotscher, where oats in winter
and C. spectabilis in summer were grown and returned to the
soil, Stuart yields were much lighter than in the all-legume plots.
 The production of nuts after 1931 was materially increased
where sulfate of ammonia was applied, except in one instance.
For the period 1932 to 1934 the greatest increase in yield was
made by the Frotscher trees where both winter and summer
legumes were returned to the soil. The additional production
amounted to 367.2 and 392.7 pounds per acre, respectively,
where Austrian peas and hairy vetch were grown and sulfate
of ammonia was applied.
 Table 4 shows further that there was practically no difference
during 1932 to 1934 in yields of the trees in each of the two
legume plots when comparing areas fertilized alike. Frotscher
produced heavier crops than the Stuart, however, but the trees
of both varieties in the legume plots responded better to the
additional ammonia applications than where either no planted
cover crops or where oats and C. spectabilis were grown.

 NUT SIZES AND KERNEL PERCENTAGES
 According to Blackmon and Ruprecht (3), fertilizers have
very little effect on size and kernel content of pecan nuts. Moist-
ure proved to be an important factor, and without an adequate
supply it was impossible for the best of varieties to produce
fully developed and well filled nuts, especially when the trees
were carrying heavy crops.
 Data on nut sizes and kernel percentages are given in Table
5 for the same grouping of years as for growth and yield; similar
data are presented in detail for the 1934 crop in Table 6. It
will be noted that sizes and kernel percentages for the first
group are identical for both sections of any one plot. This was
because yield samples were not separated until the second year
after summer applications of sulfate of ammonia were begun.