Espaçamento da batata doce em São Paulo

Abstract

SUMMARY AND CONCLUSIONS The effect of spacing on the total yield and on the size of sweet potatoes was studied in seventeen experiments comprising three series of tests with several treatments, carried out at five experiment stations in the State of Sao Paulo, from 1939/40 to 1948/49. Several combinations of spacing from 60 to 100 cm between rows and 20 to 50 cm between hills in the rows were tried out. Randomized blocks with four replications were used in all experiments. Observation were made on development of the vines, occurrence of failures and types of roots produced. These roots were classified according to weight in three types as follows : small (less than 80 grams) ; medium (from 80 to 800 grams) and large (more than 800 grams). The average weight of roots (total yield divided by number of roots) was calculated for each treatment The results obtained in these experiments indicated that in the rows 60 to 100 cm apart, the reduction of spacing between plants in the rows from 50 to 30 cm and from 30 to 20 cm resulted in an increase in total root yield and also in the amount of roots of average size, that is the type which is more valuable for the large consuming market. The smaller spacing in the rows favored also the production of small and medium sized roots and reduced considerably the amount of large-sized sweet potatoes. The average root weight was also increased. Total root yield was not affected by variations in the spacing between rows. Ho­wever, when spacing between rows was reduced from 100 to 75 cm, an increase was noted in the average root weight and also in the quantity of small and medium sized roots. The amount of large sized sweet potatoes was reduced. When the same area per plant was maintained, the variable spacing used has not influenced the size and average weight of the roots but highest total root yield was obtai­ned when plants were set 30 cm apart in rows spaced 100 cm apart. Based on the results of these experiments the following recommendations can be made for planting sweet potatoes in the State of Sao Paulo : a) When small sized sweet potatoes are desirable, the spacing of 70 to 80 cm bet­ween rows and 20 cm in the lines can be adopted. For intensive cultivation in small-areas, as is usual near the city of Sao Paulo, where the market prefers the small sized type, this spacing can be recommended. b) For more extensive plantings and when the small-sized type is not particularly required a larger spacing might be used, as at closer spacing an additional quantity of vines and more labor are necessary. The recommended spacing at this case is 90 to 100 cm between rows and 30 cm in the rows. c) When the roots are to be used for feeding livestock or for industrial purposes where there is no restriction to size and weight of roots, wider spacing between plants may be used. The recommended is 90 to 100 cm between rows and 40 cm within the row. LITERATURA CITADA 1. Anderson, W. S., E. A. Currey, E. B. Ferris e J. C. Robert. Sweetpotato plant spacing. Bull. Miss, agric. Exp. Sta. 358 : 1-19. 1941. 2. Anderson, W. S., H. L. Cochran, J. B. Edmond, O. B. Garrison, R. E. Wright e Victor R. Boswell. Regional studies of time of planting and hill spacing of sweetpotatoes. Circ. U.S. Dep. Agric. 725 : 1-20. 1945. 3. Anderson, W. S. e John W. Randolf. Sweetpotato production. Time of planting and hill spacing studies. Bull. Miss, agric. Exp. Sta. 378 : 1-22. 1943. 4. Beattie, J. H., Victor R. Boswell e E. E. Hall. Influence of spacing and time of planting on the yield and size of the Porto Rico sweetpotato. Circ. U.S. Dep. Agric. 327 : 1-10. 1934.