The effect of seed •size and variety on growth, development and yield of potatoes (Sdlanum Tuberosum L.)

Abstract

A study on the effect of seed size and variety on growth, development and yield of potatoes (8. tuberosum L.) was carried out between 1981 and 1982 at the Field Station, University of Nairobi. Three ) seed sizes (35-45 mm - small; 45-55 mm - medium; 55-6Smm - large) of three commonly grown potato varieties B53, Anett and Kerr's Pink were planted. Seed size affected emergence. Thus, plants derived from the large seed tubers emerged earlier than plants derived from medium ~nd small seed tubers. The plants from large seed tubers were bigger, more vigorous in growth and took a shorter time to cOITpletely cover the ground when compared to plants from medium and small seed tubers. The nwnber of sterns per hill was highest in the plants derived from the large seed tubers and lowest in the small seed tubers. This was true for the three varieties. Dry matter accumulation in the haulm continued to a maximum and then st.a rt ed declining as the crop matured. Tuber dry matter increased throughout the grow 1n9 per iod. At the end of the growth period, B53 had the highest dry matter as is expected while Anett and Kerr's Pi_nk had lower and comparable dry matter contents (percentage). This was true in both (xiii) seasons. In season I (short rains, 1981) which was notably dry and irrigation had to supplement the rainfall, the tubers had lower dry matter content I as compared to season II (long rains, 1982) when rainfall was more or less adequate. Total final tuber yield and ware grade yield were highest in Annet. B53 had the lowest tubRr yield while Kerr's Pink had medium yield both in terms of total tuber yield and ware yield. Although plants from large seed tubers yielded more than plants from medium and small seed tubers, seed size effect was not. significant. The variety effect was however significant (P = O.OS).