Resumo

VENTURA CHOQUE, Rosa  e  BONIFACIO FLORES, Alejandro. Reproductive phenology and growth of ñak'a t'ula seedlings (Baccharis tola) for directed multiplication purposes. RIIARn [online]. 2018, vol.5, n.1, pp. 27-36. ISSN 2409-1618.

Abstract The objectives of the research were to study the reproductive phenology and to evaluate the growth of seedlings of Baccharis tola, for the purpose of directed multiplication. In the first stage of the work, we visited natural populations and living barriers of the departments of Oruro, Potosí and La Paz, to knowthe sexual proportion and the collection of seeds, the second stage was developed in the Experimental Center of K'iphak'iphani (PROINPA), where germination, emergence and growth were evaluated. The study was carried out undera randomized complete blocks design with divided plots with 4 repetitions, we worked with substrates (peat-soil of the place) with proportions 1:1, 2:1, 3:1 and soil ofthe place (SL) and with fertilization levels of 80, 40 and 0 kgN ha^-1. The results of the work show that Baccharis tola is a dioica species, whose sexual proportion is concordant with the 1:1 ratio, although a predominance of female plants was evidenced. The seed does not present dormancy, the formation of seed lasts 81 days. Significant differences were found in the germination percentage of seeds harvested in the different localities, attributable to environmental factors with 86.5% the highest (Jatuquira) and 22% the lowest (Lacalaca). The plants of T2 (peat-SL2:1, 40 kgN ha^-1) obtained 43.9% of dry matterand the plants of T10 (SL, 0 kgN ha^-1) reached 38.8% of dry matter. The T9 (3:1, 80 kgN ha^-1), T6 (2:1, 80 kgN ha^-1) and T3 (1:1, 80 kgN ha^-1) recorded heights of 10.0, 9.9 and 9.5 cm with effect positive againstthe use of substrates and fertilization level, T12 (SL, 80 kgN ha^-1), T11 (SL, 40 kg-urea ha^-1) and T10 (SL, without incorporation of urea) had heights of 5.8, 5.1 and 4.1 cm, showing positive effect ofthe fertilizer. Regarding the slenderness index, T3 and T10 recorded 3.8 and 1.8 cm mm-¹ found in the permissible range.

Palavras-chave : ñak'a t'ula; phenology; substrates; nitrogenous fertilizer; directed multiplication; dioica; slenderness index.