Cultivar and Management Effects on Stand Persistence of Birdsfoot Trefoil¹

Abstract

Interactions between growth habit and management of birdsfoot trefoil (Lotus corniculatusL.) are reported by other researchers to affect stand persistence. Stand persistence dependent on the longevity of plants within the stand can be confused with the persistence of stand resulting from natural reseeding in this crop. A field test of 10 birdsfoot trefoil cultivars differing in growth habit was planted in May 1979 on Mexico silt loam (Fine, montmorillinitic, mesic Udollic Ocharqualf) near Columbia, Mo. Commencing April 1980, effects of four management treatments on stand persistence were studied to determine the degree of emphasis to be given to growth habit in a program of genetic improvement for trefoil persistence. Volunteer seedling establishment was controlled with simazine [2‐chloro‐4,6‐bis(ethylamino)‐s‐triazine]. Significantly lower herbage yields in stockpiled and unharvested managements were attributed to foliar blight caused by Rhizoctonia solaniKeuhn. Stand persistence, based on plant counts, was observed to be independent of management since plants within stands behaved more like biennials than perennials regardless of management. Cultivar by management effects on stand persistence were not significant (P>0.05). An average stand reduction of 90% was observed from April 1980 to 1982. Greatest reductions in stand counts were observed each year between April and October. An average disease score of 2.4, where 0 indicated root and crown tissues visibly free of decay and 5 indicated extensive decay, was obtained from 939 surviving plants examined in April 1982. Poor stand persistence could be explained in part by the foliar, crown, and root diseases found at the study site. Lack of differences in stand persistence and tolerance to disease may reflect the close ancestry of the entries tested. Emphasis on growth habit in a genetic improvement program for persistence in the Southern Corn Belt appeared less important than an examination of genetic resources for lowered susceptibility to disease.

Caracterização morfofisiológica de genótipos de cornichão (Lotus corniculatus L.)

“…Steiner & Garcia de los Santos (2001) também observaram variabilidade quanto à pubescência, tamanho e forma de folíolos em cornichão. Beuselinck et al (1996) descreveram alto grau de variabilidade em Lotus para tamanho de folhas, número de flores e comprimento de pedúnculo.…”

“…e ácaros (Tabela 7). Segundo Beuselinck et al (1984), esses patógenos podem causar perdas de até 90% nos estandes, em menos de três anos. No Uruguai, conforme Stewart & Altier (1993), a antracnose tem causado problemas na Tabela 5 -Diâmetro da coroa de genótipos de Lotus corniculatus L. Provavelmente, a incidência de Botrytis sp.…”

Desenvolvimento morfológico de Lotus spp. de diferentes hábitos de crescimento

“…Growth days florescimento continua emitindo hastes vegetativas, o que permite que nessa espécie possam ser aplicadas técnicas de manejo como o diferimento e o atraso na colheita (Beuselinck et al, 1984). O sistema subterrâneo dos cultivares foi formado pela raiz primária e suas ramificações, finas e em grande quantidade (raízes fibrosas), bem como pelos sóboles, que foram …”

Evaluation of the population dynamics of the forage legume (Lotus corniculatus), using matrix population models

“…Stress associated with management activities influences stand persistence of birdsfoot trefoil (Beuselinck et al, 1984). Although the influences of such stresses on individual plants may be known, the effects on plant population dynamics are not well understood.…”