Interaction of lime and seed pelleting on the nodulation and growth of white clover

Abstract

The interactions of lime, seed pelleting, and inoculation level were investigated on white clover (Trifolium repens) growing on a range of soils in the glasshouse.In the absence of seed pelleting, the addition of 2500 kg/ha of lime markedly increased the growth of clover on soils of low pH (4.7-5.0). The same effect was produced in the absence of lime by pclleting the seed (with lime or Gafsa-phosphate + dolomite). The increase m plant growth from lime or pelleting accompanied an increase in nodulation on one soil {pH 4.9) where nodulation was investigated. Lime or pelleting increased both crown (within 1 em of soil surface) and distal (remainder) nodules.On soils of pH 5.3-5.5, lime and pelletin~ effects were variable and less marked than al lower pH. Pelleting either had no effect or increased clover growth, whereas the effect of lime ranged from depression to enhancement. At pH 6.2, both lime and pelleting depressed growth.On two soils (pH 5.0 and 5.4), increasing the inoculation level from 2 X 103 to 2 x 104 rhizobia per seed markedly increased the growth of clover in the absence of lime and pelleting. On one of these soils (pH 5.4), increasing the inoculation level replaced the requirement for lime or pelleting for maximum plant growth.There were no significant differences between lime and Gafsa-phosphate + dolomite as rcileting materials. 317

Qualidade de sementes de algodão submetidas aos processos de encapsulamento com e sem corante

“…Além disso, o processo de encapsulação de sementes apresenta as seguintes possibilidades: aumento de tamanho das sementes muito pequenas (MEDEIROS et al, 2004), aplicação de macro e micronutrientes que ficariam disponíveis às plântulas (BAUDET; PERES, 2004), a adição de fungicidas, inseticidas, bactericidas e reguladores de crescimento (TONKIN, 1979;OLIVEIRA et al, 2003), e inoculação das sementes com bactérias fixadoras de nitrogênio (LOWTHER, 1975). O encapsulamento também pode servir para a produção de sementes sintéticas através do recobrimento de embriões assexuais obtidos de cultivo in vitro (KITTO;JANICK, 1985;GUERRA et al, 1999).…”

Sulphur, phosphate, and molybdenum coating of legume seed

“…On acid soils, coating with lime can increase nodulation by raising the pH in the vicinity of the seedling's roots (Lowther et al 1970;Lowther 1974a;Lowther & McDonald 1973;Lowther 1976).…”

“…In New Zealand, coating with a mixture of 50: 50 Gafsa phosphate: dolomite has been recommended (Hastings & Drake 1963;Taylor & Lloyd 1968) and this gives a greater number of effectively nodulated legumes than other coat combinations of lime, dolomite, or Nauru phosphate (Hastings et al 1966;Lowther & McDonald Received 13 April 1978. Recent work has suggested the superiority of lime over Gafsa phosphate-dolomite and the type of glue used may be equally important (Lowther 1974b(Lowther , 1975a(Lowther , b, 1976(Lowther , 1977. Legume seed is at present coated to 75%* in a combined rhizobia and phosphate material.…”

“…Depression of rhizobia can be further decreased by including Mo in a lime coating outside the rhizobia layer (Date & Hillier 1968). In New Zealand a 0.25% Mo coating as sodium molybdate can be obtained as an option with rhizobia coating (Lowther 1974a). A small advantage has been reported for clover growth using Mo and N in addition to Gafsa phosphatedolomite coats (Cullen et al 1969).…”

Legume inoculant usage in New Zealand

“…Many failures have been attributed to low numbers of viable rhizobia at the time of sowing (Hastings & Drake 1963;Cullen & Ludecke 1966;Lowther et al 1970;Lowther & McDonald 1973;Adams & Lowther 1970;Lowther 1975).…”