Enhanced soil temperature during very early growth and its association with maize development and yield in the Highlands of Kenya

Abstract

SummaryPrevious work has shown a strong relationship between the mean soil temperature during the first 5 weeks of growth of a maize crop, and the final grain yield, warmer soils leading to greater yields. Trials were laid down in 1975 and 1976 to establish how early in the development of a maize crop higher soil temperatures would lead to increased yields. Soil temperatures were raised by polythene mulching applied at planting with six times of mulch removal: at crop emergence, 1, 2, 3, 4 and 5 weeks after emergence. Raised soil temperature led to a greater rate of development and leaf area production during early growth. Greater leaf area was due to greater leaf emergence rate rather than increase in leaf size, since increase in soil temperature was associated with a decrease in individual leaf size. This trend was reversed from leaf number 15 onwards resulting in no differences in leaf area, leaf weight or total dry matter at tasselling. In spite of this, yield differences were observed. Increase in soil temperature during germination alone had a beneficial effect on final grain yield, and this effect increased with duration. Increasing soil temperature for longer than 3–4 weeks from emergence caused no further yield increase. Yields increased from 133 and 172 g/ plant to 220 and 238 g/plant in 1975 and 1976 respectively. Yield increases were associated with more grains per plant rather than greater grain size. The period during which increased soil temperature led to increased yields coincided with the period when the apical meristem was below ground level. The mechanism involved is not yet clear.

Adaptation of barley (Hordeum vulgare L.) to harsh Mediterranean environments

“…The mean soil temperature at a depth of 5 cm during the six weeks after sowing was 7 .2'C at BR9 compared with 10 .6° C at TH9 . An influence of soil temperature on leaf primordia initiation has been found by Cooper & Law (1978) for maize .…”

Effect of plastic mulch on growth and yield of chilli (Capsicum annuum L.)

“…The result of the present study supported the finding of Suh et al (1991). Cooper and Law (1978) found that the soil temperature raised by plastic mulching led to a greater rate of growth and development of leaf.…”

The Effect of Plastic Mulch and Greenhouse‐Raised Seedlings on Yield of Maize

“…Applying transparent plastic sheets over the rows of a maize crop and allowing the plants to grow through holes in the sheet ("plastic mulch") was found to raise soil temperature in the row by 2-4 °C during April and May (BALLiFand DUTIL 1974, STRUIK 1983. Transparent plastic mulch has brought forward silking and maturity (BALLII-and DUTIL 1974, GooPERand LAW 1978, IREMIREN and MILBOURN 1979 and increased the number of leaves at tasselling by 1-1.5 (DERIEUX 1984, GOOPER andLAW 1978). Leaf area index at silking was found to be larger when plastic mulch was used (BALLII-and DUTIL 1974, IREMIREN and MIL-BOURN 1979, DERIEUX 1984.…”