Field Establishment of Some Vegetable Crops: Response to a Range of Soil Conditions

Abstract

Calabrese, carrot, onion and red beet seeds were sown at approximately weekly intervals throughout the spring and early summer of 1972–4. In a situation where soil tilth and seed placement in the soil were apparently non-limiting, regression analysis showed that in eight of the twelve crop × year combinations there were no significant relationships between seedling emergence and soil moisture or temperature at sowing. In 1972 emergence levels of beet and calabrese were depressed by either excess or lack of soil moisture at sowing, and calabrese emergence was positively related to temperature; in 1973 and 1974 onion emergence was negatively related to temperature at sowing. Rainfall occurring shortly after sowing was identified as a major factor causing emergence problems, apparently through the formation of a soil cap, but its effect varied with crop type, seed vigour and soil moisture content at the time of seedling emergence. The results suggest that low plant stands often found in agricultural practice may be due not to soil temperature or moisture, factors dependent largely upon the weather, but to soil tilth, fertilizer level, seed or soil infection, seed drill performance and seed vigour, over all of which except the last there is, theoretically, some control.