The effect of sowing date, sowing depth and seed size on seedling emergence of wheat: A dissertation submitted in partial fulfilment of the requirements for the degree of Bachelor of Agricultural Science (Hons.) in the University of Canterbury

Abstract

In a factorial field experiment investigating the effects of sowing time, seed size and time of sowing of Rongotea wheat, variation in time of sowing between early May and late June did not affect the total population established. It is suggested that early May sowing gives higher grain yields due to a greater number of ears/plant rather than a greater number of plants. Seed size showed a significant interaction with sowing depth, in that rate and total emergence from small seed (TSW 36g) was reduced in comparison with large seed (TSW 53g), but the effect was more marked at deeper sowings. It is suggested that one of the main reasons for the reduced emergence of deep sowings was the higher proportion of "failed" seedlings: plants which rupture through the coleoptile before reaching the surface and grow haphazardly through the soil. In practice it is recommended that the drilling depth of wheat should not exceed 4-5 cm to avoid wastage of seed due to failed seedlings and to establish an optimum plant population for high yields.