M. L. Poole

Publication Date


Document Type


DAFWA Collections

Grains and field crops

Number of Pages



Western Australia



Effect of times of planting x Benlate seed

treatment on incidence of blackleg in

Span and Zephyr rapeseed.


Rapeseed Variety Trials 1973 including

times of planting.

This report provides a record of two series of trials carried

out in 1973.

Section I - Effect of times of planting x Benlate seed treatment on incidence of blackleg in Span and Zephyr rapeseed. - A series of 12 trials were set up, mainly in the southern agricultural areas, near previous years rape stubble to give a high disease pressure. Disease pressure was so high in two of the Esperance trials that all treatments were lost soon after planting. Sandblast, weeds and vermin claimed several more trials. Four trials gave meaningful results with respect to the aims of the programme. These were at Duranillin, Mt, Barker, Green Range and Jerdacuttup. Treatments were Span (B, campestris) and Zephyr (B, napus) rapeseed sown with and without a 1% Benlate seed pellet at three times of planting, June, July and August. The trials were sampled at peak flowering for blackleg stem cankers, the sample being divided into, (i) healthy stems, (ii) slightly cankered, and (iii) rotten all the way through. Yields were taken at maturity. Main results were: (1) The benlate seed pellet at 1% had almost no effect on either amount or severity of cankering, or yield. (See summary table 1) (2) Time of planting had little effect on the amount or severity of cankering in most trials. The Mt. Barker trial did however show less severe cankering at later planting times. (3) No particular time of planting was consistently better than any other with respect to yield from these trials. (Summary Table II).

Section II - Rapeseed Variety Trials 1973 - Including Times of Planting. (See Summary Table III & IV) - Nineteen trials incorporating thirty times of planting were sown. Results were obtained from sixteen trials and 24 times of planting. These trials were affected by blackleg to various degrees, and this combined with above normal variation due to site, vermin and the vagaries of headers make interpretation difficult. At best the trials show broad trends and certainly are not sufficiently sensitive to pick up fine differences between varities. The following conclusions are drawn with some trepidation! (i) Within the two species, there were no convincing differences between varieties. (ii) Overall, there was little yield difference between the species, however at the individual trial level, the previous experience of better yields from B. napus when sown in higher rainfall areas with June and July planting was confirmed. Likewise the superior yield of B. compestris in lower rainfall areas and with late sowings in higher rainfall areas was reaffirmed.